Audit Report on "The Department's Management of the ENERGY STAR Program"
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
2009-10-01
The American Recovery and Reinvestment Act (Recovery Act) authorized about $300 million in consumer rebate incentives for purchases of products rated under the 'ENERGY STAR' Program. ENERGY STAR, a voluntary labeling program established in 1992, provides consumers with energy efficiency data for a range of products so that they can make informed purchase judgments. The overall goal of the program is to encourage consumers to choose energy efficient products, advancing the nationwide goal of reducing energy consumption. The U.S. Environmental Protection Agency (EPA) managed the ENERGY STAR Program on a stand-alone basis until 1996 when it joined forces with themore » Department of Energy (Department). A Memorandum of Cooperation expanded the ENERGY STAR product categories, giving the Department responsibility for overseeing eight product categories such as windows, dishwashers, clothes washers, and refrigerators, while EPA retained responsibility for electronic product categories and heating, ventilating, and cooling equipment. Each agency is responsible for setting product efficiency specifications for those items under its control and for ensuring the proper use of the ENERGY STAR label in the marketplace. In August 2007, the EPA Office of Inspector General issued an audit report identifying significant control weaknesses in EPA's management of ENERGY STAR. The Department, concerned by the findings at EPA and eager to improve its own program, developed an approach to verify adherence to product specifications, ensure proper use of the ENERGY STAR label in the marketplace, and improve the establishment of product specifications. As evidenced by the commitment of $300 million in Recovery Act funds, the ENERGY STAR Program plays an important role in the U.S. efforts to reduce energy consumption. We initiated this audit to determine whether the Department had implemented the actions it announced in 2007 to strengthen the Program. The Department had not implemented planned improvements in the ENERGY STAR Program. Our audit revealed that officials had not: (1) Developed a formal quality assurance program to help ensure that product specifications were adhered to; (2) Effectively monitored the use of the ENERGY STAR label to ensure that only qualifying products were labeled as compliant; and (3) Formalized procedures for establishing and revising product specifications and for documenting decisions regarding those specifications. In our judgment, the delay in the Department's planned improvements in its management of the ENERGY STAR Program could reduce consumer confidence in the integrity of the ENERGY STAR label. Such loss of credibility could reduce energy savings, increase consumer risk, and diminish the value of the recent infusion of $300 million for ENERGY STAR rebates under the Recovery Act.« less
Code of Federal Regulations, 2013 CFR
2013-01-01
... for Testing” of DOE's “ENERGY STAR Program Requirements for [Compact Fluorescent Lamps] CFLs,” Version... Specifications for Qualifying Products” of the EPA's “ENERGY STAR Program Requirements for Residential Light... requirements specified in section 4, “CFL Requirements for Testing,” of the “ENERGY STAR Program Requirements...
Code of Federal Regulations, 2014 CFR
2014-01-01
... for Testing” of DOE's “ENERGY STAR Program Requirements for [Compact Fluorescent Lamps] CFLs,” Version... Specifications for Qualifying Products” of the EPA's “ENERGY STAR Program Requirements for Residential Light... requirements specified in section 4, “CFL Requirements for Testing,” of the “ENERGY STAR Program Requirements...
Code of Federal Regulations, 2012 CFR
2012-01-01
... for Testing” of DOE's “ENERGY STAR Program Requirements for [Compact Fluorescent Lamps] CFLs,” Version... Specifications for Qualifying Products” of the EPA's “ENERGY STAR Program Requirements for Residential Light... requirements specified in section 4, “CFL Requirements for Testing,” of the “ENERGY STAR Program Requirements...
EPA ENERGY STAR: Tackling Growth in Home Electronics and Small Appliances
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sanchez, Marla Christine; Brown, Richard; Homan, Gregory
2008-11-17
Over a decade ago, the electricity consumption associated with home electronics and other small appliances emerged onto the global energy policy landscape as one of the fastest growing residential end uses with the opportunity to deliver significant energy savings. As our knowledge of this end use matures, it is essential to step back and evaluate the degree to which energy efficiency programs have successfully realized energy savings and where savings opportunities have been missed.For the past fifteen years, we have quantified energy, utility bill, and carbon savings for US EPA?s ENERGY STAR voluntary product labeling program. In this paper, wemore » present a unique look into the US residential program savings claimed to date for EPA?s ENERGY STAR office equipment, consumer electronics, and other small household appliances as well as EPA?s projected program savings over the next five years. We present a top-level discussion identifying program areas where EPA?s ENERGY STAR efforts have succeeded and program areas where ENERGY STAR efforts did not successfully address underlying market factors, technology issues and/or consumer behavior. We end by presenting the magnitude of ?overlooked? savings.« less
Calendar Year 2007 Program Benefits for U.S. EPA Energy Star Labeled Products: Expanded Methodology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sanchez, Marla; Homan, Gregory; Lai, Judy
2009-09-24
This report provides a top-level summary of national savings achieved by the Energy Star voluntary product labeling program. To best quantify and analyze savings for all products, we developed a bottom-up product-based model. Each Energy Star product type is characterized by product-specific inputs that result in a product savings estimate. Our results show that through 2007, U.S. EPA Energy Star labeled products saved 5.5 Quads of primary energy and avoided 100 MtC of emissions. Although Energy Star-labeled products encompass over forty product types, only five of those product types accounted for 65percent of all Energy Star carbon reductions achieved tomore » date, including (listed in order of savings magnitude)monitors, printers, residential light fixtures, televisions, and furnaces. The forecast shows that U.S. EPA?s program is expected to save 12.2 Quads of primary energy and avoid 215 MtC of emissions over the period of 2008?2015.« less
Measuring energy-saving retrofits: Experiences from the Texas LoanSTAR program
DOE Office of Scientific and Technical Information (OSTI.GOV)
Haberl, J.S.; Reddy, T.A.; Claridge, D.E.
1996-02-01
In 1988 the Governor`s Energy Management Center of Texas received approval from the US Department of Energy to establish a $98.6 million state-wide retrofit demonstration revolving loan program to fund energy-conserving retrofits in state, public school, and local government buildings. As part of this program, a first-of-its-kind, statewide Monitoring and Analysis Program (MAP) was established to verify energy and dollar savings of the retrofits, reduce energy costs by identifying operational and maintenance improvements, improve retrofit selection in future rounds of the LoanSTAR program, and initiate a data base of energy use in institutional and commercial buildings located in Texas. Thismore » report discusses the LoanSTAR MAP with an emphasis on the process of acquiring and analyzing data to measure savings from energy conservation retrofits when budgets are a constraint. This report includes a discussion of the program structure, basic measurement techniques, data archiving and handling, data reporting and analysis, and includes selected examples from LoanSTAR agencies. A summary of the program results for the first two years of monitoring is also included.« less
Code of Federal Regulations, 2012 CFR
2012-01-01
... procedures contained in the EnergyStar Version 4.2 test, which is comprised of the ENERGY STAR Program... and 19 hours in sleep (standby) mode per day. These ENERGY STAR requirements are incorporated by... inspected or obtained at the United States Environmental Protection Agency, ENERGY STAR Hotline (6202J...
Code of Federal Regulations, 2013 CFR
2013-01-01
... procedures contained in the EnergyStar Version 4.2 test, which is comprised of the ENERGY STAR Program... and 19 hours in sleep (standby) mode per day. These ENERGY STAR requirements are incorporated by... inspected or obtained at the United States Environmental Protection Agency, ENERGY STAR Hotline (6202J...
Code of Federal Regulations, 2014 CFR
2014-01-01
... procedures contained in the ENERGY STAR Version 4.2 test, which is comprised of the ENERGY STAR Program... and 19 hours in sleep (standby) mode per day. These ENERGY STAR requirements are incorporated by... inspected or obtained at the United States Environmental Protection Agency, ENERGY STAR Hotline (6202J...
10 CFR 431.223 - Materials incorporated by reference.
Code of Federal Regulations, 2013 CFR
2013-01-01
... procedures incorporated by reference. (1) Environmental Protection Agency, “ENERGY STAR Program Requirements... Agency “ENERGY STAR Program Requirements for Traffic Signals,” Version 1.1, may be obtained from the...
10 CFR 431.223 - Materials incorporated by reference.
Code of Federal Regulations, 2014 CFR
2014-01-01
... procedures incorporated by reference. (1) Environmental Protection Agency, “ENERGY STAR Program Requirements... Agency “ENERGY STAR Program Requirements for Traffic Signals,” Version 1.1, may be obtained from the...
10 CFR 431.223 - Materials incorporated by reference.
Code of Federal Regulations, 2012 CFR
2012-01-01
... procedures incorporated by reference. (1) Environmental Protection Agency, “ENERGY STAR Program Requirements... Agency “ENERGY STAR Program Requirements for Traffic Signals,” Version 1.1, may be obtained from the...
ENERGY STAR Certified Vending Machines
Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Refrigerated Beverage Vending Machines that are effective as of March 1, 2013. A detailed listing of key efficiency criteria are available at
ENERGY STAR Certified Non-AHRI Central Air Conditioner Equipment and Air Source Heat Pump
Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Air Source Heat Pump and Central Air Conditioner Equipment that are effective as of September 15, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=airsrc_heat.pr_crit_as_heat_pumps Listed products have been submitted to EPA by ENERGY STAR partners that do not participate in the AHRI certification program. EPA will continue to update this list with products that are certified by EPA-recognized certification bodies other than AHRI. The majority of ENERGY STAR products, certified by AHRI, can be found on the CEE/AHRI Verified Directory at http://www.ceedirectory.org/
Code of Federal Regulations, 2013 CFR
2013-01-01
... “ENERGY STAR Program Requirements for [Compact Fluorescent Lamps] CFLs,” Version dated August 9, 2001... DOE's “ENERGY STAR Program Requirements for [Compact Fluorescent Lamps] CFLs,” Version dated August 9...
10 CFR 431.203 - Materials incorporated by reference.
Code of Federal Regulations, 2012 CFR
2012-01-01
.... Environmental Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0 issued January 1... Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0, may be obtained from the...
10 CFR 431.203 - Materials incorporated by reference.
Code of Federal Regulations, 2014 CFR
2014-01-01
.... Environmental Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0 issued January 1... Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0, may be obtained from the...
10 CFR 431.203 - Materials incorporated by reference.
Code of Federal Regulations, 2011 CFR
2011-01-01
.... Environmental Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0 issued January 1... Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0, may be obtained from the...
10 CFR 431.203 - Materials incorporated by reference.
Code of Federal Regulations, 2013 CFR
2013-01-01
.... Environmental Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0 issued January 1... Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0, may be obtained from the...
10 CFR 431.203 - Materials incorporated by reference.
Code of Federal Regulations, 2010 CFR
2010-01-01
.... Environmental Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0 issued January 1... Protection Agency “ENERGY STAR Program Requirements for Exit Signs,” Version 2.0, may be obtained from the...
Efficiency improvements in US Office equipment: Expected policy impacts and uncertainties
DOE Office of Scientific and Technical Information (OSTI.GOV)
Koomey, J.G.; Cramer, M.; Piette, M.A.
This report describes a detailed end-use forecast of office equipment energy use for the US commercial sector. We explore the likely impacts of the US Environmental Protection Agency`s ENERGY STAR office equipment program and the potential impacts of advanced technologies. The ENERGY STAR program encourages manufacturers to voluntarily incorporate power saving features into personal computers, monitors, printers, copiers, and fax machines in exchange for allowing manufacturers to use the EPA ENERGY STAR logo in their advertising campaigns. The Advanced technology case assumes that the most energy efficient current technologies are implemented regardless of cost.
ENERGY STAR Certified Audio Video
Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Audio Video Equipment that are effective as of May 1, 2013. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=audio_dvd.pr_crit_audio_dvd
ENERGY STAR Certified Data Center Storage
Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Data Center Storage that are effective as of December 2, 2013. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/certified-products/detail/data_center_storage
ENERGY STAR Certified Ventilating Fans
Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of October 1, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=vent_fans.pr_crit_vent_fans
ENERGY STAR Certified Ceiling Fans
Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Ceiling Fans that are effective as of April 1, 2012. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=ceiling_fans.pr_crit_ceiling_fans
ENERGY STAR Certified Geothermal Heat Pumps
Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Geothermal Heat Pumps that are effective as of January 1, 2012. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=geo_heat.pr_crit_geo_heat_pumps
ENERGY STAR Certified Commercial Hot Food Holding Cabinet
Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Commercial Hot Food Holding Cabinets that are effective as of October 1, 2011. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=hfhc.pr_crit_hfhc
Kouchri, Farrokh Mohammadzadeh
2012-11-06
A Voice over Internet Protocol (VoIP) communications system, a method of managing a communications network in such a system and a program product therefore. The system/network includes an ENERGY STAR (E-star) aware softswitch and E-star compliant communications devices at system endpoints. The E-star aware softswitch allows E-star compliant communications devices to enter and remain in power saving mode. The E-star aware softswitch spools messages and forwards only selected messages (e.g., calls) to the devices in power saving mode. When the E-star compliant communications devices exit power saving mode, the E-star aware softswitch forwards spooled messages.
48 CFR 23.103 - Sustainable acquisitions.
Code of Federal Regulations, 2013 CFR
2013-10-01
... SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL... the products are— (1) Energy-efficient (ENERGY STAR ® or Federal Energy Management Program (FEMP...
48 CFR 23.103 - Sustainable acquisitions.
Code of Federal Regulations, 2012 CFR
2012-10-01
... SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL... the products are— (1) Energy-efficient (ENERGY STAR ® or Federal Energy Management Program (FEMP...
Energy Star program benefits Con Edison
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
Impressed with savings in energy costs achieved after upgrading the lighting and air conditioning systems at its Manhattan headquarters, Home Box Office (HBO) wanted to do more, James Flock, vice president for computer and office systems, contacted Con Edison Co. of New York in March 1991 to determine what the company could do to save money by reducing energy consumed by personal computers. Arthur Kressner, Con Edison Research and Development manager contacted industry organizations and manufacturers for advice, but was told only to shut off computers at night and on weekends. Kressner arranged a series of meetings with IBM andmore » the Electric Power Research Institute (EPRI) to discuss the issue, then approached the U.S. Environmental Protection Agency (EPA), which was designing a program to promote the introduction and use of energy-efficient office equipment. In 1992, the EPA announced the Energy Star program for PCs, enabling manufacturers to display the Energy Star logo on machines meeting program criteria, including the ability to enter a sleep mode in which neither the computer nor monitor consume more than 30 W or electricity. Industry experts estimate national energy consumption by office equipment could double by the year 2000, but Energy Star equipment is expected to improve efficiency and help maintain electric loads.« less
The NuSTAR Education and Public Outreach Program
NASA Astrophysics Data System (ADS)
Cominsky, Lynn R.; McLin, K. M.; NuSTAR Team
2010-01-01
The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission led by Caltech, managed by JPL, and implemented by an international team of scientists and engineers, under the direction of CalTech Professor Fiona Harrison, principal investigator. NuSTAR is a pathfinder mission that will open the high-energy X-ray sky for sensitive study for the first time. By focusing X-rays at higher energies (up to 79 keV) NuSTAR will answer fundamental questions about the Universe: How are black holes distributed through the cosmos? How were the elements that compose our bodies and the Earth forged in the explosions of massive stars? What powers the most extreme active galaxies? Perhaps most exciting is the opportunity to fill a blank map with wonders we have not yet dreamed of: NuSTAR offers the opportunity to explore our Universe in an entirely new way. The purpose of the NuSTAR E/PO program is to increase student and public understanding of the science of the high-energy Universe, by capitalizing on the synergy of existing high-energy astrophysics E/PO programs to support the mission's objectives. Our goals are to: facilitate understanding of the nature of collapsed objects, develop awareness of the role of supernovae in creating the chemical elements and to facilitate understanding of the physical properties of the extreme Universe. We will do this through a program that includes educator workshops through NASA's Astrophysics Educator Ambassador program, by writing articles for Physics Teacher and Science Scope magazines to reach a broader community of educators, and by working with informal educators through museums and planetaria to develop an exhibit that includes a model of NuSTAR and describes the mission's science objectives. We will also develop printed materials such as a mission factsheet that describes the mission.
The NuSTAR Education and Public Outreach Program
NASA Astrophysics Data System (ADS)
Cominsky, Lynn R.; McLin, K. M.; NuSTAR Team
2010-03-01
NuSTAR is a NASA Small Explorer mission led by Caltech, managed by JPL, and implemented by an international team of scientists and engineers, under the direction of CalTech Professor Fiona Harrison, principal investigator. NuSTAR is a pathfinder mission that will open the high-energy X-ray sky for sensitive study for the first time. By focusing X-rays at higher energies (up to 79 keV) NuSTAR will answer fundamental questions about the Universe: How are black holes distributed through the cosmos? How were the elements that compose our bodies and the Earth forged in the explosions of massive stars? What powers the most extreme active galaxies? Perhaps most exciting is the opportunity to fill a blank map with wonders we have not yet dreamed of: NuSTAR offers the opportunity to explore our Universe in an entirely new way. The purpose of the NuSTAR E/PO program is to increase student and public understanding of the science of the high-energy Universe, by capitalizing on the synergy of existing high-energy astrophysics E/PO programs to support the mission's objectives. Our goals are to: facilitate understanding of the nature of collapsed objects, develop awareness of the role of supernovae in creating the chemical elements and to facilitate understanding of the physical properties of the extreme Universe. We will do this through a program that includes educator workshops through NASA's Astrophysics Educator Ambassador program, by writing articles for Physics Teacher and Science Scope magazines to reach a broader community of educators, and by working with informal educators through museums and planetaria to develop an exhibit that includes a model of NuSTAR and describes the mission's science objectives. We will also develop printed materials such as a mission factsheet that describes the mission.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zimring, Mark
2011-03-18
Launched in 2006, over 8,700 residential energy upgrades have been completed through Austin Energy's Home Performance with Energy Star (HPwES) program. The program's lending partner, Velocity Credit Union (VCU) has originated almost 1,800 loans, totaling approximately $12.5 million. Residential energy efficiency loans are typically small, and expensive to originate and service relative to larger financing products. National lenders have been hesitant to deliver attractive loan products to this small, but growing, residential market. In response, energy efficiency programs have found ways to partner with local and regional banks, credit unions, community development finance institutions (CDFIs) and co-ops to deliver energymore » efficiency financing to homeowners. VCU's experience with the Austin Energy HPwES program highlights the potential benefits of energy efficiency programs to a lending partner.« less
The NuSTAR Education and Public Outreach Program
NASA Astrophysics Data System (ADS)
Cominsky, Lynn R.; McLin, K. M.; NuSTAR Science Team
2011-09-01
NuSTAR is a NASA Small Explorer mission led by Caltech, managed by JPL, and implemented by an international team under the direction of CalTech Professor Fiona Harrison. NuSTAR is a pathfinder mission that will open the high-energy X-ray sky for sensitive study for the first time. By focusing X-rays at energies up to 79 keV, NuSTAR will answer fundamental questions about the Universe: How are black holes distributed through the cosmos? How were the elements that compose our bodies and the Earth forged in the explosions of massive stars? What powers the most extreme active galaxies? Perhaps most exciting is the opportunity to fill a blank map with wonders we have not yet dreamed of: NuSTAR offers the opportunity to explore our Universe in an entirely new way. The purpose of the NuSTAR E/PO program is to increase understanding of the science of the high-energy Universe, by capitalizing on the synergy of existing high-energy astrophysics E/PO programs to support the mission's objectives. Our goals are to: facilitate understanding of the nature of collapsed objects, develop awareness of the role of supernovae in creating the chemical elements and to facilitate understanding of the physical properties of the extreme Universe. We will do this through a program that includes educator workshops through NASA's Astrophysics Educator Ambassador program, a technology education unit for formal educators, articles for Physics Teacher and Science Scope magazines, and work with informal educators on a museum exhibit that includes a model of NuSTAR and describes the mission's science objectives. Extensive outreach is also underway by members of the Science Team, who are working with high school students, undergraduates and graduate students. We will also develop printed materials that describe the mission, and help develop the STEM pipeline through local after-school programs.
The NuSTAR Education and Public Outreach Program
NASA Astrophysics Data System (ADS)
Cominsky, Lynn R.; McLin, K. M.; Boggs, S.; Christensen, F.; Craig, W.; Hailey, C. J.; Harrison, F.; Stern, D.; Zhang, W.; NuSTAR Team
2013-01-01
NuSTAR is a NASA Small Explorer mission led by Caltech, managed by JPL, and implemented by an international team of scientists and engineers, under the direction of CalTech Professor Fiona Harrison, principal investigator. NuSTAR is a pathfinder mission that is opening the high-energy X-ray sky for sensitive study for the first time. By focusing X-rays at higher energies (up to 79 keV) NuSTAR will answer fundamental questions about the Universe: How are black holes distributed through the cosmos? How were the elements that compose our bodies and the Earth forged in the explosions of massive stars? What powers the most extreme active galaxies? Perhaps most exciting is the opportunity to fill a blank map with wonders we have not yet dreamed of: NuSTAR offers the opportunity to explore our Universe in an entirely new way. The purpose of the NuSTAR E/PO program is to increase understanding of the science of the high-energy Universe, by capitalizing on the synergy of existing high-energy astrophysics E/PO programs to support the mission’s objectives. Our goals are to: facilitate understanding of the nature of collapsed objects, develop awareness of the role of supernovae in creating the chemical elements and to facilitate understanding of the physical properties of the extreme Universe. We will do this through a program that includes educator workshops through NASA's Astrophysics Educator Ambassador program, a technology education unit for formal educators, articles for Physics Teacher and/or Science Scope magazines, and work with informal educators on a museum exhibit that includes a model of NuSTAR and describes the mission’s science objectives. Extensive outreach is also underway by members of the Science Team, who are working with high school students, undergraduates and graduate students. We are also developing printed materials that describe the mission and special workshops for girls at public libraries in order to improve the STEM pipeline.
The NuSTAR Education and Public Outreach Program
NASA Astrophysics Data System (ADS)
Cominsky, Lynn R.; McLin, K. M.; Boggs, S. E.; Christensen, F.; Hailey, C. J.; Harrison, F.; Stern, D.; Zhang, W.; NuSTAR Team
2013-04-01
NuSTAR is a NASA Small Explorer mission led by Caltech, managed by JPL, and implemented by an international team of scientists and engineers, under the direction of CalTech Professor Fiona Harrison, principal investigator. NuSTAR is a pathfinder mission that is opening the high-energy X-ray sky for sensitive study for the first time. By focusing X-rays at higher energies (up to 79 keV) NuSTAR will answer fundamental questions about the Universe: How are black holes distributed through the cosmos? How were the elements that compose our bodies and the Earth forged in the explosions of massive stars? What powers the most extreme active galaxies? Perhaps most exciting is the opportunity to fill a blank map with wonders we have not yet dreamed of: NuSTAR offers the opportunity to explore our Universe in an entirely new way. The purpose of the NuSTAR E/PO program is to increase understanding of the science of the high-energy Universe, by capitalizing on the synergy of existing high-energy astrophysics E/PO programs to support the mission’s objectives. Our goals are to: facilitate understanding of the nature of collapsed objects, develop awareness of the role of supernovae in creating the chemical elements and to facilitate understanding of the physical properties of the extreme Universe. We will do this through a program that includes educator workshops through NASA's Astrophysics Educator Ambassador program, a technology education unit for formal educators, articles for Physics Teacher and/or Science Scope magazines, and work with informal educators on a museum exhibit that includes a model of NuSTAR and describes the mission’s science objectives. Extensive outreach is also underway by members of the Science Team, who are working with high school students, undergraduates and graduate students. We are also developing printed materials that describe the mission and special workshops for girls at public libraries in order to improve the STEM pipeline.
13 CFR 101.500 - Small Business Energy Efficiency Program.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...
13 CFR 101.500 - Small Business Energy Efficiency Program.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...
13 CFR 101.500 - Small Business Energy Efficiency Program.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...
13 CFR 101.500 - Small Business Energy Efficiency Program.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...
13 CFR 101.500 - Small Business Energy Efficiency Program.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...
Energy Use and Power Levels in New Monitors and Personal Computers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roberson, Judy A.; Homan, Gregory K.; Mahajan, Akshay
2002-07-23
Our research was conducted in support of the EPA ENERGY STAR Office Equipment program, whose goal is to reduce the amount of electricity consumed by office equipment in the U.S. The most energy-efficient models in each office equipment category are eligible for the ENERGY STAR label, which consumers can use to identify and select efficient products. As the efficiency of each category improves over time, the ENERGY STAR criteria need to be revised accordingly. The purpose of this study was to provide reliable data on the energy consumption of the newest personal computers and monitors that the EPA can usemore » to evaluate revisions to current ENERGY STAR criteria as well as to improve the accuracy of ENERGY STAR program savings estimates. We report the results of measuring the power consumption and power management capabilities of a sample of new monitors and computers. These results will be used to improve estimates of program energy savings and carbon emission reductions, and to inform rev isions of the ENERGY STAR criteria for these products. Our sample consists of 35 monitors and 26 computers manufactured between July 2000 and October 2001; it includes cathode ray tube (CRT) and liquid crystal display (LCD) monitors, Macintosh and Intel-architecture computers, desktop and laptop computers, and integrated computer systems, in which power consumption of the computer and monitor cannot be measured separately. For each machine we measured power consumption when off, on, and in each low-power level. We identify trends in and opportunities to reduce power consumption in new personal computers and monitors. Our results include a trend among monitor manufacturers to provide a single very low low-power level, well below the current ENERGY STAR criteria for sleep power consumption. These very low sleep power results mean that energy consumed when monitors are off or in active use has become more important in terms of contribution to the overall unit energy consumption (UEC). Cur rent ENERGY STAR monitor and computer criteria do not specify off or on power, but our results suggest opportunities for saving energy in these modes. Also, significant differences between CRT and LCD technology, and between field-measured and manufacturer-reported power levels reveal the need for standard methods and metrics for measuring and comparing monitor power consumption.« less
A Graduate Course in Energy Conservation.
ERIC Educational Resources Information Center
Fickes, Michael
1999-01-01
Examines the University of Michigan's (Ann Arbor) success with a six-year energy conservation program (The Energy Star Program) offered by the Environmental Protection Agency. Describes the program's components and areas of savings the university has achieved. (GR)
48 CFR 23.103 - Sustainable acquisitions.
Code of Federal Regulations, 2014 CFR
2014-10-01
... SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Sustainable Acquisition Policy 23.103 Sustainable acquisitions. (a... the products are— (1) Energy-efficient (ENERGY STAR ® or Federal Energy Management Program (FEMP...
How to Launch an Energy Star Energy Efficiency Competition for K-12 Schools
ERIC Educational Resources Information Center
Utebay Kudret; McArthur, Ashley
2012-01-01
In recent years, schools have been forced by rising costs and shrinking budgets to stretch their resources further than ever before in order to meet the educational needs of today's students. EPA's ENERGY STAR program helps K-12 schools and districts improve energy efficiency, reduce operating costs and redirect critical resources into the…
Highly Insulating Windows Volume Purchase Program Final Report
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
2013-04-01
This report documents the development, execution outcomes and lessons learned of the Highly Insulating Windows Volume Purchase (WVP) Program carried out over a three-year period from 2009 through 2012. The primary goals of the program were met: 1) reduce the incremental cost of highly insulating windows compared to ENERGY STAR windows; and 2) raise the public and potential buyers’ awareness of highly insulating windows and their benefits. A key outcome of the program is that the 2013 ENERGY STAR Most Efficient criteria for primary residential windows were adopted from the technical specifications set forth in the WVP program.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Belzer, D.; Mosey, G.; Plympton, P.
2007-07-01
Home Performance with ENERGY STAR (HPwES) is a jointly managed program of the U.S. Department of Energy (DOE) and the U.S. Environmental Protection Agency (EPA). This program focuses on improving energy efficiency in existing homes via a whole-house approach to assessing and improving a home's energy performance, and helping to protect the environment. As one of HPwES's local sponsors, Austin Energy's HPwES program offers a complete home energy analysis and a list of recommendations for efficiency improvements, along with cost estimates. To determine the benefits of this program, the National Renewable Energy Laboratory (NREL) collaborated with the Pacific Northwest Nationalmore » Laboratory (PNNL) to conduct a statistical analysis using energy consumption data of HPwES homes provided by Austin Energy. This report provides preliminary estimates of average savings per home from the HPwES Loan Program for the period 1998 through 2006. The results from this preliminary analysis suggest that the HPwES program sponsored by Austin Energy had a very significant impact on reducing average cooling electricity for participating households. Overall, average savings were in the range of 25%-35%, and appear to be robust under various criteria for the number of households included in the analysis.« less
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-21
... www.regulations.gov Web site is an ``anonymous access'' system, which means EPA will not know your... public docket that are available electronically. Once in the system, select ``search,'' then key in the... homes under Home Performance with ENERGY STAR and ENERGY STAR's HVAC Quality Installation program...
Three Essays Examining Household Energy Demand and Behavior
NASA Astrophysics Data System (ADS)
Murray, Anthony G.
This dissertation consists of three essays examining household energy decisions and behavior. The first essay examines the adoption of energy efficient Energy Star home appliances by U.S. households. Program effectiveness requires that consumers be aware of the labeling scheme and also change their purchase decisions based on label information. The first essay examines the factors associated with consumer awareness of the Energy Star label of recently purchased major appliances and the factors associated with the choice of Energy Star labeled appliances. The findings suggest that eliminating identified gaps in Energy Star appliance adoption would result in house electricity cost savings of $164 million per year and associated carbon emission reductions of about 1.1 million metric tons per year. The second essay evaluates household energy security and the effectiveness of the Low-Income Home Energy Assistance Program (LIHEAP), the single largest energy assistance program available to poor households within the United States. Energy security is conceptually akin to the well-known concept of food security. Rasch models and household responses to energy security questions in the 2005 Residential Energy Consumption Survey are used to generate an energy insecurity index that is consistent with those found in the food insecurity literature. Participating in LIHEAP is found to significantly reduce household energy insecurity score in the index. Further, simulations show that the elimination of the energy assistance safety net currently available to households increases the number of energy insecure house- holds by over 16 percent. The third essay develops a five equation demand system to estimate household own-price, cross-price and income elasticities between electricity, natural gas, food at home, food away from home, and non-durable commodity groups. Household cross-price elasticities between energy and food commodities are of particular importance. Energy price shocks reduce food expenditures for low-income households, as indicated by negative cross-price elasticity estimates for food and energy commodities. Additionally, low-income households reduce energy expenditures more than other households, further indicating "heat or eat" behavior. Results from all three essays provide policy makers with helpful information to shape future federal energy programs.
Net Zero Energy Manufactured Homes May Be on their Way
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gilbride, Theresa L.; Dentz, Jordan
This article, published in Home Energy Magazine, describes a research project sponsored by the U.S. Department of Energy's Building America program, to construct and test the first manufactured home in the United States built to the performance criteria of DOE's Zero Energy Ready Home program. A 15-month study was conducted to compare the real-world performance of the DOE Zero Energy Ready home and two other manufactured homes - one built to just above industry standard construction and one built to the ENERGY STAR Certified Home criteria. The homes were built by Clayton Homes' Southern Energy Division and testing was sponsoredmore » by DOE's Building America program and conducted by the Levy Partnership. The DOE ZERH had increased initial construction costs of $6,607 compared to the standard home versus $4,340 for the ENERGY STAR home but reduced energy bills by $50 per month compared to a $33/month savings for the ENERGY STAR home, and monthly savings will continue for the life of the home. Savings were especially noticeable in the summer in this cooling-dominated test location. The DOE ZERH cut cooling costs in half compared to the ENERGY STAR home which performed only slightly better than the standard home in summer, while winter savings between the two advanced homes were more similar. Two technology advances were tested in the DOE ZERH home. Instead of the typical ducted heating and cooling system, the DOE ZERH home was equipped with a ductless heat pump; to condition the bedroom, holes were cut into bedroom walls and small fans were installed to pull air into those rooms, while door undercuts and transfer grilles provide return paths. A novel dense-pack attic insulation was also implemented.« less
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-18
...). Replacement of heating, ventilation and air conditioning (HVAC) equipment with Energy Star qualified heating, HVAC equipment. (3 points). Replacement of windows and doors with Energy Star qualified windows and... the third-party program's rating and verification systems. (2 points). Dated: August 11, 2011. Robert...
NASA Technical Reports Server (NTRS)
Bless, R. C.; Code, A. D.; Fairchild, E. T.
1976-01-01
The absolute energy distribution in the ultraviolet is given for the stars alpha Vir, eta UMa, and alpha Leo. The calibration is based on absolute heterochromatic photometry between 2920 and 1370 A carried out with an Aerobee sounding rocket. The fundamental radiation standard is the synchrotron radiation from 240-MeV electrons in a certain synchrotron storage ring. On the basis of the sounding-rocket calibration, the preliminary OAO-2 spectrometer calibration has been revised; the fluxes for the three program stars are tabulated in energy per second per square centimeter per unit wavelength interval.
Spectrophotometry of stars 9 - 12m north polar spectrophotometric sequence (NPSS) program.
NASA Astrophysics Data System (ADS)
Sharipova, L. M.; Prokof'eva, V. V.
Spectrophotometric observations of stars 9 - 12m of the NPSS program have been made with the use of hgh-sensitivity light-detecting apparatus of the digital television complex of the 0.5-m Maksutov telescope MTM-500 and original slitless spectrograph. Atmospheric extinction was controlled during the night by means of an energetically calibrated brightness standard. Absolute energy distributions of 12 stars, their synthetic magnitudes in the V band, and B-V color indices were obtained.
48 CFR 1523.7003 - Contract clause.
Code of Federal Regulations, 2011 CFR
2011-10-01
... PROGRAMS ENVIRONMENTAL, CONSERVATION, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy-Efficient...-103, Acquisition of Energy Star Compliant Microcomputers, Including Personal Computers, Monitors, and...
48 CFR 1523.7003 - Contract clause.
Code of Federal Regulations, 2012 CFR
2012-10-01
... PROGRAMS ENVIRONMENTAL, CONSERVATION, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy-Efficient...-103, Acquisition of Energy Star Compliant Microcomputers, Including Personal Computers, Monitors, and...
48 CFR 1523.7003 - Contract clause.
Code of Federal Regulations, 2010 CFR
2010-10-01
... PROGRAMS ENVIRONMENTAL, CONSERVATION, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy-Efficient...-103, Acquisition of Energy Star Compliant Microcomputers, Including Personal Computers, Monitors, and...
48 CFR 1323.204 - Procurement exemptions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 1323.204 Procurement exemptions. The designee authorized to exempt the procurement of an ENERGY STAR or Federal Energy Management...
48 CFR 1323.204 - Procurement exemptions.
Code of Federal Regulations, 2013 CFR
2013-10-01
... PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 1323.204 Procurement exemptions. The designee authorized to exempt the procurement of an ENERGY STAR or Federal Energy Management...
48 CFR 1323.204 - Procurement exemptions.
Code of Federal Regulations, 2010 CFR
2010-10-01
... PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 1323.204 Procurement exemptions. The designee authorized to exempt the procurement of an ENERGY STAR or Federal Energy Management...
48 CFR 1323.204 - Procurement exemptions.
Code of Federal Regulations, 2014 CFR
2014-10-01
... PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 1323.204 Procurement exemptions. The designee authorized to exempt the procurement of an ENERGY STAR or Federal Energy Management...
48 CFR 1323.204 - Procurement exemptions.
Code of Federal Regulations, 2012 CFR
2012-10-01
... PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 1323.204 Procurement exemptions. The designee authorized to exempt the procurement of an ENERGY STAR or Federal Energy Management...
48 CFR 1523.7000 - Background.
Code of Federal Regulations, 2012 CFR
2012-10-01
... PROGRAMS ENVIRONMENTAL, CONSERVATION, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy-Efficient... purchase only microcomputers, including personal computers, monitors and printers, which meet “EPA Energy Star” requirements for energy efficiency. This equipment is often identified by the Energy StarTM logo...
48 CFR 1523.7000 - Background.
Code of Federal Regulations, 2011 CFR
2011-10-01
... PROGRAMS ENVIRONMENTAL, CONSERVATION, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy-Efficient... purchase only microcomputers, including personal computers, monitors and printers, which meet “EPA Energy Star” requirements for energy efficiency. This equipment is often identified by the Energy StarTM logo...
48 CFR 1523.7000 - Background.
Code of Federal Regulations, 2010 CFR
2010-10-01
... PROGRAMS ENVIRONMENTAL, CONSERVATION, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy-Efficient... purchase only microcomputers, including personal computers, monitors and printers, which meet “EPA Energy Star” requirements for energy efficiency. This equipment is often identified by the Energy StarTM logo...
STAR Au + Au Fixed Target Results
NASA Astrophysics Data System (ADS)
Meehan, Kathryn; STAR Collaboration
2015-10-01
The RHIC Beam Energy Scan (BES) program was proposed to look for the turn-off of signatures of the quark gluon plasma (QGP), search for a possible QCD critical point, and study the nature of the phase transition between hadronic and partonic matter. The results from the NA49 experiment at CERN have been used to claim that the onset of deconfinement occurs at a collision energy around a center-of-mass energy of 7 GeV, the low end of the BES range. Data from lower energies are needed to test if this onset occurs. The goal of the STAR Fixed-Target Program is to extend the collision energy range in BES II with the same detector to energies that are likely below the onset of deconfinement. Currently, STAR has inserted a gold target into the beam pipe and conducted test runs at center-of-mass energies 3.9 and 4.5 GeV. Tests have been done with both Au and Al beams. First physics results from a Coulomb analysis of Au + Au fixed-target collisions, which are found to be consistent with previous experiments, will be presented. These results demonstrate that STAR has good particle identification capabilities in this novel detector setup. Furthermore, the Coulomb potential, which is sensitive to the Z of the projectile and degree of baryonic stopping, will be compared with published results from the AGS. This material is based upon work supported by the National Science Foundation under Grant No. 1068833.
48 CFR 23.204 - Procurement exemptions.
Code of Federal Regulations, 2012 CFR
2012-10-01
... PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.204 Procurement exemptions. An agency is not required to procure an ENERGY STAR ® or FEMP-designated product if the head of the agency...
48 CFR 23.204 - Procurement exemptions.
Code of Federal Regulations, 2013 CFR
2013-10-01
... PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.204 Procurement exemptions. An agency is not required to procure an ENERGY STAR ® or FEMP-designated product if the head of the agency...
48 CFR 23.204 - Procurement exemptions.
Code of Federal Regulations, 2014 CFR
2014-10-01
... PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.204 Procurement exemptions. An agency is not required to procure an ENERGY STAR ® or FEMP-designated product if the head of the agency...
Get Started: Energy Efficiency Makes More Sense Than Ever.
ERIC Educational Resources Information Center
Alban, Josh; Drabick, J. R.
2003-01-01
Describes the benefits of making school building more energy efficient. Provides examples of physical retrofits and behavioral changes to save energy costs. Describes four-step process to create an energy efficiency plan. Includes resources and information such as U.S. Department of Energy's Energy STAR program (www.energystar.gov). (PKP)
After-hours Power Status of Office Equipment and Inventory of Miscellaneous Plug-load Equipment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roberson, Judy A.; Webber, Carrie A.; McWhinney, Marla C.
2004-01-22
This research was conducted in support of two branches of the EPA ENERGY STAR program, whose overall goal is to reduce, through voluntary market-based means, the amount of carbon dioxide emitted in the U.S. The primary objective was to collect data for the ENERGY STAR Office Equipment program on the after-hours power state of computers, monitors, printers, copiers, scanners, fax machines, and multi-function devices. We also collected data for the ENERGY STAR Commercial Buildings branch on the types and amounts of ''miscellaneous'' plug-load equipment, a significant and growing end use that is not usually accounted for by building energy managers.more » This data set is the first of its kind that we know of, and is an important first step in characterizing miscellaneous plug loads in commercial buildings. The main purpose of this study is to supplement and update previous data we collected on the extent to which electronic office equipment is turned off or automatically enters a low power state when not in active use. In addition, it provides data on numbers and types of office equipment, and helps identify trends in office equipment usage patterns. These data improve our estimates of typical unit energy consumption and savings for each equipment type, and enables the ENERGY STAR Office Equipment program to focus future effort on products with the highest energy savings potential. This study expands our previous sample of office buildings in California and Washington DC to include education and health care facilities, and buildings in other states. We report data from twelve commercial buildings in California, Georgia, and Pennsylvania: two health care buildings, two large offices (> 500 employees each), three medium offices (50-500 employees), four education buildings, and one ''small office'' that is actually an aggregate of five small businesses. Two buildings are in the San Francisco Bay area of California, five are in Pittsburgh, Pennsylvania, and five are in Atlanta, Georgia.« less
Sustainable Practices Innovation
Better sustainability means more environmentally conscious and efficient businesses and communities. EPA helps modify the way we consume energy, deal with waste, and grow our economy through programs such as Energy Star, E3, Smart Growth, and WaterSense.
After-hours power status of office equipment and energy use of miscellaneous plug-load equipment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roberson, Judy A.; Webber, Carrie A.; McWhinney, Marla C.
2004-05-27
This research was conducted in support of two branches of the EPA ENERGY STAR program, whose overall goal is to reduce, through voluntary market-based means, the amount of carbon dioxide emitted in the U.S. The primary objective was to collect data for the ENERGY STAR Office Equipment program on the after-hours power state of computers, monitors, printers, copiers, scanners, fax machines, and multi-function devices. We also collected data for the ENERGY STAR Commercial Buildings branch on the types and amounts of miscellaneous plug-load equipment, a significant and growing end use that is not usually accounted for by building energy managers.more » For most types of miscellaneous equipment, we also estimated typical unit energy consumption in order to estimate total energy consumption of the miscellaneous devices within our sample. This data set is the first of its kind that we know of, and is an important first step in characterizing miscellaneous plug loads in commercial buildings. The main purpose of this study is to supplement and update previous data we collected on the extent to which electronic office equipment is turned off or automatically enters a low power state when not in active use. In addition, it provides data on numbers and types of office equipment, and helps identify trends in office equipment usage patterns. These data improve our estimates of typical unit energy consumption and savings for each equipment type, and enables the ENERGY STAR Office Equipment program to focus future effort on products with the highest energy savings potential. This study expands our previous sample of office buildings in California and Washington DC to include education and health care facilities, and buildings in other states. We report data from sixteen commercial buildings in California, Georgia, and Pennsylvania: four education buildings, two medical buildings, two large offices (> 500 employees each), three medium offices (50-500 employees each), and five small business offices (< 50 employees each). Two buildings are in the San Francisco Bay are a of California, nine (including the five small businesses) are in Pittsburgh, Pennsylvania, and five are in Atlanta, Georgia.« less
Field power measurements of imaging equipment
DOE Office of Scientific and Technical Information (OSTI.GOV)
McWhinney, Marla; Homan, Gregory; Brown, Richard
2004-05-14
According to the U.S. Department of Energy, electricity use by non-PC commercial office equipment is growing at an annual rate of nearly 5 percent (AEO 2003). To help address this growth in consumption, U.S. EPA periodically updates its ENERGY STAR specifications as products and markets change. This report presents background research conducted to help EPA update the ENERGY STAR specification for imaging equipment, which covers printers, fax machines, copiers, scanners, and multifunction devices (MFDs). We first estimated the market impact of the current ENERGY STAR imaging specification, finding over 90 percent of the current market complies with the specification. Wemore » then analyzed a sample of typical new imaging products, including 11 faxes, 57 printers and 19 copiers/MFD. For these devices we metered power levels in the most common modes: active/ready/sleep/off, and recorded features that would most likely affect energy consumption. Our metering indicates that for many products and speed bins, current models consume substantially less power than the current specification. We also found that for all product categories, power consumption varied most considerably across technology (i.e. inkjet vs. laser). Although inkjet printers consumed less energy than laser printers in active, ready and sleep-mode, they consumed more power on average while off, mostly due to the use of external power supplies. Based on these findings, we developed strategies for the ENERGY STAR program to achieve additional energy reductions. Finally, we present an assessment of manufacturer's ENERGY STAR labeling practices.« less
Early Results from NICER Observations of Accreting Neutron Stars
NASA Astrophysics Data System (ADS)
Chakrabarty, Deepto; Ozel, Feryal; Arzoumanian, Zaven; Gendreau, Keith C.; Bult, Peter; Cackett, Ed; Chenevez, Jerome; Fabian, Andy; Guillot, Sebastien; Guver, Tolga; Homan, Jeroen; Keek, Laurens; Lamb, Frederick; Ludlam, Renee; Mahmoodifar, Simin; Markwardt, Craig B.; Miller, Jon M.; Psaltis, Dimitrios; Strohmayer, Tod E.; Wilson-Hodge, Colleen A.; Wolff, Michael T.
2018-01-01
The Neutron Star Interior Composition Explorer (NICER) offers significant new capabilities for the study of accreting neuton stars relative to previous X-ray missions including large effective area, low background, and greatly improved low-energy response. The NICER Burst and Accretion Working Group has designed a 2 Ms observation program to study a number of phenomena in accreting neutron stars including type-I X-ray bursts, superbursts, accretion-powered pulsations, quasi-periodic oscillations, and accretion disk reflection spectra. We present some early results from the first six months of the NICER mission.
This project evaluated the effectiveness, first costs and operational costs of various types of residential ventilation systems in three different climates in the U.S. The Agency, through its Energy Star Program, recommends that builders construct homes that are energy efficient ...
Galactic Astronomy in the Ultraviolet
NASA Astrophysics Data System (ADS)
Rastorguev, A. S.; Sachkov, M. E.; Zabolotskikh, M. V.
2017-12-01
We propose a number of prospective observational programs for the ultraviolet space observatory WSO-UV, which seem to be of great importance to modern galactic astronomy. The programs include the search for binary Cepheids; the search and detailed photometric study and the analysis of radial distribution of UV-bright stars in globular clusters ("blue stragglers", blue horizontal-branch stars, RR Lyrae variables, white dwarfs, and stars with UV excesses); the investigation of stellar content and kinematics of young open clusters and associations; the study of spectral energy distribution in hot stars, including calculation of the extinction curves in the UV, optical and NIR; and accurate definition of the relations between the UV-colors and effective temperature. The high angular resolution of the observatory allows accurate astrometric measurements of stellar proper motions and their kinematic analysis.
Weatherization Plays a Starring Role in Mississippi: Weatherization Assistance Close-Up Fact Sheet
DOE Office of Scientific and Technical Information (OSTI.GOV)
D&R International
2001-10-10
Mississippi demonstrates its commitment to technology and efficiency through the Weatherization Program. Weatherization uses advanced technologies and techniques to reduce energy costs for low-income families by increasing the energy efficiency of their homes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
After progressively incorporating ENERGY STAR for Homes Versions 1, 2, and 3 into its standard practices over the years, builder Brookside Development was seeking to build an even more sustainable product that would further increase energy efficiency, while also addressing indoor air quality, water conservation, renewable-ready, and resiliency. These objectives align with the framework of the U.S. Department of Energy Zero Energy Ready Home program, which builds upon the comprehensive building science requirements of ENERGY STAR for Homes Version 3 and proven Building America innovations and best practices. To meet this goal, Consortium for Advanced Residential Buildings partnered with Brooksidemore » Development to design and construct the first zero energy ready home in a development of seven new homes on the old Singer Estate in Derby, Connecticut.« less
MWPC prototyping and performance test for the STAR inner TPC upgrade
NASA Astrophysics Data System (ADS)
Shen, Fuwang; Wang, Shuai; Kong, Fangang; Bai, Shiwei; Li, Changyu; Videbæk, Flemming; Xu, Zhangbu; Zhu, Chengguang; Xu, Qinghua; Yang, Chi
2018-07-01
A new prototype of STAR inner Time Projection Chamber (iTPC) MWPC sector has been fabricated and tested in an X-ray test system. The wire chamber built at Shandong University has a wire tension precision better than 6% and wire pitch precision better than 10 μm. The gas gain uniformity and energy resolution are measured to be better than 1% (RMS) and 20% (FWHM), respectively, using an 55Fe X-ray source. The iTPC upgrade project is to replace all 24 STAR TPC inner sectors as a crucial detector upgrade for the RHIC beam energy scan phase II program. The test results show that the constructed iTPC prototype meets all project requirements.
Technology Solutions Case Study: Zero Energy Ready Home and the Challenge of Hot Water on Demand
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
Production builders in the Stapleton community of Denver, Colorado, now build 2,300-ft2 or larger homes that earn the U.S. Environmental Protection Agency (EPA) ENERGY STAR® through the Certified Homes Program, Version 3. These builders are repositioning to build comparably sized homes to the standards of the U.S. Department of Energy’s (DOE’s) Zero Energy Ready Home (ZERH) program. Most ZERH criteria align closely with ENERGY STAR and are familiar to these builders.
Tierra Concrete Homes Honored with Energy Star Award
building. NREL's research on low energy residences is sponsored by DOE's Building America Program. Building America conducts systems engineering research and system cost/performance tradeoffs to increase energy performance with minimal increases in housing cost. See the Building America Web site. Tierra Concrete Homes
Atmospheric Modeling of Cool Giant and Supergiant Stars
NASA Astrophysics Data System (ADS)
Linsky, Jeffrey L.
1984-07-01
We propose to continue our collaborative program of obtaining and analysing high dispersion SWP spectra of cool stars. We request high dispersion, short wavelength IUE spectra of the stars alpha Tau (K5III), gamma Cru (M3III), epsilon Peg (K2Ib) and beta Cam (G0Ib) with exposure times of 16 hours or more. These spectra will provide measurements of line profiles, widths and Doppler shifts in addition to density-sensitive and opacity-sensitive line ratios. Models of chromospheric and transition region (where present) structure will be calculated by a combination of emission measure analysis, line opacity/probability of escape methods and model atmosphere calculations for optically thick resonance lines such as MgII h and k, including partial redistribution radiative transfer. These models will be used to investigate the atmospheric energy balance and the nature of energy transport and nonradiative energy deposition processes. The results will be considered in relation to stellar evolution and compared with the chromospheric properties of other stars previously studied by the authors and their collaborators.
Probing the X-ray Emission from the Massive Star Cluster Westerlund 2
NASA Astrophysics Data System (ADS)
Lopez, Laura
2017-09-01
We propose a 300 ks Chandra ACIS-I observation of the massive star cluster Westerlund 2 (Wd2). This region is teeming with high-energy emission from a variety of sources: colliding wind binaries, OB and Wolf-Rayet stars, two young pulsars, and an unidentified source of very high-energy (VHE) gamma-rays. Our Chandra program is designed to achieve several goals: 1) to take a complete census of Wd2 X-ray point sources and monitor variability; 2) to probe the conditions of the colliding winds in the binary WR 20a; 3) to search for an X-ray counterpart of the VHE gamma-rays; 4) to identify diffuse X-ray emission; 5) to compare results to other massive star clusters observed by Chandra. Only Chandra has the spatial resolution and sensitivity necessary for our proposed analyses.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dentz, Jordan; Alaigh, Kunal
Two multifamily buildings planned in Climate Zone 4 were analyzed to determine the cost, energy and performance implications of redesigning them to comply with Zero Energy Ready Home, a recognition program of the U.S. Department of Energy. Energy modeling was conducted on one representative apartment in each building using BEopt. Construction costs were obtained from the developer and subcontractors to determine savings and cost increases over ENERGY STAR. It was found that seven items would be necessary to change to comply with ZERH criteria when starting from the original design which was compliant with ENERGY STAR version 3.0. Design changesmore » were made to the exterior walls, domestic water heating system, duct protection, duct design, garage ventilation, and pest control to comply with ZERH requirements. Energy impacts of upgrading from the original design to ZERH resulted in 2 to 8% reduction in modeled source energy consumption, or 1.7 to 10.4 MMBtu per year, although the original design was already about 8% better than a design configured to minimum ENERGY STAR criteria. According to the BEopt analysis, annualized energy related costs of the ZERH design were slightly higher for the apartment and slightly lower for the townhome when compared to the original design.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Two multifamily buildings planned in Climate Zone 4 were analyzed to determine the cost, energy and performance implications of redesigning them to comply with Zero Energy Ready Home, a recognition program of the U.S. Department of Energy. Energy modeling was conducted on one representative apartment in each building using BEopt. Construction costs were obtained from the developer and subcontractors to determine savings and cost increases over ENERGY STAR. It was found that seven items would be necessary to change to comply with ZERH criteria when starting from the original design which was compliant with ENERGY STAR version 3.0. Design changesmore » were made to the exterior walls, domestic water heating system, duct protection, duct design, garage ventilation, and pest control to comply with ZERH requirements. Energy impacts of upgrading from the original design to ZERH resulted in 2 to 8 percent reduction in modeled source energy consumption, or 1.7 to 10.4 MMBtu per year, although the original design was already about 8 percent better than a design configured to minimum ENERGY STAR criteria. According to the BEopt analysis, annualized energy related costs of the ZERH design were slightly higher for the apartment and slightly lower for the townhome when compared to the original design.« less
The Life Story of a Star, Book 5. Guidebook. The University of Illinois Astronomy Project.
ERIC Educational Resources Information Center
Atkin, J. Myron; Wyatt, Stanley P., Jr.
Presented is book five in a series of six books in the University of Illinois Astronomy Program which introduces astronomy to upper elementary and junior high school students. This guidebook discusses the interior of stars, their source of energy, and their evolution. Topics presented include: the physical properties of the sun; model of the solar…
10 CFR 436.42 - Evaluation of Life-Cycle Cost Effectiveness.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 10 Energy 3 2014-01-01 2014-01-01 false Evaluation of Life-Cycle Cost Effectiveness. 436.42... PROGRAMS Agency Procurement of Energy Efficient Products § 436.42 Evaluation of Life-Cycle Cost...) ENERGY STAR qualified and FEMP designated products may be assumed to be life-cycle cost-effective. (b) In...
10 CFR 436.42 - Evaluation of Life-Cycle Cost Effectiveness.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 10 Energy 3 2012-01-01 2012-01-01 false Evaluation of Life-Cycle Cost Effectiveness. 436.42... PROGRAMS Agency Procurement of Energy Efficient Products § 436.42 Evaluation of Life-Cycle Cost...) ENERGY STAR qualified and FEMP designated products may be assumed to be life-cycle cost-effective. (b) In...
10 CFR 436.42 - Evaluation of Life-Cycle Cost Effectiveness.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 10 Energy 3 2013-01-01 2013-01-01 false Evaluation of Life-Cycle Cost Effectiveness. 436.42... PROGRAMS Agency Procurement of Energy Efficient Products § 436.42 Evaluation of Life-Cycle Cost...) ENERGY STAR qualified and FEMP designated products may be assumed to be life-cycle cost-effective. (b) In...
10 CFR 436.42 - Evaluation of Life-Cycle Cost Effectiveness.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 10 Energy 3 2010-01-01 2010-01-01 false Evaluation of Life-Cycle Cost Effectiveness. 436.42... PROGRAMS Agency Procurement of Energy Efficient Products § 436.42 Evaluation of Life-Cycle Cost...) ENERGY STAR qualified and FEMP designated products may be assumed to be life-cycle cost-effective. (b) In...
The STAR Detector Upgrades and Electromagnetic Probes in Beam Energy Scan Phase II
NASA Astrophysics Data System (ADS)
Yang, Chi
The Beam Energy Scan Phase II at RHIC, BES-II, is scheduled from year 2019 to 2020 and will explore the high baryon density region of the QCD phase diagram with high precision. The program will focus on the interesting energy region determined from the results of BES-I. Some of the key measurements anticipated are the chiral symmetry restoration and QGP thermal radiation in the dilepton and direct photon channels. The measurements will be possible with an order of magnitude better statistics provided by the electron cooling upgrade of RHIC and with the detector upgrades planned to extend STAR experimental reach. The upgrades are: the inner Time Projection Chamber sectors (iTPC), the Event Plane Detector (EPD), and the end-cap Time of Flight (eTOF). We present the BES-II program details and the physics opportunities in the dilepton and direct photon channels enabled by the upgrades.
MWPC prototyping and performance test for the STAR inner TPC upgrade
Shen, Fuwang; Wang, Shuai; Kong, Fangang; ...
2018-04-16
A new prototype of STAR inner Time Projection Chamber (iTPC) MWPC sector has been fabricated and tested in an X-ray test system. The wire chamber built at Shandong University has a wire tension precision better than 6% and wire pitch precision better than 10 μm. The gas gain uniformity and energy resolution are measured to be better than 1% (RMS) and 20% (FWHM), respectively, using an 55Fe X-ray source. The iTPC upgrade project is to replace all 24 STAR TPC inner sectors as a crucial detector upgrade for the RHIC beam energy scan phase II program. Furthermore, the test resultsmore » show that the constructed iTPC prototype meets all project requirements.« less
MWPC prototyping and performance test for the STAR inner TPC upgrade
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shen, Fuwang; Wang, Shuai; Kong, Fangang
A new prototype of STAR inner Time Projection Chamber (iTPC) MWPC sector has been fabricated and tested in an X-ray test system. The wire chamber built at Shandong University has a wire tension precision better than 6% and wire pitch precision better than 10 μm. The gas gain uniformity and energy resolution are measured to be better than 1% (RMS) and 20% (FWHM), respectively, using an 55Fe X-ray source. The iTPC upgrade project is to replace all 24 STAR TPC inner sectors as a crucial detector upgrade for the RHIC beam energy scan phase II program. Furthermore, the test resultsmore » show that the constructed iTPC prototype meets all project requirements.« less
Reducing Energy Use in Existing Homes by 30%: Learning From Home Performance with ENERGY STAR
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liaukus, C.
2014-12-01
The improvement of existing homes in the United States can have a much greater impact on overall residential energy use than the construction of highly efficient new homes. There are over 130 million existing housing units in the U.S., while annually new construction represents less than two percent of the total supply (U.S. Census Bureau, 2013). Therefore, the existing housing stock presents a clear opportunity and responsibility for Building America (BA) to guide the remodeling and retrofit market toward higher performance existing homes. There are active programs designed to improve the energy performance of existing homes. Home Performance with ENERGYmore » STAR (HPwES) is a market-rate program among them. BARA's research in this project verified that the New Jersey HPwES program is achieving savings in existing homes that meet or exceed BA's goal of 30%. Among the 17 HPwES projects with utility data included in this report, 15 have actual energy savings ranging from 24% to 46%. Further, two of the homes achieved that level of energy savings without the costly replacement of heating and cooling equipment, which indicates that less costly envelope packages could be offered to consumers unable to invest in more costly mechanical packages, potentially creating broader market impact.« less
NASA Astrophysics Data System (ADS)
Keller, J. M.; Rebar, B.; Buxner, S.
2012-12-01
The STEM Teacher and Researcher (STAR) Program provides pre-service and beginning teachers the opportunity to develop identity as both teachers and researchers early in their careers. Founded and implemented by the Center for Excellence in Science and Mathematics Education (CESaME) at California Polytechnic State University on behalf of the California State University (CSU) system, STAR provides cutting edge research experiences and career development for students affiliated with the CSU system. Over the past three summers, STAR has also partnered with the NSF Robert Noyce Teacher Scholarship Program to include Noyce Scholars from across the country. Key experiences are one to three summers of paid research experience at federal research facilities associated with the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Association (NOAA), and the National Optical Astronomy Observatory (NOAO). Anchoring beginning teachers in the research community enhances participant understanding of what it means to be both researchers and effective teachers. Since its inception in 2007, the STAR Program has partnered with 15 national lab facilities to provide 290 research experiences to 230 participants. Several of the 68 STAR Fellows participating in the program during Summer 2012 have submitted abstracts to the Fall AGU Meeting. Through continued partnership with the Noyce Scholar Program and contributions from outside funding sources, the CSU is committed to sustaining the STAR Program in its efforts to significantly impact teacher preparation. Evaluation results from the program continue to indicate program effectiveness in recruiting high quality science and math majors into the teaching profession and impacting their attitudes and beliefs towards the nature of science and teaching through inquiry. Additionally, surveys and interviews are being conducted of participants who are now teaching in the classroom as part of a project to investigate the impact of the STAR Program on teaching practices. Preliminary analyses indicate that STAR fellows have maintained a strong distributed community of support following their summer experience, including continued contact with their research mentors and other fellows. The STAR research experience has also reinforced and strengthened many of the teachers' commitment to teaching. Additionally, teachers report how their STAR experience contributed to specific practices they use in the classroom to help students develop hypotheses, design experiments, and report their findings to the class. The STAR Program was presented to and cited by the Presidential Council of Advisors on Science and Technology (PCAST) as a national model for addressing K-12 science and math teacher workforce needs. It has also been recognized as a uniquely promising model for recruiting, preparing and retaining outstanding STEM teachers in such national publications as the American Association of Colleges and Universities (AAC&U) Peer Review journal and the National Science Teachers Association NSTA Reports. STAR was also recently cited in an editorial in Science (May 4, 2012) as a model teacher-researcher program that enhances professionalism in science teaching.
Energy conservation awareness and practice in restaurants of Hennepin County, Minnesota.
Brondum, Jack; Palchick, Susan
2012-12-01
Greenhouse gases result mainly from the combustion of fossil fuels in energy use. Restaurants use large amounts of energy in their operation but systematically gathered information about such use is lacking. Hennepin County Human Services and Public Health Department surveyed owners of licensed restaurants to assess their energy use and awareness of energy conservation measures. Of 434 owners surveyed, 276 (63.6%) returned completed surveys. Responses indicated that large pluralities or majorities of restaurant owners often were aware of energy-efficient methods of operation and the means to achieve greater efficiency but used such means much less frequently. For example, 57% of respondents were familiar with the U.S. Environmental Protection Agency's Energy Star program, but only 33% of this group actually used Energy Star appliances. Given the gap between awareness and practice, opportunities for consultation and outreach to restaurant owners about energy-efficient business operation are manifold.
Connecting and Networking for Schools
Resources for connecting and networking for schools through e-newsletters, finding school IAQ Champions and other EPA school programs such as Asthma, Energy Star, Clean School Bus USA, School Flag, etc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Michael; Banwell, Peter
2018-01-09
The purpose of this guide is to provide a resource for state utility regulators, utilities, the evaluation community and regulatory stakeholders on methods to measure energy savings from the ENERGY STAR Retail Products Platform (link is external). The guidelines outlined in this document were developed by evaluation experts.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-21
... ENERGY STAR's HVAC Quality Installation program, sponsors promote the installation of HVAC systems in new... Energy Raters), and the Heating, Ventilation, and Cooling (HVAC) contractor. These organizations complete... (5900-08) Partnership Agreement for HVAC QI Sponsor (5900-183) Partnership Agreement for Home...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zimring, Mark; Fuller, Merrian
2011-01-24
The New York legislature passed the Green Jobs-Green New York (GJGNY) Act in 2009. Administered by the New York State Energy Research and Development Authority (NYSERDA), GJGNY programs provide New Yorkers with access to free or low-cost energy assessments,1 energy upgrade services,2 low-cost financing, and training for various 'green-collar' careers. Launched in November 2010, GJGNY's residential initiative is notable for its use of novel underwriting criteria to expand access to energy efficiency financing for households seeking to participate in New York's Home Performance with Energy Star (HPwES) program.3 The GJGNY financing program is a valuable test of whether alternatives tomore » credit scores can be used to responsibly expand credit opportunities for households that do not qualify for traditional lending products and, in doing so, enable more households to make energy efficiency upgrades.« less
NASA Technical Reports Server (NTRS)
Rosenzweig, P.; Morrison, N. D.
1986-01-01
Five early B-type stars near the main-sequence turnoff in NGC 457 have been observed at low dispersion with the short-wavelength prime and the long-wavelength redundant cameras of the IUE satellite. The equivalent widths of spectral features that are particularly strong and sensitive to temperature and luminosity were computed in the cluster stars and in 20 lightly reddened stars of types O9-B3 and luminosity classes III-V. The comparison of the equivalent widths provides a reliable method for finding matching pairs. Having identified the best comparison star for each program star, binned fluxes were used to determine the mean extinction curve. In order to cover the visible region, monochromatic fluxes of Phi Cas were derived from observations with the intensified Reticon scanner mounted on the No. 2 0.9 m telescope of KPNO, and they were dereddened with the mean extinction curve of Savage and Mathis. Thus, the intrinsic energy distribution of Phi Cas were determined from 1500 to 5800 A for use in a detailed model-atmosphere analysis.
Calibration of Star Formation Rates Across the Electromagnetic Spectrum
NASA Technical Reports Server (NTRS)
Cardiff, Ann H.
2011-01-01
Measuring and mapping star-forming activity in galaxies is a key element for our understanding of their broad- band spectra, and their structure and evolution in our local, as well as the high-redshift Universe. The main tool we use for these measurements is the observed luminosity in various spectral lines and/or continuum bands. However, the available star-formation rate (SFR) indicators are often discrepant and subject to physical biases and calibration uncertainties. We are organizing a special session at the 2012 IAU General Assembly in Beijing, China (August 20-31, 2012) in order to bring together theoreticians and observers working in different contexts of star-formation to discuss the status of current SFR indicators, to identify open issues and to define a strategic framework for their resolution. The is an ideal time to synthesize information from the current golden era of space astrophysics and still have influence on the upcoming missions that will broaden our view of star-formation. We will be including high-energy constraints on SFR in the program and encourage participation from the high energy astrophysics community.
NASA Astrophysics Data System (ADS)
Nesvadba, N. P. H.; Drouart, G.; De Breuck, C.; Best, P.; Seymour, N.; Vernet, J.
2017-04-01
We compare the kinetic energy and momentum injection rates from intense star formation, bolometric AGN radiation, and radio jets with the kinetic energy and momentum observed in the warm ionized gas in 24 powerful radio galaxies at z 2. These galaxies are among our best candidates for being massive galaxies near the end of their active formation period, when intense star formation, quasar activity, and powerful radio jets all co-exist. All galaxies have VLT/SINFONI imaging spectroscopy of the rest-frame optical line emission, showing extended emission-line regions with large velocity offsets (up to 1500 km s-1) and line widths (typically 800-1000 km s-1) consistent with very turbulent, often outflowing gas. As part of the HeRGÉ sample, they also have FIR estimates of the star formation and quasar activity obtained with Herschel/PACS and SPIRE, which enables us to measure the relative energy and momentum release from each of the three main sources of feedback in massive, star-forming AGN host galaxies during their most rapid formation phase. We find that star formation falls short by factors 10-1000 of providing the energy and momentum necessary to power the observed gas kinematics. The obscured quasars in the nuclei of these galaxies provide enough energy and momentum in about half of the sample, however, only if both are transferred to the gas relatively efficiently. We compare with theoretical and observational constraints on the efficiency of the energy and momentum transfer from jet and AGN radiation, which favors the radio jets as main drivers of the gas kinematics. Based on observations carried out with the Very Large Telescope of ESO under Program IDs 079.A-0617, 084.A-0324, 085.A-0897, and 090.A-0614.Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.
NASA Astrophysics Data System (ADS)
Quintero, Amilkar; STAR Collaboration
2017-09-01
The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory is carrying out a spin physics program in high-energy polarized proton collisions at center of mass energies up to 510 GeV, to gain a deeper insight into the spin structure and dynamics of the proton. The polarized gluon distribution function can be constrained in longitudinally polarized proton collisions through jet / di-jet production. Recent global analyses, which include results of the measurement of ALL for inclusive jet production at 200 GeV at mid-rapidity at the STAR experiment, provide evidence of a non-zero gluon polarization in the measured range of partonic momentum fraction of approximately 0.05
Hazardous Early Days In (and Beyond) the Habitable Zones Around Ultra-Low-Mass Stars
NASA Astrophysics Data System (ADS)
Kastner, Joel
Although a majority of stars in the solar neighborhood are of mid- to late-M type, the magnetically-induced coronal (X-ray) and chromospheric (UV, H-alpha) activity of such stars remain essentially unexplored for the important age range 10-100 Myr. Such information on high-energy processes associated with young M stars would provide much-needed constraints on models of the effects of stellar irradiation on the physics and chemistry of planet-forming disks and newborn planets. In addition, X-ray and UV observations of ultra-low-mass young stars can serve to probe the (presently ill-defined) spectral type boundary that determines which very low-mass objects will eventually become M stars -- as opposed to brown dwarfs (BDs) -- following their pre-main sequence evolutionary stages. Via ADAP support, we have developed the GALEX Nearby Young Star Search (GALNYSS), a search method that combines GALEX, 2MASS, WISE and proper motion catalog information to identify nearby, young, lowmass stars. We have applied this method to identify ~2000 candidate young (10-100 Myr), low-mass (M-type) stars within 150 pc. These GALNYSS-identified young star candidates are distributed over the entire GALEX-covered sky, and their spectral types peak in the M3-4 range; followup optical spectroscopic work is ongoing (Rodriguez et al. 2013, ApJ, 774, 101). We now propose an ADA program to determine the X-ray properties of representative stars among these GALNYSS candidates, so as to confirm their youth and investigate the early evolution of coronal activity near the low-mass star/BD boundary and the effects of such activity on planet formation. Specifically, we will exploit the presence in the HEASARC archives of XMM-Newton and (to a lesser extent) Chandra X-ray Observatory data for a few dozen GALNYSS candidates that have been observed serendipitously by one or both of these space observatories. The proposed ADA program will yield the full reduction and analysis of these as-yet unexplored data. The results will be used to constrain models describing the dispersal of protoplanetary disks and evaporation of planetary atmospheres due to intense irradiation by high-energy photons from young, low-mass stars, and to shed new light on the early evolution of magnetic activity of stars with masses down to near the H-burning limit.
The Nuclear Spectroscopic Telescope Array (NuSTAR) High-Energy X-ray Mission
NASA Technical Reports Server (NTRS)
Harrison, Fiona A.; Craig, Willliam W.; Christensen, Finn E.; Hailey, Charles J.; Zhang, William W.; Boggs, Steven E.; Stern, Daniel; Cook, W. Rick; Forster, Karl; Giommi, Paolo;
2013-01-01
High-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the 10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity over the collimated or coded mask instruments that have operated in this bandpass. Using its unprecedented combination of sensitivity and spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: (1) probe obscured active galactic nucleus (AGN) activity out to thepeak epoch of galaxy assembly in the universe (at z 2) by surveying selected regions of the sky; (2) study the population of hard X-ray-emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; (3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element 44Ti; (4) observe blazars contemporaneously with ground-based radio, optical, and TeV telescopes, as well as with Fermi and Swift, to constrain the structure of AGN jets; and (5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake a broad program of targeted observations. The observatory consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. Deployed into a 600 km, near-circular, 6 inclination orbit, the observatory has now completed commissioning, and is performing consistent with pre-launch expectations. NuSTAR is now executing its primary science mission, and with an expected orbit lifetime of 10 yr, we anticipate proposing a guest investigator program, to begin in late 2014.
Young Star Cluster Found Aglow With Mysterious X-Ray Cloud
NASA Astrophysics Data System (ADS)
2002-12-01
A mysterious cloud of high-energy electrons enveloping a young cluster of stars has been discovered by astronomers using NASA's Chandra X-ray Observatory. These extremely high-energy particles could cause dramatic changes in the chemistry of the disks that will eventually form planets around stars in the cluster. Known as RCW 38, the star cluster covers a region about 5 light years across. It contains thousands of stars formed less than a million years ago and appears to be forming new stars even today. The crowded environment of a star cluster is thought to be conducive to the production of hot gas, but not high-energy particles. Such particles are typically produced by exploding stars, or in the strong magnetic fields around neutron stars or black holes, none of which is evident in RCW 38. "The RCW 38 observation doesn't agree with the conventional picture," said Scott Wolk of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA, lead author of an Astrophysical Journal Letters paper describing the Chandra observation. "The data show that somehow extremely high-energy electrons are being produced there, although it is not clear how." RCW 38 RCW 38 X-ray, Radio, Infrared Composite Electrons accelerated to energies of trillions of volts are required to account for the observed X-ray spectrum of the gas cloud surrounding the ensemble of stars, which shows an excess of high-energy X-rays. As these electrons move in the magnetic field that threads the cluster, they produce X-rays. One possible origin for the high-energy electrons is a previously undetected supernova that occurred in the cluster. Although direct evidence for the supernova could have faded away thousands of years ago, a shock wave or a rapidly rotating neutron star produced by the outburst could be acting in concert with stellar winds to produce the high-energy electrons. "Regardless of the origin of the energetic electrons," said Wolk, "their presence would change the chemistry of proto-stellar disks in ways that could still be manifest billions of years later." For example, in our own solar system, we find evidence of certain short-lived radioactive nuclides (Aluminum 26 being the most well known). This implies the existence of a high-energy process late in the evolution of our solar system. If our solar system was immersed for a time in a sea of energetic particles, this could explain the rare nuclides present in meteorites found on the Earth today. RCW 38, at a distance of 6,000 light years from Earth, is one of the nearest star-forming regions with very young, hot stars. Other authors of the paper, which appeared in the 2002 December 1 issue of the Astrophysical Journal Letters, are Tyler Bourke, Randall Smith and Bradley Spitzbart of the Harvard-Smithsonian Center for Astrophysics, and Joao Alves of the European Southern Observatory in Garching, Germany. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science in Washington. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-27
...), a subsidiary of UniStar Nuclear Energy, LLC. Basis for proposed no significant hazards consideration... Frequency Control Program in accordance with guidance in Nuclear Energy Institute (NEI) 04-10, ``Risk... with 10 CFR 51.22. Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or...
Research on Spectroscopy, Opacity, and Atmospheres
NASA Technical Reports Server (NTRS)
Oliversen, Ronald (Technical Monitor); Kurucz, Robert L.
2004-01-01
I propose to continue providing observers with basic data for interpreting spectra from stars, novas, supernovas, clusters, and galaxies. These data will include allowed forbidden line lists both laboratory and computed, for the first five to ten ions of all atoms and for all relevant diatomic molecules. I will eventually expend to all ions of the first thirty elements to treat far UV end X-ray spectra, and for envelope opacities. I also include triatomic molecules providing by other researchers. I have made CDs with Partridge and Schwanke's water data for work on M stars.The luna data also serve as input to my model atmosphere and synthesis programs that generated energy distributions, photometry, limb darkening, and spectra that can be used for planning observations and for fitting observed spectra. The spectrum synthesis programs produce detailed plots with the line identified. Grids of stellar spectra can be used for radial velocity-, rotation-, or abundance templates and for population synthesis. I am fitting spectra of bright stars to test the data and to produce atlases to guide observer. For each star the whole spectrum is computed from the UV to the far IR. The line data, opacities, models, spectra, and programs are freely distributed on CDs and on my web site and represent a unique resource for many NASA programs.
Searching for X-ray Pulsations from Neutron Stars Using NICER
NASA Astrophysics Data System (ADS)
Ray, Paul S.; Arzoumanian, Zaven; Bogdanov, Slavko; Bult, Peter; Chakrabarty, Deepto; Guillot, Sebastien; Kust Harding, Alice; Ho, Wynn C. G.; Lamb, Frederick K.; Mahmoodifar, Simin; Miller, M. Coleman; Strohmayer, Tod E.; Wilson-Hodge, Colleen A.; Wolff, Michael Thomas
2017-08-01
The Neutron Star Interior Composition Explorer (NICER) presents an exciting new capability for discovering new modulation properties of X-ray emitting neutron stars, including large area, low background, extremely precise absolute time stamps, superb low-energy response and flexible scheduling. The Pulsation Searches and Multiwavelength Coordination working group has designed a 2.5 Ms observing program to search for pulsations and characterize the modulation properties of about 30 known or suspected neutron star sources across a number of source categories. A key early goal will be to search for pulsations from millisecond pulsars that might exhibit thermal pulsations from the surface suitable for pulse profile modeling to constrain the neutron star equation of state. In addition, we will search for pulsations from transitional millisecond pulsars, isolated neutron stars, LMXBs, accretion-powered millisecond pulsars, central compact objects and other sources. We will present our science plan and initial results from the first months of the NICER mission.
Searching for X-ray Pulsations from Neutron Stars Using NICER
NASA Astrophysics Data System (ADS)
Ray, Paul S.; Arzoumanian, Zaven; Gendreau, Keith C.; Bogdanov, Slavko; Bult, Peter; Chakrabarty, Deepto; Chakrabarty, Deepto; Guillot, Sebastien; Harding, Alice; Ho, Wynn C. G.; Lamb, Frederick; Mahmoodifar, Simin; Miller, Cole; Strohmayer, Tod; Wilson-Hodge, Colleen; Wolff, Michael T.; NICER Science Team Working Group on Pulsation Searches and Multiwavelength Coordination
2018-01-01
The Neutron Star Interior Composition Explorer (NICER) presents an exciting new capability for discovering new modulation properties of X-ray emitting neutron stars, including large area, low background, extremely precise absolute time stamps, superb low-energy response and flexible scheduling. The Pulsation Searches and Multiwavelength Coordination working group has designed a 2.5 Ms observing program to search for pulsations and characterize the modulation properties of about 30 known or suspected neutron star sources across a number of source categories. A key early goal will be to search for pulsations from millisecond pulsars that might exhibit thermal pulsations from the surface suitable for pulse profile modeling to constrain the neutron star equation of state. In addition, we will search for pulsations from transitional millisecond pulsars, isolated neutron stars, LMXBs, accretion-powered millisecond pulsars, central compact objects and other sources. We present our science plan and initial results from the first months of the NICER mission.
Sweep-twist adaptive rotor blade : final project report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ashwill, Thomas D.
2010-02-01
Knight & Carver was contracted by Sandia National Laboratories to develop a Sweep Twist Adaptive Rotor (STAR) blade that reduced operating loads, thereby allowing a larger, more productive rotor. The blade design used outer blade sweep to create twist coupling without angled fiber. Knight & Carver successfully designed, fabricated, tested and evaluated STAR prototype blades. Through laboratory and field tests, Knight & Carver showed the STAR blade met the engineering design criteria and economic goals for the program. A STAR prototype was successfully tested in Tehachapi during 2008 and a large data set was collected to support engineering and commercialmore » development of the technology. This report documents the methodology used to develop the STAR blade design and reviews the approach used for laboratory and field testing. The effort demonstrated that STAR technology can provide significantly greater energy capture without higher operating loads on the turbine.« less
NASA Technical Reports Server (NTRS)
Nakajima, Tadashi; Golimowski, David A.
1995-01-01
We have obtained R- and I-band coronagraphic images of the vicinities of 11 pre-main sequence (PMS) stars to search for faint, small-scale reflection nebulae. The inner radius of the search and the field of view are 1.9 arcsec and 1x1 arcmin, respectively. Reflection nebulae were imaged around RY Tau, T Tau,DG Tau, SU Aur, AB Aur, FU Ori, and Z CMa. No nebulae were detected around HBC 347, GG Tau, V773 Tau, and V830 Tau. Categorically speaking, most of the classical T Tauri program stars and all the FU Orionis-type program stars are associated with the reflection nebulae, while none of the weak-line T Tauri program stars are associated with nebulae. The detected nebulae range in size from 250 to 37 000 AU. From the brightness ratios of the stars and nebulae, we obtain a lower limit to the visual extinction of PMS star light through the nebulae of (A(sub V))(sub neb) = 0.1. The lower limits of masses and volume densities of the nebulae associated with the classical T Tauri stars are 10(exp-6) Solar mass and N(sub H) = 10(exp 5)/cu cm, respectively. Lower limits for the nebulae around FU Orionis stars are 10(exp -5) Solar mass and n(sub H) = 10 (exp 5)/cu cm, respectively. Some reflection nebulae may trace the illuminated surfaces of the optically thick dust nebulae, so these mass estimates are not stringent. All the PMS stars with associated nebulae are strong far-infrared emitters. Both the far-infrared emission and the reflection nebulae appear to originate from the remnant envelopes of star formation. The 100 micrometers emitting regions of SU Aur and FU Ori are likely to be cospatial with the reflection nebulae. A spatial discontinuity between FU Ori and its reflection nebula may explain the dip in the far-infrared spectral energy distribution at 60 micrometers. The warped, disk-like nebulae around T Tau and Z CMa are aligned with and embrace the inner star/circumstellar disk systems. The arc-shaped nebula around DG Tau may be in contact with the coaligned inner star/disk system. These three-reflection nebulae may trace the surfaces of pseudodisks from which matter accretes onto the stars or the inner circumstellar disks. 19 stellar objects brighter than I = 19 were detected around 9 program stars. Using a color-magnitude diagram, we have identified three new PMS candidates aroun Z CMa and one previously known PMS candidate, GG Tau/c.
NASA Astrophysics Data System (ADS)
Keller, John; Rebar, Bryan
2012-11-01
The STEM Teacher and Researcher (STAR) Program provides 9-week paid summer research experiences at national research laboratories for future science and math teachers. The program, run by the Cal Poly Center for Excellence in Science and Mathematics Education (CESaME) on behalf of the entire California State University (CSU) System, has arranged 290 research internships for 230 STEM undergraduates and credential candidates from 43 campuses over the past 6 years. The program has partnered with seven Department of Energy labs, four NASA centers, three NOAA facilities, and the National Optical Astronomy Observatory (NOAO). Primary components of the summer experience include a) conducting research with a mentor or mentor team, b) participating in weekly 2-3 hour workshops focused on translating lessons learned from summer research into classroom practice, and c) presenting a research poster or oral presentation and providing a lesson plan linked to the summer research experience. The central premise behind the STAR Program is that future science and math teachers can more effectively prepare the next generation of science, math, and engineering students if they themselves have authentic experiences as researchers.
NASA Astrophysics Data System (ADS)
Schneider, Glenn; Thompson, Rodger I.; Smith, Bradford A.; Terrile, Richard J.
1998-08-01
The Near IR Camera and Multi-Object Spectrometer (NICMOS), installed into the Hubble Space Telescope (HST) in February 1997, incorporates a coronagraphic imaging capability. The coronagraph is comprised of two optical elements. The camera 2 field divider mirror, upon which the HST f/24 input beam is imaged, includes a 170 micrometers diameter hole which contains approximately 93 percent of the encircled energy from a stellar Point Spread Function (PSF) at a wavelength of 1.6 micrometers . The coronagraphic hole lowers both the diffracted energy in the surrounding region by reducing the high spatial frequency components of the occulted core of the PSF< and down stream scattering. The geometrical radius of this occulting spot, when re-imaged through the camera 2 f/45 optics, is approximately 4 pixels at the detector focal plane. An oversized cold pupil-plane mask, with radial structures co-aligned with the HST secondary mirror spider, acts over the whole 19.1 inch by 19.2 field to further reduce the diffracted energy in the direction of the spider vanes. The absolute performance levels of the coronagraph were ascertained during the servicing mission observatory verification program. Using a differential imaging strategy we expect to achieve statistically significant detectors of sub-stellar companions at 1.6 micrometers with a (Delta) H of approximately 10 and separations as close as 0.5 inch. The NICMOS environments of nearby stars programs is exploiting this capability in systematic surveys of nearby, and young stars searching for brown dwarfs and giant planets, and protoplanetary disks around main-sequence stars.
NASA Astrophysics Data System (ADS)
Flores, Christopher E.
2016-12-01
The Beam Energy Scan (BES) at the Relativistic Heavy-Ion Collider was proposed to characterize the properties of the medium produced in heavy-ion interactions over a broad range of baryon chemical potential. The aptitude of the STAR detector for mid-rapidity measurements has previously been leveraged to measure identified particle yields and spectra to extract bulk properties for the BES energies for | y | ≤ 0.1. However, to extract information on expansion dynamics and full phase space particle production, it is necessary to study identified particle rapidity density distributions. We present the first rapidity density distributions of identified pions from Au+Au collisions at √{sNN} = 7.7 , 11.5, and 19.6 GeV from the BES program as measured by the STAR detector. We use these distributions to obtain the full phase space yields of the pions to provide additional information of the system's chemistry. Further, we report the width of the rapidity density distributions compared to the width expected from Landau hydrodynamics. Finally, we interpret the results as a function of collision energy and discuss them in the context of previous energy scans done at the AGS and SPS.
The Nuclear Spectroscopic Telescope Array (NuSTAR)
NASA Technical Reports Server (NTRS)
Harrison, Fiona A.; Boggs, Steven; Christensen, Finn; Craig, William; Hailey, Charles; Stern, Daniel; Zhang, William; Angelini, Lorella; An, Hong Jun; Bhalereo, Varun;
2010-01-01
The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing hard X-ray (5 - 80 keV) telescope to orbit. NuSTAR will offer a factor 50 - 100 sensitivity improvement compared to previous collimated or coded mask imagers that have operated in this energy band. In addition, NuSTAR provides sub-arcminute imaging with good spectral resolution over a 12-arcminute field of view. After launch, NuSTAR will carry out a two-year primary science mission that focuses on four key programs: studying the evolution of massive black holes through surveys carried out in fields with excellent multiwavelength coverage, understanding the population of compact objects and the nature of the massive black hole in the center of the Milky Way, constraining explosion dynamics and nucleosynthesis in supernovae, and probing the nature of particle acceleration in relativistic jets in active galactic nuclei. A number of additional observations will be included in the primary mission, and a. guest observer program will be proposed for an extended mission to expand the range of scientific targets. The payload consists of two co-aligned depth-graded multilayer coated grazing incidence optics focused onto solid state CdZnTe pixel detectors. To be launched in early 2012 on a Pegasus rocket into a low-inclination Earth orbit. NuSTAR largely avoids SAA passages, and will therefore have low and stable detector backgrounds. The telescope achieves a 10.15-meter focal length through on-orbit deployment of all mast. An aspect and alignment metrology system enable reconstruction of the absolute aspect and variations in the telescope alignment resulting from mast flexure during ground data processing. Data will be publicly available at GSFC's High Energy Astrophysics Science Archive Research Center (HEASARC) following validation at the science operations center located at Caltech.
NASA Technical Reports Server (NTRS)
Svalbonas, V.; Ogilvie, P.
1973-01-01
The user and programming information necessary for the application of the SATELLITE programs for the STARS system are presented. The individual program functions are: (1) data debugging for the STARS-2S program, (2) Fourier series conversion program, (3) data debugging for the STARS-2B program, and (4) data debugging for the STARS-2V program.
Simulation and Preliminary Design of a Cold Stream Experiment on Omega EP
NASA Astrophysics Data System (ADS)
Coffing, Shane; Angulo, Adrianna; Trantham, Matt; Malamud, Guy; Kuranz, Carolyn; Drake, R. P.
2017-10-01
Galaxies form within dark matter halos, accreting gas that may clump and eventually form stars. Infalling matter gradually increases the density of the halo, and, if cooling is insufficient, rising pressure forms a shock that slows the infalling gas, reducing star formation. However, galaxies with sufficient cooling become prolific star formers. A recent theory suggests that so called ``stream fed galaxies'' are able to acquire steady streams of cold gas via galactic ``filaments'' that penetrate the halo. The cold, dense filament flowing into a hot, less dense environment is potentially Kelvin-Helmholtz unstable. This instability may hinder the ability of the stream to deliver gas deeply enough into the halo. To study this process, we have begun preliminary design of a well-scaled laser experiment on Omega EP. We present here early simulation results and the physics involved. This work is funded by the U.S. Department of Energy, through the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956, and the National Laser User Facility Program, Grant Number DE-NA0002719, and through the Laboratory for Laser Energetics, University of Rochester by the NNSA/OICF under Cooperative Agreement No. DE-NA0001944.
Kelvin-Helmholtz evolution in subsonic cold streams feeding galaxies
NASA Astrophysics Data System (ADS)
Angulo, Adrianna; Coffing, S.; Kuranz, C.; Drake, R. P.; Klein, S.; Trantham, M.; Malamud, G.
2017-10-01
The most prolific star formers in cosmological history lie in a regime where dense filament structures carried substantial mass into the galaxy to sustain star formation without producing a shock. However, hydrodynamic instabilities present on the filament surface limit the ability of such structures to deliver dense matter deeply enough to sustain star formation. Simulations lack the finite resolution necessary to allow fair treatment of the instabilities present at the stream boundary. Using the Omega EP laser, we simulate this mode of galaxy formation with a cold, dense, filament structure within a hotter, subsonic flow and observe the interface evolution. Machined surface perturbations stimulate the development of the Kelvin-Helmholtz (KH) instability due to the resultant shear between the two media. A spherical crystal imaging system produces high-resolution radiographs of the KH structures along the filament surface. The results from the first experiments of this kind, using a rod with single-mode, long-wavelength modulations, will be discussed. This work is funded by the U.S. Department of Energy, through the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956, and the National Laser User Facility Program, Grant Number DE-NA0002719, and through.
Air, Climate and Energy (ACE) Centers: Supporting Air Quality and Climate Solutions
EPA through its Science to Achieve Results (STAR) program, is providing $30 million in funding for three university-based research centers to investigate regional differences in air pollution and the effects of global climate change.
Exploring the NRO Opportunity for a Hubble-Sized Wide-Field Near-IR Space Telescope - New WFIRST
NASA Technical Reports Server (NTRS)
Dressler, Alan; Spergel, David; Mountain, Matt; Postman, Mark; Elliott, Erin; Bendek, Eduardo; Bennett, David; Dalcanton, Julianne; Gaudi, Scott; Gehrels, Neil;
2013-01-01
We discuss scientific, technical, and programmatic issues related to the use of an NRO 2.4m telescope for the WFIRST initiative of the 2010 Decadal Survey. We show that this implementation of WFIRST, which we call "NEW WFIRST," would achieve the goals of the NWNH Decadal Survey for the WFIRST core programs of Dark Energy and Microlensing Planet Finding, with the crucial benefit of deeper and/or wider near-IR surveys for GO science and a potentially Hubble-like Guest Observer program. NEW WFIRST could also include a coronagraphic imager for direct detection of dust disks and planets around neighboring stars, a high-priority science and technology precursor for future ambitious programs to image Earth-like planets around neighboring stars.
Dark Skies are a Universal Resource: Programs Planned for the International Year of Astronomy
NASA Astrophysics Data System (ADS)
Walker, Constance E.; US IYA Dark Skies Working Group
2008-05-01
The dark night sky is a natural resource that is being lost by much of the world's population. This loss is a growing, serious issue that impacts not only astronomical research, but also human health, ecology, safety, economics and energy conservation. One of the themes of the US Node targeted for the International Year of Astronomy (IYA) is "Dark Skies are a Universal Resource". The goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved locally in a variety of dark skies-related events. To reach this goal, activities are being developed that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Teaching Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy Nights) 3) Organize events in the arts (e.g., a photography contest) 4) Involve citizen-scientists in unaided-eye and digital-meter star counting programs (e.g., GLOBE at Night, "How Many Stars?” and the Great World Wide Star Count) and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security (e.g., The Great Switch Out, Earth Hour, National Dark Skies Week, traveling exhibits and a 6-minute video tutorial on lighting issues). To deliver these programs, strategic networks have been established with the ASP's Night Sky Network's astronomy clubs, Astronomy from the Ground Up's science and nature centers and the Project and Family ASTRO programs, as well as the International Dark-Sky Association, GLOBE and the Astronomical League, among others. The poster presentation will outline the activities being developed, the plans for funding, implementation, marketing and the connections to the global cornerstone IYA project, "Dark Skies Awareness".
Dark Skies Awareness Programs for the International Year of Astronomy
NASA Astrophysics Data System (ADS)
Walker, Constance E.; US IYA Dark Skies Working Group
2009-05-01
The arc of the Milky Way seen from a truly dark location is part of our planet's cultural and natural heritage. More than 1/5 of the world population, 2/3 of the United States population and 1/2 of the European Union population have already lost naked-eye visibility of the Milky Way. This loss, caused by light pollution, is a serious and growing issue that impacts astronomical research, the economy, ecology, energy conservation, human health, public safety and our shared ability to see the night sky. For this reason, "Dark Skies” is a cornerstone project of the International Year of Astronomy. Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people worldwide involved in a variety of programs that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking on Facebook and MySpace, a Second Life presence) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Discovery Sites, Nights in the (National) Parks, Sidewalk Astronomy) 3) Organize events in the arts (e.g., a photography contest) 4) Involve citizen-scientists in naked-eye and digital-meter star hunting programs (e.g., GLOBE at Night, "How Many Stars?", the Great World Wide Star Count and the radio frequency interference equivalent: "Quiet Skies") and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security, and astronomy (e.g., The Starlight Initiative, World Night in Defense of Starlight, International Dark Sky Week, International Dark-Sky Communities, Earth Hour, The Great Switch Out, a traveling exhibit, downloadable posters and brochures). The poster will provide an update, describe how people can continue to participate, and take a look ahead at the program's sustainability. For more information, visit www.darkskiesawareness.org.
NASA Astrophysics Data System (ADS)
Liang, Xiuying; Zhu, Chunyan
2017-11-01
With rising global emphasizes on climate change and sustainable development, how to accelerate the transformation of energy efficiency has become an important question. Designing and implementing energy-efficiency policies for super-efficient products represents an important direction to achieve breakthroughs in the field of energy conservation. On December 31, 2014, China’s National Development and Reform Commission (NDRC) jointly six other ministerial agencies launched China Leading Energy Efficiency Program (LEP), which identifies top efficiency models for selected product categories. LEP sets the highest energy efficiency benchmark. Design of LEP took into consideration of how to best motivate manufacturers to accelerate technical innovation, promote high efficiency products. This paper explains core elements of LEP, such as objectives, selection criteria, implementation method and supportive policies. It also proposes recommendations to further improve LEP through international policy comparison with Japan’s Top Runner Program, U.S. Energy Star Most Efficient, and SEAD Global Efficiency Medal.
Code of Federal Regulations, 2011 CFR
2011-01-01
... product that is of a category for which an ENERGY STAR qualification or FEMP designation is established. ENERGY STAR qualified product means a product that is rated for energy efficiency under an ENERGY STAR...
Code of Federal Regulations, 2010 CFR
2010-01-01
... product that is of a category for which an ENERGY STAR qualification or FEMP designation is established. ENERGY STAR qualified product means a product that is rated for energy efficiency under an ENERGY STAR...
Code of Federal Regulations, 2012 CFR
2012-01-01
... product that is of a category for which an ENERGY STAR qualification or FEMP designation is established. ENERGY STAR qualified product means a product that is rated for energy efficiency under an ENERGY STAR...
Code of Federal Regulations, 2014 CFR
2014-01-01
... product that is of a category for which an ENERGY STAR qualification or FEMP designation is established. ENERGY STAR qualified product means a product that is rated for energy efficiency under an ENERGY STAR...
Code of Federal Regulations, 2013 CFR
2013-01-01
... product that is of a category for which an ENERGY STAR qualification or FEMP designation is established. ENERGY STAR qualified product means a product that is rated for energy efficiency under an ENERGY STAR...
Early Spacelab physics and astronomy missions
NASA Technical Reports Server (NTRS)
Chapman, R. D.
1976-01-01
Some of the scientific problems which will be investigated during the early Spacelab physics and astronomy missions are reviewed. The Solar Terrestrial Programs will include the Solar Physics Spacelab Payloads (SPSP) and the Atmospheres, Magnetospheres and Plasmas in Space (AMPS) missions. These missions will study the sun as a star and the influence of solar phenomena on the earth, including sun-solar wind interface, the nature of the solar flares, etc. The Astrophysics Spacelab Payloads (ASP) programs are divided into the Ultraviolet-Optical Astronomy and the High Energy Astrophysics areas. The themes of astrophysics Spacelab investigations will cover the nature of the universe, the fate of matter and the life cycles of stars. The paper discusses various scientific experiments and instruments to be used in the early Spacelab missions.
Li7(BH)5(+): a new thermodynamically favored star-shaped molecule.
Torres-Vega, Juan J; Vásquez-Espinal, Alejandro; Beltran, Maria J; Ruiz, Lina; Islas, Rafael; Tiznado, William
2015-07-15
The potential energy surfaces (PESs) of Lin(BH)5(n-6) systems (where n = 5, 6, and 7) were explored using the gradient embedded genetic algorithm (GEGA) program, in order to find their global minima conformations. This search predicts that the lowest-energy isomers of Li6(BH)5 and Li7(BH)5(+) contain a (BH)5(6-) pentagonal fragment, which is isoelectronic and structurally analogous to the prototypical aromatic hydrocarbon anion C5H5(-). Li7(BH)5(+), along with Li7C5(+), Li7Si5(+) and Li7Ge5(+), joins a select group of clusters that adopt a seven-peak star-shape geometry, which is favored by aromaticity in the central five-membered ring, and by the preference of Li atoms for bridging positions. The theoretical analysis of chemical bonding, based on magnetic criteria, supports the notion that electronic delocalization is an important stabilization factor in all these star-shaped clusters.
Performance of the STAR Event Plane Detector
NASA Astrophysics Data System (ADS)
Ewigleben, Justin; Justin Ewigleben Collaboration
2017-09-01
The Beam Energy Scan (BES) program at the Relativistic Heavy-Ion Collider has shown hints of a critical point and first order phase transition at the BES energies. Key measurements for locating the critical point and determining the first order phase transition are limited by poor event plane resolution, limited statistics and a TPC-only centrality determination. A new event plane and collision centrality detector (EPD) is planned to replace the existing detector, the Beam-Beam Counter (BBC), with higher granularity and acceptance. The design of the EPD consists of two scintillator discs at z = +/- 3.75m from the center of STAR, covering 2.2 < η < 5.1. One quarter of a single disc was installed in STAR for the 2017 run for commissioning. In this talk we will discuss the detector performance during this commissioning run in both proton-proton collisions at √{ s = 510 } GeV and Au-Au collisions at √{sNN = 54.4 } GeV. NSF Grant 1614474.
NASA Astrophysics Data System (ADS)
Guinan, Edward
2012-10-01
We propose HST/COS FUV spectrophotometry of a carefully selected sample of 9 dM1-5 stars with recently reliably determined ages ranging from 1-12 Gyr. This program complements our Chandra Cycle 13 program of the same targets to determine their coronal X-ray properties. Ages {of all but one star} have recently been firmly determined from memberships in wide binaries with white dwarf {WD} companions having reliable cooling time+main-sequence evolution ages {Zhao et al. 2012, Garces et al 2011}. Until these studies, reliable age determinations for dM stars >2 Gyr were nearly impossible. However, we can now carry out a comprehensive UV study of dM star atmospheres across nearly the full age-range of the current Universe. The primary goals are 1} to study the evolution of their dynamo-generated X-ray and UV {XUV} emissions with age/rotation and to better define the heating and energetics of their atmospheres {via Age-Rotation-Activity-XUV Irradiance relations} and 2} to study the effects of the XUV radiation on planets hosted by red dwarfs. The COS UV spectral region contains numerous important diagnostic emission lines for characterizing the energy transfer and atmospheric structure, while line ratios yield valuable information about the electron density. Further, these data {when combined with our coronal X-ray measures} are also important for gauging dM star XUV emissions - critical for assessing the photochemical & photoionization evolution of planetary atmospheres and ionospheres that in turn strongly affect the possible development of life on hosted extrasolar planets. We are requesting a total of 19 HST orbits to achieve the science goals of the program.
DOE Zero Energy Ready Home Case Study: United Way of Long Island, United Veterans Beacon House
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pacific Northwest National Laboratory
United Way of Long Island’s Housing Development Corporation built this 3,719-ft2 two–story, 5-bedroom home in Huntington Station, New York, to the rigorous performance requirements of the U.S. Department of Energy’s Zero Energy Ready Home Program. The home is packed with high-performance features like LED lighting and ENERGY STAR appliances. The asymmetrical, optimally angled roof provides plenty of space for roof-mounted solar panels for electric generation and hot water.
The positive binding energy envelopes of low-mass helium stars
NASA Astrophysics Data System (ADS)
Hall, Philip D.; Jeffery, C. Simon
2018-04-01
It has been hypothesized that stellar envelopes with positive binding energy may be ejected if the release of recombination energy can be triggered and the calculation of binding energy includes this contribution. The implications of this hypothesis for the evolution of normal hydrogen-rich stars have been investigated, but the implications for helium stars - which may represent mass-transfer or merger remnants in binary star systems - have not. Making a set of model helium stars, we find that those with masses between 0.9 and 2.4 M⊙ evolve to configurations with positive binding energy envelopes. We discuss consequences of the ejection hypothesis for such stars, and possible observational tests of these predictions.
Cosmic evolution of star formation properties of galaxies
NASA Astrophysics Data System (ADS)
Kim, Sungeun
2014-01-01
Development of bolometer array and camera at submillimeter wavelength has played an important role in detecting submillimeter bright galaxies, so called submillimeter galaxies. These galaxies seem to be progenitors of present-day massive galaxies and account for their considerable contributions to the light from the early universe and their expected high star formation rates if there is a close link between the submillimeter galaxies and the star formation activities, and the interstellar dust in galaxies is mainly heated by the star light. We review assembly of submillimeter galaxies chosen from the AzTEC and the Herschel SPIRE/PACS data archives, and investigate their spectral energy distribution fits including the data at other wavelengths to deduce details about stellar parameters including star formation rates and parameters yielding the metallicity, composition and abundance in dust, and disc structure of these galaxies. This work has been supported in part by Mid-career Researcher Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology 2011-0028001.
NASA Astrophysics Data System (ADS)
Thakur, Dhananjaya; Jakhar, Sunil; Garg, Prakhar; Sahoo, Raghunath
2017-04-01
The recent net-proton fluctuation results of the STAR (Solenoidal Tracker At RHIC) experiment from the beam energy scan (BES) program at the BNL Relativistic Heavy Ion Collider (RHIC) have drawn much attention to exploring the QCD critical point and the nature of deconfinement phase transition. There has been much speculation that the nonmonotonic behavior of κ σ2 of the produced protons around √{sN N} = 19.6 GeV in the STAR results may be due to the existence of a QCD critical point. However, the experimentally measured proton distributions contain protons from heavy resonance decays, from baryon stopping, and from direct production processes. These proton distributions are used to estimate the net-proton number fluctuation. Because it is difficult to disentangle the protons from the above-mentioned sources, it is better to devise a method which will account for the directly produced baryons (protons) to study the dynamical fluctuation at different center-of-mass energies. This is because it is assumed that any associated criticality in the system could affect the particle production mechanism and hence the dynamical fluctuation in various conserved numbers. In the present work, we demonstrate a method to estimate the number of stopped protons at RHIC BES energies for central 0-5% Au +Au collisions within STAR acceptance and discuss its implications on the net-proton fluctuation results.
76 FR 31599 - Southern Star Central Gas Pipeline, Inc.; Notice of Application
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-01
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP11-481-000] Southern Star Central Gas Pipeline, Inc.; Notice of Application On May 13, 2011, Southern Star Central Gas Pipeline, Inc. (Southern Star) filed with the Federal Energy Regulatory Commission (Commission) an application under...
76 FR 67160 - Southern Star Central Gas Pipeline, Inc.; Notice of Application
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-31
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP11-481-001] Southern Star Central Gas Pipeline, Inc.; Notice of Application On October 19, 2011, Southern Star Central Gas Pipeline, Inc. (Southern Star) filed with the Federal Energy Regulatory Commission (Commission) an amendment to...
VizieR Online Data Catalog: Spitzer solar-type stars list (Meyer+, 2006)
NASA Astrophysics Data System (ADS)
Meyer, M. R.; Hillenbrand, L. A.; Backman, D.; Beckwith, S.; Bouwman, J.; Brooke, T.; Carpenter, J.; Cohen, M.; Cortes, S.; Crockett, N.; Gorti, U.; Henning, T.; Hines, D.; Hollenbach, D.; Kim, J. S.; Lunine, J.; Malhotra, R.; Mamajek, E.; Metchev, S.; Moro-Martin, A.; Morris, P.; Najita, J.; Padgett, D.; Pascucci, I.; Rodmann, J.; Schlingman, W.; Silverstone, M.; Soderblom, D.; Stauffer, J.; Stobie, E.; Strom, S.; Watson, D.; Weidenschilling, S.; Wolf, S.; Young, E.
2008-01-01
We provide an overview of the Spitzer Legacy Program, Formation and Evolution of Planetary Systems, that was proposed in 2000, begun in 2001, and executed aboard the Spitzer Space Telescope between 2003 and 2006. This program exploits the sensitivity of Spitzer to carry out mid-infrared spectrophotometric observations of solar-type stars. With a sample of 328 stars ranging in age from 3Myr to 3Gyr, we trace the evolution of circumstellar gas and dust from primordial planet-building stages in young circumstellar disks through to older collisionally generated debris disks. When completed, our program will help define the timescales over which terrestrial and gas giant planets are built, constrain the frequency of planetesimal collisions as a function of time, and establish the diversity of mature planetary architectures. In addition to the observational program, we have coordinated a concomitant theoretical effort aimed at understanding the dynamics of circumstellar dust with and without the effects of embedded planets, dust spectral energy distributions, and atomic and molecular gas line emission. Together with the observations, these efforts will provide an astronomical context for understanding whether our solar system and its habitable planets a common or a rare circumstance. Additional information about the FEPS project can be found on the team Web site. (4 data files).
U.S. Department of Energy Zero Energy Ready Home Implementation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rothgeb, Stacey K; Schirber, T.; Mosiman, G.
The intention of this project is to assist home builders in the upper Midwest in achieving DOE Zero Energy Ready Home program certification, and to document the process and outcomes involved in meeting this rigorous standard. NorthernSTAR, in conjunction with our program partner Building Knowledge, Inc., provided technical support to the builders during the design and construction process. At the time of this publication, four qualifying homes have been completed and an additional three are currently under construction to be completed later this year. Three additional homes were excluded from certification due to the HVAC contractor not completing their requiredmore » credentialing until after completion of the homes, though the energy performance would have otherwise qualified the homes for program certification. Both Amaris Homes and Cobblestone Homes note that participation in the ZERH program provides them with competitive advantage in the market place at reasonable construction costs that also result in extremely satisfied clients who are willing to recommend the builders to friends and family.« less
NASA Astrophysics Data System (ADS)
Dunn, W.; Mori, K.; Hailey, C. J.; Branduardi-Raymont, G.; Grefenstette, B.; Jackman, C. M.; Hord, B. J.; Ray, L. C.
2017-12-01
The Nuclear Spectroscopic Telescope Array (NuSTAR) is the first focusing hard X-ray telescope operating in the 3-79 keV band with sub-arcminute angular resolution (18" FWHM). For the first time, NuSTAR provides sufficient sensitivity to detect/resolve hard X-ray emission from Jupiter above 10 keV, since the in-situ Ulysses observation failed to detect X-ray emission in the 27-48 keV band [Hurley et al. 1993]. The initial, exploratory NuSTAR observation of Jupiter was performed in February 2015 with 100 ksec exposure. NuSTAR detected hard X-ray emission (E > 10 keV) from the south polar region at a marginally significance of 3 sigma level [Mori et al. 2016, AAS meeting poster]. This hard X-ray emission is likely an extension of the non-thermal bremsstrahlung component detected up to 7 keV by XMM-Newton [Branduardi-Raymont et al. 2007]. The Ulysses non-detection suggests there should be a spectral cutoff between 7 and 27 keV. Most intriguingly, the NuSTAR detection of hard X-ray emission from the south aurora is in contrast to the 2003 XMM-Newton observations where soft X-ray emission below 8 keV was seen from both the north and south poles [Gladstone et al. 2002]. Given the marginal, but tantalizing, hard X-ray detection of the southern Jovian aurora, a series of NuSTAR observations with total exposure of nearly half a million seconds were approved in the NuSTAR GO and DDT program. These NuSTAR observations coincided with one Juno apojove (in June 2017) and three perijoves (in May, July and September 2017), also joining the multi-wavelength campaigns of observing Jupiter coordinating with Chandra and XMM-Newton X-ray telescope (below 10 keV) and HST. We will present NuSTAR imaging, spectral and timing analysis of Jupiter. NuSTAR imaging analysis will map hard X-ray emission in comparison with soft X-ray and UV images. In addition to investigating any distinctions between the soft and hard X-ray morphology of the Jovian aurorae, we will probe whether hard X-ray emission is spatially associated with the FUV auroral oval. NuSTAR spectral analysis will measure to how high an energy the non-thermal bremsstrahlung component extends, and detect an expected spectral cutoff between 7 and 27 keV. Since NuSTAR operates in the hard X-ray energy band, it probes the maximum energy of accelerating electrons in the Jovian magnetosphere.
Method for Evaluating Energy Use of Dishwashers, Clothes Washers, and Clothes Dryers: Preprint
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eastment, M.; Hendron, R.
Building America teams are researching opportunities to improve energy efficiency for some of the more challenging end-uses, such as lighting (both fixed and occupant-provided), appliances (clothes washer, dishwasher, clothes dryer, refrigerator, and range), and miscellaneous electric loads, which are all heavily dependent on occupant behavior and product choices. These end-uses have grown to be a much more significant fraction of total household energy use (as much as 50% for very efficient homes) as energy efficient homes have become more commonplace through programs such as ENERGY STAR and Building America. As modern appliances become more sophisticated the residential energy analyst ismore » faced with a daunting task in trying to calculate the energy savings of high efficiency appliances. Unfortunately, most whole-building simulation tools do not allow the input of detailed appliance specifications. Using DOE test procedures the method outlined in this paper presents a reasonable way to generate inputs for whole-building energy-simulation tools. The information necessary to generate these inputs is available on Energy-Guide labels, the ENERGY-STAR website, California Energy Commission's Appliance website and manufacturer's literature. Building America has developed a standard method for analyzing the effect of high efficiency appliances on whole-building energy consumption when compared to the Building America's Research Benchmark building.« less
78 FR 21929 - TexStar Crude Oil Pipeline, LP; Notice of Filing
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-12
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AC13-63-000] TexStar Crude Oil Pipeline, LP; Notice of Filing Take notice that on March 26, 2013, TexStar Crude Oil Pipeline, LP (TexStar) submitted to the Federal Energy Regulatory Commission (Commission) a request for waiver of...
NASA Astrophysics Data System (ADS)
Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, B.; Huang, X.; Huang, H. Z.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, W.; Li, Y.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, H.; Liu, P.; Liu, Y.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, Y. G.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.; STAR Collaboration
2017-10-01
We present measurements of bulk properties of the matter produced in Au+Au collisions at √{sN N}=7.7 ,11.5 ,19.6 ,27 , and 39 GeV using identified hadrons (π±, K±, p , and p ¯) from the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity (|y |<0.1 ) results for multiplicity densities d N /d y , average transverse momenta 〈pT〉 , and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-08
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [ Docket No. ER13-281-000] Star Energy Partners LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding of Star Energy...
NASA Technical Reports Server (NTRS)
Kurucz, Robert L.
1996-01-01
I discuss errors in theory and in interpreting observations that are produced by the failure to consider resolution in space, time, and energy. I discuss convection in stellar model atmospheres and in stars. Large errors in abundances are possible such as the factor of ten error in the Li abundance for extreme Population II stars. Finally I discuss the variation of microturbulent velocity with depth, effective temperature, gravity, and abundance. These variations must be dealt with in computing models and grids and in any type of photometric calibration. I have also developed a new opacity-sampling version of my model atmosphere program called ATLAS12. It recognizes more than 1000 atomic and molecular species, each in up to 10 isotopic forms. It can treat all ions of the elements up through Zn and the first 5 ions of heavier elements up through Es. The elemental and isotopic abundances are treated as variables with depth. The fluxes predicted by ATLAS12 are not accurate in intermediate or narrow bandpass intervals because the sample size is too small. A special stripped version of the spectrum synthesis program SYNTHE is used to generate the surface flux for the converged model using the line data on CD-ROMs 1 and 15. ATLAS12 can be used to produce improved models for Am and Ap stars. It should be very useful for investigating diffusion effects in atmospheres. It can be used to model exciting stars for H II regions with abundances consistent with those of the H II region. These programs and line files will be distributed on CD-ROMs.
Magnetic fields of young solar twins
NASA Astrophysics Data System (ADS)
Rosén, L.; Kochukhov, O.; Hackman, T.; Lehtinen, J.
2016-09-01
Aims: The goal of this work is to study the magnetic fields of six young solar-analogue stars both individually, and collectively, to search for possible magnetic field trends with age. If such trends are found, they can be used to understand magnetism in the context of stellar evolution of solar-like stars and to understand the past of the Sun and the solar system. This is also important for the atmospheric evolution of the inner planets, Earth in particular. Methods: We used Stokes IV data from two different spectropolarimeters, NARVAL and HARPSpol. The least-squares deconvolution multi-line technique was used to increase the signal-to-noise ratio of the data. We then applied a modern Zeeman-Doppler imaging code in order to reconstruct the magnetic topology of all stars and the brightness distribution of one of our studied stars. Results: Our results show a significant decrease in the magnetic field strength and energy as the stellar age increases from 100 Myr to 250 Myr, while there is no significant age dependence of the mean magnetic field strength for stars with ages 250-650 Myr. The spread in the mean field strength between different stars is comparable to the scatter between different observations of individual stars. The meridional field component is weaker than the radial and azimuthal field components in 15 of the 16 magnetic maps. It turns out that 89-97% of the magnetic field energy is contained in l = 1 - 3. There is also no clear trend with age and distribution of field energy into poloidal/toroidal and axisymmetric/non-axisymmetric components within the sample. The two oldest stars in this study show an octupole component that is twice as strong as the quadrupole component. This is only seen in 1 of the 13 maps of the younger stars. One star, χ1 Ori, displays two field polarity switches during almost 5 yr of observations suggesting a magnetic cycle length of 2, 6, or 8 yr. Based on observations made with the HARPSpol instrument on the ESO 3.6 m telescope at La Silla (Chile), under the program ID 091.D-0836. Also based on observations obtained at the Bernard Lyot Telescope (TBL, Pic du Midi, France) of the Midi-Pyrénées Observatory, which is operated by the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France.
NASA Astrophysics Data System (ADS)
Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration
2015-07-01
We present results of analyses of two-pion interferometry in Au +Au collisions at √{sNN}=7.7 , 11.5, 19.6, 27, 39, 62.4, and 200 GeV measured in the STAR detector as part of the BNL Relativistic Heavy Ion Collider Beam Energy Scan program. The extracted correlation lengths (Hanbury-Brown-Twiss radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass (mT) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to changes in the equation of state. A new global fit method is studied as an alternate method to directly measure the parameters in the azimuthal analysis. The eccentricity shows a monotonic decrease with beam energy that is qualitatively consistent with the trend from all model predictions and quantitatively consistent with a hadronic transport model.
Adamczyk, L.
2015-07-10
In this study, we present results of analyses of two-pion interferometry in Au+Au collisions at √s NN = 7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV measured in the STAR detector as part of the RHIC Beam Energy Scan program. The extracted correlation lengths (HBT radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass ( mT) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to changes inmore » the equation of state. A new global fit method is studied as an alternate method to directly measure the parameters in the azimuthal analysis. The eccentricity shows a monotonic decrease with beam energy that is qualitatively consistent with the trend from all model predictions and quantitatively consistent with a hadronic transport model.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Adamczyk, L.
In this study, we present results of analyses of two-pion interferometry in Au+Au collisions at √s NN = 7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV measured in the STAR detector as part of the RHIC Beam Energy Scan program. The extracted correlation lengths (HBT radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass ( mT) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to changes inmore » the equation of state. A new global fit method is studied as an alternate method to directly measure the parameters in the azimuthal analysis. The eccentricity shows a monotonic decrease with beam energy that is qualitatively consistent with the trend from all model predictions and quantitatively consistent with a hadronic transport model.« less
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2013-01-22
... NUCLEAR REGULATORY COMMISSION [Docket No. 52-016; NRC-2008-0250] UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3, Exemption 1.0 Background UniStar Nuclear Energy (UNE), on behalf of Calvert Cliffs Nuclear Project, LLC and UniStar Nuclear Operating Services...
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2010-07-14
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP10-2-001] Southern Star... Star Central Gas Pipeline, Inc. (Southern Star), 4700 Highway 56, Owensboro, Kentucky 42301, filed in... CP10-2-000. Specifically, Southern Star proposes to increase the working gas capacity and amend the...
NASA Astrophysics Data System (ADS)
Johnson, K. C.
1991-04-01
This issue of Energy and Technology Review discusses the various educational programs in which Lawrence Livermore National Laboratory (LLNL) participates or sponsors. LLNL has a long history of fostering educational programs for students from kindergarten through graduate school. A goal is to enhance the teaching of science, mathematics, and technology and thereby assist educational institutions to increase the pool of scientists, engineers, and technicians. LLNL programs described include: (1) contributions to the improvement of U.S. science education; (2) the LESSON program; (3) collaborations with Bay Area Science and Technology Education; (4) project HOPES; (5) lasers and fusion energy education; (6) a curriculum on global climate change; (7) computer and technology instruction at LLNL's Science Education Center; (8) the National Education Supercomputer Program; (9) project STAR; (10) the American Indian Program; (11) LLNL programs with historically Black colleges and Universities; (12) the Undergraduate Summer Institute on Contemporary Topics in Applied Science; (13) the National Physical Science Consortium: A Fellowship Program for Minorities and Women; (14) LLNL's participation with AWU; (15) the apprenticeship programs at LLNL; and (16) the future of LLNL's educational programs. An appendix lists all of LLNL's educational programs and activities. Contacts and their respective telephone numbers are given for all these programs and activities.
NASA Astrophysics Data System (ADS)
Krause, M.; Fierlinger, K.; Diehl, R.; Burkert, A.; Voss, R.; Ziegler, U.
2013-02-01
Context. Massive stars influence their environment through stellar winds, ionising radiation, and supernova explosions. This is signified by observed interstellar bubbles. Such feedback is an important factor for galaxy evolution theory and galactic wind models. The efficiency of the energy injection into the interstellar medium (ISM) via bubbles and superbubbles is uncertain, and is usually treated as a free parameter for galaxy scale effects. In particular, since many stars are born in groups, it is interesting to study the dependence of the effective energy injection on the concentration of the stars. Aims: We aim to reproduce observations of superbubbles, their relation to the energy injection of the parent stars, and to understand their effective energy input into the ISM, as a function of the spatial configuration of the group of parent stars. Methods: We study the evolution of isolated and merging interstellar bubbles of three stars (25, 32, and 60 M⊙) in a homogeneous background medium with a density of 10mp cm-3 via 3D-hydrodynamic simulations with standard ISM thermodynamics (optically thin radiative cooling and photo-electric heating) and time-dependent energy and mass input according to stellar evolutionary tracks. We vary the position of the three stars relative to each other to compare the energy response for cases of isolated, merging and initially cospatial bubbles. Results: Mainly due to the Vishniac instability, our simulated bubbles develop thick shells and filamentary internal structures in column density. The shell widths reach tens of per cent of the outer bubble radius, which compares favourably to observations. More energy is retained in the ISM for more closely packed groups, by up to a factor of three and typically a factor of two for intermediate times after the first supernova. Once the superbubble is established, different positions of the contained stars make only a minor difference to the energy tracks. For our case of three massive stars, the energy deposition varies only very little for distances up to about 30 pc between the stars. Energy injected by supernovae is entirely dissipated in a superbubble on a timescale of about 1 Myr, which increases slightly with the superbubble size at the time of the explosion. Conclusions: The Vishniac instability may be responsible for the broadening of the shells of interstellar bubbles. Massive star winds are significant energetically due to their - in the long run - more efficient, steady energy injection and because they evacuate the space around the massive stars. For larger scale simulations, the feedback effect of close groups of stars or clusters may be subsumed into one effective energy input with insignificant loss of energy accuracy. The movie associated to Fig. 3 is available at http://www.aanda.org
NASA Astrophysics Data System (ADS)
Walker, Constance E.
2009-05-01
The arc of the Milky Way seen from a truly dark location is part of our planet's natural heritage. More than one fifth of the world population, two thirds of the United States population and one half of the European Union population have already lost naked eye visibility of the Milky Way. This loss, caused by light pollution, is a serious and growing issue that impacts astronomical research, the economy, ecology, energy conservation, human health, public safety and our shared ability to see the night sky. For this reason, "Dark Skies” is a cornerstone project of the International Year of Astronomy. Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people worldwide involved in a variety of programs that: 1. Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking on Facebook and MySpace, a Second Life presence) 2. Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Discovery Sites, Nights in the (National) Parks, Sidewalk Astronomy) 3. Organize events in the arts (e.g., a photography contest) 4. Involve citizen-scientists in naked-eye and digital-meter star hunting programs (e.g., GLOBE at Night, "How Many Stars?", the Great World Wide Star Count and the radio frequency interference equivalent: "Quiet Skies") and 5. Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security, and astronomy (e.g., The Starlight Initiative, World Night in Defense of Starlight, International Dark Sky Week, International Dark-Sky Communities, Earth Hour, The Great Switch Out, a traveling exhibit, downloadable posters and brochures). The presentation will provide an update, describe how people can become involved and take a look ahead at the program's sustainability. For more information, visit www.darkskiesawareness.org.
The 1980-90 shuttle star catalog for onboard and ground programs
NASA Technical Reports Server (NTRS)
Richardson, S.; Killen, R.
1978-01-01
The 1980-90 shuttle star catalog for onboard and ground programs is presented. The data used in this catalog are explained according to derivation, input, format for the catalog, and preparation. The tables include the computer program listing, input star position, and the computed star positions for the years 1980-90.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-30
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2013-02-28
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP13-76-000] Southern Star..., 2013, Southern Star Central Gas Pipeline, Inc. (Southern Star), 4700 Highway 56, P.O. Box 20010... public inspection. Specifically, Southern Star proposes to construct a new compressor site gas and...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-28
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-475-000] Southern Star..., Southern Star Central Gas Pipeline, Inc. (Southern Star), 4700 Highway 56, Owensboro, Kentucky 42301, filed... amended and Southern Star's blanket certificate issued in Docket No. CP82-479-000 \\1\\ for authorization to...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-30
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP13-531-000] Southern Star..., 2013, Southern Star Central Gas Pipeline, Inc. (Southern Star), 4700 Highway 56, Owensboro, Kentucky.... Southern Star's prior notice request is more fully set forth in the application, which is on file with the...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-12
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-73-000] Southern Star..., 2012 Southern Star Central Gas Pipeline, Inc. (Southern Star), 4700 State Highway 56, Owensboro... Star proposes to replace 3 miles of 12-inch diameter XT pipeline by constructing approximately 3 miles...
75 FR 8053 - Southern Star Central Gas Pipeline, Inc.; Notice of Request Under Blanket Authorization
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-23
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP10-48-000] Southern Star... that on January 29, 2010, Southern Star Central Gas Pipeline, Inc. (Southern Star), 4700 State Highway... TTY, (202) 502-8659. Specifically, Southern Star proposes to replace two miles of 12- inch diameter XT...
Design and application of star map simulation system for star sensors
NASA Astrophysics Data System (ADS)
Wu, Feng; Shen, Weimin; Zhu, Xifang; Chen, Yuheng; Xu, Qinquan
2013-12-01
Modern star sensors are powerful to measure attitude automatically which assure a perfect performance of spacecrafts. They achieve very accurate attitudes by applying algorithms to process star maps obtained by the star camera mounted on them. Therefore, star maps play an important role in designing star cameras and developing procession algorithms. Furthermore, star maps supply significant supports to exam the performance of star sensors completely before their launch. However, it is not always convenient to supply abundant star maps by taking pictures of the sky. Thus, star map simulation with the aid of computer attracts a lot of interests by virtue of its low price and good convenience. A method to simulate star maps by programming and extending the function of the optical design program ZEMAX is proposed. The star map simulation system is established. Firstly, based on analyzing the working procedures of star sensors to measure attitudes and the basic method to design optical system by ZEMAX, the principle of simulating star sensor imaging is given out in detail. The theory about adding false stars and noises, and outputting maps is discussed and the corresponding approaches are proposed. Then, by external programming, the star map simulation program is designed and produced. Its user interference and operation are introduced. Applications of star map simulation method in evaluating optical system, star image extraction algorithm and star identification algorithm, and calibrating system errors are presented completely. It was proved that the proposed simulation method provides magnificent supports to the study on star sensors, and improves the performance of star sensors efficiently.
FLARES ON A-TYPE STARS: EVIDENCE FOR HEATING OF SOLAR CORONA BY NANOFLARES?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Švanda, Michal; Karlický, Marian, E-mail: michal@astronomie.cz
We analyzed the occurrence rates of flares on stars of spectral types K, G, F, and A, observed by Kepler . We found that the histogram of occurrence frequencies of stellar flares is systematically shifted toward a high-energy tail for A-type stars compared to stars of cooler spectral types. We extrapolated the fitted power laws toward flares with smaller energies (nanoflares) and made estimates for total energy flux to stellar atmospheres by flares. We found that, for A-type stars, the total energy flux density was at least four-times smaller than for G stars. We speculate that this deficit in energymore » supply may explain the lack of hot coronae on A-type stars. Our results indicate the importance of nanoflares for heating and formation of the solar corona.« less
Ultimate energy density of observable cold baryonic matter.
Lattimer, James M; Prakash, Madappa
2005-03-25
We demonstrate that the largest measured mass of a neutron star establishes an upper bound to the energy density of observable cold baryonic matter. An equation of state-independent expression satisfied by both normal neutron stars and self-bound quark matter stars is derived for the largest energy density of matter inside stars as a function of their masses. The largest observed mass sets the lowest upper limit to the density. Implications from existing and future neutron star mass measurements are discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Manwell, James
2013-03-19
The purpose of the project is to modify and expand the current wind energy curriculum at the University of Massachusetts Amherst and to develop plans to expand the graduate program to a national scale. The expansion plans include the foundational steps to establish the American Academy of Wind Energy (AAWE). The AAWE is intended to be a cooperative organization of wind energy research, development, and deployment institutes and universities across North America, whose mission will be to develop and execute joint RD&D projects and to organize high-level science and education in wind energy
ANSI-ASQ National Accreditation Board /ACLASS
2011-03-28
unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Laboratories – ISO / IEC 17025 Inspection...Bodies – ISO / IEC 17020 RMPs – ISO Guide 34 (Reference Materials) PT Providers – ISO 17043 Product Certifiers – ISO Guide 65 Government...Programs: DoD ELAP, EPA Energy Star, CPSC Toy Safety, NRC, NIST IPV6, NLLAP, NEFAP TRAINING Programs Certification Bodies – ISO / IEC 17021
The Effects of Galaxy Interactions on Star Formation
NASA Astrophysics Data System (ADS)
Beverage, Aliza; Weiner, Aaron; Ramos Padilla, Andres; Ashby, Matthew; Smith, Howard A.
2018-01-01
Galaxy interactions are key events in galaxy evolution, and are widely thought to trigger significant increases in star formation. However, the mechanisms and timescales for these increases are still not well understood. In order to probe the effects of mergers, we undertook an investigation based on the Spitzer Interacting Galaxies Survey (SIGS), a sample of 102 nearby galaxies in 48 systems ranging from weakly interacting to near coalescence. Our study is unique in that we use both broadband photometry and a large sample of objects chosen to be statistically meaningful. Our data come from 32 broad bands ranging from the UV to far-IR, and we model spectral energy distributions (SEDs) using the Code for Investigating Galaxy Emission (CIGALE) to estimate physical characteristics for each galaxy. We find marginal statistical correlations between galaxy interaction strength and dust luminosity and the distribution of dust mass as a function of heating intensity. The specific star formation rates, however, do not show any enhancement across the interaction stages. This result challenges conventional wisdom that mergers induce star formation throughout galaxy interaction.The SAO REU program is funded in part by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant no. 1262851, and by the Smithsonian Institution.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Adamczyk, L.; Adkins, J. K.; Agakishiev, G.
We present measurements of bulk properties of the matter produced in Au+Au collisions atmore » $$\\sqrt{s}$$$_ {NN}$$= 7.7, 11.5, 19.6, 27, and 39 GeV using identified hadrons (π ±, K ±, p, and $$\\bar{p}$$) from the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity (| y | < 0.1) results for multiplicity densities dN / dy, average transverse momenta $$\\langle$$pT$$\\rangle$$, and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.« less
Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...
2017-10-13
We present measurements of bulk properties of the matter produced in Au+Au collisions atmore » $$\\sqrt{s}$$$_ {NN}$$= 7.7, 11.5, 19.6, 27, and 39 GeV using identified hadrons (π ±, K ±, p, and $$\\bar{p}$$) from the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity (| y | < 0.1) results for multiplicity densities dN / dy, average transverse momenta $$\\langle$$pT$$\\rangle$$, and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.« less
Modeling Spectral Variations of Dusty Circumstellar Envelopes During Microlensing Events
NASA Astrophysics Data System (ADS)
Bunker, Christina; Ignace, R.; Bjorkman, J. E.
2007-12-01
Microlensing surveys have proven to be tremendously fruitful in providing valuable data products for many fields of astrophysics, from eclipse lightcurves for substellar candidates to limb darkening in stellar atmospheres. We report on a program of modeling observables from microlensing of circumstellar envelopes, particularly those of red giant stars that are the most likely to show finite source effects. Recent modeling results for the time dependent spectral energy distributions from microlensing of dusty winds are presented. In effect, wavelength-dependent continuum variations that occur as the lens-star separation changes can provide information about the emissivity distribution of dust in the wind. This project was funded by a partnership between the National Science Foundation (NSF AST-0552798), Research Experiences for Undergraduates (REU), and the Department of Defense (DoD) ASSURE (Awards to Stimulate and Support Undergraduate Research Experiences) programs.
Transformational Technologies to Expedite Space Access and Development
NASA Astrophysics Data System (ADS)
Rather, John D. G.
2010-01-01
Throughout history the emergence of new technologies has enabled unforeseen breakthrough capabilities that rapidly transformed the world. Some global examples from the twentieth century include AC electric power, nuclear energy, and turbojet engines. At the systems level, success of both Apollo and the Space Shuttle programs depended upon taming hydrogen propulsion and developing high-temperature atmospheric reentry materials. Human space development now is stymied because of a great need for breakthrough technologies and strategies. It is believed that new capabilities exist within the present states-of-the-art of superconducting technology that can be implemented to transform the future of human space development. This paper is an overview of three other papers presented within this forum, which summarizes the principles and consequences of StarTram, showing how the resulting breakthrough advantages can lead directly to safe space tourism and massive development of the moon, Mars and the outer solar system. StarTram can implement cost-effective solar power from space, simple utilization of asteroid material to protect humans from ionizing radiation, and effective defense of the Earth from devastating cosmic impacts. Synergistically, StarTram technologies will revolutionize ground transportation on the Earth, leading to enormous reduction in energy consumption and creation of millions of jobs. High energy lasers will also be discussed because of their importance to power beaming applications.
Simultaneous, multi-wavelength flare observations of nearby low-mass stars
NASA Astrophysics Data System (ADS)
Thackeray, Beverly; Barclay, Thomas; Quintana, Elisa; Villadsen, Jacqueline; Wofford, Alia; Schlieder, Joshua; Boyd, Patricia
2018-01-01
Low-mass stars are the most common stars in the Galaxy and have been targeted in the tens-of-thousands by K2, the re-purposed Kepler mission, as they are prime targets to search for and characterize small, Earth-like planets. Understanding how these fully convective stars drive magnetic activity that manifests as stochastic, short-term brightenings, or flares, provides insight into the prospects of planetary habitability. High energy radiation and energetic particle emission associated with these stars can erode atmospheres, and impact habitability. An innovative campaign to study low mass stars through simultaneous multi-wavelength observations is currently underway with observations ongoing in the X-ray, UV, optical, and radio. I will present early results of our pilot study of the nearby M-Dwarf star Wolf 359 (CN Leo) using K2, SWIFT, and ground based radio observatories, forming a comprehensive picture of flare activity from an M-Dwarf, and discuss the potential impact of these results on exoplanets. "This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE1322106. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation."
Many-particle theory of nuclear systems with application to neutron star matter
NASA Technical Reports Server (NTRS)
Chakkalakal, D. A.; Yang, C.
1973-01-01
The research is reported concerning energy-density relation for the normal state of neutron star matter, and the effects of superfluidity and polarization on neutron star matter. Considering constraints on variation, and the theory of quantum fluids, three methods for calculating the energy-density range are presented. The effects of polarization on neutron star structure, and polarization effects on condensation and superfluid-state energy are discussed.
Star adaptation for two-algorithms used on serial computers
NASA Technical Reports Server (NTRS)
Howser, L. M.; Lambiotte, J. J., Jr.
1974-01-01
Two representative algorithms used on a serial computer and presently executed on the Control Data Corporation 6000 computer were adapted to execute efficiently on the Control Data STAR-100 computer. Gaussian elimination for the solution of simultaneous linear equations and the Gauss-Legendre quadrature formula for the approximation of an integral are the two algorithms discussed. A description is given of how the programs were adapted for STAR and why these adaptations were necessary to obtain an efficient STAR program. Some points to consider when adapting an algorithm for STAR are discussed. Program listings of the 6000 version coded in 6000 FORTRAN, the adapted STAR version coded in 6000 FORTRAN, and the STAR version coded in STAR FORTRAN are presented in the appendices.
NIST Stars: Absolute Spectrophotometric Calibration of Vega and Sirius
NASA Astrophysics Data System (ADS)
Deustua, Susana; Woodward, John T.; Rice, Joseph P.; Brown, Steven W.; Maxwell, Stephen E.; Alberding, Brian G.; Lykke, Keith R.
2018-01-01
Absolute flux calibration of standard stars, traceable to SI (International System of Units) standards, is essential for 21st century astrophysics. Dark energy investigations that rely on observations of Type Ia supernovae and precise photometric redshifts of weakly lensed galaxies require a minimum accuracy of 0.5 % in the absolute color calibration. Studies that aim to address fundamental stellar astrophysics also benefit. In the era of large telescopes and all sky surveys well-calibrated standard stars that do not saturate and that are available over the whole sky are needed. Significant effort has been expended to obtain absolute measurements of the fundamental standards Vega and Sirius (and other stars) in the visible and near infrared, achieving total uncertainties between1% and 3%, depending on wavelength, that do not meet the needed accuracy. The NIST Stars program aims to determine the top-of-the-atmosphere absolute spectral irradiance of bright stars to an uncertainty less than 1% from a ground-based observatory. NIST Stars has developed a novel, fully SI-traceable laboratory calibration strategy that will enable achieving the desired accuracy. This strategy has two key components. The first is the SI-traceable calibration of the entire instrument system, and the second is the repeated spectroscopic measurement of the target star throughout the night. We will describe our experimental strategy, present preliminary results for Vega and Sirius and an end-to-end uncertainty budget
ISE structural dynamic experiments
NASA Technical Reports Server (NTRS)
Lock, Malcolm H.; Clark, S. Y.
1988-01-01
The topics are presented in viewgraph form and include the following: directed energy systems - vibration issue; Neutral Particle Beam Integrated Space Experiment (NPB-ISE) opportunity/study objective; vibration sources/study plan; NPB-ISE spacecraft configuration; baseline slew analysis and results; modal contributions; fundamental pitch mode; vibration reduction approaches; peak residual vibration; NPB-ISE spacecraft slew experiment; goodbye ISE - hello Zenith Star Program.
77 FR 41975 - Southern Star Central Gas Pipeline, Inc.; Notice of Application
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-17
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-479-000] Southern Star Central Gas Pipeline, Inc.; Notice of Application Take notice that on June 27, 2012, Southern Star Central Gas Pipeline, Inc. (Southern Star), 4700 Highway 56, Owensboro, Kentucky 42301, filed an application...
77 FR 28867 - Southern Star Central Gas Pipeline, Inc.; Notice of Application
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-16
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-285-000] Southern Star Central Gas Pipeline, Inc.; Notice of Application Take notice that on April 27, 2012, Southern Star Central Gas Pipeline, Inc. (Southern Star), 4700 Highway 56, Owensboro, Kentucky 42304, filed in Docket No...
The X-Ray View of Young Stellar Objects
NASA Astrophysics Data System (ADS)
Guedel, Manuel
2007-08-01
X-rays offer ideal access to high-energy phenomena in young, accreting stars. The energy released in magnetic flares has profound effects on the stellar environment. Star-disk magnetic reconnection has been suggested as a possible origin of bipolar jets. Such jets from have been detected at X-ray wavelengths, offering new diagnostics for the energy release and jet shock physics. Finally, eruptive phenomena of FU Ori and EX Lup-type stars have been monitored in X-rays. I will discuss observations and suggest simple models for high-energy eruptive phenomena in young stars.
Directed Energy Deflection Laboratory Measurements of Asteroids and Space Debris
NASA Astrophysics Data System (ADS)
Brashears, T.; Lubin, P. M.
2016-12-01
We report on laboratory studies of the effectiveness of directed energy planetary and space defense as a part of the DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR [1][5][6] and DE-STARLITE [2][5][6] are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid [1][2][3][4][5][6]. In the DE-STAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds an "asteroid" or a space debris sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 µN/Woptical, though we assume a more conservative value of 80 µN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 µN/Woptical in our deflection modeling. Our measurements discussed here yield about 60 µN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed.
The detection of planetary systems from Space Station - A star observation strategy
NASA Technical Reports Server (NTRS)
Mascy, Alfred C.; Nishioka, Ken; Jorgensen, Helen; Swenson, Byron L.
1987-01-01
A 10-20-yr star-observation program for the Space Station Astrometric Telescope Facility (ATF) is proposed and evaluated by means of computer simulations. The primary aim of the program is to detect stars with planetary systems by precise determination of their motion relative to reference stars. The designs proposed for the ATF are described and illustrated; the basic parameters of the 127 stars selected for the program are listed in a table; spacecraft and science constraints, telescope slewing rates, and the possibility of limiting the program sample to stars near the Galactic equator are discussed; and the effects of these constraints are investigated by simulating 1 yr of ATF operation. Viewing all sky regions, the ATF would have 81-percent active viewing time, observing each star about 200 times (56 h) per yr; only small decrements in this performance would result from limiting the viewing field.
Ultraviolet and X-ray Activity and Flaring on Low-Mass Exoplanet Host Stars
NASA Astrophysics Data System (ADS)
France, Kevin; Loyd, R. O. Parke; Brown, Alexander
2015-08-01
The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. High-energy photons (X-ray to NUV) from these stars regulate the atmospheric temperature profiles and photochemistry on orbiting planets, influencing the production of potential “biomarker” gases. We present results from the MUSCLES Treasury Survey, an ongoing study of time-resolved UV and X-ray spectroscopy of nearby M and K dwarf exoplanet host stars. This program uses contemporaneous Hubble Space Telescope and Chandra (or XMM) observations to characterize the time variability of the energetic radiation field incident on the habitable zones planetary systems at d < 15 pc. We find that all exoplanet host stars observed to date exhibit significant levels of chromospheric and transition region UV emission. M dwarf exoplanet host stars display 30 - 2000% UV emission line amplitude variations on timescales of minutes-to-hours. The relative flare/quiescent UV flux amplitudes on old (age > 1 Gyr) planet-hosting M dwarfs are comparable to active flare stars (e.g., AD Leo), despite their lack of flare activity at visible wavelengths. We also detect similar UV flare behavior on a subset of our K dwarf exoplanet host stars. We conclude that strong flares and stochastic variability are common, even on “optically inactive” M dwarfs hosting planetary systems. These results argue that the traditional assumption of weak UV fields and low flare rates on older low-mass stars needs to be revised.
Ultraviolet and X-ray irradiance and flares from low-mass exoplanet host stars
NASA Astrophysics Data System (ADS)
France, Kevin; Loyd, R. O. Parke; Brown, Alex
The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. High-energy photons (X-ray to NUV) from these stars regulate the atmospheric temperature profiles and photochemistry on orbiting planets, influencing the production of potential ``biomarker'' gases. We report first results from the MUSCLES Treasury Survey, a study of time-resolved UV and X-ray spectroscopy of nearby M and K dwarf exoplanet host stars. This program uses contemporaneous Hubble Space Telescope and Chandra (or XMM) observations to characterize the time variability of the energetic radiation field incident on the habitable zones planetary systems at d <~ 20 pc. We find that all exoplanet host stars observed to date exhibit significant levels of chromospheric and transition region UV emission. M dwarf exoplanet host stars display 30-7000% UV emission line amplitude variations on timescales of minutes-to-hours. The relative flare/quiescent UV flux amplitudes on weakly active planet-hosting M dwarfs are comparable to active flare stars (e.g., AD Leo), despite their weak optical activity indices (e.g., Ca II H and K equivalent widths). We also detect similar UV flare behavior on a subset of our K dwarf exoplanet host stars. We conclude that strong flares and stochastic variability are common, even on ``optically inactive'' M dwarfs hosting planetary systems. These results argue that the traditional assumption of weak UV fields and low flare rates on older low-mass stars needs to be revised.
Polymer Energy Rechargeable System Battery Being Developed
NASA Technical Reports Server (NTRS)
Manzo, Michelle A.
2003-01-01
Long description. Illustrations of discotic liquid crystals, rod-coil polymers, lithium-ion conducting channel dilithium phthalocyanine (Li2Pc) from top and side, novel star polyethylene oxide structures, composite polyethylene oxide materials (showing polyethylene oxide + lithium salt, carbon atoms and oxygen atoms), homopolyrotaxanes, and diblock copolymers In fiscal year 2000, NASA established a program to develop the next generation, lithium-based, polymer electrolyte batteries for aerospace applications. The goal of this program, known as Polymer Energy Rechargeable Systems (PERS), is to develop a space-qualified, advanced battery system embodying polymer electrolyte and lithium-based electrode technologies and to establish world-class domestic manufacturing capabilities for advanced batteries with improved performance characteristics that address NASA s future aerospace battery requirements.
Code of Federal Regulations, 2013 CFR
2013-01-01
... Test Procedure,” and Chapter 6, “Definitions and Acronyms,” of the EPA's “ENERGY STAR Testing Facility Guidance Manual: Building a Testing Facility and Performing the Solid State Test Method for ENERGY STAR... specified in Chapter 4, “Equipment Setup and Test Procedure,” of the EPA's “ENERGY STAR Testing Facility...
Code of Federal Regulations, 2012 CFR
2012-01-01
... Test Procedure,” and Chapter 6, “Definitions and Acronyms,” of the EPA's “ENERGY STAR Testing Facility Guidance Manual: Building a Testing Facility and Performing the Solid State Test Method for ENERGY STAR... specified in Chapter 4, “Equipment Setup and Test Procedure,” of the EPA's “ENERGY STAR Testing Facility...
Code of Federal Regulations, 2014 CFR
2014-01-01
... Test Procedure,” and Chapter 6, “Definitions and Acronyms,” of the EPA's “ENERGY STAR Testing Facility Guidance Manual: Building a Testing Facility and Performing the Solid State Test Method for ENERGY STAR... specified in Chapter 4, “Equipment Setup and Test Procedure,” of the EPA's “ENERGY STAR Testing Facility...
Code of Federal Regulations, 2011 CFR
2011-01-01
... Test Procedure,” and Chapter 6, “Definitions and Acronyms,” of the EPA's “ENERGY STAR Testing Facility Guidance Manual: Building a Testing Facility and Performing the Solid State Test Method for ENERGY STAR... specified in Chapter 4, “Equipment Setup and Test Procedure,” of the EPA's “ENERGY STAR Testing Facility...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-07
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 14379-000] North Star Hydro..., Motions To Intervene, and Competing Applications On March 30, 2012, North Star Hydro Services CA, LLC... approximately 3.8 gigawatthours. Applicant Contact: David Holland, North Star Hydro Services CA, LLC, 1110 West...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-07
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 14399-000] North Star Hydro..., Motions to Intervene, and Competing Applications On March 30, 2012, North Star Hydro Services CA, LLC... output would be approximately 4.6 gigawatthours. Applicant Contact: David Holland, North Star Hydro...
NASA Technical Reports Server (NTRS)
Freyer, Tim; Hensler, Gerhard; Yorke, Harold W.
2003-01-01
We present results of numerical simulations carried out with a two-dimensional radiation hydrodynamics code in order to study the impact of massive stars on their surrounding interstellar medium. This first paper deals with the evolution of the circumstellar gas around an isolated 60 M. star. The interaction of the photo- ionized H II region with the stellar wind bubble forms a variety of interesting structures like shells, clouds, fingers, and spokes. These results demonstrate that complex structures found in H II regions are not necessarily relics from the time before the gas became ionized but may result from dynamical processes during the course of the H II region evolution. We have also analyzed the transfer and deposit of the stellar wind and radiation energy into the circumstellar medium until the star explodes as a supernova. Although the total mechanical wind energy supplied by the star is negligible compared to the accumulated energy of the Lyman continuum photons, the kinetic energy imparted to the circumstellar gas over the star s lifetime is 4 times higher than for a comparable windless simulation. Furthermore, the thermal energy of warm photoionized gas is lower by some 55%). Our results document the necessity to consider both ionizing radiation and stellar winds for an appropriate description of the interaction of OB stars with their circumstellar environment.
Phantom stars and topology change
DOE Office of Scientific and Technical Information (OSTI.GOV)
DeBenedictis, Andrew; Garattini, Remo; Lobo, Francisco S. N.
2008-11-15
In this work, we consider time-dependent dark-energy star models, with an evolving parameter {omega} crossing the phantom divide {omega}=-1. Once in the phantom regime, the null energy condition is violated, which physically implies that the negative radial pressure exceeds the energy density. Therefore, an enormous negative pressure in the center may, in principle, imply a topology change, consequently opening up a tunnel and converting the dark-energy star into a wormhole. The criteria for this topology change are discussed and, in particular, we consider a Casimir energy approach involving quasilocal energy difference calculations that may reflect or measure the occurrence ofmore » a topology change. We denote these exotic geometries consisting of dark-energy stars (in the phantom regime) and phantom wormholes as phantom stars. The final product of this topological change, namely, phantom wormholes, have far-reaching physical and cosmological implications, as in addition to being used for interstellar shortcuts, an absurdly advanced civilization may manipulate these geometries to induce closed timelike curves, consequently violating causality.« less
A New Instrument Design for Imaging Low Energy Neutral Atoms
NASA Technical Reports Server (NTRS)
Keller, John W.; Collier, Michael R.; Chornay, Dennis; Rozmarynowski, Paul; Getty, Stephanie; Cooper, John F.; Smith, Billy
2007-01-01
The MidSTAR-2 satellite, to be built at the US Naval Academy as a follow-on to the successful MidSTAR-1 satellite (http://web.ew.usna.edu/midstar/), will launch in 2011 and carry three Goddard Space Flight Center (GSFC) experiments developed under Goddard's Internal Research and Development (IRAD) program. One of these GSFC instruments, the Miniature Imager for Neutral Ionospheric atoms and Magnetospheric Electrons (MINI-ME) builds on the heritage of the Goddard-developed Low-Energy Neutral Atom (LENA) imager launched on the IMAGE spacecraft in 2000. MINI-ME features a Venetian-blind conversion surface assembly that improves both light rejection and conversion efficiency in a smaller and lighter package than LENA making this an highly effective instrument for viewing solar wind charge exchange with terrestrial and planetary exospheres. We will describe the MINI-ME prototyping effort and its science targets.
DESGW: Optical Follow-up of BBH LIGO-Virgo Events with DECam
DOE Office of Scientific and Technical Information (OSTI.GOV)
Butler, Robert E.; Soares-Santos, M.; Annis, j.
2017-12-14
The DESGW program is a collaboration between members of the Dark Energy Survey, the wider astronomical community, and the LIGO-Virgo Collaboration to search for optical counterparts of gravitational wave events, such as those expected from binary neutron star mergers or neutron star-black hole mergers. While binary black hole (BBH) events are not expected to produce an electromagnetic (EM) signature, emission is certainly not impossible. The DESGW program has performed follow-up observations of four BBH events detected by LIGO in order to search for any possible EM counterpart. Failure to nd such counterparts is still relevant in that it produces limitsmore » on optical emission from such events. This is a review of follow-up results from O1 BBH events and a discussion of the status of ongoing uniform re-analysis of all BBH events that DESGW has followed up to date.« less
STAR adaptation of QR algorithm. [program for solving over-determined systems of linear equations
NASA Technical Reports Server (NTRS)
Shah, S. N.
1981-01-01
The QR algorithm used on a serial computer and executed on the Control Data Corporation 6000 Computer was adapted to execute efficiently on the Control Data STAR-100 computer. How the scalar program was adapted for the STAR-100 and why these adaptations yielded an efficient STAR program is described. Program listings of the old scalar version and the vectorized SL/1 version are presented in the appendices. Execution times for the two versions applied to the same system of linear equations, are compared.
X-Ray Emission from the MUSCLES Exoplanet Host Stars
NASA Astrophysics Data System (ADS)
Brown, Alexander; Schneider, P. Christian; France, Kevin; Loyd, Parke; MUSCLES Team
2016-07-01
The MUSCLES (Measurements of the Ultraviolet Spectral Characteristics of Low-mass Exoplanetary Systems) project is a multi-spectral-region investigation of the high-energy (UV/X-ray) radiation fields of K dwarf / M dwarf exoplanet host stars and how this radiation will influence the evolution of the exoplanet atmospheres. As part of this project we have used Chandra and XMM-Newton to study the X-ray emission from ten (7 M dwarf and 3 K dwarf), nearby (within 15 pc), low mass exoplanet hosts. Typically, we have coordinated the X-ray observations with HST-COS FUV and ground-based optical spectroscopy of the same targets. Even though these stars are generally considered to be inactive we find evidence for significant X-ray variability for many of the M dwarfs observed. In this poster we illustrate the coronal properties of the stars using example light-curves and spectral analyses. The UV and X-ray data are crucial input to the modeling the complete spectral energy distributions for exoplanet studies.This work was supported by Chandra grants GO4-15041X and GO5-16155X and NASA XMM grant NNX16AC09G to the University of Colorado at Boulder. The overall MUSCLES project was undertaken by HST GO programs 12464 and 13650 and supported by STScI grants HST-GO-12464.01 and HST-GO-13650.01 . P.C.S. is supported by an ESA Research Fellowship.
77 FR 68118 - TexStar Transmission, LP; Notice of Petition for Rate Approval
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-15
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [ Docket No. PR13-4-000] TexStar Transmission, LP; Notice of Petition for Rate Approval Take notice that on November 2, 2012, TexStar Transmission, LP (TexStar) filed a Petition for Rate Approval pursuant to 284.123(b)(2) of the Commissions...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-29
... NUCLEAR REGULATORY COMMISSION [Docket No. 52-016; NRC-2008-0250] UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit 3; Exemption 1.0 Background: UniStar Nuclear Energy (UNE) submitted to the U.S. Nuclear Regulatory Commission (NRC or the Commission ) a...
GOODS Far Infrared Imaging with Herschel
NASA Astrophysics Data System (ADS)
Frayer, David T.; Elbaz, D.; Dickinson, M.; GOODS-Herschel Team
2010-01-01
Most of the stars in galaxies formed at high redshift in dusty environments, where their energy was absorbed and re-radiated at infrared wavelengths. Similarly, much of the growth of nuclear black holes in active galactic nuclei (AGN) was also obscured from direct view at UV/optical and X-ray wavelengths. The Great Observatories Origins Deep Survey Herschel (GOODS-H) open time key program will obtain the deepest far-infrared view of the distant universe, mapping the history of galaxy growth and AGN activity over a broad swath of cosmic time. GOODS-H will image the GOODS-North field with the PACS and SPIRE instruments at 100 to 500 microns, matching the deep survey of GOODS-South in the guaranteed time key program. GOODS-H will also observe an ultradeep sub-field within GOODS-South with PACS, reaching the deepest flux limits planned for Herschel (0.6 mJy at 100 microns with S/N=5). GOODS-H data will detect thousands of luminous and ultraluminous infrared galaxies out to z=4 or beyond, measuring their far-infrared luminosities and spectral energy distributions, and providing the best constraints on star formation rates and AGN activity during this key epoch of galaxy and black hole growth in the young universe.
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
??National programs such as Home Performance with ENERGY STAR(R) and numerous other utility air sealing programs have brought awareness to homeowners of the benefits of energy efficiency retrofits. Yet, these programs tend to focus on the low-hanging fruit: air-sealing the thermal envelope and ductwork where accessible, switch to efficient lighting, and low-flow fixtures. At the other end of the spectrum, deep-energy retrofit programs are also being encouraged by various utilities across the country. While deep energy retrofits typically seek 50% energy savings, they are often quite costly and most applicable to gut-rehab projects. A significant potential for lowering energy usagemore » in existing homes lies between the low hanging fruit and deep energy retrofit approaches - retrofits that save approximately 30% in energy over the existing conditions. A key is to be non-intrusive with the efficiency measures so the retrofit projects can be accomplished in occupied homes. This cold climate retrofit project involved the design and optimization of a home in Connecticut that sought to improve energy savings by at least 30% (excluding solar PV) over the existing home's performance. This report documents the successful implementation of a cost-effective solution package that achieved performance greater than 30% over the pre-retrofit - what worked, what did not, and what improvements could be made. Confirmation of successfully achieving 30% source energy savings over the pre-existing conditions was confirmed through energy modeling and comparison of the utility bills pre- and post- retrofit.« less
ERIC Educational Resources Information Center
Congress of the U.S., Washington, DC. Senate Committee on Labor and Human Resources.
The purpose of this hearing was to examine the status of the Star Schools program, a federal program enacted by Congress in 1987 that enables students to be linked together via satellite or cable TV hookup with teachers in different parts of the country. Star Schools are a network of distance education programs that link remote classes of students…
MWPC prototyping and testing for STAR inner TPC upgrade
NASA Astrophysics Data System (ADS)
Shen, F.; Wang, S.; Yang, C.; Xu, Q.
2017-06-01
STAR experiment at the Relativistic Heavy Ion Collider (RHIC) is upgrading the inner sectors of the Time Projection Chamber (iTPC). The iTPC upgrade project will increase the segmentation on the inner pad plane from 13 to 40 pad rows and renew the inner sector wire chambers. The upgrade will expand the TPC's acceptance from |η|<=1.0 to |η|<=1.5. Furthermore, the detector will have better acceptance for tracks with low momentum, as well as better resolution in both momentum and dE/dx for tracks of all momenta. The enhanced measurement capabilities of STAR-iTPC upgrade are crucial to the physics program of the Phase II of Beam Energy Scan (BES-II) at RHIC during 2019-2020, in particular the QCD phase transition study. In this proceedings, I will discuss the iTPC MWPC module fabrication and testing results from the first full size iTPC MWPC pre-prototype made at Shandong University.
The Unintended Consequences of Property Tax Relief: New York's STAR Program
ERIC Educational Resources Information Center
Eom, Tae Ho; Duncombe, William; Nguyen-Hoang, Phuong; Yinger, John
2014-01-01
New York's School Tax Relief Program, STAR, provides state-funded property tax relief for homeowners. Like a matching grant, STAR changes the price of education, thereby altering the incentives of voters and school officials and leading to unintended consequences. Using data for New York State school districts before and after STAR was…
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-26
... 2012 Star- Spangled Banner Commemorative Coin Program Products AGENCY: United States Mint, Department... Infantry Soldier Silver Dollar and 2012 Star-Spangled Banner Commemorative Coin Program products. Prices.... Silver Dollar. 2012 Infantry Soldier Silver Dollar N/A $61.95. Defenders of Freedom Set. 2012 Star...
National Alliance of Business Sales Techniques and Results (STAR).
ERIC Educational Resources Information Center
Golightly, Steven J.
This paper presents an overview of the Sales Techniques and Results (STAR) training program developed by the National Alliance of Business in conjunction with IBM. The STAR training program can be used to help vocational directors, teachers, and counselors to be better salespersons for cooperative education or job placement programs. The paper…
The Star Schools Distance-Learning Program: Results from the Mandated Study.
ERIC Educational Resources Information Center
Tushnet, Naida C.; And Others
The Star Schools Assistance Program has been funding activities since 1988. It provides projects with seed money to develop distance learning programming and equip sites. In addition, Star Schools has served as a focal point for demonstrating innovative uses of technology to advance educational opportunity and improvement. This paper represents…
SIM PlanetQuest Key Project Precursor Observations to Detect Gas Giant Planets Around Young Stars
NASA Technical Reports Server (NTRS)
Tanner, Angelle; Beichman, Charles; Akeson, Rachel; Ghez, Andrea; Grankin, Konstantin N.; Herbst, William; Hillenbrand, Lynne; Huerta, Marcos; Konopacky, Quinn; Metchev, Stanimir;
2008-01-01
We present a review of precursor observing programs for the SIM PlanetQuest Key project devoted to detecting Jupiter mass planets around young stars. In order to ensure that the stars in the sample are free of various sources of astrometric noise that might impede the detection of planets, we have initiated programs to collect photometry, high contrast images, interferometric data and radial velocities for stars in both the Northern and Southern hemispheres. We have completed a high contrast imaging survey of target stars in Taurus and the Pleiades and found no definitive common proper motion companions within one arcsecond (140 AU) of the SIM targets. Our radial velocity surveys have shown that many of the target stars in Sco-Cen are fast rotators and a few stars in Taurus and the Pleiades may have sub-stellar companions. Interferometric data of a few stars in Taurus show no signs of stellar or sub-stellar companions with separations of <5 mas. The photometric survey suggests that approximately half of the stars initially selected for this program are variable to a degree (1(sigma) >0.1 mag) that would degrade the astrometric accuracy achievable for that star. While the precursor programs are still a work in progress, we provide a comprehensive list of all targets ranked according to their viability as a result of the observations taken to date. By far, the observable that removes the most targets from the SIM-YSO program is photometric variability.
Measured energy savings and performance of power-managed personal computers and monitors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nordman, B.; Piette, M.A.; Kinney, K.
1996-08-01
Personal computers and monitors are estimated to use 14 billion kWh/year of electricity, with power management potentially saving $600 million/year by the year 2000. The effort to capture these savings is lead by the US Environmental Protection Agency`s Energy Star program, which specifies a 30W maximum demand for the computer and for the monitor when in a {open_quote}sleep{close_quote} or idle mode. In this paper the authors discuss measured energy use and estimated savings for power-managed (Energy Star compliant) PCs and monitors. They collected electricity use measurements of six power-managed PCs and monitors in their office and five from two othermore » research projects. The devices are diverse in machine type, use patterns, and context. The analysis method estimates the time spent in each system operating mode (off, low-, and full-power) and combines these with real power measurements to derive hours of use per mode, energy use, and energy savings. Three schedules are explored in the {open_quotes}As-operated,{close_quotes} {open_quotes}Standardized,{close_quotes} and `Maximum` savings estimates. Energy savings are established by comparing the measurements to a baseline with power management disabled. As-operated energy savings for the eleven PCs and monitors ranged from zero to 75 kWh/year. Under the standard operating schedule (on 20% of nights and weekends), the savings are about 200 kWh/year. An audit of power management features and configurations for several dozen Energy Star machines found only 11% of CPU`s fully enabled and about two thirds of monitors were successfully power managed. The highest priority for greater power management savings is to enable monitors, as opposed to CPU`s, since they are generally easier to configure, less likely to interfere with system operation, and have greater savings. The difficulties in properly configuring PCs and monitors is the largest current barrier to achieving the savings potential from power management.« less
Transformational Technologies to Expedite Space Access and Development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rather, John D. G.
Throughout history the emergence of new technologies has enabled unforeseen breakthrough capabilities that rapidly transformed the world. Some global examples from the twentieth century include AC electric power, nuclear energy, and turbojet engines. At the systems level, success of both Apollo and the Space Shuttle programs depended upon taming hydrogen propulsion and developing high-temperature atmospheric reentry materials. Human space development now is stymied because of a great need for breakthrough technologies and strategies. It is believed that new capabilities exist within the present states-of-the-art of superconducting technology that can be implemented to transform the future of human space development. Thismore » paper is an overview of three other papers presented within this forum, which summarizes the principles and consequences of StarTram, showing how the resulting breakthrough advantages can lead directly to safe space tourism and massive development of the moon, Mars and the outer solar system. StarTram can implement cost-effective solar power from space, simple utilization of asteroid material to protect humans from ionizing radiation, and effective defense of the Earth from devastating cosmic impacts. Synergistically, StarTram technologies will revolutionize ground transportation on the Earth, leading to enormous reduction in energy consumption and creation of millions of jobs. High energy lasers will also be discussed because of their importance to power beaming applications.« less
NASA Astrophysics Data System (ADS)
Calamida, A.; Strampelli, G.; Rest, A.; Bono, G.; Ferraro, I.; Saha, A.; Iannicola, G.; Scolnic, D.; James, D.; Smith, C.; Zenteno, A.
2017-04-01
We present a multi-band photometric catalog of ≈1.7 million cluster members for a field of view of ≈2° × 2° across ω Cen. Photometry is based on images collected with the Dark Energy Camera on the 4 m Blanco telescope and the Advanced Camera for Surveys on the Hubble Space Telescope. The unprecedented photometric accuracy and field coverage allowed us, for the first time, to investigate the spatial distribution of ω Cen multiple populations from the core to the tidal radius, confirming its very complex structure. We found that the frequency of blue main-sequence stars is increasing compared to red main-sequence stars starting from a distance of ≈25‧ from the cluster center. Blue main-sequence stars also show a clumpy spatial distribution, with an excess in the northeast quadrant of the cluster pointing toward the direction of the Galactic center. Stars belonging to the reddest and faintest red-giant branch also show a more extended spatial distribution in the outskirts of ω Cen, a region never explored before. Both these stellar sub-populations, according to spectroscopic measurements, are more metal-rich compared to the cluster main stellar population. These findings, once confirmed, make ω Cen the only stellar system currently known where metal-rich stars have a more extended spatial distribution compared to metal-poor stars. Kinematic and chemical abundance measurements are now needed for stars in the external regions of ω Cen to better characterize the properties of these sub-populations. Based on observations made with the Dark Energy Camera (DECam) on the 4 m Blanco telescope (NOAO) under programs 2014A-0327, 2015A-0151, 2016A-0189, PIs: A. Calamida, A. Rest, and on observations made with the NASA/ESA Hubble Space Telescope, obtained by the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.
Accreting Neutron Star and Black Hole Binaries with NICER
NASA Astrophysics Data System (ADS)
Chakrabarty, Deepto
2018-01-01
The NICER mission on the International Space Station has significant new capabilities for the study of accreting neutron stars and blackholes, including large effective area, low background, and excellent low-energy X-ray response. Both the NICER Burst and Accretion Working Group and the Observatory Science Working Group have designed observing programs that probe various aspects of accretion physics. I will present some early results from the first six months of the NICER mission, including observations of the black hole transients MAXI J1535-571 and GX 339-4, the high-mass X-ray binary pulsars GRO J1008-57 and Swift J02436+6124, and the X-ray burster 4U 1820-30.
Solution of a large hydrodynamic problem using the STAR-100 computer
NASA Technical Reports Server (NTRS)
Weilmuenster, K. J.; Howser, L. M.
1976-01-01
A representative hydrodynamics problem, the shock initiated flow over a flat plate, was used for exploring data organizations and program structures needed to exploit the STAR-100 vector processing computer. A brief description of the problem is followed by a discussion of how each portion of the computational process was vectorized. Finally, timings of different portions of the program are compared with equivalent operations on serial machines. The speed up of the STAR-100 over the CDC 6600 program is shown to increase as the problem size increases. All computations were carried out on a CDC 6600 and a CDC STAR 100, with code written in FORTRAN for the 6600 and in STAR FORTRAN for the STAR 100.
The Beta Pictoris Phenomenon in A-Shell Stars: Detection of Accreting Gas
NASA Technical Reports Server (NTRS)
Grady, C. A.; Perez, Mario R.; Talavera, A.; McCollum, B.; Rawley, L. A.; England, M. N.; Schlegel, M.
1996-01-01
We present the results of an expanded survey of A-shell stars using IUE high-dispersion spectra and find accreting, circumstellar gas in the line of sight to nine stars, in addition to the previously identified beta Pic, HR 10, and 131 Tau, which can be followed to between +70 and 100 km/s relative to the star. Two of the program stars, HD 88195 and HD 148283, show variable high-velocity gas. Given the small number of IUE spectra for our program stars, detection of high-velocity, accreting gas in 2/3 of the A-shell stars sampled indicates that accretion is an intrinsic part of the A-shell phenomenon and that beta Pic is not unique among main-sequence A stars in exhibiting such activity. Our program stars, as a group, have smaller column densities of high-velocity gas and smaller near-IR excesses compared with beta Pic. These features are consistent with greater central clearing of a remnant debris disk, compared with beta Pic, and suggest that the majority of field A-shell stars are older than beta Pic.
DOE Zero Energy Ready Home Case Study: Manatee County Habitat for Humanity, Ellenton, Florida
DOE Office of Scientific and Technical Information (OSTI.GOV)
none,
2013-09-01
In this 18-home community, all homes are LEED Platinum and meet ENERGY STAR for Homes Version 3 requirements, HERS 23–53. Half way through the project, Habitat for Humanity heard about the DOE Challenge Home program and signed on, committing to build the next home, a three-bedroom, two-bath, 1,143 ft2 duplex, to Challenge Home criteria. The home is the first DOE Challenge Home in Manatee County, and was awarded a 2013 Housing Innovation Award in the affordable builder category.
First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign
Furniss, Amy
2015-10-08
We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Metsähovi, and the F-Gamma consortium. Some of the MAGIC observations were affected by amore » sand layer from the Saharan desert, and had to be corrected using event-by-event corrections derived with a Light Detection and Ranging (LIDAR) facility. This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current and future ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution (SED) between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability on hour timescales. None (of the four extended NuSTAR observations) show evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron self-Compton (SSC) model to five simultaneous broadband SEDs. We find that the SSC model can reproduce the observed broadband states through a decrease in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission.« less
FIRST NuSTAR OBSERVATIONS OF MRK 501 WITHIN A RADIO TO TeV MULTI-INSTRUMENT CAMPAIGN
DOE Office of Scientific and Technical Information (OSTI.GOV)
Furniss, A.; Noda, K.; Boggs, S.
2015-10-10
We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Metsähovi, and the F-Gamma consortium. Some of the MAGIC observations were affected by amore » sand layer from the Saharan desert, and had to be corrected using event-by-event corrections derived with a Light Detection and Ranging (LIDAR) facility. This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current and future ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution (SED) between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability on hour timescales. None (of the four extended NuSTAR observations) show evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron self-Compton (SSC) model to five simultaneous broadband SEDs. We find that the SSC model can reproduce the observed broadband states through a decrease in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission.« less
Full Ionisation In Binary-Binary Encounters With Small Positive Energies
NASA Astrophysics Data System (ADS)
Sweatman, W. L.
2006-08-01
Interactions between binary stars and single stars and binary stars and other binary stars play a key role in the dynamics of a dense stellar system. Energy can be transferred between the internal dynamics of a binary and the larger scale dynamics of the interacting objects. Binaries can be destroyed and created by the interaction. In a binary-binary encounter, full ionisation occurs when both of the binary stars are destroyed in the interaction to create four single stars. This is only possible when the total energy of the system is positive. For very small energies the probability of this occurring is very low and it tends towards zero as the total energy tends towards zero. Here the case is considered for which all the stars have equal masses. An asymptotic power law is predicted relating the probability of full ionisation with the total energy when this latter quantity is small. The exponent, which is approximately 2.31, is compared with the results from numerical scattering experiments. The theoretical approach taken is similar to one used previously in the three-body problem. It makes use of the fact that the most dramatic changes in scale and energies of a few-body system occur when its components pass near to a central configuration. The position, and number, of these configurations is not known for the general four-body problem, however, with equal masses there are known to be exactly five different cases. Separate consideration and comparison of the properties of orbits close to each of these five central configurations enables the prediction of the form of the cross-section for full ionisation for the case of small positive total energy. This is the relation between total energy and the probability of total ionisation described above.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vican, Laura; Zuckerman, B.; Schneider, Adam
We present results from two Herschel observing programs using the Photodetector Array Camera and Spectrometer. During three separate campaigns, we obtained Herschel data for 24 stars at 70, 100, and 160 μ m. We chose stars that were already known or suspected to have circumstellar dust based on excess infrared (IR) emission previously measured with the InfraRed Astronomical Satellite ( IRAS ) or Spitzer and used Herschel to examine long-wavelength properties of the dust. Fifteen stars were found to be uncontaminated by background sources and possess IR emission most likely due to a circumstellar debris disk. We analyzed the propertiesmore » of these debris disks to better understand the physical mechanisms responsible for dust production and removal. Seven targets were spatially resolved in the Herschel images. Based on fits to their spectral energy distributions, nine disks appear to have two temperature components. Of these nine, in three cases, the warmer dust component is likely the result of a transient process rather than a steady-state collisional cascade. The dust belts at four stars are likely stirred by an unseen planet and merit further investigation.« less
NICER: Mission Overview and Status
NASA Astrophysics Data System (ADS)
Arzoumanian, Zaven; Gendreau, Keith C.
2016-04-01
NASA's Neutron star Interior Composition Explorer (NICER) mission will explore the structure, dynamics, and energetics of neutron stars through soft X-ray (0.2-12 keV) timing and spectroscopy. An external attached payload on the International Space Station (ISS), NICER is manifested on the Commercial Resupply Services SpaceX-11 flight, with launch scheduled for late 2016. The NICER payload is currently in final integration and environmental testing. Ground calibration has provided robust performance measures of the optical and detector subsystems, demonstrating that the instrument meets or surpasses its effective area, timing resolution, energy resolution, etc., requirements. We briefly describe the NICER hardware, its continuing testing, operations and environment on ISS, and the objectives of NICER's prime mission—including precise radius measurements for a handful of neutron stars to constrain the equation of state of cold, ultra-dense matter. Other contributions at this meeting address specific scientific investigations that are enabled by NICER, for neutron stars in their diverse manifestations as well as for broader X-ray astrophysics through a brief, approved Guest Observer program beginning in 2018.
Assessment of the NASA AvSTAR Project Plan
NASA Technical Reports Server (NTRS)
Ulrey, Michael L.; Haraldsdottir, Aslaug; Berge, Matthew E.; Hopperstad, Craig A.; Schwab, Robert W.
2004-01-01
This report is a preliminary evaluation of NASA's proposed Aviation System Technology Advanced Research (AvSTAR) Program during the early stages of its definition, in the first half of the year 2001. This evaluation focuses on how well the program goals address the needs of the U.S. National Airspace System, the technical feasibility of the program goals, and the logistical feasibility of the program plan. This report also provides recommendations on how the AvSTAR program could be strengthened and improved. This document has two appendices.
NASA Astrophysics Data System (ADS)
Mayo, Elizabeth A.
2009-01-01
Interstellar magnetic fields are believed to play a crucial role in the star-formation process, therefore a comprehensive study of magnetic fields is necessary in understanding the origins of stars. These projects use observational data obtained from the Very Large Array (VLA) in Socorro, NM. The data reveal interstellar magnetic field strengths via the Zeeman effect in radio frequency spectral lines. This information provides an estimate of the magnetic energy in star-forming interstellar clouds in the Galaxy, and comparisons can be made with these energies and the energies of self-gravitation and internal motions. From these comparisons, a better understanding of the role of magnetic fields in the origins of stars will emerge. NGC 6334 A is a compact HII region at the center of what is believed to be a large, rotating molecular torus (Kramer et al. (1997)). This is a continuing study based on initial measurements of the HI and OH Zeeman effect (Sarma et al. (2000)). The current study includes OH observations performed by the VLA at a higher spatial resolution than previously published data, and allows for a better analysis of the spatial variations of the magnetic field. A new model of the region is also developed based on OH opacity studies, dust continuum maps, radio spectral lines, and infrared (IR) maps. The VLA has been used to study the Zeeman effect in the 21cm HI line seen in absorption against radio sources in the Cygnus-X region. These sources are mostly galactic nebulae or HII regions, and are bright and compact in this region of the spectrum. HI absorption lines are strong against these regions and the VLA is capable of detecting the weak Zeeman effect within them. Support for this work was provided by the NSF PAARE program to South Carolina State University under award AST-0750814.
Star sub-pixel centroid calculation based on multi-step minimum energy difference method
NASA Astrophysics Data System (ADS)
Wang, Duo; Han, YanLi; Sun, Tengfei
2013-09-01
The star's centroid plays a vital role in celestial navigation, star images which be gotten during daytime, due to the strong sky background, have a low SNR, and the star objectives are nearly submerged in the background, takes a great trouble to the centroid localization. Traditional methods, such as a moment method, weighted centroid calculation method is simple but has a big error, especially in the condition of a low SNR. Gaussian method has a high positioning accuracy, but the computational complexity. Analysis of the energy distribution in star image, a location method for star target centroids based on multi-step minimum energy difference is proposed. This method uses the linear superposition to narrow the centroid area, in the certain narrow area uses a certain number of interpolation to pixels for the pixels' segmentation, and then using the symmetry of the stellar energy distribution, tentatively to get the centroid position: assume that the current pixel is the star centroid position, and then calculates and gets the difference of the sum of the energy which in the symmetric direction(in this paper we take the two directions of transverse and longitudinal) and the equal step length(which can be decided through different conditions, the paper takes 9 as the step length) of the current pixel, and obtain the centroid position in this direction when the minimum difference appears, and so do the other directions, then the validation comparison of simulated star images, and compare with several traditional methods, experiments shows that the positioning accuracy of the method up to 0.001 pixel, has good effect to calculate the centroid of low SNR conditions; at the same time, uses this method on a star map which got at the fixed observation site during daytime in near-infrared band, compare the results of the paper's method with the position messages which were known of the star, it shows that :the multi-step minimum energy difference method achieves a better effect.
11 New England Organizations Recognized as Energy Star Partners
The U.S. Environmental Protection Agency’s New England office, along with the U.S. Department of Energy are honoring 11 ENERGY STAR partners for their outstanding contributions to public health and the environment.
A vectorization of the Hess McDonnell Douglas potential flow program NUED for the STAR-100 computer
NASA Technical Reports Server (NTRS)
Boney, L. R.; Smith, R. E., Jr.
1979-01-01
The computer program NUED for analyzing potential flow about arbitrary three dimensional lifting bodies using the panel method was modified to use vector operations and run on the STAR-100 computer. A high speed of computation and ability to approximate the body surface with a large number of panels are characteristics of NUEDV. The new program shows that vector operations can be readily implemented in programs of this type to increase the computational speed on the STAR-100 computer. The virtual memory architecture of the STAR-100 facilitates the use of large numbers of panels to approximate the body surface.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-22
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER11-2354-000] Sustainable Star, LLC; Supplemental Notice That Initial Market- Based Rate Filing Includes Request for Blanket... proceeding of Sustainable Star, LLC's application for market-based rate authority, with an accompanying rate...
Technical and Economic Aspects of Designing an Efficient Room Air-Conditioner Program in India
DOE Office of Scientific and Technical Information (OSTI.GOV)
Abhyankar, Nikit; Shah, Nihar; Phadke, Amol
Several studies have projected a massive increase in the demand for air conditioners (ACs) over the next two decades in India. By 2030, room ACs could add 140 GW to the peak load, equivalent to over 30% of the total projected peak load. Therefore, there is significant interest among policymakers, regulators, and utilities in managing room AC demand by enhancing energy efficiency. Building on the historical success of the Indian Bureau of Energy Efficiency’s star-labeling program, Energy Efficiency Services Limited recently announced a program to accelerate the sale of efficient room ACs using bulk procurement, similar to their successful UJALAmore » light-emitting diode (LED) bulk procurement program. This report discusses some of the key considerations in designing a bulk procurement or financial incentive program for enhancing room AC efficiency in India. We draw upon our previous research to demonstrate the overall technical potential and price impact of room AC efficiency improvement and its technical feasibility in India. We also discuss the importance of using low global warming potential (GWP) refrigerants and smart AC equipment that is demand response (DR) ready.« less
Adiabatic Mass Loss Model in Binary Stars
NASA Astrophysics Data System (ADS)
Ge, H. W.
2012-07-01
Rapid mass transfer process in the interacting binary systems is very complicated. It relates to two basic problems in the binary star evolution, i.e., the dynamically unstable Roche-lobe overflow and the common envelope evolution. Both of the problems are very important and difficult to be modeled. In this PhD thesis, we focus on the rapid mass loss process of the donor in interacting binary systems. The application to the criterion of dynamically unstable mass transfer and the common envelope evolution are also included. Our results based on the adiabatic mass loss model could be used to improve the binary evolution theory, the binary population synthetic method, and other related aspects. We build up the adiabatic mass loss model. In this model, two approximations are included. The first one is that the energy generation and heat flow through the stellar interior can be neglected, hence the restructuring is adiabatic. The second one is that he stellar interior remains in hydrostatic equilibrium. We model this response by constructing model sequences, beginning with a donor star filling its Roche lobe at an arbitrary point in its evolution, holding its specific entropy and composition profiles fixed. These approximations are validated by the comparison with the time-dependent binary mass transfer calculations and the polytropic model for low mass zero-age main-sequence stars. In the dynamical time scale mass transfer, the adiabatic response of the donor star drives it to expand beyond its Roche lobe, leading to runaway mass transfer and the formation of a common envelope with its companion star. For donor stars with surface convection zones of any significant depth, this runaway condition is encountered early in mass transfer, if at all; but for main sequence stars with radiative envelopes, it may be encountered after a prolonged phase of thermal time scale mass transfer, so-called delayed dynamical instability. We identify the critical binary mass ratio for the onset of dynamical time scale mass transfer; if the ratio of donor to accretor masses exceeds this critical value, the dynamical time scale mass transfer ensues. The grid of criterion for all stars can be used to be the basic input as the binary population synthetic method, which will be improved absolutely. In common envelope evolution, the dissipation of orbital energy of the binary provides the energy to eject the common envelope; the energy budget for this process essentially consists of the initial orbital energy of the binary and the initial binding energies of the binary components. We emphasize that, because stellar core and envelope contribute mutually to each other's gravitational potential energy, proper evaluation of the total energy of a star requires integration over the entire stellar interior, not the ejected envelope alone as commonly assumed. We show that the change in total energy of the donor star, as a function of its remaining mass along an adiabatic mass-loss sequence, can be calculated. This change in total energy of the donor star, combined with the requirement that both remnant donor and its companion star fit within their respective Roche lobes, then circumscribes energetically possible survivors of common envelope evolution. It is the first time that we can calculate the accurate total energy of the donor star in common envelope evolution, while the results with the old method are inconsistent with observations.
29 CFR 1952.97 - Changes to approved plan.
Code of Federal Regulations, 2013 CFR
2013-07-01
... generally identical to the Federal STAR Voluntary Protection Program. South Carolina's “Palmetto” VPP is limited to the STAR Program in general industry, excludes the MERIT AND DEMONSTRATION Programs and...
29 CFR 1952.97 - Changes to approved plan.
Code of Federal Regulations, 2012 CFR
2012-07-01
... generally identical to the Federal STAR Voluntary Protection Program. South Carolina's “Palmetto” VPP is limited to the STAR Program in general industry, excludes the MERIT AND DEMONSTRATION Programs and...
29 CFR 1952.97 - Changes to approved plan.
Code of Federal Regulations, 2011 CFR
2011-07-01
... generally identical to the Federal STAR Voluntary Protection Program. South Carolina's “Palmetto” VPP is limited to the STAR Program in general industry, excludes the MERIT AND DEMONSTRATION Programs and...
29 CFR 1952.97 - Changes to approved plan.
Code of Federal Regulations, 2010 CFR
2010-07-01
... generally identical to the Federal STAR Voluntary Protection Program. South Carolina's “Palmetto” VPP is limited to the STAR Program in general industry, excludes the MERIT AND DEMONSTRATION Programs and...
29 CFR 1952.97 - Changes to approved plan.
Code of Federal Regulations, 2014 CFR
2014-07-01
... generally identical to the Federal STAR Voluntary Protection Program. South Carolina's “Palmetto” VPP is limited to the STAR Program in general industry, excludes the MERIT AND DEMONSTRATION Programs and...
The Initial Mass Function of the First Stars Inferred from Extremely Metal-poor Stars
NASA Astrophysics Data System (ADS)
Ishigaki, Miho N.; Tominaga, Nozomu; Kobayashi, Chiaki; Nomoto, Ken’ichi
2018-04-01
We compare the elemental abundance patterns of ∼200 extremely metal-poor (EMP; [Fe/H] < ‑3) stars to the supernova yields of metal-free stars, in order to obtain insights into the characteristic masses of the first (Population III or Pop III) stars in the universe. The supernova yields are prepared with nucleosynthesis calculations of metal-free stars with various initial masses (M = 13, 15, 25, 40 and 100 M ⊙) and explosion energies (E 51 = E/1051[erg] = 0.5–60), to include low-energy, normal-energy, and high-energy explosions. We adopt the mixing-fallback model, to take into account possible asymmetry in the supernova explosions, and the yields that best fit the observed abundance patterns of the EMP stars are searched by varying the model parameters. We find that the abundance patterns of the EMP stars are predominantly best-fitted by the supernova yields with initial masses M < 40 M ⊙, and that more than than half of the stars are best-fitted by the M = 25 M ⊙ hypernova (E 51 = 10) models. The results also indicate that the majority of the primordial supernovae have ejected 10‑2–10‑1 M ⊙ of 56Ni, leaving behind a compact remnant (either a neutron star or a black hole), with a mass in the range of ∼1.5–5 M ⊙. These results suggest that the masses of the first stars responsible for the first metal enrichment are predominantly <40 M ⊙. This implies that the higher-mass first stars were either less abundant, directly collapsed into a black hole without ejecting heavy elements, or a supernova explosion of a higher-mass first star inhibits the formation of the next generation of low-mass stars at [Fe/H] < ‑3.
Horizontal branch stars, and galactic and magellanic cloud globular clusters
NASA Technical Reports Server (NTRS)
Deboer, K. S.
1981-01-01
Seven blue horizontal branch stars in the field were observed and a few HB stars were isolated in globular clusters. Energy distributions are compared to assess possible differences and also used in comparison with model atmospheres. Observed energy distributions of HB stars in NGC 6397 are used to estimate the total number of HB stars which produced the integrated fluxes as observed by ANS. Preliminary results are given for colors of globular clusters observed in the Magellanic Clouds and for their extent, based on the Washburn IUE extraction.
YoungStar: We're Turning Five! Five Year Analysis as of July 2015. YoungStar Progress Report 6
ERIC Educational Resources Information Center
Wisconsin Council on Children and Families, 2015
2015-01-01
This report is the sixth in a series of Wisconsin Council on Children & Families (WCCF) reports tracking the progress of Wisconsin's YoungStar program, a quality rating and improvement system (QRIS) launched in 2010 to improve the quality of Wisconsin child care programs. YoungStar focuses on children of low-income working families receiving…
The MiMeS Survey of Magnetism in Massive Stars
NASA Astrophysics Data System (ADS)
Wade, G. A.; Grunhut, J. H.; MiMeS Collaboration
2012-12-01
The Magnetism in Massive Stars (MiMeS) survey represents a high-precision systematic search for magnetic fields in hot, massive OB stars. To date, MiMeS Large Programs (ESPaDOnS@CFHT, Narval@TBL, HARPSpol@ESO3.6 m) and associated PI programs (FORS@VLT) have yielded nearly 1200 circular spectropolarimetric observations of over 350 OB stars. Within this sample, 20 stars are detected as magnetic. Follow-up observations of new detections reveals (i) a large diversity of magnetic properties, (ii) ubiquitous evidence for magnetic wind confinement in optical spectra of all magnetic O stars, and (iii) the presence of strong, organized magnetic fields in all known Galactic Of?p stars, and iv) a complete absence of magnetic fields in classical Be stars.
Study of isotropic compact stars in f(R,T,R_{μν}T^{μν}) gravity
NASA Astrophysics Data System (ADS)
Sharif, M.; Waseem, Arfa
2016-06-01
In this paper, we investigate physical behavior and stability of compact stars filled with isotropic fluid in f(R,T,R_{μν}T^{μν}) gravity. We consider the static spherically symmetric spacetime and choose the simplest model of this gravity, i.e., R+α R_{μν}T^{μν} . To examine the basic features of compact stars like Her X-1, SAX J 1808.4-3658 and 4U 1820-30, we apply analytic solutions of Krori and Barua metric using the mass-radius relation. We study the behavior of effective energy density, pressure, equation of state parameter and energy conditions in the interior of compact stars. We also explore the stability criteria of compact stars via the speed of sound. It is concluded that all the energy conditions are satisfied and the compact stars are found to be stable at the boundary for this particular model.
Uniform Recovery Bounds for Structured Random Matrices in Corrupted Compressed Sensing
NASA Astrophysics Data System (ADS)
Zhang, Peng; Gan, Lu; Ling, Cong; Sun, Sumei
2018-04-01
We study the problem of recovering an $s$-sparse signal $\\mathbf{x}^{\\star}\\in\\mathbb{C}^n$ from corrupted measurements $\\mathbf{y} = \\mathbf{A}\\mathbf{x}^{\\star}+\\mathbf{z}^{\\star}+\\mathbf{w}$, where $\\mathbf{z}^{\\star}\\in\\mathbb{C}^m$ is a $k$-sparse corruption vector whose nonzero entries may be arbitrarily large and $\\mathbf{w}\\in\\mathbb{C}^m$ is a dense noise with bounded energy. The aim is to exactly and stably recover the sparse signal with tractable optimization programs. In this paper, we prove the uniform recovery guarantee of this problem for two classes of structured sensing matrices. The first class can be expressed as the product of a unit-norm tight frame (UTF), a random diagonal matrix and a bounded columnwise orthonormal matrix (e.g., partial random circulant matrix). When the UTF is bounded (i.e. $\\mu(\\mathbf{U})\\sim1/\\sqrt{m}$), we prove that with high probability, one can recover an $s$-sparse signal exactly and stably by $l_1$ minimization programs even if the measurements are corrupted by a sparse vector, provided $m = \\mathcal{O}(s \\log^2 s \\log^2 n)$ and the sparsity level $k$ of the corruption is a constant fraction of the total number of measurements. The second class considers randomly sub-sampled orthogonal matrix (e.g., random Fourier matrix). We prove the uniform recovery guarantee provided that the corruption is sparse on certain sparsifying domain. Numerous simulation results are also presented to verify and complement the theoretical results.
Lessons Learned from the Arizona Galileoscope Star Party Program
NASA Astrophysics Data System (ADS)
Pompea, Stephen M.; Sparks, R. T.; Dugan, C.; Walker, C. E.
2013-01-01
The National Optical Astronomy Observatory has joined together multiple audiences in various communities to conduct outreach using Galileoscopes. The audience consists of 5th grade students and teachers, their families and friends, and anyone else who wants to attend a special star party led by students using Galileoscopes. However, across one community there are many subcultures that one should be responsive to in the program design. The program model, which has been independently evaluated, combines professional development and classroom visits by NOAO education practitioners with the goal of a community star party. We have conducted the program in several mid-sized Arizona cities after an initial prototype star party held near the state capitol building in Phoenix. In this program, with Galileoscopes purchased with funding from Science Foundation Arizona, we have now held Galileoscope star parties in Flagstaff, Safford, and Globe, with two programs in Yuma, Arizona. We will discuss planning efforts, professional development plans and lessons learned, and specific logistical issues that have arisen in the program. Although the professional development component for teachers is rather traditional, the overall lessons learned are applicable to many astronomy programs for non-traditional audiences.
SPECTROSCOPIC ANALYSIS OF METAL-POOR STARS FROM LAMOST: EARLY RESULTS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Hai-Ning; Zhao, Gang; Wang, Liang
2015-01-10
We report on early results from a pilot program searching for metal-poor stars with LAMOST and follow-up high-resolution observation acquired with the MIKE spectrograph attached to the Magellan II telescope. We performed detailed abundance analysis for eight objects with iron abundances [Fe/H] < -2.0, including five extremely metal-poor (EMP; [Fe/H] < -3.0) stars with two having [Fe/H] < -3.5. Among these objects, three are newly discovered EMP stars, one of which is confirmed for the first time with high-resolution spectral observations. Three program stars are regarded as carbon-enhanced metal-poor (CEMP) stars, including two stars with no enhancement in their neutron-capturemore » elements, which thus possibly belong to the class of CEMP-no stars; one of these objects also exhibits significant enhancement in nitrogen, and is thus a potential carbon and nitrogen-enhanced metal-poor star. The [X/Fe] ratios of the sample stars generally agree with those reported in the literature for other metal-poor stars in the same [Fe/H] range. We also compared the abundance patterns of individual program stars with the average abundance pattern of metal-poor stars and find only one chemically peculiar object with abundances of at least two elements (other than C and N) showing deviations larger than 0.5 dex. The distribution of [Sr/Ba] versus [Ba/H] agrees that an additional nucleosynthesis mechanism is needed aside from a single r-process. Two program stars with extremely low abundances of Sr and Ba support the prospect that both main and weak r-processes may have operated during the early phase of Galactic chemical evolution. The distribution of [C/N] shows that there are two groups of carbon-normal giants with different degrees of mixing. However, it is difficult to explain the observed behavior of the [C/N] of the nitrogen-enhanced unevolved stars based on current data.« less
Gravitational radiation emitted when a mass falls onto a compact star.
NASA Astrophysics Data System (ADS)
Borelli, A.
1997-03-01
The authors study the energy spectrum related to the axial perturbations of a compact star when a particle falls spiralling onto it. They find that both slowly-damped quasi-normal modes and strongly damped w-modes are excited, and that a part of the energy in the process is associated to these w-modes. A substantial difference between the energy spectra of compact stars and black holes is shown.
29 CFR 1952.157 - Changes to approved plan.
Code of Federal Regulations, 2012 CFR
2012-07-01
... generally identical to the Federal STAR Voluntary Protection Program. North Carolina's “Carolina” VVP is limited to the STAR Program, and excludes the MERIT and DEMONSTRATION Programs. Also, injury rates must be...
29 CFR 1952.157 - Changes to approved plan.
Code of Federal Regulations, 2010 CFR
2010-07-01
... generally identical to the Federal STAR Voluntary Protection Program. North Carolina's “Carolina” VVP is limited to the STAR Program, and excludes the MERIT and DEMONSTRATION Programs. Also, injury rates must be...
29 CFR 1952.157 - Changes to approved plan.
Code of Federal Regulations, 2014 CFR
2014-07-01
... generally identical to the Federal STAR Voluntary Protection Program. North Carolina's “Carolina” VVP is limited to the STAR Program, and excludes the MERIT and DEMONSTRATION Programs. Also, injury rates must be...
29 CFR 1952.157 - Changes to approved plan.
Code of Federal Regulations, 2011 CFR
2011-07-01
... generally identical to the Federal STAR Voluntary Protection Program. North Carolina's “Carolina” VVP is limited to the STAR Program, and excludes the MERIT and DEMONSTRATION Programs. Also, injury rates must be...
29 CFR 1952.157 - Changes to approved plan.
Code of Federal Regulations, 2013 CFR
2013-07-01
... generally identical to the Federal STAR Voluntary Protection Program. North Carolina's “Carolina” VVP is limited to the STAR Program, and excludes the MERIT and DEMONSTRATION Programs. Also, injury rates must be...
NASA Astrophysics Data System (ADS)
Meyer, Michael; NIRCam Star and Planet Formation Theme Team
2017-06-01
With its extraordinary sensitivity, wavelength coverage from < 1 to 5 microns, 2.2x4.4 arc minute field of view, and diversity of observing modes, NIRCam on JWST offers very powerful capabilities to explore the origins of stars and planets. Here we describe programs planned within the NIRCam GTO Program including: i) extinction mapping of pre-stellar cores; ii) massive star formation; iii) embedded clusters and the end of the IMF; iv) imaging and spectroscopy of young stellar objects; and v) excitation of PAH features. We will describe the scope of each program, selection of observing modes and rationale, as well as provide some explicit examples of program design. We will also review the expected outcomes, illustrating the power of NIRCam to answer questions fundamental to understanding the origins of stars and planets.
EPA Recognizes Holcim for Achieving 2015 ENERGY STAR Certification
(02/24/16 - ATLANTA ) -- The U.S. Environmental Protection Agency (EPA) announced today that Holcim in Holly Hill, South Carolina, is among 70 manufacturing plants to have achieved Energy Star certification for their superior energy performance in 201
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-05
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-1829-000] Shooting Star Wind Project, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for... Shooting Star Wind Project, LLC's application for market-based rate authority, with an accompanying rate...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-17
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER13-1441-000] Solar Star California XIX, LLC; Supplemental Notice that Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding, of Solar Star...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-17
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER13-1442-000] Solar Star California XX, LLC; Supplemental Notice that Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding, of Solar Star...
Quark matter symmetry energy and quark stars
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chu, Peng-Cheng; Chen, Lie-Wen, E-mail: lwchen@sjtu.edu.cn
2014-01-10
We extend the confined-density-dependent-mass (CDDM) model to include isospin dependence of the equivalent quark mass. Within the confined-isospin-density-dependent-mass (CIDDM) model, we study the quark matter symmetry energy, the stability of strange quark matter, and the properties of quark stars. We find that including isospin dependence of the equivalent quark mass can significantly influence the quark matter symmetry energy as well as the properties of strange quark matter and quark stars. While the recently discovered large mass pulsars PSR J1614–2230 and PSR J0348+0432 with masses around 2 M {sub ☉} cannot be quark stars within the CDDM model, they can bemore » well described by quark stars in the CIDDM model. In particular, our results indicate that the two-flavor u-d quark matter symmetry energy should be at least about twice that of a free quark gas or normal quark matter within the conventional Nambu-Jona-Lasinio model in order to describe PSR J1614–2230 and PSR J0348+0432 as quark stars.« less
Keller, S C; Bessell, M S; Frebel, A; Casey, A R; Asplund, M; Jacobson, H R; Lind, K; Norris, J E; Yong, D; Heger, A; Magic, Z; Da Costa, G S; Schmidt, B P; Tisserand, P
2014-02-27
The element abundance ratios of four low-mass stars with extremely low metallicities (abundances of elements heavier than helium) indicate that the gas out of which the stars formed was enriched in each case by at most a few--and potentially only one--low-energy supernova. Such supernovae yield large quantities of light elements such as carbon but very little iron. The dominance of low-energy supernovae seems surprising, because it had been expected that the first stars were extremely massive, and that they disintegrated in pair-instability explosions that would rapidly enrich galaxies in iron. What has remained unclear is the yield of iron from the first supernovae, because hitherto no star has been unambiguously interpreted as encapsulating the yield of a single supernova. Here we report the optical spectrum of SMSS J031300.36-670839.3, which shows no evidence of iron (with an upper limit of 10(-7.1) times solar abundance). Based on a comparison of its abundance pattern with those of models, we conclude that the star was seeded with material from a single supernova with an original mass about 60 times that of the Sun (and that the supernova left behind a black hole). Taken together with the four previously mentioned low-metallicity stars, we conclude that low-energy supernovae were common in the early Universe, and that such supernovae yielded light-element enrichment with insignificant iron. Reduced stellar feedback both chemically and mechanically from low-energy supernovae would have enabled first-generation stars to form over an extended period. We speculate that such stars may perhaps have had an important role in the epoch of cosmic reionization and the chemical evolution of early galaxies.
Photoionization-regulated star formation and the structure of molecular clouds
NASA Technical Reports Server (NTRS)
Mckee, Christopher F.
1989-01-01
A model for the rate of low-mass star formation in Galactic molecular clouds and for the influence of this star formation on the structure and evolution of the clouds is presented. The rate of energy injection by newly formed stars is estimated, and the effect of this energy injection on the size of the cloud is determined. It is shown that the observed rate of star formation appears adequate to support the observed clouds against gravitational collapse. The rate of photoionization-regulated star formation is estimated and it is shown to be in agreement with estimates of the observed rate of star formation if the observed molecular cloud parameters are used. The mean cloud extinction and the Galactic star formation rate per unit mass of molecular gas are predicted theoretically from the condition that photionization-regulated star formation be in equilibrium. A simple model for the evolution of isolated molecular clouds is developed.
Azimuthal anisotropy measurements by STAR
NASA Astrophysics Data System (ADS)
Yi, Li
2014-06-01
The recent study of centrality and transverse momentum (pT) dependence of inclusive charged hardron elliptic anisotropy (v2) at midrapidity (|η|<1.0) in Au+Au collision at √{sNN}=7.7,11.5,19.6,27, and 39 GeV in STAR Beam Energy Scan program is presented. We show that the observed increase of inclusive v2 is mainly due to the average pT increase with energy. In Au+Au 200 GeV collisions, the triangular anisotropy (v3) measurements highly depend on measurement methods; v3 is strongly dependent on Δη. The difference between two- and four-particle cumulants v2{2} and v2{4} for Au+Au and Cu+Cu collision at √{sNN}=62.4 and 200 GeV is used to explore flow fluctuations. Furthermore, by exploiting the symmetry of average flow in pseudorapidity η about midrapidity, the Δη-dependent and independent components are separated using v2{2} and v2{4}.
Stellar equilibrium configurations of compact stars in f ( R , T ) theory of gravity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moraes, P.H.R.S.; Arbañil, José D.V.; Malheiro, M., E-mail: moraes.phrs@gmail.com, E-mail: arbanil@ita.br, E-mail: malheiro@ita.br
In this article we study the hydrostatic equilibrium configuration of neutron stars and strange stars, whose fluid pressure is computed from the equations of state p =ωρ{sup 5/3} and p =0.28(ρ−4B), respectively, with ω and B being constants and ρ the energy density of the fluid. We start by deriving the hydrostatic equilibrium equation for the f ( R , T ) theory of gravity, with R and T standing for the Ricci scalar and trace of the energy-momentum tensor, respectively. Such an equation is a generalization of the one obtained from general relativity, and the latter can be retrievedmore » for a certain limit of the theory. For the f ( R , T )= R +2λ T functional form, with λ being a constant, we find that some physical properties of the stars, such as pressure, energy density, mass and radius, are affected when λ is changed. We show that for a fixed central star energy density, the mass of neutron and strange stars can increase with λ. Concerning the star radius, it increases for neutron stars and it decreases for strange stars with the increment of λ. Thus, in f ( R , T ) theory of gravity we can push the maximum mass above the observational limits. This implies that the equation of state cannot be eliminated if the maximum mass within General Relativity lies below the limit given by observed pulsars.« less
Stellar equilibrium configurations of compact stars in f(R,T) theory of gravity
NASA Astrophysics Data System (ADS)
Moraes, P. H. R. S.; Arbañil, José D. V.; Malheiro, M.
2016-06-01
In this article we study the hydrostatic equilibrium configuration of neutron stars and strange stars, whose fluid pressure is computed from the equations of state p=ωρ5/3 and p=0.28(ρ-4Script B), respectively, with ω and Script B being constants and ρ the energy density of the fluid. We start by deriving the hydrostatic equilibrium equation for the f(R,T) theory of gravity, with R and T standing for the Ricci scalar and trace of the energy-momentum tensor, respectively. Such an equation is a generalization of the one obtained from general relativity, and the latter can be retrieved for a certain limit of the theory. For the f(R,T)=R+2λ T functional form, with λ being a constant, we find that some physical properties of the stars, such as pressure, energy density, mass and radius, are affected when λ is changed. We show that for a fixed central star energy density, the mass of neutron and strange stars can increase with λ. Concerning the star radius, it increases for neutron stars and it decreases for strange stars with the increment of λ. Thus, in f(R,T) theory of gravity we can push the maximum mass above the observational limits. This implies that the equation of state cannot be eliminated if the maximum mass within General Relativity lies below the limit given by observed pulsars.
High energy neutrinos and gamma-ray emission from supernovae in compact star clusters
NASA Astrophysics Data System (ADS)
Bykov, A. M.; Ellison, D. C.; Gladilin, P. E.; Osipov, S. M.
2017-01-01
Compact clusters of young massive stars are observed in the Milky Way and in starburst galaxies. The compact clusters with multiple powerful winds of young massive stars and supernova shocks are favorable sites for high-energy particle acceleration. We argue that expanding young supernova (SN) shells in compact stellar clusters can be very efficient PeV CR accelerators. At a stage when a supernova shock is colliding with collective fast winds from massive stars in a compact cluster the Fermi mechanism allows particle acceleration to energies well above the standard limits of diffusive shock acceleration in an isolated SNR. The energy spectrum of protons in such an accelerator is a hard power-law with a broad spectral upturn above TeV before a break at multi-PeV energies, providing a large energy flux in the high-energy end of the spectrum. The acceleration stage in the colliding shock flow lasts for a few hundred years after the supernova explosion producing high-energy CRs that escape the accelerator and diffuse through the ambient matter producing γ-rays and neutrinos in inelastic nuclear collisions. In starburst galaxies a sizeable fraction of core collapse supernovae is expected to occur in compact star clusters and therefore their high energy gamma-ray and neutrino spectra in the PeV energy regime may differ strongly from that of our Galaxy. To test the model with individual sources we briefly discuss the recent H.E.S.S. detections of gamma-rays from two potential candidate sources, Westerlund 1 and HESS J1806-204 in the Milky Way. We argue that this model of compact star clusters, with typical parameters, could produce a neutrino flux sufficient to explain a fraction of the recently detected IceCube South Pole Observatory neutrinos.
Go Green, Save Green with ENERGY STAR[R
ERIC Educational Resources Information Center
Hatcher, Caterina
2010-01-01
Did you know that the nation's 17,450 K-12 school districts spend more on energy than on computers and textbooks combined? Energy costs represent a typical school district's second largest operating expense after salaries. Schools that have earned the ENERGY STAR--EPA's mark of superior energy performance--cost 40 cents per square foot less to…
NASA Astrophysics Data System (ADS)
Howard, Ward S.; Law, Nicholas M.; Ziegler, Carl A.; Baranec, Christoph; Riddle, Reed
2018-02-01
Adaptive optics laser guide-star systems perform atmospheric correction of stellar wavefronts in two parts: stellar tip-tilt and high-spatial-order laser correction. The requirement of a sufficiently bright guide star in the field-of-view to correct tip-tilt limits sky coverage. In this paper, we show an improvement to effective seeing without the need for nearby bright stars, enabling full sky coverage by performing only laser-assisted wavefront correction. We used Robo-AO, the first robotic AO system, to comprehensively demonstrate this laser-only correction. We analyze observations from four years of efficient robotic operation covering 15000 targets and 42000 observations, each realizing different seeing conditions. Using an autoguider (or a post-processing software equivalent) and the laser to improve effective seeing independent of the brightness of a target, Robo-AO observations show a 39% ± 19% improvement to effective FWHM, without any tip-tilt correction. We also demonstrate that 50% encircled energy performance without tip-tilt correction remains comparable to diffraction-limited, standard Robo-AO performance. Faint-target science programs primarily limited by 50% encircled energy (e.g., those employing integral field spectrographs placed behind the AO system) may see significant benefits to sky coverage from employing laser-only AO.
NASA Astrophysics Data System (ADS)
Klopfer, Eric; Scheintaub, Hal; Huang, Wendy; Wendel, Daniel
Computational approaches to science are radically altering the nature of scientific investigatiogn. Yet these computer programs and simulations are sparsely used in science education, and when they are used, they are typically “canned” simulations which are black boxes to students. StarLogo The Next Generation (TNG) was developed to make programming of simulations more accessible for students and teachers. StarLogo TNG builds on the StarLogo tradition of agent-based modeling for students and teachers, with the added features of a graphical programming environment and a three-dimensional (3D) world. The graphical programming environment reduces the learning curve of programming, especially syntax. The 3D graphics make for a more immersive and engaging experience for students, including making it easy to design and program their own video games. Another change to StarLogo TNG is a fundamental restructuring of the virtual machine to make it more transparent. As a result of these changes, classroom use of TNG is expanding to new areas. This chapter is concluded with a description of field tests conducted in middle and high school science classes.
ERIC Educational Resources Information Center
Densmore, Marycay; Kolecki, Joseph C.; Miller, Allan; Petersen, Ruth; Terrell, Mike
2005-01-01
Science Through ARts (STAR) is a free, international, cross-curricular program thematically aligned with "The Vision for Space Exploration," a framework of goals and objectives published by NASA in February 2004. Through the STAR program, students in grades 5 through 12 are encouraged to apply their knowledge in creative ways as they approach a…
Selected highlights from the Extreme Ultraviolet Explorer
NASA Technical Reports Server (NTRS)
Bowyer, S.; Malina, R. F.
1995-01-01
We present a few scientific highlights from the Extreme Ultraviolet Explorer (EUVE) all-sky and deep surveys, from the EUVE Righ Angle Program, and from the EUVE Guest Observer Program. The First EUVE Source Catalog includes 410 extreme ultraviolet (EUV) sources detected in the initial processing of the EUVE all-sky data. A program of optical identification indicates that counterparts include cool star coronae, flare stars, hot white dwarfs, central stars of planetary nebulae, B star photospheres and winds, an X-ray binary, extragalactic objects (active galactic nuclei, BL Lacertae), solar system objects (Moon, Mars, Io,), supernova remnants, and two novae.
Educational Programs at the Lake Afton Public Observatory
NASA Astrophysics Data System (ADS)
Alexander, D. R.; Novacek, G. R.
1994-05-01
The Lake Afton Public Observatory was founded 14 years ago as a joint project of the city, county, local schools, and Wichita State University to provide educational programs for the public and school children. A staff of 4 professional astronomers presents daytime and evening programs at the Observatory and makes presentations in schools to over 20,000 people per year. Programs are scheduled 6 days a week during the academic year and 3 days a week in the summer. Our public programs deviate significantly from the traditional observatory open house by following a specific theme. Selection and discussion of each object is centered on that theme. For example, a program on The Life Story of a Star would view a diffuse nebula (to discuss star formation), a young star cluster (to discuss one outcome of star formation), a double star (to discuss how the properties of stars are determined), and a planetary nebula (to discuss the death of a star). To complement the observing experiences of our visitors, we have developed a wide range of interactive exhibits to develop the concepts touched on in the viewing programs. We have also developed exhibit lending kits for extended use in school classrooms, educational games, activity manuals for teachers, and short videos to introduce single concepts in the classroom. In the past year we have begun to offer a series of workshops for in-service teachers to expand their knowledge of astronomy and to provide them with additional resources for teaching astronomy. This work is supported in part by NSF EPSCoR grant OSR-9255223.
NASA Technical Reports Server (NTRS)
Etchberger, F. R.
1983-01-01
Reduction of skin friction drag by suction of boundary layer air to maintain laminar flow has been known since Prandtl's published work in 1904. The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program in 1976 to develop technologies to improve fuel efficiency. This report documents the Lockheed-Georgia Company accomplishments in designing and fabricating a leading-edge flight test article incorporating boundary layer suction slots to be flown by NASA on their modified JetStar aircraft. Lockheed-Georgia Company performed as the integration contractor to design the JetStar aircraft modification to accept both a Lockheed and a McDonnell Douglas flight test article. McDonnell Douglas uses a porous skin concept. The report describes aerodynamic analyses, fabrication techniques, JetStar modifications, instrumentation requirements, and structural analyses and testing for the Lockheed test article. NASA will flight test the two LFC leading-edge test articles in a simulated commercial environment over a 6 to 8 month period in 1984. The objective of the flight test program is to evaluate the effectiveness of LFC leading-edge systems in reducing skin friction drag and consequently improving fuel efficiency.
Lai, Dong; Ho, Wynn C G
2003-08-15
In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.
NASA Astrophysics Data System (ADS)
Lai, Dong; Ho, Wynn C.
2003-08-01
In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.
Efficient Windows Collaborative
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nils Petermann
2010-02-28
The project goals covered both the residential and commercial windows markets and involved a range of audiences such as window manufacturers, builders, homeowners, design professionals, utilities, and public agencies. Essential goals included: (1) Creation of 'Master Toolkits' of information that integrate diverse tools, rating systems, and incentive programs, customized for key audiences such as window manufacturers, design professionals, and utility programs. (2) Delivery of education and outreach programs to multiple audiences through conference presentations, publication of articles for builders and other industry professionals, and targeted dissemination of efficient window curricula to professionals and students. (3) Design and implementation of mechanismsmore » to encourage and track sales of more efficient products through the existing Window Products Database as an incentive for manufacturers to improve products and participate in programs such as NFRC and ENERGY STAR. (4) Development of utility incentive programs to promote more efficient residential and commercial windows. Partnership with regional and local entities on the development of programs and customized information to move the market toward the highest performing products. An overarching project goal was to ensure that different audiences adopt and use the developed information, design and promotion tools and thus increase the market penetration of energy efficient fenestration products. In particular, a crucial success criterion was to move gas and electric utilities to increase the promotion of energy efficient windows through demand side management programs as an important step toward increasing the market share of energy efficient windows.« less
The HST-pNFL program: Mapping the Fluorescent Emission of Galactic Outflows
NASA Astrophysics Data System (ADS)
Heckman, Timothy
2017-08-01
Galactic outflows associated with star formation are believed to play a crucial role in the evolution of galaxies and the IGM. Most of our knowledge about outflows has come from down-the-barrel UV absorption spectroscopy of star-forming galaxies. However, absorption-line data alone provide only indirect information about the radial structure of the gas flows, which introduces large systematic uncertainties in some of the most important quantities, such as the outflow rate, the mass loading factor, and the momentum, metal, and energy fluxes. Recent spectroscopic observations of star-forming galaxies with large (projected physical) apertures have revealed non-resonant (fluorescent) emission in the UV, e.g., FeII* and SiII*, that can be naturally produced by spatially extended emission from the same outflowing material traced in absorption. Encouraged by the most recent observations of FeII* emission by the SDSS-IV/eBOSS survey (Zhu et al. 2015), we propose a pilot program to use narrow-band filter UVIS F280N images to map the extended FeII* 2626 and 2613 fluorescent emission in a carefully-chosen sample of 4 starburst galaxies at z=0.065, and COS G130M to obtain down-the- barrel spectra for SiII absorption and SiII* emission. This HST pilot program can provide unique information about the spatial structure of galactic outflows and can potentially lead to a revolution in our understanding of outflow physics and its impact on galaxies and the IGM.
Modelling the Dust Around Vega-Like Stars
NASA Technical Reports Server (NTRS)
Sylvester, Roger J.; Skinner, C. J.; Barlow, M. J.
1996-01-01
Models are presented of four Vega-like stars: main-sequence stars with infrared emission from circumstellar dust. The dusty environments of the four stars are rather diverse, as shown by their spectral energy distributions. Good fits to the observations were obtained for all four stars.
NASA Technical Reports Server (NTRS)
Chiu, Hong-Yee
1990-01-01
The structure of nontopological solutions of Einstein field equations as proposed by Friedberg, Lee, and Pang (1987) is examined. This analysis incorporates finite temperature effects and pair creation. Quarks are assumed to be the only species that exist in interior of soliton stars. The possibility of primordial creation of soliton stars in the incomplete decay of the degenerate vacuum in early universe is explored. Because of dominance of pair creation inside soliton stars, the luminosity of soliton stars is not determined by its radiative transfer characteristics, and the surface temperature of soliton stars can be the same as its interior temperature. It is possible that soliton stars are intense X-ray radiators at large distances. Soliton stars are nearly 100 percent efficient energy converters, converting the rest energy of baryons entering the interior into radiation. It is possible that a sizable number of baryons may also be trapped inside soliton stars during early epochs of the universe. In addition, if soliton stars exist they could assume the role played by massive black holes in galactic centers.
QCD axion star collapse with the chiral potential
Eby, Joshua; Leembruggen, Madelyn; Suranyi, Peter; ...
2017-06-05
In a previous study, we analyzed collapsing axion stars using the low-energy instanton potential, showing that the total energy is always bounded and that collapsing axion stars do not form black holes. In this paper, we provide a proof that the conclusions are unchanged when using instead the more general chiral potential for QCD axions.
Light element production by low energy nuclei from massive stars
NASA Technical Reports Server (NTRS)
Vangioni-Flam, E.; Casse, M.; Ramaty, R.
1997-01-01
The Orion complex is a source of gamma rays attributed to the de-excitation of fast carbon and oxygen nuclei excited through interactions with ambient hydrogen and helium. This has consequences for the production and evolution of light isotopes in the Galaxy, as massive stars appear as prolific sources of C-O rich low energy nuclei. The different stages of massive star evolution are considered in relation to the acceleration of nuclei to moderate energies. It is concluded that the low energy nuclear component originating from massive stars plays a larger role than the usual Galactic cosmic rays in shaping the evolution of Li-6, Be-9, B-10 and B-11, especially in the early Galactic evolution. The enhancement of the B-11/B-10 ratio observed in meteorites and in the interstellar medium is attributed to the interaction of low energy carbon nuclei with ambient H and to a lesser degree, to neutrino spallation.
Gamma-ray bursts generated from phase transition of neutron stars to quark stars
NASA Astrophysics Data System (ADS)
Shu, Xiao-Yu; Huang, Yong-Feng; Zong, Hong-Shi
2017-02-01
The evolution of compact stars is believed to be able to produce various violent phenomena in our universe. In this paper, we discuss the possibility that gamma-ray bursts (GRBs) might result from the phase transition of a neutron star to a quark star and calculate the energy released from the conversion. In our study, we utilize the relativistic mean field (RMF) theory to describe the hadronic phase of neutron stars, while an improved quasi-particle model is adopted to describe the quark phase of quark stars. With quark matter equation-of-state (EOS) more reliable than models used before, it is found that the energy released is of the order of 1052 erg, which confirms the validity of the phase transition model.
Dark Skies Awareness Programs for the U.S. International Year of Astronomy
NASA Astrophysics Data System (ADS)
Walker, Constance E.; U. S. IYA Dark Skies Working Group
2009-01-01
The loss of a dark night sky as a natural resource is a growing concern. It impacts not only astronomical research, but also our ecology, health, safety, economics and energy conservation. For this reason, "Dark Skies are a Universal Resource” is one of seven primary themes of the U.S. International Year of Astronomy program in 2009. Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved in a variety of dark skies-related programs. To reach this goal, activities have been developed that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking, Second Life) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Discovery Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy Nights) 3) Organize an event in the arts (e.g., a photography contest) 4) Involve citizen-scientists in unaided-eye and digital-meter star counting programs, as well as RFI monitoring (e.g., GLOBE at Night and Quiet Skies) and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security (e.g., the Dark Skies Toolkit, Good Neighbor Lighting, Earth Hour, National Dark Skies Week, traveling exhibits and a 6-minute video tutorial). To deliver these programs, strategic networks have been established with astronomy clubs (ASP's Night Sky Network's astronomy clubs and the Astronomical League), science and nature centers (Astronomy from the Ground Up and the Association of Science and Technology), educational programs (Project ASTRO and GLOBE) and the International Dark-sky Association. The poster will describe the "know-how” and the means for people to become community advocates in promoting Dark Skies programs as public events at their home institutions. For more information, visit http://astronomy2009.us/darkskies/.
High energy neutrino absorption and its effects on stars in close X-ray binaries
NASA Technical Reports Server (NTRS)
Gaisser, T. K.; Stecker, F. W.
1986-01-01
The physics and astrophysics of high energy neutrino production and interactions in close X-ray binary systems are studied. These studies were stimulated by recent observations of ultrahigh energy gamma-rays and possibly other ultrahigh energy particles coming from the directions of Cygnus X-3 and other binary systems and possessing the periodicity characteristics of these systems. Systems in which a compact object, such as a neutron star, is a strong source of high energy particles which, in turn, produce photons, neutronos and other secondary particles by interactions in the atmosphere of the companion star were considered. The highest energy neutrinos are absorbed deep in the companion and the associated energy deposition may be large enough to effect its structure or lead to its ultimate disruption. This neutrino heating was evaluated, starting with a detailed numerical calculation of the hadronic cascade induced in the atmosphere of the companion star. For some theoretical models, the resulting energy deposition from neutrino absorption may be so great as to disrupt the companion star over an astronomically small timescale of the order of 10,000 years. Even if the energy deposition is smaller, it may still be high enough to alter the system substantially, perhaps leading to quenching of high energy signals from the source. Given the cosmic ray luminosities required to produce the observed gamma rays from cygnus X-3 and LMX X-4, such a situation may occur in these sources.
ERIC Educational Resources Information Center
Utebay, Kudret
2011-01-01
Every building, from the smallest school to the tallest skyscraper, uses energy. This energy is most often generated by burning fossil fuels, which releases greenhouse gases into the atmosphere and contributes to climate change. Existing commercial buildings offer a significant opportunity for low-cost, immediate emissions and energy cost…
NASA Astrophysics Data System (ADS)
Kruckow, M. U.; Tauris, T. M.; Langer, N.; Szécsi, D.; Marchant, P.; Podsiadlowski, Ph.
2016-11-01
Context. The recently detected gravitational wave signals (GW150914 and GW151226) of the merger event of a pair of relatively massive stellar-mass black holes (BHs) calls for an investigation of the formation of such progenitor systems in general. Aims: We analyse the common-envelope (CE) stage of the traditional formation channel in binaries where the first-formed compact object undergoes an in-spiral inside the envelope of its evolved companion star and ejects the envelope in this process. Methods: We calculated envelope binding energies of donor stars with initial masses between 4 and 115M⊙ for metallicities of Z = ZMilky Way ≃ Z⊙/ 2 and Z = Z⊙/ 50, and derived minimum masses of in-spiralling objects needed to eject these envelopes. Results: In addition to producing double white dwarf and double neutron star binaries, CE evolution may also produce massive BH-BH systems with individual BH component masses of up to 50 - 60M⊙, in particular for donor stars evolved to giants beyond the Hertzsprung gap. However, the physics of envelope ejection of massive stars remains uncertain. We discuss the applicability of the energy-budget formalism, the location of the bifurcation point, the recombination energy, and the accretion energy during in-spiral as possible energy sources, and also comment on the effect of inflated helium cores. Conclusions: Massive stars in a wide range of metallicities and with initial masses of up to at least 115M⊙ may shed their envelopes and survive CE evolution, depending on their initial orbital parameters, similarly to the situation for intermediate- and low-mass stars with degenerate cores. In addition to being dependent on stellar radius, the envelope binding energies and λ-values also depend on the applied convective core-overshooting parameter, whereas these structure parameters are basically independent of metallicity for stars with initial masses below 60M⊙. Metal-rich stars ≳60M⊙ become luminous blue variables and do not evolve to reach the red giant stage. We conclude that based on stellar structure calculations, and in the view of the usual simple energy budget analysis, events like GW150914 and GW151226 might be produced by the CE channel. Calculations of post-CE orbital separations, however, and thus the estimated LIGO detection rates, remain highly uncertain.
An outburst powered by the merging of two stars inside the envelope of a giant
NASA Astrophysics Data System (ADS)
Hillel, Shlomi; Schreier, Ron; Soker, Noam
2017-11-01
We conduct 3D hydrodynamical simulations of energy deposition into the envelope of a red giant star as a result of the merger of two close main sequence stars or brown dwarfs, and show that the outcome is a highly non-spherical outflow. Such a violent interaction of a triple stellar system can explain the formation of `messy', I.e. lacking any kind of symmetry, planetary nebulae and similar nebulae around evolved stars. We do not simulate the merging process, but simply assume that after the tight binary system enters the envelope of the giant star the interaction with the envelope causes the two components, stars or brown dwarfs, to merge and liberate gravitational energy. We deposit the energy over a time period of about 9 h, which is about 1 per cent of the the orbital period of the merger product around the centre of the giant star. The ejection of the fast hot gas and its collision with previously ejected mass are very likely to lead to a transient event, I.e. an intermediate luminosity optical transient.
Statistical studies of superflares on G-, K-, M- type stars from Kepler data
NASA Astrophysics Data System (ADS)
Notsu, Yuta; Maehara, Hiroyuki; Honda, Satoshi; Notsu, Shota; Namekata, Kosuke; Ikuta, Kai; Nogami, Daisaku; Shibata, Kazunari
2017-05-01
Flares are thought to be sudden releases of magnetic energy stored around starspots. Recent space high-precision photometry shows “superflares”, 10-104 times more energetic than the largest solar flares, occur on many G, K, M-type stars (e.g., Maehara+2012 Nature). Harmful UV/X-ray radiation and high-energy particles such as protons are caused by such superflares. This may suggest that exoplanet host stars have severe effects on the physical and chemical evolution of exoplanetary atmospheres (cf. Segura+2010 Astrobiology, Takahashi+2016 ApJL).We here present statistical properties of superflares on G, K, M-type stars on the basis of our analyses of Kepler photometric data (Maehara+2012 Nature, Shibayama+2013 ApJS, Notsu+2013 ApJ, Canderaresi+2014 ApJ, Maehara+2015 EPS, Maehara+2017 PASJ). We found more than 5000 superflares on 800 G, K, M-type main-sequence stars, and the occurrence frequency (dN/dE) of superflares as a function of flare energy (E) shows the power-law distribution with the index of -1.8 -1.9. This power-law distribution is consistent with that of solar flares.Flare frequency increases as stellar temperature decreases. As for M-type stars, energy of the largest flares is smaller compared with G,K-type stars, but more frequent “hazardous” flares for the habitable planets since the habitable zone around M-type stars is much smaller compared with G, K-type stars.Rotation period and starspot coverage can be estimated from the quasi-periodic brightness variation of the superflare stars. The intensity of Ca II 8542 line of superflare stars, which is measured from spectroscopic observations with Subaru Telescope, has a well correlation with the brightness variation amplitude (Notsu+2015a&b PASJ).Flare frequency has a correlation with rotation period, and this suggests young rapidly-rotating stars (like “young Sun”) have more severe impacts of flares on the planetary atmosphere (cf. Airapetian+2016 ApJL). Flare energy and frequency also depends on starspot coverage, and this suggests existence of large starspots is important factor of superflares.These statistical properties of superflares discussed here can be one of the basic information for considering the impacts of flares on planet-host stars.
77 FR 22566 - Combined Notice of Filings #1
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-16
...-000. Applicants: BlueStar Energy Services Inc. Description: BlueStar Energy Services Inc. submits... and Electric Light Company. Description: FG&E Request for Updated Depreciation Rates to be effective 6...
GEM*STAR: Time for an Alternative Way Forward
NASA Astrophysics Data System (ADS)
Vogelaar, R. Bruce
2011-10-01
The presumption that nuclear reactors will retain their role in global energy production is constantly being challenged - even more so following recent events at Fukushima. Nuclear energy, despite being ``green,'' has inexorably been coupled in the public mind with three paramount concerns: safety, weapons proliferation, and waste (and then ultimately cost). Over the past four decades, the safety of deployed fleets has greatly improved, yet the capital and political costs of a ``nuclear energy option'' appear insurmountable in several countries. The US approach to civilian nuclear energy has become deeply entrenched, first through choices made by the military, and then by the deployed nuclear reactor fleet. This extends to the research agencies as well, to the point where basic sciences and nuclear energy operate in separate spheres. But technologies and priorities have changed, and the time has arrived where a transformative re-think of nuclear energy is not only possible, but urgent. And nuclear physicists are uniquely positioned to accomplish this. This talk will show that by asking, and answering,``what would an accelerator-driven civilian nuclear energy program look like,'' ADNA Corporation's GEM*STAR design directly addresses all three fundamental concerns: safety, proliferation, and waste - and also the final hurdle: cost. GEM*STAR is not an ``add-on'' (to either Project-X, or GEN III+), but rather a base-line energy production capacity, for either electricity or transport fuel production. It integrates and advances the molten-salt reactor technology developed at ORNL, the MW beam accelerator technologies developed by basic sciences, and a reactor/target design optimized for accelerator driven-systems. The results include: the ability to use LWR spent fuel without reprocessing or additional waste; the ability to use natural uranium; no critical mass ever present; orders-of-magnitude less volatile radioactivity in the core; more efficient use of, and deeper burn of actinides, without additional waste; proliferation resistance (no enrichment or reprocessing); high-tolerance to ``beam-trips'' and ultimately, and perhaps most importantly, lower cost electricity or diesel fuel than any currently envisioned new energy source.
Gravitational-Wave Luminosity of Binary Neutron Stars Mergers
NASA Astrophysics Data System (ADS)
Zappa, Francesco; Bernuzzi, Sebastiano; Radice, David; Perego, Albino; Dietrich, Tim
2018-03-01
We study the gravitational-wave peak luminosity and radiated energy of quasicircular neutron star mergers using a large sample of numerical relativity simulations with different binary parameters and input physics. The peak luminosity for all the binaries can be described in terms of the mass ratio and of the leading-order post-Newtonian tidal parameter solely. The mergers resulting in a prompt collapse to black hole have the largest peak luminosities. However, the largest amount of energy per unit mass is radiated by mergers that produce a hypermassive neutron star or a massive neutron star remnant. We quantify the gravitational-wave luminosity of binary neutron star merger events, and set upper limits on the radiated energy and the remnant angular momentum from these events. We find that there is an empirical universal relation connecting the total gravitational radiation and the angular momentum of the remnant. Our results constrain the final spin of the remnant black hole and also indicate that stable neutron star remnant forms with super-Keplerian angular momentum.
Gravitational-Wave Luminosity of Binary Neutron Stars Mergers.
Zappa, Francesco; Bernuzzi, Sebastiano; Radice, David; Perego, Albino; Dietrich, Tim
2018-03-16
We study the gravitational-wave peak luminosity and radiated energy of quasicircular neutron star mergers using a large sample of numerical relativity simulations with different binary parameters and input physics. The peak luminosity for all the binaries can be described in terms of the mass ratio and of the leading-order post-Newtonian tidal parameter solely. The mergers resulting in a prompt collapse to black hole have the largest peak luminosities. However, the largest amount of energy per unit mass is radiated by mergers that produce a hypermassive neutron star or a massive neutron star remnant. We quantify the gravitational-wave luminosity of binary neutron star merger events, and set upper limits on the radiated energy and the remnant angular momentum from these events. We find that there is an empirical universal relation connecting the total gravitational radiation and the angular momentum of the remnant. Our results constrain the final spin of the remnant black hole and also indicate that stable neutron star remnant forms with super-Keplerian angular momentum.
Spectral energy distributions and colours of hot subluminous stars
NASA Astrophysics Data System (ADS)
Heber, Ulrich; Irrgang, Andreas; Schaffenroth, Johannes
2018-02-01
Photometric surveys at optical, ultraviolet, and infrared wavelengths provide ever-growing datasets as major surveys proceed. Colour-colour diagrams are useful tools to identify classes of star and provide large samples. However, combining all photometric measurements of a star into a spectral energy distribution will allow quantitative analyses to be carried out. We demonstrate how to construct and exploit spectral energy distributions and colours for sublumious B (sdB) stars. The aim is to identify cool companions to hot subdwarfs and to determine atmospheric parameters of apparently single sdB stars as well as composite spectrum sdB binaries.We analyse two sdB stars with high-quality photometric data which serve as our benchmarks, the apparently single sdB HD205805 and the sdB + K5 binary PG 0749+658, briefly present preliminary results for the sample of 142 sdB binaries with known orbits, and discuss future prospects from ongoing all-sky optical space- (Gaia) and ground-based (e.g. SkyMapper) as well as NIR surveys.
Radial velocity detection of extra-solar planetary systems
NASA Technical Reports Server (NTRS)
Cochran, William D.
1991-01-01
The goal of this program was to detect planetary systems in orbit around other stars through the ultra high precision measurement of the orbital motion of the star around the star-planet barycenter. The survey of 33 nearby solar-type stars is the essential first step in understanding the overall problem of planet formation. The program will accumulate the necessary statistics to determine the frequency of planet formation as a function of stellar mass, age, and composition.
NASA Astrophysics Data System (ADS)
Jurdana-Šepić, R.; Poljančić Beljan, I.
Searching for T Tauri stars or related early type variables we carried out a BVRI photometric measurements of five candidates with positions within the field of the pre-main sequence object V733 Cephei (Persson's star) located in the dark cloud L1216 near to Cepheus OB3 Association: VES 946, VES 950, NSV 14333, NSV 25966 and V385 Cep. Their magnitudes are determined on the plates from Asiago Observatory historical photographic archive exposed 1971 - 1978. We provide finding charts for program stars and comparison sequence stars, magnitude estimations, magnitude mean values and BVR_cI_c light curves of program stars.
The Formation and Evolution of Planetary Systems: Placing Our Solar System in Context with Spitzer
NASA Astrophysics Data System (ADS)
Meyer, Michael R.; Hillenbrand, Lynne A.; Backman, Dana; Beckwith, Steve; Bouwman, Jeroen; Brooke, Tim; Carpenter, John; Cohen, Martin; Cortes, Stephanie; Crockett, Nathan; Gorti, Uma; Henning, Thomas; Hines, Dean; Hollenbach, David; Kim, Jinyoung Serena; Lunine, Jonathan; Malhotra, Renu; Mamajek, Eric; Metchev, Stanimir; Moro-Martin, Amaya; Morris, Pat; Najita, Joan; Padgett, Deborah; Pascucci, Ilaria; Rodmann, Jens; Schlingman, Wayne; Silverstone, Murray; Soderblom, David; Stauffer, John; Stobie, Elizabeth; Strom, Steve; Watson, Dan; Weidenschilling, Stuart; Wolf, Sebastian; Young, Erick
2006-12-01
We provide an overview of the Spitzer Legacy Program, Formation and Evolution of Planetary Systems, that was proposed in 2000, begun in 2001, and executed aboard the Spitzer Space Telescope between 2003 and 2006. This program exploits the sensitivity of Spitzer to carry out mid-infrared spectrophotometric observations of solar-type stars. With a sample of ~328 stars ranging in age from ~3 Myr to ~3 Gyr, we trace the evolution of circumstellar gas and dust from primordial planet-building stages in young circumstellar disks through to older collisionally generated debris disks. When completed, our program will help define the timescales over which terrestrial and gas giant planets are built, constrain the frequency of planetesimal collisions as a function of time, and establish the diversity of mature planetary architectures. In addition to the observational program, we have coordinated a concomitant theoretical effort aimed at understanding the dynamics of circumstellar dust with and without the effects of embedded planets, dust spectral energy distributions, and atomic and molecular gas line emission. Together with the observations, these efforts will provide an astronomical context for understanding whether our solar system-and its habitable planet-is a common or a rare circumstance. Additional information about the FEPS project can be found on the team Web site.
Black Hole Event Horizons and Advection-Dominated Accretion
NASA Technical Reports Server (NTRS)
McClintock, Jeffrey; Mushotzky, Richard F. (Technical Monitor)
2001-01-01
The XMM data on black-hole X-ray novae are only now becoming available and they have so far not been included in any publications. This work is part of a larger project that makes use of both XMM and Chandra data. Our first publication on the Chandra results is the following: "New Evidence for Black Hole Event Horizons from Chandra" by M.R. Garcia, J.E. McClintock, R. Narayan, P. Callanan, D. Barret and S. Murray (2001, ApJ, 553, L47). Therein we present the luminosities of the two black-hole X-ray novae, GRO J0422+22 and 4U1 543-47, which were observed by Chandra. These results are combined with the luminosities of four additional black-hole X-ray novae, which were observed as part of a Chandra GTO program (PI: S. Murray). The very low, but nonzero, quiescent X-ray luminosities of these black hole binaries is very difficult to understand in the context of standard viscous accretion disk theory. The principal result of this work is that X-ray novae that contain black hole primaries are about 100 times fainter that X-ray novae that contain neutron star primaries. This result had been suggested in earlier work, but the present work very firmly establishes this large luminosity difference. The result is remarkable because the black-hole and the neutron-star systems are believed to be similar in many respects. Most importantly, the mass transfer rate from the secondary star is believed to be very comparable for the two kinds of systems for similar orbital periods. The advection-dominated accretion flow (ADAF) model provides a natural framework for understanding the extraordinarily low luminosities of the black hole systems and the hundred-fold greater luminosities of the neutron star systems. The chief feature of an ADAF is that the heat energy in the accreting gas is trapped in the gas and travels with it, rather than being radiated promptly. Thus the accreting gas reaches the central object with a huge amount of thermal energy. If the accretor is a black hole, the thermal energy will disappear through the event horizon, and the object will be very dim. On the other hand, if the central object is a neutron star or any other object with a surface, then the energy will be radiated from the surface, and the object will be bright.
ERIC Educational Resources Information Center
Kanu, Mohamed; Hepler, Nancy; Labi, Halima
2015-01-01
Background: Since 1984, Students Taking a Right Stand (STARS) Nashville has implemented Student Assistance Programs (SAPs) in the middle Tennessee area, to include 14 counties and 16 school districts. STARS Nashville serves K-12 with a focus in middle and high schools. Methods: The current study reviewed studies that utilized quasi-experimental…
NASA Astrophysics Data System (ADS)
Aller, Lawrence H.
1991-09-01
1. Introducing stars and nebulae; 2. Stellar rainbows; 3. Atoms and molecules; 4. The climate in a stellar atmosphere; 5. Analysing the stars; 6. Dwarfs, giants, and supergiants; 7. What makes a star shine?; 8. The youth and middle age of a common star; 9. Wind, dust and pulsations; 10. A star's last hurray?; 11. The interstellar medium and gaseous nebulae; 12. Uncommon stars and their sometimes violent behaviour; 13. High energy astronomy.
Directed energy deflection laboratory measurements
NASA Astrophysics Data System (ADS)
Brashears, Travis; Lubin, Phillip; Hughes, Gary B.; Meinhold, Peter; Suen, Jonathan; Batliner, Payton; Motta, Caio; Griswold, Janelle; Kangas, Miikka; Johansson, Isbella; Alnawakhtha, Yusuf; Prater, Kenyon; Lang, Alex; Madajian, Jonathan
2015-09-01
We report on laboratory studies of the effectiveness of directed energy planetary defense as a part of the DESTAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR [1][5][6] and DE-STARLITE [2][5][6] are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid [1][2][3][4][5][6]. In the DE-STAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds an "asteroid" sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 μN/Woptical, though we assume a more conservative value of 80 μN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 μN/Woptical in our deflection modeling. Our measurements discussed here yield about 45 μN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Holzhauser, Andy; Jones, Chris; Faust, Jeremy
2013-12-30
The Greater Cincinnati Energy Alliance (Energy Alliance) is a nonprofit economic development agency dedicated to helping Greater Cincinnati and Northern Kentucky communities reduce energy consumption. The Energy Alliance has launched programs to educate homeowners, commercial property owners, and nonprofit organizations about energy efficiency opportunities they can use to drive energy use reductions and financial savings, while extending significant focus to creating/retaining jobs through these programs. The mission of the Energy Alliance is based on the premise that investment in energy efficiency can lead to transformative economic development in a region. With support from seven municipalities, the Energy Alliance began operationmore » in early 2010 and has been among the fastest growing nonprofit organizations in the Greater Cincinnati/Northern Kentucky area. The Energy Alliance offers two programs endorsed by the Department of Energy: the Home Performance with ENERGY STAR® Program for homeowners and the Better Buildings Performance Program for commercial entities. Both programs couple expert guidance, project management, and education in energy efficiency best practices with incentives and innovative energy efficiency financing to help building owners effectively invest in the energy efficiency, comfort, health, longevity, and environmental impact of their residential or commercial buildings. The Energy Alliance has raised over $23 million of public and private capital to build a robust market for energy efficiency investment. Of the $23 million, $17 million was a direct grant from the Department of Energy Better Buildings Neighborhood Program (BBNP). The organization’s investments in energy efficiency projects in the residential and commercial sector have led to well over $50 million in direct economic activity and created over 375,000 hours of labor created or retained. In addition, over 250 workers have been trained through the Building Performance Training Center, a program that was developed and funded by the Energy Alliance and housed at Cincinnati State Technical and Community College. Nearly 100 residential and commercial contractors currently participate in the Energy Alliance’s two major programs, which have together served over 2,800 residential and 100 commercial customers. Additionally, the Energy Alliance established loan programs for homeowners, nonprofits and commercial businesses. The GC-HELP program was established to provide up to ten year low interest, unsecured loans to homeowners to cover the energy efficiency products they purchased through the Energy Alliance approved contractor base. To date the Energy Alliance has financed over $1 million in energy efficiency loans for homeowners, without any loans written off. The nonprofit business community is offered five year, fixed-interest rate loans through the Building Communities Loan Fund of $250,000. Additionally, the Energy Alliance has developed GC-PACE, a commercial financing tool that enables buildings owners to finance their energy upgrades through voluntary property assessments deploying low-interest extended-term capital from the bond market. The Energy Alliance and its partners are actively evaluating additional market-based financing solutions.« less
The CNO Bi-cycle in the Open Cluster NGC 752
NASA Astrophysics Data System (ADS)
Hawkins, Keith; Schuler, S.; King, J.; The, L.
2011-01-01
The CNO bi-cycle is the primary energy source for main sequence stars more massive than the sun. To test our understanding of stellar evolution models using the CNO bi-cycle, we have undertaken light-element (CNO) abundance analysis of three main sequence dwarf stars and three red giant stars in the open cluster NGC 752 utilizing high resolution (R 50,000) spectroscopy from the Keck Observatory. Preliminary results indicate, as expected, there is a depletion of carbon in the giants relative to the dwarfs. Additional analysis is needed to determine if the amount of depletion is in line with model predictions, as seen in the Hyades open cluster. Oxygen abundances are derived from the high-excitation O I triplet, and there is a 0.19 dex offset in the [O/H] abundances between the giants and dwarfs which may be explained by non-local thermodynamic equilibrium (NLTE), although further analysis is needed to verify this. The standard procedure for spectroscopically determining stellar parameters used here allows for a measurement of the cluster metallicity, [Fe/H] = 0.04 ± 0.02. In addition to the Fe abundances we have determined Na, Mg, and Al abundances to determine the status of other nucleosynthesis processes. The Na, Mg and Al abundances of the giants are enhanced relative to the dwarfs, which is consistent with similar findings in giants of other open clusters. Support for K. Hawkins was provided by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 13 (AST-0754223) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.
Yellow supergiants in open clusters
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sowell, J.R.
1986-01-01
Superluminous giant stars (SLGs) have been reported in young globular clusters in the Large Magellanic Cloud (LMC). These stars appear to be in the post-asymptotic-giant-branch phase of evolution. This program was an investigation of galactic SLG candidates in open clusters, which are more like the LMC young globular clusters. These were chosen because luminosity, mass, and age determinations can be made for members since cluster distances and interstellar reddenings are known. Color magnitude diagrams were searched for candidates, using the same selection criteria as for SLGs in the LMC. Classification spectra were obtained of 115 program stars from McGraw-Hill Observatorymore » and of 68 stars from Cerro Tololo Inter-American Observatory Chile. These stars were visually classified on the MK system using spectral scans of standard stars taken at the respective observations. Published information was combined with this program's data for 83 stars in 30 clusters. Membership probabilities were assigned to these stars, and the clusters were analyzed according to age. It was seen that the intrinsically brightest supergiants are found in the youngest clusters. With increasing cluster age, the absolute luminosities attained by the supergiants decline. Also, it appears that the evolutionary tracks of luminosity class II stars are more similar to those of class I than of class III.« less
ERIC Educational Resources Information Center
Tushnet, Naida C.
The Star Schools Program has funded projects to explore innovative educational applications of technology in distance education. Funded projects have applied a variety of technologies, including videodisks, compressed data transmission, fiber optic technology, and computer networks. Program evaluation is a mandated aspect of the program. This…
Boston in Top 25 of EPA’s List of Cities with the Most Energy Star Certified Buildings
The U.S. Environmental Protection Agency (EPA) has announced its tenth annual Top Cities list, which ranks the 25 U.S. metropolitan areas with the most Energy Star certified buildings and superior energy performance in the preceding calendar year.
NASA Technical Reports Server (NTRS)
Svalbonas, V.; Ogilvie, P.
1975-01-01
A special data debugging package called SAT-1P created for the STARS-2P computer program is described. The program was written exclusively in FORTRAN 4 for the IBM 370-165 computer, and then converted to the UNIVAC 1108.
NASA Astrophysics Data System (ADS)
Lubowich, Donald A.
2009-05-01
This NASA-funded Music and Astronomy Under the Stars outreach program brings telescopes and astronomy information (via a video display and outdoor exhibit) to community parks during and after music concerts and outdoor family films attended by 500 to 50,000 people. This program will permit the entire community to participate with telescope observations and will enhance the public appreciation of astronomy. The telescopes will be accessible to those with physical disabilities. This program combines music, telescope observations, and astronomy information and targets people who may not attend star parties, planetariums, or science museums. I update this program and discus the lessons learned such as the importance of coordination with local governments, community park districts, and amateur astronomer clubs. This program can be expanded and modified for the local communities. I have expanded this program to large and small venues from New York Philharmonic concert at Heckscher State Park, the boardwalk and a "tail-gate” star party by at pop-music concerts at Jones Beach State Park, and at the Tanglewood Music Festival in Lenox, MA, summer home of the Boston Symphony Orchestra (http://www.bso.org/bso/mods/perf_detail.jsp?pid=prod2880024). This program is expandable to include outdoor dance or theatre programs, festivals in parks or beaches or amusement parks. Music and Astronomy Under the Stars is program that should continue beyond IYA-2009 beaches. Special events such as a Super Bowl Star Party and Halloween Stars will be presented as will the results form NASA-funded hands-on astronomy activities to children and their families receiving medical treatment at the Children's Medical Center at Winthrop University Hospital (Mineola, NY) and the Ronald McDonald House of Long Island (New Hyde Park, NY).
Extra X-rays at the Hub of Our Milky Way Galaxy
2015-04-29
NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, has captured a new high-energy X-ray view (magenta, Figure 1) of the bustling center of our Milky Way galaxy. The smaller circle shows the area where the NuSTAR image was taken -- the very center of our galaxy, where a giant black hole resides. That region is enlarged to the right, in the larger circle, to show the NuSTAR data. The NuSTAR picture is one of the most detailed ever taken of the center of our galaxy in high-energy X-rays. The X-ray light, normally invisible to our eyes, has been assigned the color magenta. The brightest point of light near the center of the X-ray picture is coming from a spinning dead star, known as a pulsar, which is near the giant black hole. While the pulsar's X-ray emissions were known before, scientists were surprised to find more high-energy X-rays than predicted in the surrounding regions, seen here as the elliptical haze. Astronomers aren't sure what the sources of the extra X-rays are, but one possibility is a population of dead stars. The background picture was captured in infrared light by NASA's Spitzer Space Telescope. The NuSTAR image has an X-ray energy range of 20 to 40 kiloelectron volts. http://photojournal.jpl.nasa.gov/catalog/PIA19334
O Star Wind Mass-Loss Rates and Shock Physics from X-ray Line Profiles in Archival XMM RGS Data
NASA Astrophysics Data System (ADS)
Cohen, David
O stars are characterized by their dense, supersonic stellar winds. These winds are the site of X-ray emission from shock-heated plasma. By analyzing high-resolution X-ray spectra of these O stars, we can learn about the wind-shock heating and X-ray production mechanism. But in addition, the X-rays can also be used to measure the mass-loss rate of the stellar wind, which is a key observational quantity whose value affects stellar evolution and energy, momentum, and mass input to the Galactic interstellar medium. We make this X-ray based mass-loss measurement by analyzing the profile shapes of the X-ray emission lines observed at high resolution with the Chandra and XMM-Newton grating spectrometers. One advantage of our method is that it is insensitive to small-scale clumping that affects density-squared diagnostics. We are applying this analysis technique to O stars in the Chandra archive, and are finding mass-loss rates lower than those traditionally assumed for these O stars, and in line with more recent independent determinations that do account for clumping. By extending this analysis to the XMM RGS data archive, we will make significant contributions to the understanding of both X-ray production in O stars and to addressing the issue of the actual mass-loss rates of O stars. The XMM RGS data archive provides several extensions and advantages over the smaller Chandra HETGS archive: (1) there are roughly twice as many O and early B stars in the XMM archive; (2) the longer wavelength response of the RGS provides access to diagnostically important lines of nitrogen and carbon; (3) the very long, multiple exposures of zeta Pup provide the opportunity to study this canonical O supergiant's X-ray spectrum in unprecedented detail, including looking at the time variability of X-ray line profiles. Our research team has developed a sophisticated empirical line profile model as well as a computational infrastructure for fitting the model to high-resolution X-ray spectra in order to determine the values of physically meaningful model parameters, and to place confidence limits on them. We have incorporated second-order effects into our models, including resonance scattering. We have also developed tools for modeling the X-ray opacity of the cold, X-ray absorbing wind component, which is a crucial ingredient of the technique we have developed for determining wind mass-loss rates from analyzing the ensemble of emission lines from a given star's X-ray spectrum. In addition to testing state-of-the-art wind shock models and measuring O star mass-loss rates, an important component of our proposed research program is the education of talented undergraduates. Swarthmore undergraduates have made significant contributions to the development of our line profile modeling, the wind opacity modeling, and related research topics such as laboratory astrophysics before going on to PhD programs. Two have been named as finalists for the APS's Apker prize. The research we propose here will involve two undergraduates and will likely lead to honors theses, refereed papers, and the opportunity to present their research results at national and international meetings. By measuring mass-loss rates for all the O stars for which high-resolution X-ray spectra exist and by constraining X-ray production mechanisms, we will address issues important to our understanding of stellar and galactic evolution: including the frequency of core collapse supernovae, the energetics of the Galactic interstellar medium, and the radiation conditions in star formation regions where not only new, solar-type stars form, but also where their planetary systems form and are subject to effects of high-energy emission from nearby stars. In this way, the work we are proposing in this project will make a contribution to NASA's mission to understand cosmic evolution and the conditions for generating and sustaining life in the Universe.
Wolf-Rayet stars in the central region of the Milky Way
NASA Astrophysics Data System (ADS)
Hamann, Wolf-Rainer; Graefener, Goetz; Oskinova, Lidia; Zinnecker, Hans
2004-09-01
We propose to take mid-IR spectra of two Wolf-Rayet stars in the inner part of our Galaxy, within 30pc projected distance from the central Black Hole. Massive stars dominate the central galactic region by their mass-loss and ionizing radiation. A quantitative analysis of this stellar inventory is essential for understanding the energy, momentum and mass budget, for instance with respect to the feeding of the central black hole. Our group developed a highly advanced model code for the expanding atmospheres of WR stars. Recently we extended the spectrum synthesis to IR wavelengths. These models will be applied for the analysis of the Spitzer IRS data. The proposed mid-IR observations will provide a wide spectral range with many lines which are needed to determine the stellar parameters, such as stellar luminosity, effective temperature, mass-loss rate and chemical composition. Near-IR spectra of the program stars are available and will augment the analysis. The capability of our code to reproduce the observed mid-IR spectrum of a WN star has been demonstrated. The two targets we selected are sufficiently isolated, while the Galactic center cluster is too crowded for the size of Spitzer's spectrograph slit. As estimated from the K-band spectra, one of the stars (WR102ka) is of very late subtype (WN9), while the other star (WR102c) has the early subtype WN6. Hence they represent different stages in the evolutionary sequence of massive stars, the late-WN just having entered the Wolf-Rayet phase and the early WN being further evolved. We expect that the parameters of massive stars in the inner galaxy differ from the usual Galactic population. One reason is that higher metallicity should lead to stronger mass-loss, which affects the stellar evolution. The Spitzer IRS, with its high sensitivity, provides a unique opportunity to study representative members of the stellar population in the vicinity of the Galactic center.
High School Students Watching Stars Evolve
NASA Astrophysics Data System (ADS)
Percy, J. R.; MacNeil, D.; Meema-Coleman, L.; Morenz, K.
2012-06-01
(Abstract only) Some stars pulsate (vibrate). Their pulsation period depends primarily on their radius. The pulsation period changes if the radius changes, due to evolution, for instance. Even though the evolution is slow, the period change is measurable because it is cumulative. The observed time of maximum brightness (O) minus the calculated time (C), assuming that the period is constant, is plotted against time to produce an (O-C) diagram. If there is a uniform period change, this diagram will be a parabola, whose curvature - positive or negative - is proportional to the rate of period change. In this project, we study the period changes of RR Lyrae stars, old sun-like stars which are in the yellow giant phase, generating energy by thermonuclear fusion of helium into carbon. We chose 59 well-studied stars in the GEOS database, which consists of times of maximum measured by AAVSO and other observers. We included about a dozen RRc (first overtone pulsator) stars, since these have not been as well studied as the RRab (fundamental mode) stars because the maxima in their light curves are not as sharp. We will describe our results: about 2/3 of the stars showed parabolic (O-C) diagrams with period changes of up to 1.0 s/century, some with increasing periods and some with decreasing periods. The characteristic times for period changes (i.e. period divided by rate of change of period) were mostly 5-30 million years. These numbers are consistent with evolutionary models. Some stars showed too much scatter for analysis; we will discuss why. A few stars showed unusual (O-C) diagrams which cannot be explained simply by evolution. This project was carried out by coauthors MacNeil, Meema-Coleman, and Morenz, who were participants in the prestigious University of Toronto Mentorship Program, which enables outstanding senior high school students to participate in research at the university. We thank the AAVSO and other observers who made the measurements which were used in our project.
Infrared Space Observatory (ISO) Key Project: the Birth and Death of Planets
NASA Technical Reports Server (NTRS)
Stencel, Robert E.; Creech-Eakman, Michelle; Fajardo-Acosta, Sergio; Backman, Dana
1999-01-01
This program was designed to continue to analyze observations of stars thought to be forming protoplanets, using the European Space Agency's Infrared Space Observatory, ISO, as one of NASA Key Projects with ISO. A particular class of Infrared Astronomy Satellite (IRAS) discovered stars, known after the prototype, Vega, are principal targets for these observations aimed at examining the evidence for processes involved in forming, or failing to form, planetary systems around other stars. In addition, this program continued to provide partial support for related science in the WIRE, SOFIA and Space Infrared Telescope Facility (SIRTF) projects, plus approved ISO supplementary time observations under programs MCREE1 29 and VEGADMAP. Their goals include time dependent changes in SWS spectra of Long Period Variable stars and PHOT P32 mapping experiments of recognized protoplanetary disk candidate stars.
Distant intense starbursts: evidence for self-regulated star formation?
NASA Astrophysics Data System (ADS)
Lehnert, M. D.
From an analysis of the Halpha and [NII]∼λ6583 rest-frame optical emission lines in a large sample of intensely star forming galaxies at z=1.3 to 2.7 observed with SINFONI on the ESO-VLT, we have reached a number of conclusions. The galaxies all have broad optical emission lines (sigma ˜50-250 km s-1) which are a function of the underlying star formation intensity as determined from the Halpha surface brightness. These broad lines are intrinsic to the galaxies and not due to beam smearing. The velocity dispersions appear to be related to the star formation intensity (Sigma SFR, star formation rate per unit area) of the form, sigma ˜ epsilon Sigma SFR1/2. This is a simple and direct relationship between the energy injection rate and the kinetic energy of the emission line gas with a coupling efficiency of epsilon . In this contribution, we outline a simple model whereby the energy output of massive stars, both mechanical and radiative, feeds a mass and energy cycle within the interstellar media of these distant galaxies. The mass and energy cycle pushes the global ISM towards the line of stability, Toomre parameter Q˜1, but only if the molecular gas captures, to some extent, the kinematics of the warm ionized gas as probed by the optical emission lines. In such a picture, the star formation intensity is self-regulating.} This work and many of the ideas presented here were developed in collaboration with L. Le Tiran, W. van Driel, P. Di Matteo (GEPI), N. Nesvadba, and F. Boulanger (IAS, Orsay, France).
Prager, Stewart; Zwicker, Andrew; Hammet, Greg; Tresemer, Kelsey; Diallo, Ahmed
2018-02-14
At the Energy Department's Princeton Plasma Physics Lab, scientists are trying to accomplish what was once considered the realm of science fiction: create a star on Earth. The National Spherical Torus Experiment (NSTX) is a magnetic fusion device that is used to study the physics principles of spherically shaped plasmas -- hot ionized gases in which, under the right conditions, nuclear fusion will occur. Fusion is the energy source of the sun and all of the stars. Not just limited to theoretical work, the NSTX is enabling cutting-edge research to develop fusion as a future energy source.
The Productivity of Oxygenic Photosynthesis around Cool, M Dwarf Stars
NASA Astrophysics Data System (ADS)
Lehmer, Owen R.; Catling, David C.; Parenteau, Mary N.; Hoehler, Tori M.
2018-06-01
In the search for life around cool stars, the presence of atmospheric oxygen is a prominent biosignature, as it may indicate oxygenic photosynthesis (OP) on the planetary surface. On Earth, most oxygenic photosynthesizing organisms (OPOs) use photons between 400 and 750 nm, which have sufficient energy to drive the photosynthetic reaction that generates O2 from H2O and CO2. OPOs around cool stars may evolve similar biological machinery capable of producing oxygen from water. However, in the habitable zones (HZs) of the coolest M dwarf stars, the flux of 400–750 nm photons may be just a few percent that of Earth’s. We show that the reduced flux of 400–750 nm photons around M dwarf stars could result in Earth-like planets being growth limited by light, unlike the terrestrial biosphere, which is limited by nutrient availability. We consider stars with photospheric temperatures between 2300 and 4200 K and show that such light-limited worlds could occur at the outer edge of the HZ around TRAPPIST-1-like stars. We find that even if OP can use photons longer than 750 nm, there would still be insufficient energy to sustain the Earth’s extant biosphere throughout the HZ of the coolest stars. This is because such stars emit largely in the infrared and near-infrared, which provide sufficient energy to make the planet habitable, but limits the energy available for OP. TRAPPIST-1f and g may fall into this category. Biospheres on such planets, potentially limited by photon availability, may generate small biogenic signals, which could be difficult for future observations to detect.
Adaptation of a program for nonlinear finite element analysis to the CDC STAR 100 computer
NASA Technical Reports Server (NTRS)
Pifko, A. B.; Ogilvie, P. L.
1978-01-01
The conversion of a nonlinear finite element program to the CDC STAR 100 pipeline computer is discussed. The program called DYCAST was developed for the crash simulation of structures. Initial results with the STAR 100 computer indicated that significant gains in computation time are possible for operations on gloval arrays. However, for element level computations that do not lend themselves easily to long vector processing, the STAR 100 was slower than comparable scalar computers. On this basis it is concluded that in order for pipeline computers to impact the economic feasibility of large nonlinear analyses it is absolutely essential that algorithms be devised to improve the efficiency of element level computations.
The elastic energy and character of quakes in solid stars and planets
NASA Technical Reports Server (NTRS)
Pines, D.; Shaham, J.
1972-01-01
The quadrupolar mechanical energy of a rotating axially symmetric solid planet (with or without a liquid interior) is calculated using methods previously developed for neutron stars in which an elastic reference tensor is introduced to describe the build-up of elastic energy in the star. The basic parameters of the theory (the gravitational energy A and elastic energy B) depend upon the internal structure of the planet and may be calculated from specific planetary models. Explicit expressions are obtained for the Love numbers, and for the planetary wobble frequency. The theory provides a simple relationship between changes in shape or axis of figure of the planet and elastic energy release. The theory is extended to describe the Earth by taking into account isostasy, triaxiality and the observed lithospheric configuration.
ERIC Educational Resources Information Center
Eom, Tae Ho; Killeen, Kieran M.
2007-01-01
Similar to many property tax relief programs, New York State's School Tax Relief (STAR) program has been shown to exacerbate school resource inequities across urban, suburban, and rural schools. STAR's inherent conflict with the wealth equalization policies of New York State's school finance system are highlighted in a manner that effectively…
Recent Upgrades at the Safety and Tritium Applied Research Facility
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cadwallader, Lee Charles; Merrill, Brad Johnson; Stewart, Dean Andrew
This paper gives a brief overview of the Safety and Tritium Applied Research (STAR) facility operated by the Fusion Safety Program (FSP) at the Idaho National Laboratory (INL). FSP researchers use the STAR facility to carry out experiments in tritium permeation and retention in various fusion materials, including wall armor tile materials. FSP researchers also perform other experimentation as well to support safety assessment in fusion development. This lab, in its present two-building configuration, has been in operation for over ten years. The main experiments at STAR are briefly described. This paper discusses recent work to enhance personnel safety atmore » the facility. The STAR facility is a Department of Energy less than hazard category 3 facility; the personnel safety approach calls for ventilation and tritium monitoring for radiation protection. The tritium areas of STAR have about 4 to 12 air changes per hour, with air flow being once through and then routed to the facility vent stack. Additional radiation monitoring has been installed to read the laboratory room air where experiments with tritium are conducted. These ion chambers and bubblers are used to verify that no significant tritium concentrations are present in the experiment rooms. Standby electrical power has been added to the facility exhaust blower so that proper ventilation will now operate during commercial power outages as well as the real-time tritium air monitors.« less
NASA Technical Reports Server (NTRS)
Dolan, Joseph F.; Fisher, Richard R. (Technical Monitor)
2001-01-01
When asked to discuss Cyg XR-1, E. E. Salpeter once concluded, 'A black hole in Cyg X(R)-1 is the most conservative hypothesis.' Recent observations now make it likely that a black hole in Cyg XR-1 is the only hypothesis tenable. Chandrasekhar first showed that compact stars - those with the inward force of gravity on their outer layers balanced by the pressure generated by the Pauli exclusion principle acting on its electrons (in white dwarfs) or nucleons (in neutron stars) - have a maximum mass. Equilibrium is achieved at a minimum of the total energy of the star, which is the sum of the positive Fermi energy and the negative gravitational energy. The maximum mass attainable in equilibrium is found by setting E = 0: M(max) = 1.5 M(Sun). If the mass of the star is larger than this, then E can be decreased without bound by decreasing the star's radius and increasing its (negative) gravitational energy. No equilibrium value of the radius exist, and general relativity predicts that gravitational collapse to a point occurs. This point singularity is a black hole.
Neutrino-heated stars and broad-line emission from active galactic nuclei
NASA Technical Reports Server (NTRS)
Macdonald, James; Stanev, Todor; Biermann, Peter L.
1991-01-01
Nonthermal radiation from active galactic nuclei indicates the presence of highly relativistic particles. The interaction of these high-energy particles with matter and photons gives rise to a flux of high-energy neutrinos. In this paper, the influence of the expected high neutrino fluxes on the structure and evolution of single, main-sequence stars is investigated. Sequences of models of neutrino-heated stars in thermal equilibrium are presented for masses 0.25, 0.5, 0.8, and 1.0 solar mass. In addition, a set of evolutionary sequences for mass 0.5 solar mass have been computed for different assumed values for the incident neutrino energy flux. It is found that winds driven by the heating due to high-energy particles and hard electromagnetic radiation of the outer layers of neutrino-bloated stars may satisfy the requirements of the model of Kazanas (1989) for the broad-line emission clouds in active galactic nuclei.
A Gamma-Ray Burst Model Via Compressional Heating of Binary Neutron Stars
NASA Astrophysics Data System (ADS)
Salmonson, J. D.; Wilson, J. R.; Mathews, G. J.
1998-12-01
We present a model for gamma-ray bursts based on the compression of neutron stars in close binary systems. General relativistic (GR) simulations of close neutron star binaries have found compression of the neutron stars estimated to produce 1053 ergs of thermal neutrinos on a timescale of seconds. The hot neutron stars will emit neutrino pairs which will partially recombine to form 1051 to 1052 ergs of electron-positron (e^-e^+) pair plasma. GR hydrodynamic computational modeling of the e^-e^+ plasma flow and recombination yield a gamma-ray burst in good agreement with general characteristics (duration ~10 seconds, spectrum peak energy ~100 keV, total energy ~1051 ergs) of many observed gamma-ray bursts.
Development of a performance-based industrial energy efficiency indicator for corn refining plants.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boyd, G. A.; Decision and Information Sciences; USEPA
2006-07-31
Organizations that implement strategic energy management programs have the potential to achieve sustained energy savings if the programs are carried out properly. A key opportunity for achieving energy savings that plant managers can take is to determine an appropriate level of energy performance by comparing their plant's performance with that of similar plants in the same industry. Manufacturing facilities can set energy efficiency targets by using performance-based indicators. The U.S. Environmental Protection Agency (EPA), through its ENERGY STAR{reg_sign} program, has been developing plant energy performance indicators (EPIs) to encourage a variety of U.S. industries to use energy more efficiently. Thismore » report describes work with the corn refining industry to provide a plant-level indicator of energy efficiency for facilities that produce a variety of products--including corn starch, corn oil, animal feed, corn sweeteners, and ethanol--for the paper, food, beverage, and other industries in the United States. Consideration is given to the role that performance-based indicators play in motivating change; the steps needed to develop indicators, including interacting with an industry to secure adequate data for an indicator; and the actual application and use of an indicator when complete. How indicators are employed in the EPA's efforts to encourage industries to voluntarily improve their use of energy is discussed as well. The report describes the data and statistical methods used to construct the EPI for corn refining plants. Individual equations are presented, as are the instructions for using them in an associated Excel spreadsheet.« less
The Explosive Counterparts of Gravitational Waves
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
Astronomy collaborations like the Dark Energy Survey, which Fermilab leads, can track down the visible sources of gravitational waves caused by binary neutron stars. This animation takes you through the collision of two neutron stars, and shows you the explosion of light and energy seen by the Dark Energy Camera on August 17, 2017.
78 FR 52523 - Notice of Effectiveness of Exempt Wholesale Generator Status
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-23
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Notice of Effectiveness of Exempt Wholesale Generator Status Docket Nos. Dominion Bridgeport Fuel Cell, LLC EG13-31-000 Arlington Valley Solar Energy II, LLC EG13-32-000 Solar Star California XIX, LLC EG13-33-000 Solar Star California XX, LLC EG13...
ERIC Educational Resources Information Center
Child Trends, 2010
2010-01-01
This paper presents a profile of Tennessee's Star-Quality Child Care Program prepared as part of the Child Care Quality Rating System (QRS) Assessment Study. The profile consists of several sections and their corresponding descriptions including: (1) Program Information; (2) Rating Details; (3) Quality Indicators for Center-Based Programs; (4)…
How Does The Universe Work? The Physics Of The Cosmos Program (PCOS)
NASA Astrophysics Data System (ADS)
Sambruna, Rita M.
2011-09-01
The Physics of the Cosmos (PCOS) program incorporates cosmology, high-energy astrophysics, and fundamental physics projects aimed at addressing central questions about the nature of complex astrophysical phenomena such as black holes, neutron stars, dark energy, and gravitational waves. Its overarching theme is, How does the Universe work? PCOS includes a suite of operating (Chandra, Fermi, Planck, XMM-Newton, INTEGRAL) and future missions across the electromagnetic spectrum and beyond, which are in concept development and/or formulation. The PCOS program directly supports development of intermediate TRL (4-6) technology relevant to future missions through the Strategic Astrophysics Technology (SAT) program, as well as data analysis, theory, and experimental astrophysics via other R&A avenues (e.g., ADAP, ATP). The Einstein Fellowship is a vital and vibrant PCOS component funded by the program. PCOS receives community input via its Program Analysis Group, the PhysPAG (www.pcos.gsfc.nasa.gov/physpag.php), whose membership and meetings are open to the community at large. In this poster, we describe the detailed science questions addressed within PCOS, with special emphasis on future opportunities. Details about the PhysPAG operations and functions will be provided, as well as an update on future meetings.
Constraint on energy-momentum squared gravity from neutron stars and its cosmological implications
NASA Astrophysics Data System (ADS)
Akarsu, Özgür; Barrow, John D.; ćıkıntoǧlu, Sercan; Ekşi, K. Yavuz; Katırcı, Nihan
2018-06-01
Deviations from the predictions of general relativity due to energy-momentum squared gravity (EMSG) are expected to become pronounced in the high density cores of neutron stars. We derive the hydrostatic equilibrium equations in EMSG and solve them numerically to obtain the neutron star mass-radius relations for four different realistic equations of state. We use the existing observational measurements of the masses and radii of neutron stars to constrain the free parameter, α , that characterizes the coupling between matter and spacetime in EMSG. We show that -10-38 cm3/erg <α <+10-37 cm3/erg . Under this constraint, we discuss what contributions EMSG can provide to the physics of neutron stars, in particular, their relevance to the so called hyperon puzzle in neutron stars. We also discuss how EMSG alters the dynamics of the early universe from the predictions of the standard cosmological model. We show that EMSG leaves the standard cosmology safely unaltered back to t ˜10-4 seconds at which the energy density of the universe is ˜1034 erg cm-3 .
NASA Technical Reports Server (NTRS)
Venters, Tonia M.
2011-01-01
We present new theoretical estimates of the contribution of unresolved star-forming galaxies to the extragalactic gamma-ray background (EGB) as measured by EGRET and the Fermi-LAT. We employ several methods for determining the star-forming galaxy contribution the the EGB, including a method positing a correlation between the gamma-ray luminosity of a galaxy and its rate of star formation as calculated from the total infrared luminosity, and a method that makes use of a model of the evolution of the galaxy gas mass with cosmic time. We find that depending on the model, unresolved star-forming galaxies could contribute significantly to the EGB as measured by the Fermi-LAT at energies between approx. 300 MeV and approx. few GeV. However, the overall spectrum of unresolved star-forming galaxies can explain neither the EGRET EGB spectrum at energies between 50 and 200 MeV nor the Fermi-LAT EGB spectrum at energies above approx. few GeV.
Neutron stars: Observational diversity and evolution
NASA Astrophysics Data System (ADS)
Safi-Harb, S.
2017-12-01
Ever since the discovery of the Crab and Vela pulsars in their respective Supernova Remnants, our understanding of how neutron stars manifest themselves observationally has been dramatically shaped by the surge of discoveries and dedicated studies across the electromagnetic spectrum, particularly in the high-energy band. The growing diversity of neutron stars includes the highly magnetized neutron stars (magnetars) and the Central Compact Objects shining in X-rays and mostly lacking pulsar wind nebulae. These two subclasses of high-energy objects, however, seem to be characterized by anomalously high or anomalously low surface magnetic fields (thus dubbed as ‘magnetars’ and ‘anti-magnetars’, respectively), and have pulsar characteristic ages that are often much offset from their associated SNRs’ ages. In addition, some neutron stars act ‘schizophrenic’ in that they occasionally display properties that seem common to more than one of the defined subclasses. I review the growing diversity of neutron stars from an observational perspective, then highlight recent and on-going theoretical and observational work attempting to address this diversity, particularly in light of their magnetic field evolution, energy loss mechanisms, and supernova progenitors’ studies.
Stellar population of the superbubble N 206 in the LMC. I. Analysis of the Of-type stars
NASA Astrophysics Data System (ADS)
Ramachandran, Varsha; Hainich, R.; Hamann, W.-R.; Oskinova, L. M.; Shenar, T.; Sander, A. A. C.; Todt, H.; Gallagher, J. S.
2018-01-01
Context. Massive stars severely influence their environment by their strong ionizing radiation and by the momentum and kinetic energy input provided by their stellar winds and supernovae. Quantitative analyses of massive stars are required to understand how their feedback creates and shapes large scale structures of the interstellar medium. The giant H II region N 206 in the Large Magellanic Cloud contains an OB association that powers a superbubble filled with hot X-ray emitting gas, serving as an ideal laboratory in this context. Aims: We aim to estimate stellar and wind parameters of all OB stars in N 206 by means of quantitative spectroscopic analyses. In this first paper, we focus on the nine Of-type stars located in this region. We determine their ionizing flux and wind mechanical energy. The analysis of nitrogen abundances in our sample probes rotational mixing. Methods: We obtained optical spectra with the multi-object spectrograph FLAMES at the ESO-VLT. When possible, the optical spectroscopy was complemented by UV spectra from the HST, IUE, and FUSE archives. Detailed spectral classifications are presented for our sample Of-type stars. For the quantitative spectroscopic analysis we used the Potsdam Wolf-Rayet model atmosphere code. We determined the physical parameters and nitrogen abundances of our sample stars by fitting synthetic spectra to the observations. Results: The stellar and wind parameters of nine Of-type stars, which are largely derived from spectral analysis are used to construct wind momentum - luminosity relationship. We find that our sample follows a relation close to the theoretical prediction, assuming clumped winds. The most massive star in the N 206 association is an Of supergiant that has a very high mass-loss rate. Two objects in our sample reveal composite spectra, showing that the Of primaries have companions of late O subtype. All stars in our sample have an evolutionary age of less than 4 million yr, with the O2-type star being the youngest. All these stars show a systematic discrepancy between evolutionary and spectroscopic masses. All stars in our sample are nitrogen enriched. Nitrogen enrichment shows a clear correlation with increasing projected rotational velocities. Conclusions: The mechanical energy input from the Of stars alone is comparable to the energy stored in the N 206 superbubble as measured from the observed X-ray and Hα emission.
Sun, Ting; Xing, Fei; You, Zheng; Wang, Xiaochu; Li, Bin
2014-03-10
The star tracker is one of the most promising attitude measurement devices widely used in spacecraft for its high accuracy. High dynamic performance is becoming its major restriction, and requires immediate focus and promotion. A star image restoration approach based on the motion degradation model of variable angular velocity is proposed in this paper. This method can overcome the problem of energy dispersion and signal to noise ratio (SNR) decrease resulting from the smearing of the star spot, thus preventing failed extraction and decreased star centroid accuracy. Simulations and laboratory experiments are conducted to verify the proposed methods. The restoration results demonstrate that the described method can recover the star spot from a long motion trail to the shape of Gaussian distribution under the conditions of variable angular velocity and long exposure time. The energy of the star spot can be concentrated to ensure high SNR and high position accuracy. These features are crucial to the subsequent star extraction and the whole performance of the star tracker.
DOE Office of Scientific and Technical Information (OSTI.GOV)
IBACOS investigated the performance of a small-diameter high velocity heat pump system compared to a conventional system in a new construction triplex townhouse. A ductless heat pump system also was installed for comparison, but the homebuyer backed out because of aesthetic concerns about that system. In total, two buildings, having identical solar orientation and comprised of six townhomes, were monitored for comfort and energy performance. Results show that the small-diameter system provides more uniform temperatures from floor to floor in the three-story townhome. No clear energy consumption benefit was observed from either system. The builder is continuing to explore themore » small-diameter system as its new standard system to provide better comfort and indoor air quality. The homebuilder also explored the possibility of shifting its townhome product to meet the U.S. Department of Energy Challenge Home National Program Requirements. Ultimately, the builder decided that adoption of these practices would be too disruptive midstream in the construction cycle. However, the townhomes met the ENERGY STAR Version 3.0 program requirements.« less
Comparative Cooling Season Performance of Air Distribution Systems in Multistory Townhomes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Poerschke, Andrew; Beach, Rob; Beggs, Timothy
2016-08-01
IBACOS investigated the performance of a small-diameter high velocity heat pump system compared to a conventional system in a new construction triplex townhouse. A ductless heat pump system also was installed for comparison, but the homebuyer backed out because of aesthetic concerns about that system. In total, two buildings, having identical solar orientation and comprised of six townhomes, were monitored for comfort and energy performance. Results show that the small-diameter system provides more uniform temperatures from floor to floor in the three-story townhome. No clear energy consumption benefit was observed from either system. The builder is continuing to explore themore » small-diameter system as its new standard system to provide better comfort and indoor air quality. The homebuilder also explored the possibility of shifting its townhome product to meet the U.S. Department of Energy Challenge Home National Program Requirements. Ultimately, the builder decided that adoption of these practices would be too disruptive midstream in the construction cycle. However, the townhomes met the ENERGY STAR Version 3.0 program requirements.« less
Lick Northern Proper Motion Program: NPM2
NASA Astrophysics Data System (ADS)
Jones, B. F.; Hanson, R. B.; Klemola, A. R.
2000-05-01
The Lick Northern Proper Motion (NPM) program is nearing completion after a half-century of work. Two-epoch photography began in 1947 and was completed in 1988. Measurements and reductions for proper motions, positions, and two-color photometry in the sky outside the Milky Way (``NPM1'') began in 1975 and were completed in 1992. The Lick NPM1 Catalog, containing 149,000 stars, was distributed in 1993. Work on the Milky Way sky (``NPM2'') comprising some 300,000 stars, began in 1996, and plate measurements were finished in 1999. The NPM program will be completed with the publication of the Lick NPM2 Catalog in 2003. The NPM program will provide absolute proper motions, measured on an inertial system defined by some 50,000 faint galaxies, for over 400,000 stars from 9 < B < 18, covering the northern two-thirds of the sky. Included in the NPM catalogs are many stars of astrophysical interest, anonymous stars for galactic studies, and stars from positional catalogues and proper motion surveys. Current work at Lick encompasses data reductions and star identifications for NPM2. Procedures are based on NPM1, with appropriate modifications. Reference galaxies are not available in the Milky Way sky, so the Hipparcos Catalogue is used to link the NPM2 proper motions to the inertial system defined by NPM1. The large number of stars in NPM2 reflects the higher density of stars near the Galactic plane and toward the Galactic center. The NPM catalogs will have lasting value as a unique database for future studies in galactic structure, stellar kinematics, and astrometry. As we produce NPM2, we are also applying the NPM data to several outstanding problems in these research fields. We would like to thank Dave Monet and the USNO for measuring the NPM2 plates. We thank the National Science Foundation for its continued support of the NPM program. The work reported here was supported by NSF grant AST 9530632.
SKYMAP system description: Star catalog data base generation and utilization
NASA Technical Reports Server (NTRS)
Gottlieb, D. M.
1979-01-01
The specifications, design, software description, and use of the SKYMAP star catalog system are detailed. The SKYMAP system was developed to provide an accurate and complete catalog of all stars with blue or visual magnitudes brighter than 9.0 for use by attitude determination programs. Because of the large number of stars which are brighter than 9.0 magnitude, efficient techniques of manipulating and accessing the data were required. These techniques of staged distillation of data from a Master Catalog to a Core Catalog, and direct access of overlapping zone catalogs, form the basis of the SKYMAP system. The collection and tranformation of data required to produce the Master Catalog data base is described. The data flow through the main programs and levels of star catalogs is detailed. The mathematical and logical techniques for each program and the format of all catalogs are documented.
NASA Astrophysics Data System (ADS)
Stelea, Cristian; Dariescu, Marina-Aura; Dariescu, Ciprian
2018-05-01
We extend a known solution-generating technique for isotropic fluids in order to construct more general models of anisotropic stars with poloidal magnetic fields. In particular, we discuss the magnetized versions of some well-known exact solutions describing anisotropic stars and dark energy stars, and we describe some of their properties.
VentureStar(trademark) Reaping the Benefits of the X-33 Program
NASA Technical Reports Server (NTRS)
Sumrall, J.; Lane, C.
1998-01-01
Major X-33 flight hardware has been delivered, and assembly of the vehicle is well underway in anticipation of its flight test program commencing in the summer of 1999. Attention has now turned to the operational VentureStar(trademark), the first single-stage-to-orbit (SSTO) reusable launch vehicle. Activities are grouped under two broad categories: (1) vehicle development and (2) market/business planning, each of which is discussed. The mission concept is presented for direct payload delivery to the International Space Station and to low Earth orbit, as well as payload delivery with an upper stage to Geosynchronous Transfer Orbit (GTO) and other high energy orbits. System requirements include flight segment and ground segment. Vehicle system sizing and design status is provided including the application of X-33 traceability and lessons learned. Technology applications to the VentureStar(trademark) are described including the structure, propellant tanks, thermal protection system, aerodynamics, subsystems, payload bay and propulsion. Developing a market driven low cost launch services system for the 21 st Century requires traditional and non-traditional ways of being able to forecast the evolution of the potential market. The challenge is balancing both the technical and financial assumptions of the market. This involves the need to provide a capability to meet market segments that in some cases are very speculative, while at the same time providing the financial community with a credible revenue stream.
NASA Technical Reports Server (NTRS)
Borchardt, G. C.
1994-01-01
The Simple Tool for Automated Reasoning program (STAR) is an interactive, interpreted programming language for the development and operation of artificial intelligence (AI) application systems. STAR provides an environment for integrating traditional AI symbolic processing with functions and data structures defined in compiled languages such as C, FORTRAN and PASCAL. This type of integration occurs in a number of AI applications including interpretation of numerical sensor data, construction of intelligent user interfaces to existing compiled software packages, and coupling AI techniques with numerical simulation techniques and control systems software. The STAR language was created as part of an AI project for the evaluation of imaging spectrometer data at NASA's Jet Propulsion Laboratory. Programming in STAR is similar to other symbolic processing languages such as LISP and CLIP. STAR includes seven primitive data types and associated operations for the manipulation of these structures. A semantic network is used to organize data in STAR, with capabilities for inheritance of values and generation of side effects. The AI knowledge base of STAR can be a simple repository of records or it can be a highly interdependent association of implicit and explicit components. The symbolic processing environment of STAR may be extended by linking the interpreter with functions defined in conventional compiled languages. These external routines interact with STAR through function calls in either direction, and through the exchange of references to data structures. The hybrid knowledge base may thus be accessed and processed in general by either side of the application. STAR is initially used to link externally compiled routines and data structures. It is then invoked to interpret the STAR rules and symbolic structures. In a typical interactive session, the user enters an expression to be evaluated, STAR parses the input, evaluates the expression, performs any file input/output required, and displays the results. The STAR interpreter is written in the C language for interactive execution. It has been implemented on a VAX 11/780 computer operating under VMS, and the UNIX version has been implemented on a Sun Microsystems 2/170 workstation. STAR has a memory requirement of approximately 200K of 8 bit bytes, excluding externally compiled functions and application-dependent symbolic definitions. This program was developed in 1985.
NASA Technical Reports Server (NTRS)
Borchardt, G. C.
1994-01-01
The Simple Tool for Automated Reasoning program (STAR) is an interactive, interpreted programming language for the development and operation of artificial intelligence (AI) application systems. STAR provides an environment for integrating traditional AI symbolic processing with functions and data structures defined in compiled languages such as C, FORTRAN and PASCAL. This type of integration occurs in a number of AI applications including interpretation of numerical sensor data, construction of intelligent user interfaces to existing compiled software packages, and coupling AI techniques with numerical simulation techniques and control systems software. The STAR language was created as part of an AI project for the evaluation of imaging spectrometer data at NASA's Jet Propulsion Laboratory. Programming in STAR is similar to other symbolic processing languages such as LISP and CLIP. STAR includes seven primitive data types and associated operations for the manipulation of these structures. A semantic network is used to organize data in STAR, with capabilities for inheritance of values and generation of side effects. The AI knowledge base of STAR can be a simple repository of records or it can be a highly interdependent association of implicit and explicit components. The symbolic processing environment of STAR may be extended by linking the interpreter with functions defined in conventional compiled languages. These external routines interact with STAR through function calls in either direction, and through the exchange of references to data structures. The hybrid knowledge base may thus be accessed and processed in general by either side of the application. STAR is initially used to link externally compiled routines and data structures. It is then invoked to interpret the STAR rules and symbolic structures. In a typical interactive session, the user enters an expression to be evaluated, STAR parses the input, evaluates the expression, performs any file input/output required, and displays the results. The STAR interpreter is written in the C language for interactive execution. It has been implemented on a VAX 11/780 computer operating under VMS, and the UNIX version has been implemented on a Sun Microsystems 2/170 workstation. STAR has a memory requirement of approximately 200K of 8 bit bytes, excluding externally compiled functions and application-dependent symbolic definitions. This program was developed in 1985.
Dynamical Models for High-Energy Emission from Massive Stars
NASA Astrophysics Data System (ADS)
Owocki, Stanley %FAA(University of Delaware)
Massive stars are prominent sources of X-rays and gamma-rays detected by both targeted and survey observations from orbiting telescopes like Chandra, XMM/Newton, RXTE, and Fermi. Such high-energy emissions represent key probes of the dynamics of massive-star mass loss, and their penetration through many magnitudes of visible interstellar extinction makes them effective beacons of massive stars in distant reaches of the Galaxy, and in young, active star-forming regions. The project proposed here will develop a comprehensive theoretical framework for interpreting both surveys and targeted observations of high-energy emission from massive stars. It will build on our team's extensive experience in both theoretical models and observational analyses for three key types of emission mechanisms in the stellar wind outflows of these stars, namely: 1) Embedded Wind Shocks (EWS) arising from internal instabilities in the wind driving; 2) shocks in Colliding Wind Binary (CWB) systems; and 3) High-Mass X-ray Binaries (HMXB) systems with interaction between massive-star wind with a compact companion (neutron star or black hole). Taking advantage of commonalities in the treatment of radiative driving, hydrodynamics, shock heating and cooling, and radiation transport, we will develop radiation hydrodynamical models for the key observational signatures like energy distribution, emission line spectrum, and variability, with an emphasis on how these can be used in affiliated analyses of both surveys like the recent Chandra mapping of the Carina association, and targeted observations of galactic X-ray and gamma-ray sources associated with each of the above specific model types. The promises of new clumping-insensitive diagnostics of mass loss rates, and the connection to mass transfer and binarity, all have broad relevance for understanding the origin, evolution, and fate of massive stars, in concert with elements of NASA's Strategic Subgoal 3D. Building on our team's expertise, the project emphasizes training of a new generation of students and post-doctoral researchers to model and analyze observations by current and future NASA X-ray and gamma-ray observatories.
Simultaneous Chandra/Swift Observations of the RT Cru Symbiotic System
NASA Astrophysics Data System (ADS)
Kashyap, Vinay; Kennea, J. A.; Karovska, M.; Calibration, Chandra
2013-04-01
The symbiotic star RT Cru was observed simultaneously by the Chandra/HRC-I and Swift/XRT in Dec 2012. The observations were carried out as part of a program to calibrate the Chandra PSF. The Chandra light curve shows a number of brightenings by factors of 2, with strong indications of a softening of the spectrum at these times. Swift observations cover a brief part of the Chandra light curve, and the intensities over this duration are tightly correlated. The Swift spectral data confirm the anticorrelation between intensity and spectral hardness. However, there are differences in the correlations at different periods that are not understood. We report on our analysis of the data, with emphasis on the spectral modeling at different times and intensity levels, and discuss the implications of the results on the emission mechanisms on symbiotic stars. We also report our inferences on the structure and energy dependence of the Chandra PSF anomaly, and on the high-energy cross-calibration between the HRC-I and XRT. This work is supported by the NASA contract NAS8-03060 to the Chandra X-ray Center.
ToO Galactic Nova -- Michelle ``Quick Response''
NASA Astrophysics Data System (ADS)
Helton, L. Andrew; Woodward, Chick; Evans, Nye; Geballe, Tom; Spitzer Nova Team
2006-08-01
Stars are the engines of energy production and chemical evolution in our Universe, depositing radiative and mechanical energy into their environments and enriching the ambient ISM with elements synthesized in their interiors and dust grains condensed in their atmospheres. Classical novae (CN) contribute to this cycle of chemical enrichment through explosive nucleosynthesis and the violent ejection of material dredged from the white dwarf progenitor and mixed with the accreted surface layers. We propose to obtain mid-IR spectra of a new galactic CN in outburst to investigate aspects of the CN phenomenon including the in situ formation and mineralogy of nova dust and the elemental abundances resulting from thermonuclear runaway. Synoptic, high S/N Michelle spectra permit: 1) determination of the grain size distribution and mineral composition of nova dust; 2) estimation of chemical abundances of nova ejecta from coronal and other emission line spectroscopy; and 3) measurement of the density and masses of the ejecta. This Gemini `Target of Opportunity' initiative (trigger K=5- 8 mag, assuming adequate PWFS guide stars exist) complements our extensive Spitzer, Chandra, Swift, XMM-Newton CN DDT/ToO programs.
Synoptic Mid-IR Spectra ToO Novae
NASA Astrophysics Data System (ADS)
Helton, L. Andrew; Woodward, Chick; Evans, Nye; Geballe, Tom; Spitzer Nova Team
2007-02-01
Stars are the engines of energy production and chemical evolution in our Universe, depositing radiative and mechanical energy into their environments and enriching the ambient ISM with elements synthesized in their interiors and dust grains condensed in their atmospheres. Classical novae (CN) contribute to this cycle of chemical enrichment through explosive nucleosynthesis and the violent ejection of material dredged from the white dwarf progenitor and mixed with the accreted surface layers. We propose to obtain mid-IR spectra of a new galactic CN in outburst to investigate aspects of the CN phenomenon including the in situ formation and mineralogy of nova dust and the elemental abundances resulting from thermonuclear runaway. Synoptic, high S/N Michelle spectra permit: 1) determination of the grain size distribution and mineral composition of nova dust; 2) estimation of chemical abundances of nova ejecta from coronal and other emission line spectroscopy; and 3) measurement of the density and masses of the ejecta. This Gemini `Target of Opportunity' initiative (trigger K=5- 8 mag, assuming adequate PWFS guide stars exist) complements our extensive Spitzer, Chandra, Swift, XMM-Newton CN DDT/ToO programs.
The Resolved Stellar Populations Early Release Science Program
NASA Astrophysics Data System (ADS)
Weisz, Daniel; Anderson, J.; Boyer, M.; Cole, A.; Dolphin, A.; Geha, M.; Kalirai, J.; Kallivayalil, N.; McQuinn, K.; Sandstrom, K.; Williams, B.
2017-11-01
We propose to obtain deep multi-band NIRCam and NIRISS imaging of three resolved stellar systems within 1 Mpc (NOI 104). We will use this broad science program to optimize observational setups and to develop data reduction techniques that will be common to JWST studies of resolved stellar populations. We will combine our expertise in HST resolved star studies with these observations to design, test, and release point spread function (PSF) fitting software specific to JWST. PSF photometry is at the heart of resolved stellar populations studies, but is not part of the standard JWST reduction pipeline. Our program will establish JWST-optimized methodologies in six scientific areas: star formation histories, measurement of the sub-Solar mass stellar IMF, extinction maps, evolved stars, proper motions, and globular clusters, all of which will be common pursuits for JWST in the local Universe. Our observations of globular cluster M92, ultra-faint dwarf Draco II, and star-forming dwarf WLM, will be of high archival value for other science such as calibrating stellar evolution models, measuring properties of variable stars, and searching for metal-poor stars. We will release the results of our program, including PSF fitting software, matched HST and JWST catalogs, clear documentation, and step-by-step tutorials (e.g., Jupyter notebooks) for data reduction and science application, to the community prior to the Cycle 2 Call for Proposals. We will host a workshop to help community members plan their Cycle 2 observations of resolved stars. Our program will provide blueprints for the community to efficiently reduce and analyze JWST observations of resolved stellar populations.
Close Encounters of the Stellar Kind
NASA Astrophysics Data System (ADS)
2003-07-01
NASA's Chandra X-ray Observatory has confirmed that close encounters between stars form X-ray emitting, double-star systems in dense globular star clusters. These X-ray binaries have a different birth process than their cousins outside globular clusters, and should have a profound influence on the cluster's evolution. A team of scientists led by David Pooley of the Massachusetts Institute of Technology in Cambridge took advantage of Chandra's unique ability to precisely locate and resolve individual sources to determine the number of X-ray sources in 12 globular clusters in our Galaxy. Most of the sources are binary systems containing a collapsed star such as a neutron star or a white dwarf star that is pulling matter off a normal, Sun-like companion star. "We found that the number of X-ray binaries is closely correlated with the rate of encounters between stars in the clusters," said Pooley. "Our conclusion is that the binaries are formed as a consequence of these encounters. It is a case of nurture not nature." A similar study led by Craig Heinke of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. confirmed this conclusion, and showed that roughly 10 percent of these X-ray binary systems contain neutron stars. Most of these neutron stars are usually quiet, spending less than 10% of their time actively feeding from their companion. NGC 7099 NGC 7099 A globular cluster is a spherical collection of hundreds of thousands or even millions of stars buzzing around each other in a gravitationally-bound stellar beehive that is about a hundred light years in diameter. The stars in a globular cluster are often only about a tenth of a light year apart. For comparison, the nearest star to the Sun, Proxima Centauri, is 4.2 light years away. With so many stars moving so close together, interactions between stars occur frequently in globular clusters. The stars, while rarely colliding, do get close enough to form binary star systems or cause binary stars to exchange partners in intricate dances. The data suggest that X-ray binary systems are formed in dense clusters known as globular clusters about once a day somewhere in the universe. Observations by NASA's Uhuru X-ray satellite in the 1970's showed that globular clusters seemed to contain a disproportionately large number of X-ray binary sources compared to the Galaxy as a whole. Normally only one in a billion stars is a member of an X-ray binary system containing a neutron star, whereas in globular clusters, the fraction is more like one in a million. The present research confirms earlier suggestions that the chance of forming an X-ray binary system is dramatically increased by the congestion in a globular cluster. Under these conditions two processes, known as three-star exchange collisions, and tidal captures, can lead to a thousandfold increase in the number of X-ray sources in globular clusters. 47 Tucanae 47 Tucanae In an exchange collision, a lone neutron star encounters a pair of ordinary stars. The intense gravity of the neutron star can induce the most massive ordinary star to "change partners," and pair up with the neutron star while ejecting the lighter star. A neutron star could also make a grazing collision with a single normal star, and the intense gravity of the neutron star could distort the gravity of the normal star in the process. The energy lost in the distortion, could prevent the normal star from escaping from the neutron star, leading to what is called tidal capture. "In addition to solving a long-standing mystery, Chandra data offer an opportunity for a deeper understanding of globular cluster evolution," said Heinke. "For example, the energy released in the formation of close binary systems could keep the central parts of the cluster from collapsing to form a massive black hole." NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. The image and additional information are available at: http://chandra.harvard.edu and http://chandra.nasa.gov
Truncation of the Binary Distribution Function in Globular Cluster Formation
NASA Astrophysics Data System (ADS)
Vesperini, E.; Chernoff, David F.
1996-02-01
We investigate a population of primordial binaries during the initial stage of evolution of a star cluster. For our calculations we assume that equal-mass stars form rapidly in a tidally truncated gas cloud, that ˜10% of the stars are in binaries, and that the resulting star cluster undergoes an epoch of violent relaxation. We study the collisional interaction of the binaries and single stars, in particular, the ionization of the binaries and the energy exchange between binaries and single stars. We find that for large N systems (N > 1000), even the most violent beginning leaves the binary distribution function largely intact. Hence, the binding energy originally tied up in the cloud's protostellar pairs is preserved during the relaxation process, and the binaries are available to interact at later times within the virialized cluster.
Radio Emission from Binary Stars
NASA Astrophysics Data System (ADS)
Hjellming, R.; Murdin, P.
2000-11-01
Stellar radio emission is most common in double star systems where each star provides something essential in producing the large amounts of radio radiation needed for it to be detectable by RADIO TELESCOPES. They transfer mass, supply energy or, when one of the stars is a NEUTRON STAR or BLACK HOLE, have the strong gravitational fields needed for the energetic particles and magnetic fields needed...
NASA Astrophysics Data System (ADS)
Savage, B.; Murdin, P.
2000-11-01
The enormous volume of space between the stars in the Milky Way Galaxy is filled with interstellar matter (ISM). The ISM plays a central role in the processes of STAR FORMATION and GALAXY EVOLUTION. Stars form from the ISM in dense molecular clouds. The radiant and mechanical energy produced by stars heats, ionizes, and produces structures in the ISM. Gradual or catastrophic mass loss from stars ...
Five-Star Schools: Defining Quality in Early Childhood Programs
ERIC Educational Resources Information Center
Hertzog, Nancy B.
2012-01-01
Hakeem, Emily, Jose, and Latisha are all entering preschool in the fall. Their mothers are looking for the highest quality early childhood program they can find. Is there a guide for them to find a five-star program? Are all certified or accredited programs of equal quality? How do these parents and guardians know what defines quality in early…
NASA Technical Reports Server (NTRS)
Rarig, P. L.
1980-01-01
A program to calculate upwelling infrared radiation was modified to operate efficiently on the STAR-100. The modified software processes specific test cases significantly faster than the initial STAR-100 code. For example, a midlatitude summer atmospheric model is executed in less than 2% of the time originally required on the STAR-100. Furthermore, the optimized program performs extra operations to save the calculated absorption coefficients. Some of the advantages and pitfalls of virtual memory and vector processing are discussed along with strategies used to avoid loss of accuracy and computing power. Results from the vectorized code, in terms of speed, cost, and relative error with respect to serial code solutions are encouraging.
The Explosive Counterparts of Gravitational Waves (Silent Animation)
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
Astronomy collaborations like the Dark Energy Survey, which Fermilab leads, can track down the visible sources of gravitational waves caused by binary neutron stars. This animation, presented here without sound, takes you through the collision of two neutron stars, and shows you the explosion of light and energy seen by the Dark Energy Camera on August 17, 2017.
Habitat for Humanity: La Grange, Georgia, 2003 Jimmy Carter Work Project
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
2005-06-01
The Troup-Chambers Habitat for Humanity built a Habitat house to ENERGY STAR standards in LaGrange, Georgia, in 2003. The project was so successfully that all Troup-Chambers houses will now be built to ENERGY STAR standards.
Pre-supernova outbursts via wave heating in massive stars - II. Hydrogen-poor stars
NASA Astrophysics Data System (ADS)
Fuller, Jim; Ro, Stephen
2018-05-01
Pre-supernova (SN) outbursts from massive stars may be driven by hydrodynamical wave energy emerging from the core of the progenitor star during late nuclear-burning phases. Here, we examine the effects of wave heating in stars containing little or no hydrogen, i.e. progenitors of Type IIb/Ib SNe. Because there is no massive hydrogen envelope, wave energy is thermalized near the stellar surface where the overlying atmospheric mass is small but the optical depth is large. Wave energy can thus unbind this material, driving an optically thick, super-Eddington wind. Using 1D hydrodynamic MESA simulations of ˜5 M⊙ He stars, we find that wave heating can drive pre-SN outbursts composed of a dense wind whose mass-loss rate can exceed ˜0.1 M⊙ yr-1. The wind terminal velocities are a few 100 km s-1, and outburst luminosities can reach ˜106 L⊙. Wave-driven outbursts may be linked with observed or inferred pre-SN outbursts of Type Ibn/transitional/transformational SNe, and pre-SN wave-driven mass loss is a good candidate to produce these types of SNe. However, we also show that non-linear wave breaking in the core of the star may prevent such outbursts in stars with thick convective helium-burning shells. Hence, only a limited subset of SN progenitors is likely to experience wave-driven pre-SN outbursts.
Systematic search for high-energy gamma-ray emission from bow shocks of runaway stars
Schulz, A.; Ackermann, M.; Buehler, R.; ...
2014-05-01
Context. It has been suggested that the bow shocks of runaway stars are sources of high-energy gamma rays (E > 100 MeV). Theoretical models predicting high-energy gamma-ray emission from these sources were followed by the first detection of non-thermal radio emission from the bow shock of BD+43°3654 and non-thermal X-ray emission from the bow shock of AE Aurigae. Aims. We perform the first systematic search for MeV and GeV emission from 27 bow shocks of runaway stars using data collected by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope (Fermi). Methods. We analysed 57 months of Fermi-LATmore » data at the positions of 27 bow shocks of runaway stars extracted from the Extensive stellar BOw Shock Survey catalogue (E-BOSS). A likelihood analysis was performed to search for gamma-ray emission that is not compatible with diffuse background or emission from neighbouring sources and that could be associated with the bow shocks. Results. None of the bow shock candidates is detected significantly in the Fermi-LAT energy range. We therefore present upper limits on the high-energy emission in the energy range from 100MeV to 300 GeV for 27 bow shocks of runaway stars in four energy bands. For the three cases where models of the high-energy emission are published we compare our upper limits to the modelled spectra. Our limits exclude the model predictions for ζ Ophiuchi by a factor ≈ 5.« less
STAR Graduate and GRO Undergraduate Fellowship Recipient List
EPA's STAR graduate fellowship program supports masters and doctoral candidates in environmental studies. Each year, students in the United States compete for STAR fellowships through a rigorous review process.
Plasmoid Impacts on Neutron Stars and Highest Energy Cosmic Rays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Litwin, C.; Rosner, R.
Particle acceleration by electrostatic polarization fields that arise in plasmas streaming across magnetic fields is discussed as a possible acceleration mechanism of highest energy ({approx}>10{sup 20} eV) cosmic rays. Specifically, plasmoids arising in planetoid impacts onto neutron star magnetospheres are considered. We find that such impacts at plausible rates may account for the observed flux and energy spectrum of the highest energy cosmic rays.
Near-IR Spectroscopy of Herbig Ae/Be Companion Stars
NASA Astrophysics Data System (ADS)
Rodgers, B. M.; van der Bliek, N. S.; Brandvig, B.; Thomas, S.; Doppmann, G.; Bouvier, J.
2005-12-01
We present first results of a program to obtain near-infrared spectra of candidate companions to intermediate mass pre-main sequence Herbig Ae/Be (HAEBE) stars. Accurate spectral classification is critical to proper identification of the secondary star and interpretation of its spectral energy distribution. Spectra also allow analysis of emission lines and other stellar charcteristics such as veiling and rotation, to determine the companion's evolutionary status and help establish binarity. Of the first six objects observed with GNIRS on Gemini South (AS310 NW, HD76534, HD150193, HR5999, HD141569 and CO Ori), we find two B+B companion pairs, three early A primaries with T Tauri type secondaries (G, K and M type), and a peculiar F+F pair in which the secondary star is the primary emission star (respectively). If true binaries, three systems are similar spectral type pairs but with very different extinction and emission properties. The three late-type secondaries all exhibit significant near-infrared excess, but only weak emission lines. Other components of our project are an AO-fed near-infrared imaging survey of a large sample of HAEBE systems (N. S. van der Bliek et al. poster) and modeling of companion spectral energy distributions (B. Brandvig et al. poster). Together, these three complementary approaches will result in the most thorough accounting of multiple HAEBE systems to date. Our initial spectroscopy sample contains about 40 objects taken from the literature, roughly half from Bouvier and Corporon (2001). Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil) and CONICET (Argentina).
Notification: Review of Science to Achieve Results (STAR) Grant Program
Project #OA-FY12-0606, July 16, 2012. EPA’s Office of Inspector General (OIG) plans to begin preliminary research for an audit of grants awarded under EPA’s Science to Achieve Results (STAR) program.
Constraints on the symmetry energy from neutron star observations
NASA Astrophysics Data System (ADS)
Newton, W. G.; Gearheart, M.; Wen, De-Hua; Li, Bao-An
2013-03-01
The modeling of many neutron star observables incorporates the microphysics of both the stellar crust and core, which is tied intimately to the properties of the nuclear matter equation of state (EoS). We explore the predictions of such models over the range of experimentally constrained nuclear matter parameters, focusing on the slope of the symmetry energy at nuclear saturation density L. We use a consistent model of the composition and EoS of neutron star crust and core matter to model the binding energy of pulsar B of the double pulsar system J0737-3039, the frequencies of torsional oscillations of the neutron star crust and the instability region for r-modes in the neutron star core damped by electron-electron viscosity at the crust-core interface. By confronting these models with observations, we illustrate the potential of astrophysical observables to offer constraints on poorly known nuclear matter parameters complementary to terrestrial experiments, and demonstrate that our models consistently predict L < 70 MeV.
The Magnetar Model of the Superluminous Supernova GAIA16apd and the Explosion Jet Feedback Mechanism
NASA Astrophysics Data System (ADS)
Soker, Noam
2017-04-01
Under the assumption that jets explode core collapse supernovae (CCSNe) in a negative jet feedback mechanism (JFM), this paper shows that rapidly rotating neutron stars are likely to be formed when the explosion is very energetic. Under the assumption that an accretion disk or an accretion belt around the just-formed neutron star launch jets and that the accreted gas spins-up the just-formed neutron star, I derive a crude relation between the energy that is stored in the spinning neutron star and the explosion energy. This relation is (E NS-spin/E exp) ≈ E exp/1052 erg; It shows that within the frame of the JFM explosion model of CCSNe, spinning neutron stars, such as magnetars, might have significant energy in super-energetic explosions. The existence of magnetars, if confirmed, such as in the recent super-energetic supernova GAIA16apd, further supports the call for a paradigm shift from neutrino-driven to jet-driven CCSN mechanisms.
Chandra Uncovers New Evidence For Event Horizons Surrounding Black Holes
NASA Astrophysics Data System (ADS)
2001-01-01
SAN DIEGO -- Astronomers have used NASA's Chandra X-ray Observatory to study some of the darkest black holes yet observed. Their work strongly confirms the reality of the "event horizon," the one-way membrane around black holes predicted by Einstein's theory of relativity. The findings were presented today at the American Astronomical Society meeting by Drs. Michael Garcia, Jeffrey McClintock, Ramesh Narayan, and Stephen Murray of the Harvard-Smithsonian Center for Astrophysics and Dr. Paul Callanan of University College, Cork, Ireland. With results that fundamentally differ from earlier black hole studies, Garcia and his colleagues have shown that some recently discovered black holes are not only ultra-dense, but actually possess event horizons that "vacuum up" energy from their surroundings. "It is a bit odd to say we've discovered something by seeing almost nothing at all -- less than the smile of the Cheshire cat, so to speak," said Garcia, lead author on a paper submitted to the Astrophysical Journal, "but, in essence, this is what we have done." Using data from Chandra and previous X-ray satellites like ROSAT, the Chandra team studied a dozen "X-ray novas," so named because they occasionally erupt as brilliant X-ray sources then settle into decades of dormancy. The great outpouring of X rays is due to a stream of gas that is pulled from the surface of a Sun-like companion star onto a compact object, either a black hole or a neutron star. By comparing the energy output from the dormant X-ray novas, the team discovered that the sources with black holes emitted only one percent as much energy while dormant as did the X-ray novae with neutron stars. "The most straightforward explanation of these observations is that the black hole candidates we have studied have event horizons that swallow just about all of the energy that surrounds them," said Murray. "Indeed, one could even say that this work shows why black holes deserve to be called ‘black.’" "The event horizon is the defining characteristic of a black hole, but obviously it is very difficult to detect since any infalling material at the event horizon is observable for only an instant as it plunges inward at the speed of light," said McClintock. "The comparison of black holes and their close cousins, the neutron stars, may be the most promising way to get a handle on the event horizon." If the collapsed star is a neutron star with a solid surface, energy must be released when infalling matter strikes that surface. In contrast, if the accreting object is a black hole, there is no surface for the matter to strike. Instead, both the energy and the matter will be lost from view forever once they cross the event horizon. A small amount of energy can escape just before the matter crosses the event horizon, but the scientists believe that it should be much less than the energy released by matter hitting a neutron star surface. "Watching matter flowing into a black hole is like sitting upstream of a waterfall and watching the water seemingly vanish over the edge," said Narayan, chairman of the Harvard Astronomy Department. "However, if the waterfall were replaced by a dam -- the analog of a neutron star surface -- then the water would pile up and one would see a mighty lake". Why are dormant black hole sources a hundred times fainter than the neutron star sources? The amount of material falling towards the collapsed star and the subsequent energy release are believed to be nearly the same, whether the compact object is a black hole or a neutron star. Therefore, the remarkable difference in brightness comes, according to the team, because of the event horizon, where the inward pull of gravity becomes infinitely strong. This is in contrast to the situation of neutron stars that have a more normal surface. By observing the motion of the companion star in an X-ray nova, the mass of the collapsed star can be estimated. In some cases, this mass is more than three times that of the Sun. Over that limit, gravitational forces would crush a neutron star or any compact object into a black hole, according to Einstein’s relativity theory. This provides a crucial test for identifying black holes. "It is difficult to appreciate the astounding sensitivity of Chandra to X rays," said Callanan. "For the faintest black hole we detected, Chandra measured literally a handful of photons." The researchers used the Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory for exposure times varying roughly from 10,000 to 40,000 seconds per object. The ACIS X-ray camera was developed for NASA by Pennsylvania State University and MIT. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. This work was supported by funds from NASA and NSF. During the AAS meeting, the scientists involved in this release can be reached at the AAS Press Room at the Town & Country Resort in San Diego, CA. The phone numbers for the Press Room are (619) 908-5057, (619) 908-5040, and (619) 908-5041 from January 8-11. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov
2015-07-08
Flaring, active regions of our sun are highlighted in this image combining observations from several telescopes. High-energy X-rays from NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) are shown in blue; low-energy X-rays from Japan's Hinode spacecraft are green; and extreme ultraviolet light from NASA's Solar Dynamics Observatory (SDO) is yellow and red. All three telescopes captured their solar images around the same time on April 29, 2015. The NuSTAR image is a mosaic made from combining smaller images. The active regions across the sun's surface contain material heated to several millions of degrees. The blue-white areas showing the NuSTAR data pinpoint the most energetic spots. During the observations, microflares went off, which are smaller versions of the larger flares that also erupt from the sun's surface. The microflares rapidly release energy and heat the material in the active regions. NuSTAR typically stares deeper into the cosmos to observe X-rays from supernovas, black holes and other extreme objects. But it can also look safely at the sun and capture images of its high-energy X-rays with more sensitivity than before. Scientists plan to continue to study the sun with NuSTAR to learn more about microflares, as well as hypothesized nanoflares, which are even smaller. In this image, the NuSTAR data shows X-rays with energies between 2 and 6 kiloelectron volts; the Hinode data, which is from the X-ray Telescope instrument, has energies of 0.2 to 2.4 kiloelectron volts; and the Solar Dynamics Observatory data, taken using the Atmospheric Imaging Assembly instrument, shows extreme ultraviolet light with wavelengths of 171 and 193 Angstroms. Note the green Hinode image frame edge does not extend as far as the SDO ultraviolet image, resulting in the green portion of the image being truncated on the right and left sides. http://photojournal.jpl.nasa.gov/catalog/PIA19821
Finding High Quality Young Star Candidates in Ceph C using X-ray, Optical, and IR data
NASA Astrophysics Data System (ADS)
Orr, Laura; Rebull, Luisa M.; Johnson, Milton; Miller, Alexandra; Aragon Orozco, Anthony; Bakhaj, Benjamin; Bakshian, Jacquelyn; Chiffelle, Elizabeth; DeLint, Arie; Gerber, Stefan; Mader, Jared; Marengo, Amelia; McAdams, Jesse; Montufar, Cassandra; Orr, Quinton; San Emeterio, Lis; Stern, Eliyah; Weisserman, Drew
2017-01-01
We looked for new candidate young stars within the star forming region of Ceph OB3, more specifically in a region of this molecular cloud called Ceph C. While this region lies in the galactic plane and is included in several large surveys, Ceph C has not been well studied in the past and few young stellar objects (YSOs) have been identified there. The YSOVAR team (Rebull et al. 2014) has time-series monitoring data of this region, and in order to understand the diversity of the light curves, it is crucial to understand which objects in the field of view are likely YSOs, and which are foreground/background objects. The goal of our study is to identify candidate YSO sources as well as support the greater understanding of the variety, evolution, and variability of young stars. Our search for young stars includes data in X-ray, optical, and IR. Data points used are from Chandra, SDSS, IPHAS, 2MASS, Spitzer IRAC and MIPS, and WISE, giving us data over many orders of magnitude, 0.001 to 25 microns (0.36 to 25 microns without the X-rays). The catalogs were merged across all available wavelengths. Each source was inspected in all available images to insure good matches and quality of data across wavelengths and to eliminate poor candidates, those with contamination or confusion, and non-YSO objects. Spectral energy distributions (SEDs) for each candidate YSO were constructed and compared to images for greater assessment and reliable YSO identification. Color-color and color-magnitude diagrams have been created for the sources in this region and are used in conjunction with images, SEDs, X-ray, IR excess, and variability properties to identify candidate YSOs. Support provided for this work by the NASA/IPAC Teacher Archive Research Program (NITARP), which receives funding from the NASA ADP program.
NASA Astrophysics Data System (ADS)
Moore, Patrick
2002-11-01
With more than 3,000 alphabetically arranged entries and 500 stunning color and black-and-white photographs, star maps, and diagrams, The Astronomy Encyclopedia covers everything that the general enthusiast--and the more serious researcher--would want to know about planets, stars, galaxies, and our universe. Here is concise, reliable information on the whole field of astronomy, ranging from adaptive optics and cold dark matter, to Islamic astronomy and the lens defect known as vignetting. It includes a host of major articles on the cornerstones of astronomical investigation, such as the Milky Way, the sun and the planets, optical and radio telescopes, stars, black holes, astrophysics, observatories, astronomical photography, space programs, the constellations, and famous astronomers. And there are concise entries on planetary features and satellites, asteroids, observational techniques, comets, satellite launchers, meteors, and subjects as diverse as life in the Universe and the structure of meteorites. Scores of tables list the brightest stars in the major constellations, annual meteor showers, major variable stars, dwarf stars, energy production processes in the Sun, and other relevant data. More than 100 astronomers from leading universities and observatories around the world, each an expert in their own particular field, wrote and reviewed the entries to ensure their authority. Readers can thus be assured that the Encyclopedia provides the most up-to-date and reliable information available. Under the general editorship of Patrick Moore, one of the world's best-known and most trusted voices on astronomy, The Astronomy Encyclopedia is an authoritative and strikingly attractive roadmap for exploring the last great frontier of the world in which we live.
A Legacy Imaging Survey of M33.
NASA Astrophysics Data System (ADS)
Dalcanton, Julianne
2016-10-01
We propose a panoramic imaging survey of M33 to extend the M31 PHAT survey to regions with 10x higher star formation intensity and markedly lower metallicity. Deep six-filter UV/optical/IR stellar photometry will provide (1) precision measurement of the high-mass IMF slope; (2) spatially-resolved maps of the recent star formation history (SFH) with 5-10 Myr resolution; (3) maps of the cool, dusty ISM with 25 pc resolution; (4) temperatures and luminosities for 15 million stars; (5) maps of extinction law variations; and (6) 1000 star clusters with well-measured ages and masses. We will combine these products with archival multi-wavelength data to elucidate the astrophysics of the interstellar medium (ISM). We will constrain the energetics of the ISM by linking the history of stellar energy input to the observed properties of the ISM; reconcile widely-used, but discrepant, dust emission models; disentangle the drivers that control dust composition; and measure lifetimes of molecular clouds. We will survey nearly all the molecular clouds and high extinction (A_V>1) regions in M33, as well as regimes of star formation rate intensity, spiral arm strength, metallicity, and ISM pressure that are distinct from those in comparable surveys of M31 and the Magellanic Clouds. This survey adds M33 to the Milky Way, M31, and Magellanic Clouds as the fundamental calibrators of ISM physics, star-formation processes, and stellar evolution. The resulting data set will be comprehensive, highly versatile, and have tremendous legacy value. This program can only be accomplished with HST.
NASA Astrophysics Data System (ADS)
Nesvadba, Nicole
2018-01-01
Strongly gravitationally lensed galaxies are veritable gems for our understanding of high-redshift galaxy evolution, allowing us to study dust, gas, and star formation even in the most intense starbursts on scales of individual star-forming regions. On these scales, below one to few 100 pc in the source plane, kpc-scale rotational support no longer dominates, and star formation is regulated by the local gas and stellar mass surface densities and energy injection from turbulence and winds driven by star formation and AGN. I will report on our on-going follow-up of Planck's Dusty GEMS, a small sample of 11 of the brightest, gravitationally lensed high-redshift galaxies on the extragalactic sub-mm sky. SMA 850-micron imaging is playing a critical role in identifying and characterizing the dusty starburst regions, their star-formation properties, and the gravitational lens modeling, and has been paving the way towards a rich multi-wavelength program, which would not have been possible without. This includes VLT, HST and ALMA high-resolution studies of the gas and stellar populations, amongst others. These observations enabled us, e.g., to study theinterplay between gravity and turbulence in an Eddington-limited starburst for the first time, and to detect the first absorption line of [CII] from diffuse gas outside the Milky Way. I will also discussthe first direct lensing estimate of a (bottom-heavy) initial mass function in the early Universe and outline how these and similar observations would benefit from increased bandwidth.
Project Longshot: A mission to Alpha Centauri
NASA Technical Reports Server (NTRS)
West, Curtis; Chamberlain, Sally; Pagan, Neftali; Stevens, Robert
1989-01-01
Project Longshot, an exercise in the Advanced Design Program for Space, had as its destination Alpha Centauri, the closest star system to our own solar system. Alpha Centauri, a trinary star system, is 4.34 light years from earth. Although Project Longshot is impossible based on existing technologies, areas that require further investigation in order to make this feat possible are identified. Three areas where advances in technology are needed are propulsion, data processing for autonomous command and control functions, and reliability. Propulsion, possibly by antimatter annihilation; navigation and navigation aids; reliable hardware and instruments; artificial intelligence to eliminate the need for command telemetry; laser communication; and a reliable, compact, and lightweight power system that converts energy efficiently and reliably present major challenges. Project Longshot promises exciting advances in science and technology and new information concerning the universe.
History of Chandra X-Ray Observatory
2004-08-12
NASA’s Chandra X-Ray Observatory (CXO) was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. This image was produced by combining a dozen CXO observations made of a 130 light-year region in the center of the Milky Way over the last 5 years. The colors represent low (red), medium (green) and high (blue) energy x-rays. Thanks to Chandra's unique resolving power, astronomers have now been able to identify thousands of point-like x-ray sources due to neutron stars, black holes, white dwarfs, foreground stars, and background galaxies. What remains is a diffuse x-ray glow extending from the upper left to the lower right, along the direction of the disk of the galaxy. NASA’s Marshall Space Flight Center in Huntsville, Alabama manages the Chandra program. (NASA/CXC/UCLA/M. Muno et al.)
NASA Astrophysics Data System (ADS)
Brown, Alexander; Herczeg, G. J.; Brown, J. M.; Walter, F. M.; Valenti, J.; Ardila, D.; Hillenbrand, L. A.; Edwards, S.; Johns-Krull, C. M.; Alexander, R.; Bergin, E. A.; Calvet, N.; Bethell, T. J.; Ingleby, L.; Bary, J. S.; Audard, M.; Baldovin, C.; Roueff, E.; Abgrall, H.; Gregory, S. G.; Ayres, T. R.; Linsky, J. L.
2010-03-01
Pre-main-sequence (PMS) stars are strong X-ray and UV emitters and the high energy radiation from the central stars directly influences the physical and chemical processes in their protoplanetary disks. Gas and dust in protoplanetary systems are excited by these photons, which are the dominant ionization source for hundreds of AU around the star. X-rays penetrate deep into disks and power complex chemistry on grain surfaces. ``Transitional disks'' are an important short-lived evolutionary stage for PMS stars and protoplanetary systems. These disks have transformed most of the dust and gas in their inner regions into planetesimals or larger solid bodies. As dust disks disappear after ages of roughly 5 Myr high levels of stellar magnetic activity persist and continue to bathe the newly-forming protoplanetary systems with intense high energy radiation. We present new X-ray and UV spectra for a sample of PMS stars at a variety of evolutionary stages, including the classical T Tauri stars DE Tau and DK Tau, the transitional disk stars GM Aur and HD135344B, the Herbig Ae star HD104237, and the weak-lined T Tauri star LkCa4, the Eta Cha cluster [age 7 Myr] members RECX1, RECX-11, and RECX-15, and TW Hya association [age 8 Myr] member TWA-2. These include the first results from our 111 orbit HST Large project and associated X-ray data. New and archival Chandra, XMM, and Swift X-ray spectra and HST COS+STIS FUV spectra are being used to reconstruct the full high energy (X-ray/EUV/FUV/NUV) spectra of these stars, thus allowing detailed modeling of the physics and chemistry of their circumstellar environments. The UV spectra provide improved emission line profiles revealing details of the magnetically-heated plasma and accretion and outflow processes. This work is supported by Chandra grants GO8-9024X, GO9-0015X and GO9-0020B and proposal 11200754 and HST GO grants 11336, 11616, and 11828.
NASA Astrophysics Data System (ADS)
Broggini, C.; Bemmerer, D.; Caciolli, A.; Trezzi, D.
2018-01-01
The essential ingredients of nuclear astrophysics are the thermonuclear reactions which shape the life and death of stars and which are responsible for the synthesis of the chemical elements in the Universe. Deep underground in the Gran Sasso Laboratory the cross sections of the key reactions responsible for the hydrogen burning in stars have been measured with two accelerators of 50 and 400 kV voltage right down to the energies of astrophysical interest. As a matter of fact, the main advantage of the underground laboratory is the reduction of the background. Such a reduction has allowed, for the first time, to measure relevant cross sections at the Gamow energy. The qualifying features of underground nuclear astrophysics are exhaustively reviewed before discussing the current LUNA program which is mainly devoted to the study of the Big-Bang nucleosynthesis and of the synthesis of the light elements in AGB stars and classical novae. The main results obtained during the study of reactions relevant to the Sun are also reviewed and their influence on our understanding of the properties of the neutrino, of the Sun and of the Universe itself is discussed. Finally, the future of LUNA during the next decade is outlined. It will be mainly focused on the study of the nuclear burning stages after hydrogen burning: helium and carbon burning. All this will be accomplished thanks to a new 3.5 MV accelerator able to deliver high current beams of proton, helium and carbon which will start running under Gran Sasso in 2019. In particular, we will discuss the first phase of the scientific case of the 3.5 MV accelerator focused on the study of 12C+12C and of the two reactions which generate free neutrons inside stars: 13C(α,n)16O and 22Ne(α,n)25Mg.
NASA Astrophysics Data System (ADS)
Torres, A. F.; Ringuelet, A. E.
The aim of this study is to analyse the Hot Temperature Region (HTR) that surrounds the photospheres of Be stars. Consequently, we have chosen 54 Be stars of spectral types B0, B1, B2, B3, B8 and B9; the sample is representative of a considerable range of temperature. We have analysed different lines that originate in the HTR from archival IUE spectra reprocessed by the INES: He II λ1640, Si IV λλ1394, 1403 and Al III λλ1855, 1863. From the measured values, we derive several relations that provide information on the geometry and thermodynamical properties of the HTR. Our major findings can be summarised as follows: 1) The equivalent widths of the selected lines in the spectrum of the program stars persist with similar values through all v sin(i) inclinations. 2) The equivalent widths of the Si IV lines are well correlated with the kinetic energy expansion of the wind. This suggests that the dissipation of mechanical energy in the HTR is an important source of heating. 3) The He II lines formation region, which is located at the dense base of the wind, shows full spherical symmetry. 4) The formation region of Si IV lines is located in a low-density well-developed wind and it extends over very high latitudes (˜75o). 5) The Al III lines are formed in an elongated region which is the beginning of the cool envelope. The analysis followed in this work has been completely independent from any theoretical model. Consequently, these results will be useful for deciding whether the circunstellar envelope of Be stars has an ellipsoidal geometry or a disklike shape.
Hard x-ray optics: from HEFT to NuSTAR
NASA Astrophysics Data System (ADS)
Koglin, Jason E.; Chen, C. M. H.; Chonko, Jim C.; Christensen, Finn E.; Craig, William W.; Decker, Todd R.; Hailey, Charles J.; Harrison, Fiona A.; Jensen, Carsten P.; Madsen, Kristin K.; Pivovaroff, Michael J.; Stern, Marcela; Windt, David L.; Ziegler, Eric
2004-10-01
Focusing optics are now poised to dramatically improve the sensitivity and angular resolution at energies above 10 keV to levels that were previously unachievable by the past generation of background limited collimated and coded-aperture instruments. Active balloon programs (HEFT), possible Explorer-class satellites (NuSTAR - currently under Phase A study), and major X-ray observatories (Con-X HXT) using focusing optics will play a major role in future observations of a wide range of objects including young supernova remnants, active galactic nuclei, and galaxy clusters. These instruments call for low cost, grazing incidence optics coated with depth-graded multilayer films that can be nested to achieve large collecting areas. Our approach to building such instruments is to mount segmented mirror shells with our novel error-compensating, monolithic assembly and alignment (EMAAL) procedure. This process involves constraining the mirror segments to successive layers of graphite rods that are precisely machined to the required conic-approximation Wolter-I geometry. We present results of our continued development of thermally formed glass substrates that have been used to build three HEFT telescopes and are proposed for NuSTAR. We demonstrate how our experience in manufacturing complete HEFT telescopes, as well as our experience developing higher performance prototype optics, will lead to the successful production of telescopes that meet the NuSTAR design goals.
Turbovelocity Stars: Kicks Resulting from the Tidal Disruption of Solitary Stars
NASA Astrophysics Data System (ADS)
Manukian, Haik; Guillochon, James; Ramirez-Ruiz, Enrico; O'Leary, Ryan M.
2013-07-01
The centers of most known galaxies host supermassive black holes (SMBHs). In orbit around these black holes are a centrally concentrated distribution of stars, both in single and in binary systems. Occasionally, these stars are perturbed onto orbits that bring them close to the SMBH. If the star is in a binary system, the three-body interaction with the SMBH can lead to large changes in orbital energy, depositing one of the two stars on a tightly-bound orbit, and its companion into a hyperbolic orbit that may escape the galaxy. In this Letter, we show that the disruption of solitary stars can also lead to large positive increases in orbital energy. The kick velocity depends on the amount of mass the star loses at pericenter, but not on the ratio of black hole to stellar mass, and are at most the star's own escape velocity. We find that these kicks are usually too small to result in the ejection of stars from the Milky Way, but can eject the stars from the black hole's sphere of influence, reducing their probability of being disrupted again. We estimate that {\\mathord {\\sim }} 10^5 stars, {\\mathord {\\sim }} 1% of all stars within 10 pc of the galactic center, are likely to have had mass removed by the central black hole through tidal interaction, and speculate that these "turbovelocity" stars will at first be redder, but eventually bluer, and always brighter than their unharassed peers.
NASA Astrophysics Data System (ADS)
Chan, S. Josephine
1993-04-01
This dissertation is concerned with the nature of the carbon stars, unusual late-type stars in which the abundance of carbon in the photosphere is greater than that of oxygen. Data from the Infrared Astronomical Satellite (IRAS) survey has shown that carbon stars which were identified from optical surveys and those identified from the SiC dust features in their IRAS Low Resolution Spectrometer LRS spectra have different IRAS colours. The former (which will be referred to as visual carbon stars) are visually bright and have large excesses at 6 microns, while the latter group (which will be referred to as infrared carbon stars) have blackbody energy distributions. The origin of visual carbon stars has been discussed by Chan and Kwok (1988) based on the hypothesis of Willems and de Jong (1988). A complete sample of visual carbon stars detected by IRAS with 12 microns flux densities greater than 5 Jy was selected, and 207 LRS spectra were extracted for those sources without previous \\lrs data. Of these, 152 sources had new LRS spectra with reasonably good signal-to-noise ratio and 575 sources had previously released LRS spectra. All these spectra have been classified with the scheme of Volk and Cohen (1989). When the LRS spectra of these 727 IRAS CCGCS sources were examined, 15 were found to show the 9.7 microns silicate emission feature which is expected to occur only in an oxygen-rich circumstellar shell. Eight of these are reported for the first time in this dissertation. This group of visual carbon stars (hereafter called silicate carbon stars) may represent transition objects between oxygen-rich and carbon stars on the asymptotic giant branch (AGB) because the photosphere is carbon-rich while the circumstellar material resembles that from a typical M-type star. A radiative transfer dust shell model for these silicate carbon stars is presented. The model spectra produce excellent fits to the observed energy distributions of these silicate carbon stars. The J-type stars (^13C-rich carbon stars) have been suggested to be transition objects between M-type stars and C-type stars. An optical spectroscopic study of these silicate carbon stars was performed at the Dominion Astrophysical Observatory (DAO) in Victoria in 1991. CCGCS 1653, CCGCS 4222, CCGCS 4923 and CCGCS 5848 have been confirmed to be J stars. CCGCS 1158 and CCGCS 4729 are provisionally identified as J stars. A preliminary spectral analysis has also been carried out. Model calculations are presented on the evolution from the visual carbon stars to infrared carbon stars, and on the evolution of infrared carbon stars. A new empirical opacity function for the SiC grain is derived based on the LRS spectra of a selected sample of infrared carbon stars. A two-shell model has been developed with an oxygen-rich detached shell and a newly-forming SiC dust shell. The energy distributions of ~110 transition objects which are late-stage visual carbon stars or early-stage infrared carbon stars are fitted with this Interrupted Mass Loss Model. Furthermore, the model tracks successfully explain the "C" shaped distribution of the transition objects in the IRAS 12 microns/25 microns/60 microns colour-colour diagram. The energy distributions of ~150 infrared carbon stars are also matched with a radiative transfer dust shell model using only SiC dust. The colour evolution of infrared carbon stars can be explained with a continuous increase in mass loss rate on the AGB. An evolutionary scenario of AGB stars is suggested. There is a branching of M-type and C-type stars on the AGB with each branch evolving independently to the planetary nebula stage. The initial mass of the star in the main sequence may be the factor that determines which branch the star will follow. (SECTION: Dissertation Abstracts)
NuSTAR constraints on coronal cutoffs in Swift-BAT selected Seyfert 1 AGN
NASA Astrophysics Data System (ADS)
Kamraj, Nikita; Harrison, Fiona; Balokovic, Mislav; Brightman, Murray; Stern, Daniel
2017-08-01
The continuum X-ray emission from Active Galactic Nuclei (AGN) is believed to originate in a hot, compact corona above the accretion disk. Compton upscattering of UV photons from the inner accretion disk by coronal electrons produces a power law X-ray continuum with a cutoff at energies determined by the electron temperature. The NuSTAR observatory, with its high sensitivity in hard X-rays, has enabled detailed broadband modeling of the X-ray spectra of AGN, thereby allowing tight constraints to be placed on the high-energy cutoff of the X-ray continuum. Recent detections of low cutoff energies in Seyfert 1 AGN in the NuSTAR band have motivated us to pursue a systematic search for low cutoff candidates in Swift-BAT detected Seyfert 1 AGN that have been observed with NuSTAR. We use our constraints on the cutoff energy to map out the location of these sources on the compactness - temperature diagram for AGN coronae, and discuss the implications of low cutoff energies for the cooling and thermalization mechanisms in the corona.
Skysurvey Results of RotseIIID Data
NASA Astrophysics Data System (ADS)
Bilir, Cansu; Varol Keskin, MR..
2016-07-01
The aim of this thesis is to find variable stars from the ROTSEIIID fields data files. In order to determine the variable stars, a simple but effective software, that works seamlessly, has been developed. Robotic Optical Transient Search Experiment (ROTSE) is a worldwide project with four robotic telescopes, established in order to follow the optical afterglow radiation of the Gamma-Ray Bursts (GRB). In this study, the observations of the fields obtained from the ROTSEIIID Telescope located in the TÜBİTAK (Scientific and Technological Research Council of Turkey) National Observatory were used. ROTSEIIID creates a calibrated object list (cobj) from the observations gathered automatically. The different values of each star (RA, DEC, Pixel Coordinates, M, MERR, Flags etc.) can be found in this generated list. In this thesis these values are extracted from data files. A php programme was developed in order to extract time series data of every star in a field. It also searches period, and if found, calculates phases for this data. The goal of this study is to determine the variable stars, especially unknown variables. Ds9 and fv programs are used for dealing with FITS files. Also flowchart of program is given in this thesis. In addition Debil (for finding some parameters of detached eclipsing binary stars) and Gnuplot (for drawing graphics) are used by php program. Using gnuplot, magnitude-time and period-time graphics of each star are plotted. The searching program is used for some different fields of RotseIIID data files. On the basis of the results of this research, 42 variable stars found and 14 of them are listed end of the thesis with their light curves. The data used in this thesis will be studied more detailed and research results of new/unknown variable stars will be published along the Msc thesis. We are still studying on the data of new variable stars which were discovered by this research and the results will be published in near future...
A physical model of mass ejection in failed supernovae
NASA Astrophysics Data System (ADS)
Coughlin, Eric R.; Quataert, Eliot; Fernández, Rodrigo; Kasen, Daniel
2018-06-01
During the core collapse of massive stars, the formation of the proto-neutron star is accompanied by the emission of a significant amount of mass energy (˜0.3 M⊙) in the form of neutrinos. This mass-energy loss generates an outward-propagating pressure wave that steepens into a shock near the stellar surface, potentially powering a weak transient associated with an otherwise-failed supernova. We analytically investigate this mass-loss-induced wave generation and propagation. Heuristic arguments provide an accurate estimate of the amount of energy contained in the outgoing sound pulse. We then develop a general formalism for analysing the response of the star to centrally concentrated mass loss in linear perturbation theory. To build intuition, we apply this formalism to polytropic stellar models, finding qualitative and quantitative agreement with simulations and heuristic arguments. We also apply our results to realistic pre-collapse massive star progenitors (both giants and compact stars). Our analytic results for the sound pulse energy, excitation radius, and steepening in the stellar envelope are in good agreement with full time-dependent hydrodynamic simulations. We show that prior to the sound pulses arrival at the stellar photosphere, the photosphere has already reached velocities ˜ 20-100 per cent of the local sound speed, thus likely modestly decreasing the stellar effective temperature prior to the star disappearing. Our results provide important constraints on the physical properties and observational appearance of failed supernovae.
Physics in Strong Magnetic Fields Near Neutron Stars.
ERIC Educational Resources Information Center
Harding, Alice K.
1991-01-01
Discussed are the behaviors of particles and energies in the magnetic fields of neutron stars. Different types of possible research using neutron stars as a laboratory for the study of strong magnetic fields are proposed. (CW)
The Creation of Titanium in Stars
2014-02-19
This diagram illustrates why NASA NuSTAR can see radioactivity in the remains of exploded stars for the first time. The observatory detects high-energy X-ray photons that are released by a radioactive substance called titanium-44.
Formation environment of Pop II stars affected by the feedbacks from Pop III stars
NASA Astrophysics Data System (ADS)
Chiaki, G.; Susa, H.; Hirano, S.
Stars with metallicities abH Fe < -3 are called extremely metal-poor (EMP) stars, and considered to be formed in clouds enriched with metal from a single or several supernovae (SNe) of the first-generation (Pop III) stars. To confirm this, we numerically follow the enrichment process of minihalos (MHs) which have hosted Pop III stars. During their main-sequence (MS), the ionizing photons can not or partly break the gas around the Pop III stars because the halo binding energy is marginally larger than the radiation energy. After SN explosions, the gas continues to accrete along filaments of the large-scale structures, and the gas collapses again in the MHs within ˜ 10 Myr for low-mass MHs (3E 5 M⊙) while ˜ 1 Myr for massive MHs (3E 6 M⊙). The metallicity in the recollapsing regions is 10-4-10-2 Z⊙ /SUB and 10-6-10-5 Z⊙, respectively. This indicates that EMP stars are formed in the clouds enriched by a single SN in low-mass MHs.
Dead Star Creates Celestial Havoc
NASA Technical Reports Server (NTRS)
2006-01-01
A star's spectacular death in the constellation Taurus was observed on Earth as the supernova of 1054 A.D. Now, almost a thousand years later, a superdense neutron star left behind by the stellar death is spewing out a blizzard of extremely high-energy particles into the expanding debris field known as the Crab Nebula. This composite image uses data from three of NASA's Great Observatories. The Chandra X-ray image is shown in light blue, the Hubble Space Telescope optical images are in green and dark blue, and the Spitzer Space Telescope's infrared image is in red. The size of the X-ray image is smaller than the others because ultrahigh-energy X-ray emitting electrons radiate away their energy more quickly than the lower-energy electrons emitting optical and infrared light. The neutron star, which has the mass equivalent to the sun crammed into a rapidly spinning ball of neutrons twelve miles across, is the bright white dot in the center of the image.Dead Star Creates Celestial Havoc
2006-10-27
A star's spectacular death in the constellation Taurus was observed on Earth as the supernova of 1054 A.D. Now, almost a thousand years later, a superdense neutron star left behind by the stellar death is spewing out a blizzard of extremely high-energy particles into the expanding debris field known as the Crab Nebula. This composite image uses data from three of NASA's Great Observatories. The Chandra X-ray image is shown in light blue, the Hubble Space Telescope optical images are in green and dark blue, and the Spitzer Space Telescope's infrared image is in red. The size of the X-ray image is smaller than the others because ultrahigh-energy X-ray emitting electrons radiate away their energy more quickly than the lower-energy electrons emitting optical and infrared light. The neutron star, which has the mass equivalent to the sun crammed into a rapidly spinning ball of neutrons twelve miles across, is the bright white dot in the center of the image. http://photojournal.jpl.nasa.gov/catalog/PIA01320
NASA Astrophysics Data System (ADS)
Kennedy, Mike O.
An internship with the Martin Marietta Astronautics Group that was performed in partial fulfillment of the requirements for the Doctor of Engineering degree is documented. The internship included assignments with two Martin Marietta companies, on three different programs and in four areas of engineering. A first-hand look is taken at system engineering, SDI and advanced program management, and the way Martin Marietta conducts business. The five internship objectives were related to assignments in system modeling, system integration, engineering analysis and technical management: (1) The effects of thermally and mechanically induced mirror surface distortions upon the wavefront intensity field of a high energy laser beam passing through the optical train of a space-based laser system were modeled. (2) The restrictive as opposed to the broad interpretation of the 1972 ABM Treaty, and the capability of the Strategic Defense Initiative Zenith Star Program to comply with the Treaty were evaluated. (3) The capability of Martin Marietta to develop an automated analysis system to integrate and analyze Superconducting Super Collider detector designs was investigated. (4) The thermal models that were developed in support of the Small Intercontinental Ballistic Missile flight tests were described. (5) The technical management role of the Product Integrity Engineer assigned to the Zenith Star spacecraft's Beam Control and Transfer Subsystem was discussed. The relationships between the engineering, business, security and social concerns associated with the practice of engineering and the management of programs by a major defense contractor are explored.
Pre-main Sequence Evolution and the Hydrogen-Burning Minimum Mass
NASA Astrophysics Data System (ADS)
Nakano, Takenori
There is a lower limit to the mass of the main-sequence stars (the hydrogen-burning minimum mass) below which the stars cannot replenish the energy lost from their surfaces with the energy released by the hydrogen burning in their cores. This is caused by the electron degeneracy in the stars which suppresses the increase of the central temperature with contraction. To find out the lower limit we need the accurate knowledge of the pre-main sequence evolution of very low-mass stars in which the effect of electron degeneracy is important. We review how Hayashi and Nakano (1963) carried out the first determination of this limit.
Far-ultraviolet energy distributions of the metal-poor A stars HD 109995 and HD 161817
NASA Technical Reports Server (NTRS)
Boehm-Vitense, E.
1981-01-01
Low-resolution IUE spectra at wavelengths between 1300 and 3400 A of the metal-poor stars HD 109995 (A1p) and HD 161817 (A4p) have been compared with model-atmosphere energy distributions computed by Kurucz (1979). Good overall agreement is found. Effective temperatures, metal abundances, and angular diameters could be determined. Assuming an absolute visual magnitude of 0.7, the previously determined gravity log = 3 yields masses of 0.5 solar masses for both stars. It is found that the theoretical UBV colors calculated earlier agree reaonably well with the ones observed for these stars.
Dynamics of H II regions around exiled O stars
NASA Astrophysics Data System (ADS)
Mackey, Jonathan; Langer, Norbert; Gvaramadze, Vasilii V.
2013-11-01
At least 25 per cent of massive stars are ejected from their parent cluster, becoming runaways or exiles, travelling with often-supersonic space velocities through the interstellar medium (ISM). Their overpressurized H II regions impart kinetic energy and momentum to the ISM, compress and/or evaporate dense clouds, and can constrain properties of both the star and the ISM. Here, we present one-, two- and (the first) three-dimensional simulations of the H II region around a massive star moving supersonically through a uniform, magnetized ISM, with properties appropriate for the nearby O star ζ Oph. The H II region leaves an expanding overdense shell behind the star and, inside this, an underdense wake that should be filled with hot gas from the shocked stellar wind. The gas column density in the shell is strongly influenced by the ISM magnetic field strength and orientation. Hα emission maps show that H II region remains roughly circular, although the star is displaced somewhat from the centre of emission. For our model parameters, the kinetic energy feedback from the H II region is comparable to the mechanical luminosity of the stellar wind, and the momentum feedback rate is >100 times larger than that from the wind and ≈10 times larger than the total momentum input rate available from radiation pressure. Compared to the star's eventual supernova explosion, the kinetic energy feedback from the H II region over the star's main-sequence lifetime is >100 times less, but the momentum feedback is up to 4 times larger. H II region dynamics are found to have only a small effect on the ISM conditions that a bow shock close to the star would encounter.
Nucleosynthesis in Primordial Hypernovae
NASA Astrophysics Data System (ADS)
Grimmett, J. J.; Heger, Alexander; Karakas, Amanda I.; Müller, Bernhard
2018-06-01
We investigate the relationship between explosion energy and nucleosynthesis in Population III supernovae and provide nucleosynthetic results for the explosions of stars with progenitor masses of 15 M⊙, 20 M⊙, 30 M⊙, 40 M⊙, 60 M⊙, and 80 M⊙, and explosion energies between approximately 1050 erg and 1053 erg. We find that the typical abundance pattern observed in metal-poor stars are best matched by supernovae with progenitor mass in the range 15 M⊙ - 30 M⊙, and explosion energy of ˜(5 - 10) × 1051 erg. In these models, a reverse shock caused by jumps in density between shells of different composition serves to decrease synthesis of chromium and manganese, which is favourable to matching the observed abundances in metal-poor stars. Spherically symmetric explosions of our models with progenitor mass ≥40 M⊙ do not provide yields that are compatible with the iron-peak abundances that are typically observed in metal-poor stars, however, by approximating the yields that we might expect from these models in highly aspherical explosions, we find indications that explosions of stars 40 M⊙ - 80 M⊙ with bipolar jets may be good candidates for the enrichment sources of metal-poor stars with enhanced carbon abundances.
[A wavelet-transform-based method for the automatic detection of late-type stars].
Liu, Zhong-tian; Zhao, Rrui-zhen; Zhao, Yong-heng; Wu, Fu-chao
2005-07-01
The LAMOST project, the world largest sky survey project, urgently needs an automatic late-type stars detection system. However, to our knowledge, no effective methods for automatic late-type stars detection have been reported in the literature up to now. The present study work is intended to explore possible ways to deal with this issue. Here, by "late-type stars" we mean those stars with strong molecule absorption bands, including oxygen-rich M, L and T type stars and carbon-rich C stars. Based on experimental results, the authors find that after a wavelet transform with 5 scales on the late-type stars spectra, their frequency spectrum of the transformed coefficient on the 5th scale consistently manifests a unimodal distribution, and the energy of frequency spectrum is largely concentrated on a small neighborhood centered around the unique peak. However, for the spectra of other celestial bodies, the corresponding frequency spectrum is of multimodal and the energy of frequency spectrum is dispersible. Based on such a finding, the authors presented a wavelet-transform-based automatic late-type stars detection method. The proposed method is shown by extensive experiments to be practical and of good robustness.
NASA Technical Reports Server (NTRS)
Flowers, E. G.; Ruderman, M. A.; Lee, J.-F.; Sutherland, P. G.; Hillebrandt, W.; Mueller, E.
1977-01-01
Variational calculations of the binding energies of iron atoms and condensed matter in strong magnetic fields (greater than 10 to the 12th gauss). These calculations include the electron exchange energy. The cohesive energy of the condensed matter, which is the difference between these two binding energies, is of interest in pulsar theories and in the description of the surfaces of neutron stars. It is found that the cohesive energy ranges from 2.6 keV to 8.0 keV.
A computer program for modeling non-spherical eclipsing binary star systems
NASA Technical Reports Server (NTRS)
Wood, D. B.
1972-01-01
The accurate analysis of eclipsing binary light curves is fundamental to obtaining information on the physical properties of stars. The model described accounts for the important geometric and photometric distortions such as rotational and tidal distortion, gravity brightening, and reflection effect. This permits a more accurate analysis of interacting eclipsing star systems. The model is designed to be useful to anyone with moderate computing resources. The programs, written in FORTRAN 4 for the IBM 360, consume about 80k bytes of core. The FORTRAN program listings are provided, and the computational aspects are described in some detail.
Predicting Success: How Predictive Analytics Are Transforming Student Support and Success Programs
ERIC Educational Resources Information Center
Boerner, Heather
2015-01-01
Every year, Lone Star College in Texas hosts a "Men of Honor" program to provide assistance and programming to male students, but particularly those who are Hispanic and black, in hopes their academic performance will improve. Lone Star might have kept directing its limited resources toward these students--and totally missed the subset…
Morning Star Cycle Two (1977-1979): Evaluation.
ERIC Educational Resources Information Center
Sloan, L. V.
Evaluation of cycle two of the (1977-1979) Morning Star program (a 2-year Native teacher education program at the Blue Quills Native Education Centre leading to a Bachelor of Education degree from the University of Alberta) used a systems model to collect data on 24 variables for the 33 participating students, the academic program, and first and…
Standard Energy Efficiency Data Platform
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cheifetz, D. Magnus
2014-07-15
The SEED platform is expected to be a building energy performance data management tool that provides federal, state and local governments, building owners and operators with an easy, flexible and cost-effective method to collect information about groups of buildings, oversee compliance with energy disclosure laws and demonstrate the economic and environmental benefits of energy efficiency. It will allow users to leverage a local application to manage data disclosure and large data sets without the IT investment of developing custom applications. The first users of SEED will be agencies that need to collect, store, and report/share large data sets generated bymore » benchmarking, energy auditing, retro-commissioning or retrofitting of many buildings. Similarly, building owners and operators will use SEED to manage their own energy data in a common format and centralized location. SEED users will also control the disclosure of their information for compliance requirements, recognition programs such as ENERGY STAR, or data sharing with the Buildings Performance Database and/or other third parties at their discretion.« less
The Balloon-borne Large Aperture Telescope for Polarization - BLASTPol
NASA Astrophysics Data System (ADS)
Devlin, Mark
We are proposing a comprehensive program to study the link between Galactic magnetic fields and star formation. After decades of study, the physical processes regulating star formation still remain poorly understood. Large-scale observations of star forming regions provide counts of the number of dense clouds each of which will eventually evolve into tens to hundreds of stars. However, when simple models of gravitational collapse are applied to the clouds they yield a Galactic star formation rate (SFR) which is many times what is actually observed. Some process or combination of processes must be slowing the collapse of the clouds. The two prevailing theories involve turbulence which prevents the effective dissipation of energy and Galactic magnetic fields which are captured and squeezed by the collapsing cloud provide a mechanism for mechanical support. Understanding these effects fits very well the SMD 2010 Science Plan's Cosmic Origins program. The Balloon-borne Large Aperture Telescope - BLAST was originally designed to conduct confusion-limited and wide-area extragalactic and Galactic surveys at submillimeter wavelengths from a long-duration balloon (LDB) platform. These wavelengths are impossible or very difficult to observe from even the best groundbased telescope sites. After a series of successful flights (Ft. Sumner 2003, Sweden 2005, and Antarctica 2006) resulting in over 25 publications, BLAST was converted to BLASTPol. The combination of a polarizing grid in front of each of the 266 feed horns at 250, 350 and 500 micron with a stepped Half Wave Plate (HWP) provided a quick and inexpensive way to make initial measurements of polarized dust emission in star forming regions. By mapping polarization from dust grains aligned with respect to their local magnetic field, the field orientation (projected on the sky) can be traced. The development of the Next Generation BLASTPol instrument is now complete. It has increased spatial resolution (22 arcseconds at 250 microns), four times the field of view (340 square arcminutes) and 12 times the mapping speed of the previous instrument. The focus of this three year proposal is to fly BLASTPol, make deep maps of star forming regions with sizes ranging from 0.25 to 20 square degrees, and to probe galactic dust as a foreground for future Cosmic Microwave Background experiments. This work also includes an extensive data analysis phase.
High Energy Replicated Optics to Explore the Sun: Hard X-Ray Balloon-Borne Telescope
NASA Technical Reports Server (NTRS)
Gaskin, Jessica; Apple, Jeff; StevensonChavis, Katherine; Dietz, Kurt; Holt, Marlon; Koehler, Heather; Lis, Tomasz; O'Connor, Brian; RodriquezOtero, Miguel; Pryor, Jonathan;
2013-01-01
Set to fly in the Fall of 2013 from Ft. Sumner, NM, the High Energy Replicated Optics to Explore the Sun (HEROES) mission is a collaborative effort between the NASA Marshall Space Flight Center and the Goddard Space Flight Center to upgrade an existing payload, the High Energy Replicated Optics (HERO) balloon-borne telescope, to make unique scientific measurements of the Sun and astrophysical targets during the same flight. The HEROES science payload consists of 8 mirror modules, housing a total of 109 grazing-incidence optics. These modules are mounted on a carbon-fiber - and Aluminum optical bench 6 m from a matching array of high pressure xenon gas scintillation proportional counters, which serve as the focal-plane detectors. The HERO gondola utilizes a differential GPS system (backed by a magnetometer) for coarse pointing in the azimuth and a shaft angle encoder plus inclinometer provides the coarse elevation. The HEROES payload will incorporate a new solar aspect system to supplement the existing star camera, for fine pointing during both the day and night. A mechanical shutter will be added to the star camera to protect it during solar observations. HEROES will also implement two novel alignment monitoring system that will measure the alignment between the optical bench and the star camera and between the optics and detectors for improved pointing and post-flight data reconstruction. The overall payload will also be discussed. This mission is funded by the NASA HOPE (Hands On Project Experience) Training Opportunity awarded by the NASA Academy of Program/Project and Engineering Leadership, in partnership with NASA's Science Mission Directorate, Office of the Chief Engineer and Office of the Chief Technologist
High Energy Replicated Optics to Explore the Sun: Hard X-ray balloon-borne telescope
NASA Astrophysics Data System (ADS)
Gaskin, J.; Apple, J.; Chavis, K. S.; Dietz, K.; Holt, M.; Koehler, H.; Lis, T.; O'Connor, B.; Otero, M. R.; Pryor, J.; Ramsey, B.; Rinehart-Dawson, M.; Smith, L.; Sobey, A.; Wilson-Hodge, C.; Christe, S.; Cramer, A.; Edgerton, M.; Rodriguez, M.; Shih, A.; Gregory, D.; Jasper, J.; Bohon, S.
Set to fly in the Fall of 2013 from Ft. Sumner, NM, the High Energy Replicated Optics to Explore the Sun (HEROES) mission is a collaborative effort between the NASA Marshall Space Flight Center and the Goddard Space Flight Center to upgrade an existing payload, the High Energy Replicated Optics (HERO) balloon-borne telescope, to make unique scientific measurements of the Sun and astrophysical targets during the same flight. The HEROES science payload consists of 8 mirror modules, housing a total of 109 grazing-incidence optics. These modules are mounted on a carbon-fiber - and Aluminum optical bench 6 m from a matching array of high pressure xenon gas scintillation proportional counters, which serve as the focal-plane detectors. The HERO gondola utilizes a differential GPS system (backed by a magnetometer) for coarse pointing in the azimuth and a shaft angle encoder plus inclinometer provides the coarse elevation. The HEROES payload will incorporate a new solar aspect system to supplement the existing star camera, for fine pointing during both the day and night. A mechanical shutter will be added to the star camera to protect it during solar observations. HEROES will also implement two novel alignment monitoring system that will measure the alignment between the optical bench and the star camera and between the optics and detectors for improved pointing and post-flight data reconstruction. The overall payload will also be discussed. This mission is funded by the NASA HOPE (Hands On Project Experience) Training Opportunity awarded by the NASA Academy of Program/Project and Engineering Leadership, in partnership with NASA's Science Mission Directorate, Office of the Chief Engineer and Office of the Chief Technologist.
VizieR Online Data Catalog: HST FGS-1r parallaxes for 8 metal-poor stars (Chaboyer+, 2017)
NASA Astrophysics Data System (ADS)
Chaboyer, B.; McArthur, B. E.; O'Malley, E.; Benedict, G. F.; Feiden, G. A.; Harrison, T. E.; McWilliam, A.; Nelan, E. P.; Patterson, R. J.; Sarajedini, A.
2017-08-01
Each program star was observed with the HST Advanced Camera for Surveys-Wide Field Camera (ACS/WFC) in the F606W and F814W filters. The CTE-corrected ACS/WFC images for the program stars were retrieved from MAST. These instrumental magnitudes were corrected for exposure time, matched to form colors, and calibrated to the VEGAMag and ground-based VI systems using the Sirianni+ (2005PASP..117.1049S) photometric transformations. Ground based photometry for all of our program stars were obtained using the New Mexico State University (NMSU) 1m telescope, the MDM 1.3m telescope, and the SMARTS 0.9m telescope. See appendix A1 for further details. We used HST FGS-1r, a two-axis interferometer, to make the astrometric observations. Eighty-nine orbits of HST astrometric observations were made between 2008 December and 2013 June. Every orbit contained several observations of the target and surrounding reference stars. (4 data files).
The Top 30 Rising Stars Program: an inter-organizational approach to leadership succession planning.
Dilworth, Katie; Lankshear, Sara; Cava, Maureen; Aldred, Jacqueline; Hawkes, Nancy; Lefebre, Nancy; Price, Jennifer; Lawler, Valerie
2011-01-01
An effective leadership development program is an organizational investment that advances individual performance while strengthening organizational capabilities. The Top 30 Rising Stars Program is a leadership succession program designed to enable leadership capacity building within and across organizations. Key components of the program include formal learning, stretch opportunities, and mentorship. Evaluation results reveal high participant satisfaction and an increase in reported self-confidence in their ability to assume a formal leadership position.
NASA Astrophysics Data System (ADS)
2000-10-01
NASA's Chandra X-ray Observatory has found evidence that massive stars may be much more like the Sun than previously thought. Astronomers determined that magnetic loop structures, similar to those on the Sun, may exist on the surface of so-called O-type stars, some of the most luminous stars in the universe. "This result is quite surprising," says Wayne Waldron of Emergent Information Technologies, Inc., and co-author of a paper submitted to the Astrophysical Journal Letters. "This bucks conventional wisdom to find that these stars may really resemble our Sun." Zeta Orionis Press Image and Caption Using Chandra's High-Energy Transmission Grating Spectrometer (HETGS) in conjunction with a CCD X-ray camera, astronomers observed the star Zeta Orionis (one of the three belt stars in the constellation of Orion) and found strong X-ray line emission from ions of iron, oxygen, and other elements. The high-resolution X-ray spectrum enabled astronomers to determine that the X-ray emitting gas has a density 1000 times larger than predicted by current models, an amount comparable to the atmospheric density just above the surface of the star. For many years, solar astronomers have derived densities of X-ray producing plasmas on the Sun using emission lines of ions like helium, those with just two bound electrons remaining. Chandra allows this approach to be used for other stars and it has detected X-rays from silicon ions that have been stripped of 12 of their usual complement of 14 electrons. This ion is an especially useful diagnostic of plasma densities in the extremely ultraviolet-bright environment surrounding O-stars. Following the discovery of X-ray emission from O-class stars some 20 years ago, astronomers assumed that the X-rays were created in a hot corona near the star, similar to the Sun's corona. Those models were then abandoned in favor of the currently preferred explanation: the X-ray radiation is created by energetic shocks in the stellar winds (steady streams of matter ejected from many stars, including the Sun). However, these new Chandra spectral data reveal a much higher density for the hot, X-ray producing gas than predicted if such shock models were correct. The Chandra observations also contradict current understanding since the team of researchers found no evidence of expansion in the emission lines - a fundamental prediction for shock models. According to Waldron and co-author Joseph Cassinelli of the University of Wisconsin, Madison, their observations are best explained if the high density X-ray emission comes from confined structures of very hot plasma, similar to the magnetic loops found on the Sun. [For recent results on the Sun's magnetic loops, see the NASA HQ press release, "Fountains of Fire Illuminate Solar Mystery," issued September 26, 2000.] A challenge for scientists will be to explain how these magnetic loops are generated and maintained. Although O-type stars have inner convection zones in their core, they are believed to lack outer convection zones, an ingredient scientists considered necessary to create such hot and energetic plasmas confined in magnetic loops. Convection zones are regions where most of the energy is transported by fluid motions from hotter regions to cooler ones. Without these zones being located near the stellar surface, astronomers are currently unable to explain how such high-densities knots of X-rays could exist. O-type stars, often found in groups of similar stars known as "OB associations," are massive objects, which are typically 10 or more times the Sun's mass. These stars are known to have relatively short life spans, since they burn their nuclear fuel much faster than smaller stars. The star Waldron and Cassinelli observed with Chandra, Zeta Orionis, is classified as an O "supergiant," which is 30 times larger, 30 times more massive, and radiates one hundred thousand times more energy than the Sun. The binary system of Zeta Orionis can be seen with the unaided eye from both Hemispheres for much of the year. Viewing them east to west, Zeta Orionis is the first star in the belt of the famous constellation of Orion, the Hunter. The High Energy Transmission Grating Spectrometer was built by the Massachusetts Institute of Technology (MIT), Cambridge, MA. The Advanced CCD X-ray spectrometer (ACIS) X-ray camera was developed for NASA by Penn State and MIT. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov
NeutronSTARS: A segmented neutron and charged particle detector for low-energy reaction studies
Akindele, O. A.; Casperson, R. J.; Wang, B. S.; ...
2017-08-10
NeutronSTARS (Neutron-S ilicon T elescope A rray for R eaction S tudies) consists of 2.2-tons of gadolinium-doped liquid scintillator for neutron detection and large area silicon detectors for charged particle identification. This detector array is intended for low-energy-nuclear-reaction measurements that result in the emission of neutrons such as and fission. This paper describes the NeutronSTARS experimental setup, calibration, and the array’s response to neutral and charged particles.
Green digital signage using nanoparticle embedded narrow-gap field sequential TN-LCDs
NASA Astrophysics Data System (ADS)
Kobayashi, Shunsuke; Shiraishi, Yukihide; Sawai, Hiroya; Toshima, Naoki; Okita, Masaya; Takeuchi, Kiyofumi; Takatsu, Haruyoshi
2012-03-01
We have fabricated field sequential color (FSC)-LCDs using cells and modules of narrow-gap TN-LCDs with and without doping the nanoparticles of PCyD-ZrO2 and AF-SiO2. It is shown that the FSC-LCD exhibits a high optical efficiency of OE=4.5 that is defined as OE=[Luminance]/[W/m2]=(cd/W). This figure may provide us a good reference or to clear the Energy Star Program Version 5-3 that issues a guideline: LCD with 50 inch on the diagonal consumes the energy of 108W. Through this research it is claimed that our FSC=LCD may be a novel green digital signage.
STAR grantees will describe their planned research and hear from EPA programs and a regional schools coordinator about EPA’s programs and resources. A guest speaker will provide a lunchtime seminar.
Future Probes of the Neutron Star Equation of State Using X-ray Bursts
NASA Technical Reports Server (NTRS)
Strohmayer, Tod E.
2004-01-01
Observations with NASA s Rossi X-ray Timing Explorer (RXTE) have resulted in the discovery of fast (200 - 600 Hz), coherent X-ray intensity oscillations (hereafter, %urstoscillations ) during thermonuclear X-ray bursts from 12 low mass X-ray binaries (LMXBs). Although many of their detailed properties remain to be fully understood, it is now beyond doubt that these oscillations result from spin modulation of the thermonuclear burst flux from the neutron star surface. Among the new timing phenomena revealed by RXTE the burst oscillations are perhaps the best understood, in the sense that many of their properties can be explained in the framework of this relatively simple model. Because of this, detailed modelling of burst oscillations can be an extremely powerful probe of neutron star structure, and thus the equation of state (EOS) of supra-nuclear density matter. Both the compactness parameter beta = GM/c(sup 2)R, and the surface velocity, nu(sub rot) = Omega(sub spin)R, are encoded in the energy-dependent amplitude and shape of the modulation pulses. The new discoveries have spurred much new theoretical work on thermonuclear burning and propagation on neutron stars, so that in the near future it is not unreasonable to think that detailed physical models of the time dependent flux from burning neutron stars will be available for comparison with the observed pulse profiles from a future, large collecting area X-ray timing observatory. In addition, recent high resolution burst spectroscopy with XMM/Newton suggests the presence of redshifted absorption lines from the neutron star surface during bursts. This leads to the possibility of using large area, high spectral resolution measurements of X-ray bursts as a precise probe of neutron star structure. In this work I will explore the precision with which constraints on neutron star structure, and hence the dense matter EOS, can be made with the implementation of such programs.
Energy Efficiency Measures to Incorporate into Remodeling Projects
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liaukus, C.
2014-12-01
Energy improvements in a home are often approached as one concerted effort, beginning with a simple walk-through assessment or more in-depth energy audit and followed by the installation of recommended energy measures. While this approach allows for systems thinking to guide the efforts, comprehensive energy improvements of this nature are undertaken by a relatively small number of the households in our nation compared to more piecemeal remodeling efforts. Even when programs like the Weatherization Assistance Program and Home Performance with ENERGY STAR are considered, homes that have had a comprehensive energy makeover still represent a small fraction of the 111.1more » million households. In this report, the U.S Department of Energy Building America Retrofit Alliance research team looks at the improvement of a home's energy performance in an opportunistic way: it examines what can be done to incorporate energy efficiency measures into general remodeling work and home repair projects. This allows for the possibility for people who would not normally pursue energy efficiency but will remodel their kitchen or re-side their home to improve their home's performance at the same time. There are challenges to this approach, not the least of which being that the work will take place over time in potentially many separate projects. The opportunity to improve a home's energy efficiency at one time expands or contracts with the scope of the remodel. As such, guidance on how to do each piece thoughtfully and with consideration for potential future projects, is critical.« less
Software and mathematical support of Kazakhstani star tracker
NASA Astrophysics Data System (ADS)
Akhmedov, D.; Yelubayev, S.; Ten, V.; Bopeyev, T.; Alipbayev, K.; Sukhenko, A.
2016-10-01
Currently the specialists of Kazakhstan have been developing the star tracker that is further planned to use on Kazakhstani satellites of various purposes. At the first stage it has been developed the experimental model of star tracker that has following characteristics: field of view 20°, update frequency 2 Hz, exclusion angle 40°, accuracy of attitude determination of optical axis/around optical axis 15/50 arcsec. Software and mathematical support are the most high technology parts of star tracker. The results of software and mathematical support development of experimental model of Kazakhstani star tracker are represented in this article. In particular, there are described the main mathematical models and algorithms that have been used as a basis for program units of preliminary image processing of starry sky, stars identification and star tracker attitude determination. The results of software and mathematical support testing with the help of program simulation complex using various configurations of defects including image sensor noises, point spread function modeling, optical system distortion up to 2% are presented. Analysis of testing results has shown that accuracy of attitude determination of star tracker is within the permissible range
Determinants of Household Use of Selected Energy Star Appliances
2016-01-01
The main objective of this paper is to test a series of hypotheses regarding the influences of household characteristics (such as education, age, sex, race, income, and size of household), building characteristics (such as age, ownership, and type), and electricity prices on the use of ENERGY STAR appliances.
77 FR 73639 - Combined Notice of Filings #1
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-11
...-281-000. Applicants: Star Energy Partners LLC. Description: Supplemental Information of Star Energy... filing per 35.1: Electricity New Hampshire FERC Tariff to be effective 12/4/2012. Filed Date: 12/3/12... Numbers: ER13-510-000. Applicants: ISO New England Inc. Description: ISO New England Inc. submits tariff...
Solar UV Radiation and the Origin of Life On Earth
NASA Technical Reports Server (NTRS)
Heap, S. R.; Lanz, T.; Hubeny, I.; Gaidos, E.; Oegerle, William R. (Technical Monitor)
2002-01-01
We have embarked on a program aimed at understanding the atmosphere of the early Earth, because of its importance as a greenhouse, radiation shield and energy source for life. Here, we give a progress report on the first phase of this program to establish the UV radiation from the early Sun. We have obtained ultraviolet spectra (STIS, FUSE, EUVE) of carefully selected nearby, young solar-type stars, which act as surrogates for the early Sun We are making detailed non-LTE analyses of the spectra and constructing models of their photospheres + chromospheres. Once validated, these models will allow us to extrapolate our theoretical spectra to other metallicities and to unobserved spectral regions.
Community Exoplanet Follow-up Program
NASA Technical Reports Server (NTRS)
Howell, Steve
2017-01-01
During the Kepler mission, our team provided the community with the highest resolution images available anywhere of exoplanet host stars. Using speckle interferometry on the 3.5-m WIYN, and 8-m Gemini telescopes, thousands of observations have been obtained reaching the diffraction limit of the telescope. From these public data available at the NASA Exoplanet Archive, numerous publications have resulted and many scientific results have been obtained for exoplanets including the fact that high-resolution imaging is critical to fully characterize the planet host stars and the planets themselves (e.g., planet radius and incident flux). Exoplanet host star observations have also occurred (and continue) for K2 mission candidates with archival data available as well. Observational programs for TESS candidates, WFIRST program stars, and Zodiacal light candidates are currently on-going. Availability to propose or obtain such observations are possible through 1) collaboration with our team, 2) successfully proposing to WIYN or GEMINI for telescope time, or 3) using publically available archival data. This poster will highlight the observational program, how time is allocated and how our queue observational program works, and new features and observational modes that are available now.
NASA Astrophysics Data System (ADS)
Williams, Michael D.; Milone, E. F.
2013-12-01
We describe a variable star search program and present the fully reduced results of a search in a 19 square degree (4.4 × 4.4) field centered on J2000 RA = 22:03:24, DEC= +18:54:32. The search was carried out with the Baker-Nunn Patrol Camera located at the Rothney Astrophysical Observatory in the foothills of the Canadian Rockies. A total of 26,271 stars were detected in the field, over a range of about 11-15 (instrumental) magnitudes. Our image processing made use of the IRAF version of the DAOPHOT aperture photometry routine and we used the ANOVA method to search for periodic variations in the light curves. We formally detected periodic variability in 35 stars, that we tentatively classify according to light curve characteristics: 6 EA (Algol), 5 EB (?? Lyrae), 19 EW (W UMa), and 5 RR (RR Lyrae) stars. Eleven of the detected variable stars have been reported previously in the literature. The eclipsing binary light curves have been analyzed with a package of light curve modeling programs and 25 have yielded converged solutions. Ten of these are of systems that are detached, 3 semi-detached, 10 overcontact, and 2 are of systems that appear to be in marginal contact. We discuss these results as well as the advantages and disadvantages of the instrument and of the program.
Smelter, Andrey; Astra, Morgan; Moseley, Hunter N B
2017-03-17
The Biological Magnetic Resonance Data Bank (BMRB) is a public repository of Nuclear Magnetic Resonance (NMR) spectroscopic data of biological macromolecules. It is an important resource for many researchers using NMR to study structural, biophysical, and biochemical properties of biological macromolecules. It is primarily maintained and accessed in a flat file ASCII format known as NMR-STAR. While the format is human readable, the size of most BMRB entries makes computer readability and explicit representation a practical requirement for almost any rigorous systematic analysis. To aid in the use of this public resource, we have developed a package called nmrstarlib in the popular open-source programming language Python. The nmrstarlib's implementation is very efficient, both in design and execution. The library has facilities for reading and writing both NMR-STAR version 2.1 and 3.1 formatted files, parsing them into usable Python dictionary- and list-based data structures, making access and manipulation of the experimental data very natural within Python programs (i.e. "saveframe" and "loop" records represented as individual Python dictionary data structures). Another major advantage of this design is that data stored in original NMR-STAR can be easily converted into its equivalent JavaScript Object Notation (JSON) format, a lightweight data interchange format, facilitating data access and manipulation using Python and any other programming language that implements a JSON parser/generator (i.e., all popular programming languages). We have also developed tools to visualize assigned chemical shift values and to convert between NMR-STAR and JSONized NMR-STAR formatted files. Full API Reference Documentation, User Guide and Tutorial with code examples are also available. We have tested this new library on all current BMRB entries: 100% of all entries are parsed without any errors for both NMR-STAR version 2.1 and version 3.1 formatted files. We also compared our software to three currently available Python libraries for parsing NMR-STAR formatted files: PyStarLib, NMRPyStar, and PyNMRSTAR. The nmrstarlib package is a simple, fast, and efficient library for accessing data from the BMRB. The library provides an intuitive dictionary-based interface with which Python programs can read, edit, and write NMR-STAR formatted files and their equivalent JSONized NMR-STAR files. The nmrstarlib package can be used as a library for accessing and manipulating data stored in NMR-STAR files and as a command-line tool to convert from NMR-STAR file format into its equivalent JSON file format and vice versa, and to visualize chemical shift values. Furthermore, the nmrstarlib implementation provides a guide for effectively JSONizing other older scientific formats, improving the FAIRness of data in these formats.
Atmospheric mass-loss of extrasolar planets orbiting magnetically active host stars
NASA Astrophysics Data System (ADS)
Lalitha, Sairam; Schmitt, J. H. M. M.; Dash, Spandan
2018-06-01
Magnetic stellar activity of exoplanet hosts can lead to the production of large amounts of high-energy emission, which irradiates extrasolar planets, located in the immediate vicinity of such stars. This radiation is absorbed in the planets' upper atmospheres, which consequently heat up and evaporate, possibly leading to an irradiation-induced mass-loss. We present a study of the high-energy emission in the four magnetically active planet-bearing host stars, Kepler-63, Kepler-210, WASP-19, and HAT-P-11, based on new XMM-Newton observations. We find that the X-ray luminosities of these stars are rather high with orders of magnitude above the level of the active Sun. The total XUV irradiation of these planets is expected to be stronger than that of well-studied hot Jupiters. Using the estimated XUV luminosities as the energy input to the planetary atmospheres, we obtain upper limits for the total mass- loss in these hot Jupiters.
Eby, Joshua; Leembruggen, Madelyn; Suranyi, Peter; ...
2016-12-15
Axion stars, gravitationally bound states of low-energy axion particles, have a maximum mass allowed by gravitational stability. Weakly bound states obtaining this maximum mass have sufficiently large radii such that they are dilute, and as a result, they are well described by a leading-order expansion of the axion potential. Here, heavier states are susceptible to gravitational collapse. Inclusion of higher-order interactions, present in the full potential, can give qualitatively different results in the analysis of collapsing heavy states, as compared to the leading-order expansion. In this work, we find that collapsing axion stars are stabilized by repulsive interactions present inmore » the full potential, providing evidence that such objects do not form black holes. In the last moments of collapse, the binding energy of the axion star grows rapidly, and we provide evidence that a large amount of its energy is lost through rapid emission of relativistic axions.« less
The Chemical Abundances of New Extremely Metal-Poor Giants with [Fe/H] < -3.0
NASA Astrophysics Data System (ADS)
Rhee, Jaehyon; Fink, M.; Rhee, W.
2012-01-01
Extremely metal-poor (EMP) stars with [Fe/H] < -3.0 observable in the Galactic halo and thick disk today are believed to be the second-generation stars born out of those materials that were slightly chemically polluted by the extinct, metal-free first stars. If true, these oldest surviving stars with the lowest metal abundances are astrophysical laboratories that may shed essential light on the origins and evolution of the chemical elements and on the formation of the Milky Way. In order to newly discover field metal-deficient stars in the inner halo of the Galaxy, the Purdue Ultra Metal-Poor Star Survey (PUMPSS) program was conducted. Candidate metal-poor stars were initially selected utilizing the photometric data of the GALEX and the 2MASS, and subsequent medium- and high-resolution spectroscopy were carried out for the identification of true metal-poor giant stars and detailed chemical abundance analyses, respectively. We present an overview of the PUMPSS program and the results of the abundance analysis for high-dispersion spectra of EMP giant stars taken at the KPNO 4m telescope. We acknowledge support for this work from NASA grants 07-ADP07-0080 and 05-GALEX05-27.
Simulation of ultra-high energy photon propagation with PRESHOWER 2.0
NASA Astrophysics Data System (ADS)
Homola, P.; Engel, R.; Pysz, A.; Wilczyński, H.
2013-05-01
In this paper we describe a new release of the PRESHOWER program, a tool for Monte Carlo simulation of propagation of ultra-high energy photons in the magnetic field of the Earth. The PRESHOWER program is designed to calculate magnetic pair production and bremsstrahlung and should be used together with other programs to simulate extensive air showers induced by photons. The main new features of the PRESHOWER code include a much faster algorithm applied in the procedures of simulating the processes of gamma conversion and bremsstrahlung, update of the geomagnetic field model, and a minor correction. The new simulation procedure increases the flexibility of the code so that it can also be applied to other magnetic field configurations such as, for example, encountered in the vicinity of the sun or neutron stars. Program summaryProgram title: PRESHOWER 2.0 Catalog identifier: ADWG_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWG_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3968 No. of bytes in distributed program, including test data, etc.: 37198 Distribution format: tar.gz Programming language: C, FORTRAN 77. Computer: Intel-Pentium based PC. Operating system: Linux or Unix. RAM:< 100 kB Classification: 1.1. Does the new version supercede the previous version?: Yes Catalog identifier of previous version: ADWG_v1_0 Journal reference of previous version: Comput. Phys. Comm. 173 (2005) 71 Nature of problem: Simulation of a cascade of particles initiated by UHE photon in magnetic field. Solution method: The primary photon is tracked until its conversion into an e+ e- pair. If conversion occurs each individual particle in the resultant preshower is checked for either bremsstrahlung radiation (electrons) or secondary gamma conversion (photons). Reasons for new version: Slow and outdated algorithm in the old version (a significant speed up is possible); Extension of the program to allow simulations also for extraterrestrial magnetic field configurations (e.g. neutron stars) and very long path lengths. Summary of revisions: A veto algorithm was introduced in the gamma conversion and bremsstrahlung tracking procedures. The length of the tracking step is now variable along the track and depends on the probability of the process expected to occur. The new algorithm reduces significantly the number of tracking steps and speeds up the execution of the program. The geomagnetic field model has been updated to IGRF-11, allowing for interpolations up to the year 2015. Numerical Recipes procedures to calculate modified Bessel functions have been replaced with an open source CERN routine DBSKA. One minor bug has been fixed. Restrictions: Gamma conversion into particles other than an electron pair is not considered. Spatial structure of the cascade is neglected. Additional comments: The following routines are supplied in the package, IGRF [1, 2], DBSKA [3], ran2 [4] Running time: 100 preshower events with primary energy 1020 eV require a 2.66 GHz CPU time of about 200 sec.; at the energy of 1021 eV, 600 sec.
An expert computer program for classifying stars on the MK spectral classification system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gray, R. O.; Corbally, C. J.
2014-04-01
This paper describes an expert computer program (MKCLASS) designed to classify stellar spectra on the MK Spectral Classification system in a way similar to humans—by direct comparison with the MK classification standards. Like an expert human classifier, the program first comes up with a rough spectral type, and then refines that spectral type by direct comparison with MK standards drawn from a standards library. A number of spectral peculiarities, including barium stars, Ap and Am stars, λ Bootis stars, carbon-rich giants, etc., can be detected and classified by the program. The program also evaluates the quality of the delivered spectralmore » type. The program currently is capable of classifying spectra in the violet-green region in either the rectified or flux-calibrated format, although the accuracy of the flux calibration is not important. We report on tests of MKCLASS on spectra classified by human classifiers; those tests suggest that over the entire HR diagram, MKCLASS will classify in the temperature dimension with a precision of 0.6 spectral subclass, and in the luminosity dimension with a precision of about one half of a luminosity class. These results compare well with human classifiers.« less
NASA Technical Reports Server (NTRS)
Lada, Charles J.
2004-01-01
This grant funds a research program to use infrared extinction measurements to probe the detailed structure of dark molecular cloud cores and investigate the physical conditions which give rise to star and planet formation. The goals of this program are to acquire, reduce and analyze deep infrared and molecular-line observations of a carefully selected sample of nearby dark clouds in order to determine the detailed initial conditions for star formation from quantitative measurements of the internal structure of starless cloud cores and to quantitatively investigate the evolution of such structure through the star and planet formation process.
The Herschel Virgo Cluster Survey. XIX. Physical properties of low luminosity FIR sources at z < 0.5
NASA Astrophysics Data System (ADS)
Pappalardo, Ciro; Bizzocchi, Luca; Fritz, Jacopo; Boselli, Alessandro; Boquien, Mederic; Boissier, Samuel; Baes, Maarten; Ciesla, Laure; Bianchi, Simone; Clemens, Marcel; Viaene, Sebastien; Bendo, George J.; De Looze, Ilse; Smith, Matthew W. L.; Davies, Jonathan
2016-05-01
Context. The star formation rate is a crucial parameter for the investigation galaxy evolution. At low redshift the cosmic star formation rate density declines smoothly, and massive active galaxies become passive, reducing their star formation activity. This implies that the bulk of the star formation rate density at low redshift is mainly driven by low mass objects. Aims: We investigate the properties of a sample of low luminosity far-infrared sources selected at 250 μm. We have collected data from ultraviolet to far-infrared in order to perform a multiwavelengths analysis. The main goal is to investigate the correlation between star formation rate, stellar mass, and dust mass for a galaxy population with a wide range in dust content and stellar mass, including the low mass regime that most probably dominates the star formation rate density at low redshift. Methods: We define a main sample of ~800 sources with full spectral energy distribution coverage between 0.15 <λ< 500 μm and an extended sample with ~5000 sources in which we remove the constraints on the ultraviolet and near-infrared bands. We analyze both samples with two different spectral energy distribution fitting methods: MAGPHYS and CIGALE, which interpret a galaxy spectral energy distribution as a combination of different simple stellar population libraries and dust emission templates. Results: In the star formation rate versus stellar mass plane our samples occupy a region included between local spirals and higher redshift star forming galaxies. These galaxies represent the population that at z< 0.5 quenches their star formation activity and reduces their contribution to the cosmic star formation rate density. The subsample of galaxies with the higher masses (M∗> 3 × 1010 M⊙) do not lie on the main sequence, but show a small offset as a consequence of the decreased star formation. Low mass galaxies (M∗< 1 × 1010 M⊙) settle in the main sequence with star formation rate and stellar mass consistent with local spirals. Conclusions: Deep Herschel data allow the identification of a mixed galaxy population with galaxies still in an assembly phase or galaxies at the beginning of their passive evolution. We find that the dust luminosity is the parameter that allow us to discriminate between these two galaxy populations. The median spectral energy distribution shows that even at low star formation rate our galaxy sample has a higher mid-infrared emission than previously predicted. Herschel is an ESA space observatory with science instruments provided by a European-led principal investigator consortia and with an important participation from NASA.
The Resolved Stellar Populations Early Release Science Program
NASA Astrophysics Data System (ADS)
Gilbert, Karoline; Weisz, Daniel; Resolved Stellar Populations ERS Program Team
2018-06-01
The Resolved Stellar Populations Early Release Science Program (PI D. Weisz) will observe Local Group targets covering a range of stellar density and star formation histories, including a globular cluster, and ultra-faint dwarf galaxy, and a star-forming dwarf galaxy. Using observations of these diverse targets we will explore a broad science program: we will measure star formation histories, the sub-solar stellar initial mass function, and proper motions, perform studies of evolved stars, and map extinction in the target fields. Our observations will be of high archival value for other science such as calibrating stellar evolution models, studying variable stars, and searching for metal-poor stars. We will determine optimal observational setups and develop data reduction techniques that will be common to JWST studies of resolved stellar populations. We will also design, test, and release point spread function (PSF) fitting software specific to NIRCam and NIRISS, required for the crowded stellar regime. Prior to the Cycle 2 Call for Proposals, we will release PSF fitting software, matched HST and JWST catalogs, and clear documentation and step-by-step tutorials (such as Jupyter notebooks) for reducing crowded stellar field data and producing resolved stellar photometry catalogs, as well as for specific resolved stellar photometry science applications.
The Magnetar Model of the Superluminous Supernova GAIA16apd and the Explosion Jet Feedback Mechanism
DOE Office of Scientific and Technical Information (OSTI.GOV)
Soker, Noam, E-mail: soker@physics.technion.ac.il
Under the assumption that jets explode core collapse supernovae (CCSNe) in a negative jet feedback mechanism (JFM), this paper shows that rapidly rotating neutron stars are likely to be formed when the explosion is very energetic. Under the assumption that an accretion disk or an accretion belt around the just-formed neutron star launch jets and that the accreted gas spins-up the just-formed neutron star, I derive a crude relation between the energy that is stored in the spinning neutron star and the explosion energy. This relation is ( E {sub NS-spin}/ E {sub exp}) ≈ E {sub exp}/10{sup 52} erg;more » It shows that within the frame of the JFM explosion model of CCSNe, spinning neutron stars, such as magnetars, might have significant energy in super-energetic explosions. The existence of magnetars, if confirmed, such as in the recent super-energetic supernova GAIA16apd, further supports the call for a paradigm shift from neutrino-driven to jet-driven CCSN mechanisms.« less
Diffuse γ-ray emission in the vicinity of young star cluster Westerlund 2
NASA Astrophysics Data System (ADS)
Yang, Rui-zhi; de Oña Wilhelmi, Emma; Aharonian, Felix
2018-04-01
We report the results of our analysis of the publicly available data obtained by the Large Area Telescope (LAT) on board the Fermi satellite towards the direction of the young massive star cluster Westerlund 2. We found significant extended γ-ray emission in the vicinity of Westerlund 2 with a hard power-law energy spectrum extending from 1 to 250 GeV with a photon index of 2.0 ± 0.1. We argue that amongst several alternatives, the luminous stars in Westerlund 2 are likely sites of acceleration of particles responsible for the diffuse γ-ray emission of the surrounding interstellar medium. In particular, the young star cluster Westerlund 2 can provide sufficient non-thermal energy to account for the γ-ray emission. In this scenario, since the γ-ray production region is significantly larger than the area occupied by the star cluster, we conclude that the γ-ray production is caused by hadronic interactions of accelerated protons and nuclei with the ambient gas. In that case, the total energy budget in relativistic particles is estimated of the order of 1050 erg.
NASA Astrophysics Data System (ADS)
Gochis, E. E.; Huntoon, J. E.
2015-12-01
Mi-STAR (Michigan Science Teaching and Assessment Reform, http://mi-star.mtu.edu/) was funded by the Herbert H. and Grace A. Dow Foundation to reform K-12 science education to present science as an integrated body of knowledge that is applied to address societal issues. To achieve this goal, Mi-STAR is developing an integrated science curriculum for the middle grades that will be aligned with the Next Generation Science Standards (NGSS). Similar to the geosciences, the curriculum requires the integration of science, engineering and math content to explore 21st-century issues and demonstrates how these concepts can be used in service of society. The curriculum is based on the Mi-STAR Unit Specification Chart which pairs interdisciplinary themes with bundled NGSS Performance Expectations. Each unit is developed by a collaborative team of K-12 teachers, university STEM content experts and science education experts. Prior to developing a unit, each member on the team attends the on-line Mi-STAR Academy, completing 18+ hours of professional development (PD). This on-line PD program familiarizes teachers and experts with necessary pedagogical and content background knowledge, including NGSS and three-dimensional learning. With this background, teams use a staged, backwards design process to craft a multi-week unit based on a series of performance based tasks, or 'challenges' that engage students in actively doing science and engineering. Each unit includes Disciplinary Core Ideas from multiple disciplines, which focus on local and familiar examples that demonstrate the relevance of science in student's lives. Performance-based assessments are interwoven throughout the unit. Mi-STAR units will go through extensive pilot testing in several school districts across the state of Michigan. Additionally, the Mi-STAR program will develop teacher professional development programs to support implementation of the curriculum and design a pre-service teacher program in integrated science. We will share preliminary results on the collaborative Mi-STAR process of designing integrated science curriculum to address NGSS.
Massive neutron stars and Λ-hypernuclei in relativistic mean field models
NASA Astrophysics Data System (ADS)
Sun, Ting-Ting; Xia, Cheng-Jun; Zhang, Shi-Sheng; Smith, M. S.
2018-02-01
Based on relativistic mean field (RMF) models, we study finite Λ-hypernuclei and massive neutron stars. The effective N-N interactions PK1 and TM1 are adopted, while the N-Λ interactions are constrained by reproducing the binding energy of Λ-hyperon at 1s orbit of {}{{Λ }}{}40{Ca}. It is found that the Λ-meson couplings follow a simple relation, indicating a fixed Λ potential well for symmetric nuclear matter at saturation densities, i.e., around {V}{{Λ }}=-29.786 {MeV}. With those interactions, a large mass range of Λ-hypernuclei can be described well. Furthermore, the masses of PSR J1614-2230 and PSR J0348+0432 can be attained adopting the Λ-meson couplings {g}{{σ }{{Λ }}}/{g}{{σ }N}≳ 0.73, {g}{{ω }{{Λ }}}/{g}{{ω }N}≳ 0.80 for PK1 and {g}{{σ }{{Λ }}}/{g}{{σ }N}≳ 0.81, {g}{{ω }{{Λ }}}/{g}{{ω }N}≳ 0.90 for TM1, respectively. This resolves the hyperon puzzle without introducing any additional degrees of freedom. Supported by National Natural Science Foundation of China (11525524, 11505157, 11375022, 11705163, 11621131001), National Key Basic Research Program of China (2013CB834400), the Physics Research and Development Program of Zhengzhou University (32410017) and the Office of Nuclear Physics in the U.S. Dept. of Energy. The computation for this work was supported by the HPC Cluster of SKLTP/ITP-CAS and the Supercomputing Center, CNIC, of the CAS
Project management lessons learned on SDIO's Delta Star and Single Stage Rocket Technology programs
NASA Technical Reports Server (NTRS)
Klevatt, Paul L.
1992-01-01
The topics are presented in viewgraph form and include the following: a Delta Star (Delta 183) Program Overview, lessons learned, and rapid prototyping and the Single Stage Rocket Technology (SSRT) Program. The basic objective of the Strategic Defense Initiative Programs are to quickly reduce key uncertainties to a manageable range of parameters and solutions, and to yield results applicable to focusing subsequent research dollars on high payoff areas.
Accessorizing Building Science – A Web Platform to Support Multiple Market Transformation Programs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Madison, Michael C.; Antonopoulos, Chrissi A.; Dowson, Scott T.
As demand for improved energy efficiency in homes increases, builders need information on the latest findings in building science, rapidly ramping-up energy codes, and technical requirements for labeling programs. The Building America Solution Center is a Department of Energy (DOE) website containing hundreds of expert guides designed to help residential builders install efficiency measures in new and existing homes. Builders can package measures with other media for customized content. Website content provides technical support to market transformation programs such as ENERGY STAR and has been cloned and adapted to provide content for the Better Buildings Residential Program. The Solution Centermore » uses the Drupal open source content management platform to combine a variety of media in an interactive manner to make information easily accessible. Developers designed a unique taxonomy to organize and manage content. That taxonomy was translated into web-based modules that allow users to rapidly traverse structured content with related topics, and media. We will present information on the current design of the Solution Center and the underlying technology used to manage the content. The paper will explore development of features, such as “Field Kits” that allow users to bundle and save content for quick access, along with the ability to export PDF versions of content. Finally, we will discuss development of an Android based mobile application, and a visualization tool for interacting with Building Science Publications that allows the user to dynamically search the entire Building America Library.« less
Image Comparisons of Black Hole vs. Neutron Dark Star by Ray Tracing
NASA Astrophysics Data System (ADS)
Froedge, D. T.
2015-04-01
In previous papers we have discussed the concept of a theory of gravitation with local energy conservation, and the properties of a large neutron star resulting when the energy of gravitation resides locally with the particle mass and not in the gravitational field. A large neutron star's surface radius grows closer to the gravitational radius as the mass increases. Since the localization of energy applies to the photon, they do not decrease energy rising in a gravitational field, and can escape. Photon trajectories in a strong gravitational field can be investigated by the use of ray tracing procedures. Only a fraction of the blackbody radiation emitted from the surface escapes into space (about 0.00004% for Sag A*). Because of the low % of escaping radiation, the heavy neutron stars considered in this paper will be referred to as a Neutron Dark Star (NDS). In contrast to the Black Hole (BH) which should be totally dark inside the photon shadow, the NDS will appear as a fuzzy low luminosity ball. For Sag A* a full width half maximum diameter is about 3.85 Schwarzschild radii inside the shadow. (http://www.arxdtf.org/css/Image%20Comparisons.pdf). The Event Horizon Telescope should be able to distinguish the difference between the theories.
HOBYS and W43-HERO: Two more steps toward a Galaxy-wide understanding of high-mass star formation
NASA Astrophysics Data System (ADS)
Motte, Frédérique; Bontemps, Sylvain; Tigé, Jérémy
The Herschel/HOBYS key program allows to statistically study the formation of 10-20 M ⊙ stars. The IRAM/W43-HERO large program is itself dedicated to the much more extreme W43 molecular complex, which forms stars up to 50 M ⊙. Both reveal high-density cloud filaments of several pc3, which are forming clusters of OB-type stars. Given their activity, these so-called mini-starburst cloud ridges could be seen as ``miniature and instant models'' of starburst galaxies. Both surveys also strongly suggest that high-mass prestellar cores do not exist, in agreement with the dynamical formation of cloud ridges. The HOBYS and W43 surveys are necessary steps towards Galaxy-wide studies of high-mass star formation.
Ultra high energy gamma rays, cosmic rays and neutrinos from accreting degenerate stars
NASA Technical Reports Server (NTRS)
Brecher, K.; Chanmugam, G.
1985-01-01
Super-Eddington accretion for a recently proposed unipolar induction model of cosmic ray acceleration in accreting binary star systems containing magnetic white dwarfs or neutron stars is considered. For sufficiently high accretion rates and low magnetic fields, the model can account for: (1) acceleration of cosmic ray nuclei up to energies of 10 to the 19th power eV; (2) production of more or less normal solar cosmic ray composition; (3) the bulk of cosmic rays observed with energies above 1 TeV, and probably even down to somewhat lower energies as well; and (4) possibly the observed antiproton cosmic ray flux. It can also account for the high ultra high energy (UHE) gamma ray flux observed from several accreting binary systems (including Cygnus X-3), while allowing the possibility of an even higher neutrino flux from these sources, with L sub nu/L sub gamma is approximately 100.
Directed energy deflection laboratory measurements of common space based targets
NASA Astrophysics Data System (ADS)
Brashears, Travis; Lubin, Philip; Hughes, Gary B.; Meinhold, Peter; Batliner, Payton; Motta, Caio; Madajian, Jonathan; Mercer, Whitaker; Knowles, Patrick
2016-09-01
We report on laboratory studies of the effectiveness of directed energy planetary defense as a part of the DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR and DE-STARLITE are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid. In the DESTAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds a common space target sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 , which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 μN/Woptical, though we assume a more conservative value of 80 μN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 μN/Woptical in our deflection modeling. Our measurements discussed here yield about 45 μN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed. Results vary depending on the material tested and are limited to measurements of 1 axis, so further tests must be performed.
The Evolving Universe: Structure and Evolution of the Universe Roadmap 2000-2020
NASA Technical Reports Server (NTRS)
1997-01-01
The Roadmap for the Structure and Evolution of the Universe (SEU) theme embraces three fundamental, scientific quests: (1) To explain structure in the Universe and forecast our cosmic destiny. (2) To explore the cycles of matter and energy in the evolving Universe. (3) To examine the ultimate limits of gravity and energy in the Universe. These quests are developed into six, focused research campaigns addressing the objectives of one or more quests: Identify dark matter and learn how it shapes galaxies and systems of galaxies; Find out where and when the chemical elements were made; Understand the cycles in which matter, energy, and magnetic field are exchanged between stars and the gas between stars; Discover how gas flows in disks and how cosmic jets are formed; Identify the sources of gamma-ray bursts and high-energy cosmic rays; and Measure how strong gravity operates near black holes and how it affects the early Universe. These campaigns lead to a portfolio of future major missions of strong scientific and popular appeal, strongly endorsed by the scientific community and which has undergone significant initial study. Some of these missions are in a state of readiness that makes ideal candidates for the present Office of Space Science Strategic Plan; others may well feature in the next Strategic Plan. Each provides a golden scientific opportunity to advance our understanding of the Universe. Our highest priority science objectives are addressed by five Observatory Class Missions, unranked by science, but in approximate order of readiness: A high-energy gamma-ray facility that will observe relativistic jets and study the sources of cosmic gamma ray bursts; An ultra-sensitive X-ray telescope, optimized for spectroscopy, to examine the hot gas linked with clusters of galaxies, the disks around black holes, and supernova explosions; A large, radio telescope in deep space to map central regions of distant quasars and perform astrometric investigations; An orbiting gravitational coalescing, massive black holes and test how gravity waves distort spacetime; A pair of Earth-orbiting, optical telescopes that will detect flashes of light produced when ultra high-energy cosmic rays impact the upper atmosphere so as to determine their arrival directions and energies. A new program for supporting pertinent international collaboration is strongly endorsed and maintaining a strong Explorer program is important. The flexibility to exploit exceptional opportunities, such as attaching payloads to space station, should also be acquired. A strong technology development program must be initiated now to enable this mission set.
Calibrating Star Formation: The Link between Feedback and Galaxy Evolution
NASA Astrophysics Data System (ADS)
Calzetti, Daniela
2005-07-01
Stellar feedback - the return of mass and energy from star formation to the interstellar medium - is one of the primary engines of galaxy evolution. Yet, the theoretical foundation of mechanical feedback is, to date, unconstrained by observations. We propose to investigate this fundamental aspect of star formation on a sample of two local actively star-forming galaxies, NGC4449, and Holmberg II. The two galaxies have been selected to occupy an unexplored, yet crucial for quantifying mechanical feedback, niche in the two-parameter space of star formation intensity and galaxy mass. ACS/WFC and WFPC2 narrow-band observations in the light of H-beta, [OIII], H-alpha, and [NII] will be obtained for both galaxies, in order to: {1} discriminate the feedback-induced shock fronts from the photoionization regions; {2} map the shocks inside and around the starburst regions; and {3} measure the energy budget of the star-formation-produced shocks. These observations, complemented by existing data, will yield: {1} the efficiency of the feedback, i.e. the fraction of the star formation's mechanical energy that is transported out of the starburst volume rather than confined or radiated away; {2} the dependence of this efficiency on the two fundamental parameters of star formation intensity and stellar mass. The high angular resolution of HST is crucial for separating the spatially narrow shock fronts { 5 pc, 0.25" at 4 Mpc} from the more extended photoionization fronts. The legacy from this project will be the most complete quantitative measurement of the energetics associated with feedback processes. We will secure the first milestone for placing feedback mechanisms on a solid physical ground, and for understanding quantitatively their role on the energetics, structure, and star formation history of galaxies at all redshifts.
Acoustic flight testing of advanced design propellers on a JetStar aircraft
NASA Technical Reports Server (NTRS)
Lasagna, P.; Mackall, K.
1981-01-01
Advanced turboprop-powered aircraft have the potential to reduce fuel consumption by 15 to 30 percent as compared with an equivalent technology turbofan-powered aircraft. An important obstacle to the use of advanced design propellers is the cabin noise generated at Mach numbers up to .8 and at altitudes up to 35,000 feet. As part of the NASA Aircraft Energy Efficiency Program, the near-field acoustic characteristics on a series of advanced design propellers are investigated. Currently, Dryden Flight Research Center is flight testing a series of propellers on a JetStar airplane. The propellers used in the flight test were previously tested in wind tunnels at the Lewis Research Center. Data are presented showing the narrow band spectra, acoustic wave form, and acoustic contours on the fuselage surface. Additional flights with the SR-3 propeller and other advanced propellers are planned in the future.
Central exclusive production at RHIC
DOE Office of Scientific and Technical Information (OSTI.GOV)
Adamczyk, Leszek; Guryn, Włodek; Turnau, Jacek
The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment’s Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at ps = 200 GeV. The preliminary spectra of two pion and four pion invariant mass reconstructed by STAR TPC in central region of pseudo-rapidity | |more » < 1, are presented. Near future plans to take data with the current system at center-of-mass energy ps = 200 GeV and plans to upgrade the forward proton tagging sys- tem are presented. Also a possible addition of the Roman Pots to the sPHENIX detector is discussed.« less
Symmetry Energy Effects in the Neutron Star Properties
NASA Astrophysics Data System (ADS)
Alvarez-Castillo, D. E.; Kubis, S.
2012-12-01
The functional form of the nuclear symmetry energy has only been determined in a very narrow range of densities. Uncertainties concern both the low as well as the high density behaviour of this function. In this work different shapes of the symmetry energy, consistent with the experimental data, were introduced and their consequences for the crustal properties of neutron stars are presented. The resulting models are in agreement with astrophysical observations.
High-Energy Astrophysics: An Overview
NASA Technical Reports Server (NTRS)
Fishman, Gerald J.
2007-01-01
High-energy astrophysics is the study of objects and phenomena in space with energy densities much greater than that found in normal stars and galaxies. These include black holes, neutron stars, cosmic rays, hypernovae and gamma-ray bursts. A history and an overview of high-energy astrophysics will be presented, including a description of the objects that are observed. Observing techniques, space-borne missions in high-energy astrophysics and some recent discoveries will also be described. Several entirely new types of astronomy are being employed in high-energy astrophysics. These will be briefly described, along with some NASA missions currently under development.
The Time-domain Spectroscopic Survey: Target Selection for Repeat Spectroscopy
NASA Astrophysics Data System (ADS)
MacLeod, Chelsea L.; Green, Paul J.; Anderson, Scott F.; Eracleous, Michael; Ruan, John J.; Runnoe, Jessie; Nielsen Brandt, William; Badenes, Carles; Greene, Jenny; Morganson, Eric; Schmidt, Sarah J.; Schwope, Axel; Shen, Yue; Amaro, Rachael; Lebleu, Amy; Filiz Ak, Nurten; Grier, Catherine J.; Hoover, Daniel; McGraw, Sean M.; Dawson, Kyle; Hall, Patrick B.; Hawley, Suzanne L.; Mariappan, Vivek; Myers, Adam D.; Pâris, Isabelle; Schneider, Donald P.; Stassun, Keivan G.; Bershady, Matthew A.; Blanton, Michael R.; Seo, Hee-Jong; Tinker, Jeremy; Fernández-Trincado, J. G.; Chambers, Kenneth; Kaiser, Nick; Kudritzki, R.-P.; Magnier, Eugene; Metcalfe, Nigel; Waters, Chris Z.
2018-01-01
As astronomers increasingly exploit the information available in the time domain, spectroscopic variability in particular opens broad new channels of investigation. Here we describe the selection algorithms for all targets intended for repeat spectroscopy in the Time Domain Spectroscopic Survey (TDSS), part of the extended Baryon Oscillation Spectroscopic Survey within the Sloan Digital Sky Survey (SDSS)-IV. Also discussed are the scientific rationale and technical constraints leading to these target selections. The TDSS includes a large “repeat quasar spectroscopy” (RQS) program delivering ∼13,000 repeat spectra of confirmed SDSS quasars, and several smaller “few-epoch spectroscopy” (FES) programs targeting specific classes of quasars as well as stars. The RQS program aims to provide a large and diverse quasar data set for studying variations in quasar spectra on timescales of years, a comparison sample for the FES quasar programs, and an opportunity for discovering rare, serendipitous events. The FES programs cover a wide variety of phenomena in both quasars and stars. Quasar FES programs target broad absorption line quasars, high signal-to-noise ratio normal broad line quasars, quasars with double-peaked or very asymmetric broad emission line profiles, binary supermassive black hole candidates, and the most photometrically variable quasars. Strongly variable stars are also targeted for repeat spectroscopy, encompassing many types of eclipsing binary systems, and classical pulsators like RR Lyrae. Other stellar FES programs allow spectroscopic variability studies of active ultracool dwarf stars, dwarf carbon stars, and white dwarf/M dwarf spectroscopic binaries. We present example TDSS spectra and describe anticipated sample sizes and results.
Gamma ray bursts of black hole universe
NASA Astrophysics Data System (ADS)
Zhang, T. X.
2015-07-01
Slightly modifying the standard big bang theory, Zhang recently developed a new cosmological model called black hole universe, which has only a single postulate but is consistent with Mach's principle, governed by Einstein's general theory of relativity, and able to explain existing observations of the universe. In the previous studies, we have explained the origin, structure, evolution, expansion, cosmic microwave background radiation, quasar, and acceleration of black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present state with hundred billion-trillions of solar masses by accreting ambient matter and merging with other black holes. This study investigates gamma ray bursts of black hole universe and provides an alternative explanation for the energy and spectrum measurements of gamma ray bursts according to the black hole universe model. The results indicate that gamma ray bursts can be understood as emissions of dynamic star-like black holes. A black hole, when it accretes its star or merges with another black hole, becomes dynamic. A dynamic black hole has a broken event horizon and thus cannot hold the inside hot (or high-frequency) blackbody radiation, which flows or leaks out and produces a GRB. A star when it collapses into its core black hole produces a long GRB and releases the gravitational potential energy of the star as gamma rays. A black hole that merges with another black hole produces a short GRB and releases a part of their blackbody radiation as gamma rays. The amount of energy obtained from the emissions of dynamic star-like black holes are consistent with the measurements of energy from GRBs. The GRB energy spectra derived from this new emission mechanism are also consistent with the measurements.
NASA Astrophysics Data System (ADS)
Kuhar, Matej; Krucker, Säm; Hannah, Iain G.; Glesener, Lindsay; Saint-Hilaire, Pascal; Grefenstette, Brian W.; Hudson, Hugh S.; White, Stephen M.; Smith, David M.; Marsh, Andrew J.; Wright, Paul J.; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Hailey, Charles J.; Harrison, Fiona A.; Stern, Daniel; Zhang, William W.
2017-01-01
We present observations of the occulted active region AR 12222 during the third Nuclear Spectroscopic Telescope ARray (NuSTAR) solar campaign on 2014 December 11, with concurrent Solar Dynamics Observatory (SDO)/AIA and FOXSI-2 sounding rocket observations. The active region produced a medium-size solar flare 1 day before the observations, at ˜18 UT on 2014 December 10, with the post-flare loops still visible at the time of NuSTAR observations. The time evolution of the source emission in the SDO/AIA 335 Å channel reveals the characteristics of an extreme-ultraviolet late-phase event, caused by the continuous formation of new post-flare loops that arch higher and higher in the solar corona. The spectral fitting of NuSTAR observations yields an isothermal source, with temperature 3.8-4.6 MK, emission measure (0.3-1.8) × 1046 cm-3, and density estimated at (2.5-6.0) × 108 cm-3. The observed AIA fluxes are consistent with the derived NuSTAR temperature range, favoring temperature values in the range of 4.0-4.3 MK. By examining the post-flare loops’ cooling times and energy content, we estimate that at least 12 sets of post-flare loops were formed and subsequently cooled between the onset of the flare and NuSTAR observations, with their total thermal energy content an order of magnitude larger than the energy content at flare peak time. This indicates that the standard approach of using only the flare peak time to derive the total thermal energy content of a flare can lead to a large underestimation of its value.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kuhar, Matej; Krucker, Säm; Hannah, Iain G.
We present observations of the occulted active region AR 12222 during the third Nuclear Spectroscopic Telescope ARray ( NuSTAR ) solar campaign on 2014 December 11, with concurrent Solar Dynamics Observatory ( SDO )/AIA and FOXSI-2 sounding rocket observations. The active region produced a medium-size solar flare 1 day before the observations, at ∼18 UT on 2014 December 10, with the post-flare loops still visible at the time of NuSTAR observations. The time evolution of the source emission in the SDO/ AIA 335 Å channel reveals the characteristics of an extreme-ultraviolet late-phase event, caused by the continuous formation of newmore » post-flare loops that arch higher and higher in the solar corona. The spectral fitting of NuSTAR observations yields an isothermal source, with temperature 3.8–4.6 MK, emission measure (0.3–1.8) × 10{sup 46} cm{sup −3}, and density estimated at (2.5–6.0) × 10{sup 8} cm{sup −3}. The observed AIA fluxes are consistent with the derived NuSTAR temperature range, favoring temperature values in the range of 4.0–4.3 MK. By examining the post-flare loops’ cooling times and energy content, we estimate that at least 12 sets of post-flare loops were formed and subsequently cooled between the onset of the flare and NuSTAR observations, with their total thermal energy content an order of magnitude larger than the energy content at flare peak time. This indicates that the standard approach of using only the flare peak time to derive the total thermal energy content of a flare can lead to a large underestimation of its value.« less
NASA Technical Reports Server (NTRS)
Kuhar, Matej; Krucker, Sam; Hannah, Iain G.; Glesener, Lindsay; Saint-Hilaire, Pascal; Grefenstette, Brian W.; Hudson, Hugh S.; White, Stephen M.; Smith, David M.; Marsh, Andrew J.;
2017-01-01
We present observations of the occulted active region AR 12222 during the third Nuclear Spectroscopic Telescope ARray (NuSTAR) solar campaign on 2014 December 11, with concurrent Solar Dynamics Observatory (SDO)/ AIA and FOXSI-2 sounding rocket observations. The active region produced a medium-size solar flare 1 day before the observations, at approximately 18 UT on 2014 December 10, with the post-flare loops still visible at the time of NuSTAR observations. The time evolution of the source emission in the SDO/AIA 335 Å channel reveals the characteristics of an extreme-ultraviolet late-phase event, caused by the continuous formation of new post-flare loops that arch higher and higher in the solar corona. The spectral fitting of NuSTAR observations yields an isothermal source, with temperature 3.8-4.6 MK, emission measure (0.3-1.8) × 1046 cm-3, and density estimated at (2.5-6.0) × 108 cm-3. The observed AIA fluxes are consistent with the derived NuSTAR temperature range, favoring temperature values in the range of 4.0-4.3 MK. By examining the post-flare loops' cooling times and energy content, we estimate that at least 12 sets of post-flare loops were formed and subsequently cooled between the onset of the flare and NuSTAR observations, with their total thermal energy content an order of magnitude larger than the energy content at flare peak time. This indicates that the standard approach of using only the flare peak time to derive the total thermal energy content of a flare can lead to a large underestimation of its value.
The Formation and Early Evolution of Embedded Massive Star Clusters
NASA Astrophysics Data System (ADS)
Barnes, Peter
We propose to combine Spitzer, WISE, Herschel, and other archival spacecraft data with an existing ground- and space-based mm-wave to near-IR survey of molecular clouds over a large portion of the Milky Way, in order to systematically study the formation and early evolution of massive stars and star clusters, and provide new observational calibrations for a theoretical paradigm of this key astrophysical problem. Central Objectives: The Galactic Census of High- and Medium-mass Protostars (CHaMP) is a large, unbiased, uniform, and panchromatic survey of massive star and cluster formation and early evolution, covering 20°x6° of the Galactic Plane. Its uniqueness lies in the comprehensive molecular spectroscopy of 303 massive dense clumps, which have also been included in several archival spacecraft surveys. Our objective is a systematic demographic analysis of massive star and cluster formation, one which has not been possible without knowledge of our CHaMP cloud sample, including all clouds with embedded clusters as well as those that have not yet formed massive stars. For proto-clusters deeply embedded within dense molecular clouds, analysis of these space-based data will: 1. Yield a complete census of Young Stellar Objects in each cluster. 2. Allow systematic measurements of embedded cluster properties: spectral energy distributions, luminosity functions, protostellar and disk fractions, and how these vary with cluster mass, age, and density. Combined with other, similarly complete and unbiased infrared and mm data, CHaMP's goals include: 3. A detailed comparison of the embedded stellar populations with their natal dense gas to derive extinction maps, star formation efficiencies and feedback effects, and the kinematics, physics, and chemistry of the gas in and around the clusters. 4. Tying the demographics, age spreads, and timescales of the clusters, based on pre-Main Sequence evolution, to that of the dense gas clumps and Giant Molecular Clouds. 5. A measurement of the local star formation rate per gas mass surface density in the Milky Way, as well as examining arm versus interarm dependencies. Methods and Techniques: We will primarily use archival cryogenic-Spitzer, WISE, and Herschel data, and support this with existing data from ground- and space-based facilities, to conduct a comprehensive assay of critical metrics (as above) and provide observational calibration of theoretical models over the entire massive star formation process. The mm-wave molecular maps of 303 dense gas clumps in multiple species, comprising all the gas above a column density limit of 100 Msun/pc^2, are already inhand. We have also surveyed the embedded stellar content of these clumps, down to subsolar masses, in the near-infrared J, H, and K bands and with deep Warm Spitzer data. Relevance to NASA programs: Analysis to date of the space- and ground-based data has yielded several new insights into evolutionary timescales and the chemical & energy evolution of clumps during the cluster formation process. Investigations as described in this proposal will yield new demographic insights on how the properties and evolution of molecular clouds relate to the properties of massive stars and clusters that form within them, and significantly enhance the science return from these spacecraft missions. The large number of resulting data products are already being made publicly available to the astronomical community, providing crucial information for future NASA science targets. This research will be performed within the framework of a broad international collaboration spanning four continents. This ambitious but practical program will therefore maximise the science payoff from these archival data sets, provide enhanced legacy data for more advanced studies with the next generation of ground- and space-based instruments such as JWST, and open up several new windows into the discovery space of Galactic star formation & interstellar medium studies.
Chandra Adds to Story of the Way We Were
NASA Astrophysics Data System (ADS)
2003-05-01
Data from NASA's Chandra X-ray Observatory have enabled astronomers to use a new way to determine if a young star is surrounded by a planet-forming disk like our early Sun. These results suggest that disks around young stars can evolve rapidly to form planets, or they can be disrupted by close encounters with other stars. Chandra observed two young star systems, TW Hydrae and HD 98800, both of which are in the TW Hydrae Association, a loose cluster of 10 million-year-old stars. Observations at infrared and other wavelengths have shown that several stars in the TW Hydrae Association are surrounded by disks of dust and gas. At a distance of about 180 light years from Earth, these systems are among the nearest analogs to the early solar nebula from which Earth formed. "X-rays give us an excellent new way to probe the disks around stars," said Joel Kastner of the Rochester Institute of Technology in Rochester, NY during a press conference today in Nashville, Tenn. at a meeting of the American Astronomical Society. "They can tell us whether a disk is very near to its parent star and dumping matter onto it, or whether such activity has ceased to be important. In the latter case, presumably the disk has been assimilated into larger bodies - perhaps planets--or disrupted." TW Hydrae and HD 98800A Chandra 0th Order Image of HD98800 Kastner and his colleagues found examples of each type of behavior in their study. One star, TW Hydrae, namesake of the TW Hydrae Association, exhibited features in its X-ray spectrum that provide strong, new evidence that matter is accreting onto the star from a circumstellar disk. They concluded that matter is guided by the star's magnetic field onto one or more hot spots on the surface of the star. In contrast, Chandra observations of the young multiple star system HD 98800 revealed that its brightest star, HD 98800A, is producing X-rays much as the Sun does, from a hot upper atmosphere or corona. HD 98800 is a complex multiple-star system consisting of two pairs of stars, called HD 98800A and HD 98800B. These pairs, each of which is about an Earth-Sun distance apart, orbit each other at about the same distance as Pluto orbits the Sun. "Our X-ray results are fully consistent with other observations that show that accretion of matter from a disk in HD 98800A has dropped to a low level," said Kastner. "So Chandra has thrown new weight behind the evidence that any disk in this system has been greatly diminished or destroyed in ten million years, perhaps by the ongoing formation of planets or by the companion stars." The new X-ray technique for studying disks around stars relies on the ability of Chandra's spectrometers to measure the energies of individual X-rays very precisely. By comparing the number of X-rays emitted by hot gas at specific energies from ions such as oxygen and neon, the temperature and density of particles can be determined. This new technique will help astronomers to distinguish between an accretion disk and a stellar corona as the origin of intense X-ray emission from a young star. Other members of the research team are David Huenemoerder, Norbert Schulz, and Claude Canizares from the Massachusetts Institute of Technology, and David Weintraub from Vanderbilt University. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass., for the Office of Space Science at NASA Headquarters, Washington. The image and additional information are available at: http://chandra.harvard.edu and http://chandra.nasa.gov
Noise measurement flight test for Aerospatiale AS 355F Twin Star helicopter : data and analyses
DOT National Transportation Integrated Search
1999-09-30
This report is the fourth in a series of seven documenting the FAA helicopter noise measurement program conducted at Dulles International Airport during the summer of 1983. The TwinStar test program involved the acquisition of detailed acoustical, po...
Morning Star Students: Looking Back to Find Direction for the Future.
ERIC Educational Resources Information Center
Sloan, Leroy V.
1981-01-01
Follow-up of Morning Star Native teacher education program graduates indicates increased post-secondary educational opportunities, greater numbers of qualified Native teachers, and community acceptance of program graduates. Available from: Canadian Journal of Native Education, Department of Educational Foundations, 5-109 Education North,…
2011-06-09
Stennis Space Center Deputy Director Rick Gilbrech (right) accepts a plaque designating the test facility as a Voluntary Protection Program Star site. Presenting the plaque is Clyde Payne, area director for the Occupational Safety and Health Administration in Jackson, Miss. OSHA established VPP in 1982 as a proactive safety management model to recognize excellence in safety and health. Since then, more than 2,000 organizations have been designated VPP Star sites. To reach that goal, an organization must demonstrate comprehensive and successful safety and health management programs in the workplace.
Oxygen-Sodium Anticorrelation in Field RR Lyr-Type Stars
NASA Astrophysics Data System (ADS)
Andrievsky, S.; Korotin, S.; Lyashko, D.; Tsymbal, V.
2017-06-01
We have performed analysis of a large amount of the fields RR Lyr type stars spectra with the aim to derive NLTE oxygen and sodium abundances in our program stars. Fundamental parameters (Teff, log g, Vt) and metallicity were found using the method of the fitting between synthetic and observed spectra using the SME program which was developed by N. Piskunov and J. A. Valenti. As a result of this analysis anticorrelation between oxygen (O/H) and sodium (Na/H) abundances was found.
Using Stars to Align a Steered Laser System for Cosmic Ray Simulation
NASA Astrophysics Data System (ADS)
Krantz, Harry; Wiencke, Lawrence
2016-03-01
Ultra high energy cosmic rays (UHECRs) are the highest energy cosmic particles with kinetic energy above 1018eV . UHECRs are detected from the air shower of secondary particles and UV florescence that results from interaction with the atmosphere. A high power UV laser beam can be used to simulate the optical signature of a UHCER air shower. The Global Light System (GLS) is a planned network of ground-based light sources including lasers to support the planned space-based Extreme Universe Space Observatory (EUSO). A portable prototype GLS laser station has been constructed at the Colorado School of Mines. Currently the laser system uses reference targets on the ground but stars can be used to better align the beam by providing a complete hemisphere of targets. In this work, a CCD camera is used to capture images of known stars through the steering head optics. The images are analyzed to find the steering head coordinates of the target star. The true coordinates of the star are calculated from the location and time of observation. A universal adjustment for the steering head is determined from the differences between the two pairs of coordinates across multiple stars. This laser system prototype will also be used for preflight tests of the ESUO Super Pressure Balloon mission.
Kepler Flares. IV. A Comprehensive Analysis of the Activity of the dM4e Star GJ 1243
NASA Astrophysics Data System (ADS)
Silverberg, Steven M.; Kowalski, Adam F.; Davenport, James R. A.; Wisniewski, John P.; Hawley, Suzanne L.; Hilton, Eric J.
2016-10-01
We present a comprehensive study of the active dM4e star GJ 1243. We use previous observations and ground-based echelle spectroscopy to determine that GJ 1243 is a member of the Argus association of field stars, suggesting it is ∼ 30{--}50 {{Myr}} old. We analyze 11 months of 1 minute cadence data from Kepler, presenting Kepler flare frequency distributions, as well as determining correlations between flare energy, amplitude, duration, and decay time. We find that the exponent α of the power-law flare energy distribution varies in time, primarily due to completeness of sample and the low frequency of high-energy flares. We also find a deviation from a single power law at high energy. We use ground-based spectroscopic observations that were simultaneous with the Kepler data to provide simultaneous photometric and spectroscopic analysis of three low-energy flares, the lowest-energy dMe flares with detailed spectral analysis to date on any star. The spectroscopic data from these flares extend constraints for radiative hydrodynamic flare models to a lower energy regime than has previously been studied. We use this simultaneous spectroscopy and Kepler photometry to develop approximate conversions from the Kepler bandpass to the traditional U and B bands. This conversion will be a critical factor in comparing any Kepler flare analyses to the canon of previous ground-based flare studies.
Energy flux determines magnetic field strength of planets and stars.
Christensen, Ulrich R; Holzwarth, Volkmar; Reiners, Ansgar
2009-01-08
The magnetic fields of Earth and Jupiter, along with those of rapidly rotating, low-mass stars, are generated by convection-driven dynamos that may operate similarly (the slowly rotating Sun generates its field through a different dynamo mechanism). The field strengths of planets and stars vary over three orders of magnitude, but the critical factor causing that variation has hitherto been unclear. Here we report an extension of a scaling law derived from geodynamo models to rapidly rotating stars that have strong density stratification. The unifying principle in the scaling law is that the energy flux available for generating the magnetic field sets the field strength. Our scaling law fits the observed field strengths of Earth, Jupiter, young contracting stars and rapidly rotating low-mass stars, despite vast differences in the physical conditions of the objects. We predict that the field strengths of rapidly rotating brown dwarfs and massive extrasolar planets are high enough to make them observable.
Dynamical Mass Segregation Versus Disruption of Binary Stars in Dense Stellar Systems
NASA Astrophysics Data System (ADS)
de Grijs, Richard; Li, C.; Deng, L.
2013-01-01
Upon their formation, dynamically cool (collapsing) star clusters will, within only a few million years, achieve stellar mass segregation for stars down to a few solar masses due to gravitational two-body encounters. Since binary systems are, on average, more massive than single stars, one would expect them to also rapidly mass segregate dynamically. Contrary to these expectations and based on high-resolution Hubble Space Telescope observations, we show that the compact, 15-30 Myr-old Large Magellanic Cloud cluster NGC 1818 is characterized by an increasing fraction of F-star binary systems (with combined masses of 1.3-1.6 solar masses) with increasing distance from the cluster center. This offers unprecedented support of the theoretically predicted but thus far unobserved dynamical disruption processes of the significant population of "soft" binary systems (with relatively low binding energies compared to the kinetic energy of their stellar members) in star clusters, which we could unravel by virtue of the cluster's unique combination of youth and high stellar density.
NASA Technical Reports Server (NTRS)
Goodyear, M. D.
1987-01-01
NASA sponsored the Aircraft Energy Efficiency (ACEE) program in 1976 to develop technologies to improve fuel efficiency. Laminar flow control was one such technology. Two approaches for achieving laminar flow were designed and manufactured under NASA sponsored programs: the perforated skin concept used at McDonnell Douglas and the slotted design used at Lockheed-Georgia. Both achieved laminar flow, with the slotted design to a lesser degree (JetStar flight test program). The latter design had several fabrication problems concerning springback and adhesive flow clogging the air flow passages. The Lockheed-Georgia Company accomplishments is documented in designing and fabricating a small section of a leading edge article addressing a simpler fabrication method to overcome the previous program's manufacturing problems, i.e., design and fabrication using advanced technologies such as diffusion bonding of aluminum, which has not been used on aerospace structures to date, and the superplastic forming of aluminum.
78 FR 25262 - TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Filings
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-30
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. PR13-16-002; PR13-17-002; Not Consolidated] TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Filings Take notice that on April 23, 2013, the applicants listed above submitted an amendment to the December...
The spectral energy distribution of Zeta Puppis and HD 50896
NASA Technical Reports Server (NTRS)
Holm, A. V.; Cassinelli, J. P.
1977-01-01
The ultraviolet spectral energy distribution of the O5f star Zeta Pup and the WN5 star HD 50896 are derived from OAO-2 observations with the calibration of Bless, Code, and Fairchild (1976). An estimate of the interstellar reddening (0.12 magnitude) of the Wolf-Rayet star is determined from the size of the characteristic interstellar extinction bump at 4.6 inverse microns. After correction for extinction, both stars show a flat energy distribution in the ultraviolet. The distribution of HD 50896 from 1100 A to 2 microns is in good agreement with results of extended model atmospheres, but some uncertainty remains because of the interstellar-extinction correction. The absolute energy distribution of Zeta Pup is fitted by a 42,000-K plane-parallel model if the model's flux is adjusted for the effects of electron scattering in the stellar wind and for UV line blanketing that was determined empirically from high-resolution Copernicus satellite observations. To achieve this fit, it is necessary to push both the spectroscopically determined temperature and the ultraviolet calibration to the limits of their probable errors.
Can You See the Stars? Citizen-Science Programs to Measure Night Sky Brightness
NASA Astrophysics Data System (ADS)
Walker, Constance E.
2009-05-01
For the IYA2009 Dark Skies Awareness Cornerstone Project, partners in dark-sky, astronomy and environmental education are promoting three citizen-scientist programs that measure light pollution at local levels worldwide. These programs take the form of "star hunts", providing people with fun and direct ways to acquire heightened awareness about light pollution through first-hand observations of the night sky. Together the programs are spanning the entire IYA, namely: GLOBE at Night in March, Great World Wide Star Count in October, and How Many Stars during the rest of the year. Citizen-scientists - students, educators, amateur astronomers and the general public - measure the darkness of their local skies and contribute observations online to a world map. Anyone anywhere anytime can look within particular constellations for the faintest stars and match them to one of seven star maps. For more precise measurements, digital sky-brightness meters can be used. Measurements, along with the measurement location, time, and date, are submitted online, and within a few days to weeks a world map showing results is available. These measurements can be compared with data from previous years, as well as with satellite data, population densities, and electrical power-usage maps. Measurements are available online via Google Earth or other tools and as downloadable datasets. Data from multiple locations in one city or region are especially interesting, and can be used as the basis of a class project or science fair experiment, or even to inform the development of public policy. In the last few years these programs successfully conducted campaigns in which more than 35,000 observations were submitted from over 100 countries. The presentation will provide an update, describe how people can become involved and take a look ahead at the program's sustainability. For further information about these and other Dark Skies Awareness programs, please visit www.darkskiesawareness.org.
CU-STARs: Promoting STEM Diversity by Addressing First-year Attrition of Underrepresented Minorities
NASA Astrophysics Data System (ADS)
Battersby, Cara; Silvia, Devin W.; Ellingson, Erica; Sturner, Andrew P.; Peck, Courtney
2015-01-01
Upon first entering university, the fraction of students interested in pursuing a STEM major are distributed according to societal demographics (with 25% being underrepresented minorities), but by graduation, the fraction of students receiving STEM degrees is unbalanced, with underrepresented minorities receiving only 15% of STEM bachelor's degrees. The CU-STARs (CU Science, Technology, and Astronomy Recruits) program at the University of Colorado, Boulder is targeted to address the main triggers of early career attrition for underrepresented minorities in STEM disciplines. A select group of students are given financial support through work-study at the Fiske planetarium on campus, while resources to address other triggers of attrition are available to the entire cohort of interested students (typically ~5-10 per year). These resources are designed to promote social engagement and mentorship, while also providing a support network and resources to combat inadequate high school preparation for STEM courses. We achieve these goals through activities that include social events, mentor meetings, free tutoring, and special events to meet and talk with scientists. The culmination of the program for the recruits are a series of high school outreach events in underserved areas (inner city and rural alike), in which they become the expert. The STARs are paid for their time and take the lead in planning, teaching, and facilitating programs for the high school students, including classroom presentations, interactive lab activities, solar observing, and star parties. The high school outreach events provide role models and STEM exposure for the underserved high school community while simultaneously cementing the personal achievements and successes for the STARs. CU-STARs is now in its 4th year and is still growing. We are beginning the process of formal assessments of the program's success. We present details of the program implementation, a discussion of potential obstacles and future plans, and initial results of the program assessment, which speak highly of the program's contribution to individual student success.
ERIC Educational Resources Information Center
Thompson, Walter R.
2009-01-01
Physical education time has been reduced or even eliminated in middle and high schools in favor of more time for standardized test preparation, especially in urban schools and inner cities. One way to replace the time lost is by providing it after school as part of a comprehensive program. After-School All-Stars (ASAS) is such a program, networked…
The symmetry energy {\\boldsymbol{\\gamma }} parameter of relativistic mean-field models
NASA Astrophysics Data System (ADS)
Dutra, Mariana; Lourenço, Odilon; Hen, Or; Piasetzky, Eliezer; Menezes, Débora P.
2018-05-01
The relativistic mean-field models tested in previous works against nuclear matter experimental values, critical parameters and macroscopic stellar properties are revisited and used in the evaluation of the symmetry energy γ parameter obtained in three different ways. We have checked that, independent of the choice made to calculate the γ values, a trend of linear correlation is observed between γ and the symmetry energy ({{\\mathscr{S}}}0) and a more clear linear relationship is established between γ and the slope of the symmetry energy (L 0). These results directly contribute to the arising of other linear correlations between γ and the neutron star radii of {R}1.0 and {R}1.4, in agreement with recent findings. Finally, we have found that short-range correlations induce two specific parametrizations, namely, IU-FSU and DD-MEδ, simultaneously compatible with the neutron star mass constraint of 1.93≤slant {M}{{\\max }}/{M}ȯ ≤slant 2.05 and with the overlap band for the {L}0× {{\\mathscr{S}}}0 region, to present γ in the range of γ =0.25+/- 0.05. This work is a part of the project INCT-FNA Proc. No. 464898/2014-5 and was partially supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil under grants 300602/2009-0 and 306786/2014-1. E. P. acknowledges support from the Israel Science Foundation. O. H. acknowledges the U.S. Department of Energy Office of Science, Office of Nuclear Physics program under award number DE-FG02-94ER40818
NASA Technical Reports Server (NTRS)
Johansson, Sveneric; Carpenter, Kenneth G.
1988-01-01
Two fluorescence processes operating in atmospheres of cool stars, symbiotic stars, and the Sun are presented. Two emission lines, at 1347.03 and 1360.17 A, are identified as fluorescence lines of Cr II and Fe II. The lines are due to transitions from highly excited levels, which are populated radiatively by the hydrogen Lyman alpha line due to accidental wavelength coincidences. Three energy levels, one in Cr II and two in Fe II, are reported.
Space Motions of Low-Mass Stars. III.
NASA Astrophysics Data System (ADS)
Upgren, A. R.; Sperauskas, J.; Boyle, R. P.
Radial velocity observations are presented for 149 stars taken from the McCormick lists of dwarf K and M stars in a continuing program of radial velocities of faint nearby stars. The data will serve to derive a total stellar density of these kinds of stars in the solar neighborhood. These data were obtained with the spectrometer of the Vilnius University Observatory mounted on the 1.6 m Kuiper Telescope of the Steward Observatory.
TEMPLATES: Targeting Extremely Magnified Panchromatic Lensed Arcs and Their Extended Star Formation
NASA Astrophysics Data System (ADS)
Rigby, Jane; Vieira, Joaquin; Bayliss, M.; Fischer, T.; Florian, M.; Gladders, M.; Gonzalez, A.; Law, D.; Marrone, D.; Phadke, K.; Sharon, K.; Spilker, J.
2017-11-01
We propose high signal-to-noise NIRSpec and MIRI IFU spectroscopy, with accompanying imaging, for 4 gravitationally lensed galaxies at 1
A Decade of Field Changing Atmospheric Aerosol Research: Outcomes of EPA’s STAR Program
Conference: Gordon Research Conference in Atmospheric Chemistry, July 28 – August 2, 2013, VermontPresentation Type: PosterTitle: An Analysis of EPA’s STAR Program and a Decade of Field Changing Research in Atmospheric AerosolsAuthors: Kristina M. Wagstrom1,2, Sherri ...
ERIC Educational Resources Information Center
Kalinowski, Michael
2007-01-01
This article features StarBright Learning Exchange, a program that provides a cross-cultural exchange between Australian and South African early childhood educators. The program was originated when its president, Carol Allen, and her colleague, Karen Williams, decided that they could no longer sit by and watch the unfolding social catastrophe that…
Mass Loss at Higher Metallicity: Quantifying the Mass Return from Evolved Stars in the Galactic
NASA Astrophysics Data System (ADS)
Sargent, Benjamin
Bulge Mass-losing evolved stars, and in particular asymptotic giant branch (AGB) stars and red supergiant (RSG) stars, are expected to be the major producers of dust in galaxies. This dust will help form planetary systems around future generations of stars. Our ADAP program to measure the mass loss from the AGB and RSG stars in the Magellanic Clouds is nearing completion, and we wish to extend this successful study to the Galactic bulge of the Milky Way Galaxy. Metallicity should determine the amount of elements available to condense dust in the star's outflow, so evolved stars of differing metallicities should have differing mass-loss rates. Building upon our work on evolved stars in the Magellanic Clouds, we will compare the mass-loss rates from AGB and RSG stars in the older and potentially more metal-rich Bulge to the mass-loss rates of AGB and RSG stars in the Magellanic Clouds, which have lower metallicity, making for an interesting contrast. In addition, the Galactic bulge, like the Clouds, is located at a well-determined distance ( 8 kpc), thereby removing the distance ambiguities that present a major uncertainty in determining mass-loss rates and luminosities for evolved stars. To model photometric observations of outflowing dust shells around evolved stars, we have constructed the Grid of Red supergiant and Asymptotic giant branch ModelS (GRAMS; Sargent et al 2011; Srinivasan et al 2011) using the radiative transfer code 2Dust (Ueta and Meixner 2003). Our study will apply these models to the large photometric database of sources identified in the Spitzer Space Telescope GLIMPSE survey of the Milky Way and also to the various infrared spectra of Bulge AGB and RSG stars from Spitzer, ISO, etc. We have already modeled a few Galactic bulge evolved stars with GRAMS, and we will use these results as the foundation for modeling a large and representative sample of Galactic bulge evolved stars identified and measured photometrically by GLIMPSE. We will use our GRAMS grid, expanding as necessary to enable modeling of the higher metallicity evolved stars of the Galactic bulge, along with models of other types of stars, such as YSOs (Robitaille et al 2006), to identify the evolved stars in the GLIMPSE sample of the Galactic bulge. We will use these well-tested GRAMS models, which we have already extensively applied to study populations of mass losing evolved stars in the Magellanic Clouds, to fit the Spectral Energy Distributions (SEDs; plots of emitted power versus wavelength) of GLIMPSE Galactic bulge sources identified as RSG stars and oxygen-rich (O-rich), carbon-rich (C-rich), and extreme AGB stars. This modeling will yield stellar luminosities and mass-loss rates, as well as general dust chemistry (Orich versus C-rich) and other essential characteristics of the dust produced by evolved stars in the galactic plane. Our ongoing Magellanic Cloud and proposed Milky Way Galactic bulge evolved star studies will lay the groundwork for future studies of evolved stars in other nearby galaxies using data from the James Webb Space Telescope and other planned missions.
TEMPLATES: Targeting Extremely Magnified Panchromatic Lensed Arcs and Their Extended Star formation
NASA Astrophysics Data System (ADS)
Spilker, Justin; Rigby, Jane R.; Vieira, Joaquin D.; TEMPLATES Team
2018-06-01
TEMPLATES is a JWST Early Release Science program designed to produce high signal-to-noise imaging and IFU spectroscopic data cubes for four gravitationally lensed galaxies at high redshift. The program will spatially resolve the star formation in galaxies across the peak of cosmic star formation in an extinction-robust manner. Lensing magnification pushes JWST to the highest spatial resolutions possible at these redshifts, to map the key spectral diagnostics of star formation and dust extinction: H-alpha, Pa-alpha, and 3.3um PAH emission within individual distant galaxies. Our targets are among the brightest, best-characterized lensed systems known, and include both UV-bright 'normal' galaxies and heavily dust-obscured submillimeter galaxies, at a range of stellar masses and luminosities. I will describe the scientific motivation for this program, detail the targeted galaxies, and describe the planned data products to be delivered to the community in advance of JWST Cycle 2.
Simple Activities for Powerful Impact
NASA Astrophysics Data System (ADS)
LaConte, K.; Shupla, C. B.; Dusenbery, P.; Harold, J. B.; Holland, A.
2016-12-01
STEM education is having a transformational impact on libraries across the country. The STAR Library Education Network (STAR_Net) provides free Science-Technology Activities & Resources that are helping libraries to engage their communities in STEM learning experiences. Hear the results of a national 2015 survey of library and STEM professionals and learn what STEM programming is currently in place in public libraries and how libraries approach and implement STEM programs. Experience hands-on space science activities that are being used in library programs with multiple age groups. Through these hands-on activities, learners explore the nature of science and employ science and engineering practices, including developing and using models, planning and carrying out investigations, and engaging in argument from evidence (NGSS Lead States, 2013). Learn how STAR_Net can help you print (free!) mini-exhibits and educator guides. Join STAR_Net's online community and access STEM resources and webinars to work with libraries in your local community.
Knowing our neighbors: Fundamental properties of nearby stars
NASA Astrophysics Data System (ADS)
Bartlett, Jennifer Lynn
The stars within 25 parsecs (pc) of our Sun constitute the one stellar sample that we aspire to know thoroughly, but we still have not even identified all of the stars within 10 pc. We have still less knowledge of the nearby substellar population, especially the planets. The four studies described herein expand our knowledge of the solar neighborhood. First, a re-analysis of the Leander McCormick Observatory photographic plates of Barnard's Star failed to detect any planets orbiting it, and this study would have detected planets with 2.2 Jupiter masses or greater. In addition, its parallax, proper motion, and secular acceleration were measured with results comparable with those from more modern equipment. Second, increased information about nearby planets was sought through time series analyses of astrometric residuals to stars observed by the University of Virginia Southern Parallax Program. Of these, LHS 288 displays an intriguing signal, which might be caused by a very low mass companion. Twelve other stars demonstrate no astrometric perturbations. While astrometry could reveal the presence of unseen companions, distances from trigonometric parallaxes define the solar neighborhood and identify its inhabitants. Preliminary parallaxes for 43 potential nearby stars being observed by the Cerro Tololo Inter-American Observatory Parallax Investigation (CTIOPI) confirmed 28 stars as being within 25 pc, including three stars---LP 991-84, LHS 6167, and LP 876-10---that probably lie within 10 pc. Three more stars lie near the 25-pc boundary and their final parallaxes may qualify them as nearby. One recently established neighbor, LP 869-26, is a potential binary. For many stars in this third sample, preliminary photometry ( V, R, and I bands), spectroscopy, and proper motions are also available. Despite the continuing importance of ground-based parallax measurements, few active programs remain. The final project tested the recently installed infrared camera on the 31-inch (0.8-meter) telescope at Fan Mountain Observatory for astrometric stability. A parallax program would be feasible there and could provide much needed distances for brown dwarfs and very low mass stars. Through this and similar efforts, we are establishing the foundations for understanding our Milky Way Galaxy, including its component stars and populations.
Post-AGB Stars in Nearby Galaxies as Calibrators for HST
NASA Technical Reports Server (NTRS)
Bond, Howard E.
2003-01-01
This report summarizes activities carried out with support from the NASA Ultraviolet, Visible, and Gravitational Astrophysics Research and Analysis Program under Grant NAG 5-6821. The Principal Investigator is Howard E. Bond (Space Telescope Science Institute). STScI Postdoctoral Associates Laura K. Fullton (1998), David Alves (1998-2001), and Michael Siegel (2001) were partially supported by this grant. The aim of the program is to calibrate the absolute magnitudes of post-asymptotic- giant-branch (post-AGB or PAGB) stars, which we believe will be an excellent new "standard candle" for measuring extragalactic distances. The argument is that, in old populations, the stars that are evolving through the PAGB region of the HR diagram arise from only a single main-sequence turnoff mass. In addition, theoretical PAGB evolutionary tracks show that they evolve through this region at constant luminosity; hence the PAGB stars should have an extremely narrow luminosity function. Moreover, as the PAGB stars evolve through spectral types F and A (en route from the AGB to hot stellar remnants and white dwarfs), they have the highest luminosities attained by old stars (both bolometrically and in the visual band). Finally, PAGB stars of these spectral types are very easily identified. because of their large Balmer jumps, which are due to their very low surface gravities. Our approach is first to identify PAGB stars in Milky Way globular clusters and in other Local Group galaxies, which are at known distances, and thus to measure accurate absolute magnitudes for the PAGB stars. With this Milky Way and Local Group luminosity calibration, we will then be in a position to find PAGB stars in more distant galaxies from the ground, and ultimately from the Hubble Space Telescope. and thus derive distances. These PAGB stars are, as noted above, the visually brightest members of Population II, and hence will allow distance measurements to galaxies that do not contain Cepheids, such as elliptical galaxies, as well as distances to spirals using PAGB stars in their halos. Moreover, the method is entirely independent of Cepheids. and thus provides a direct test of the Cepheid distance scale. The program will also provide information on the evolutionary lifetimes of PAGB stars.
Bright Young Star Clusters in NGC5253 with LEGUS
NASA Astrophysics Data System (ADS)
Calzetti, Daniela; Johnson, Kelsey E.; Adamo, Angela; Gallagher, John S.; Andrews, Jennifer E.; Smith, Linda J.; Clayton, Geoffrey C.; Lee, Janice C.; Sabbi, Elena; Ubeda, Leonardo; Kim, Hwihyun; Ryon, Jenna E.; Thilker, David A.; Bright, Stacey N.; Zackrisson, Erik; Kennicutt, Robert; de Mink, Selma E.; Whitmore, Bradley C.; Aloisi, Alessandra; Chandar, Rupali; Cignoni, Michele; Cook, David; Dale, Daniel A.; Elmegreen, Bruce; Elmegreen, Debra M.; Evans, Aaron S.; Fumagalli, Michele; Gouliermis, Dimitrios; Grasha, Kathryn; Grebel, Eva; Krumholz, Mark R.; Walterbos, Rene A. M.; Wofford, Aida; Brown, Thomas M.; Christian, Carol A.; Dobbs, Claire; Herrero-Davo`, Artemio; Kahre, Lauren; Messa, Matteo; Nair, Preethi; Nota, Antonella; Östlin, Göran; Pellerin, Anne; Sacchi, Elena; Schaerer, Daniel; Tosi, Monica
2016-01-01
Using UV-to-H broad and narrow-band HST imaging, we derive the ages and masses of the 11 brightest star clusters in the dwarf galaxy NGC5253. This galaxy, located at ~3 Mpc, hosts an intense starburst, which includes a centrally-concentrated dusty region with strong thermal radio emission (the `radio nebula'). The HST imaging includes data from the Cycle 21 Treasury Program LEGUS (Legacy ExtraGalactic UV Survey), in addition to narrow--band H-alpha (6563 A), P-beta (12820 A), and P-alpha (18756 A). The bright clusters have ages ~1-15 Myr and masses ~1E4 - 2.5E5 Msun. Two of the 11 star clusters are located within the radio nebula, and suffer from significant dust attenuation. Both are extremely young, with a best-fit age around 1 Myr, and masses ~7.5E4 and ~2.5E5 Msun, respectively. The most massive of the two `radio nebula' clusters is 2-4 times less massive than previously estimated and is embedded within a cloud of dust with A_V~50 mag. The two clusters account for about half of the ionizing photon rate in the radio nebula, and will eventually supply about 2/3 of the mechanical energy in present-day shocks. Additional sources are required to supply the remaining ionizing radiation, and may include very massive stars.
Research on Spectroscopy, Opacity, and Atmospheres
NASA Technical Reports Server (NTRS)
Kurucz, Robert L.
2005-01-01
I propose to continue providing observers with basic data for interpreting spectra from stars, novas, supernovas, clusters, and galaxies. These data will include allowed and forbidden line lists, both laboratory and computed, for the first five to ten ions of all atoms and for all relevant diatomic molecules. I will eventually expand to all ions of the first thirty elements to treat far UV and X-ray spectra, and for envelope opacities. I also include triatomic molecules provided by other researchers. I have also made CDs with Partridge and Schwenke's water data for work on UV stars. The line data also serve as input to my model atmosphere and synthesis programs that generate energy distributions, photometry, limb darkening, and spectra that can be used for planning observations and for fitting observed spectra. The spectrum synthesis programs produce detailed plots with the lines identified. Grids of stellar spectra can be used for radial velocity-, rotation-, or abundance templates and for population synthesis. I am fitting spectra of bright stars to test the data and to produce atlases to guide observers. For each star the whole spectrum is computed from the UV to the far IR. The line data, opacities, models, spectra, and programs are freely distributed on CDs and on my Web site and represent a unique resource for many NASA programs. I am now in full production of new line lists for atoms. I am computing all ions of all elements from H to Zn and the first 5 ions of all the heavier elements, about 800 ions. For each ion I treat as many as 61 even and 61 odd configurations, computing all energy levels and eigenvectors. The Hamiltonian is determined from a scaled-Hartree-Fock starting guess by least squares fitting the observed energy levels. The average energy of each configuration is used in computing scaled-Thomas-Fermi-Dirac wavefunctions for each configuration which in turn are used to compute allowed and forbidden transition integrals. These are multiplied into the LS allowed and forbidden transition arrays. The transition arrays are transformed to the observed coupling to yield the allowed and forbidden line lists. Results are put on the web as they are finished. Provided I get funding,there will be more than 500 million lines. I will then compare ion by ion, to all the laboratory and computed data in the literature and make up a working line list for spectrum synthesis and opacity calculations with the best available data. As the laboratory spectrum analyses are improved, I will redo the calculations with the new energy levels. My original plan when I started the new calculations was to run through all the atoms using my old Cray programs from the 1980's that were limited to 1100 x 1100 arrays in the Hamiltonian for each J. Then I would go back and rerun the more complicated cases with 3000 x 3000 arrays so that I could include many more configurations and more configuration interactions. At present I am limited to 61 even and 61 odd configurations and I try to include everything up through n = 9. The current program runs on Alpha workstations. I decided to test the big program on Fe I and Fe II to see whether there was any great difference in the low configurations compared to those from the Cray program. Besides increasing the number of E1 lines by a factor of 6 to 7.7 million, there was an unexpected result: the electric quadrupole transitions were 10 times stronger than before because the transition integrals are weighted by r(exp 2) ---they become very large for high n, and because there are numerous configuration interactions that mix the low and high configurations. As a check I was able to reproduce Carstang's (1962) lower results by running his three configurations with my program. Since my model atom is still only a subset of a real Fe II ion, the true quadrupole A values are probably larger than mine. The magnetic dipole lines are affected by the mixing but the overall scale does not change. Because of this scovery I decided that there was no point in computing the small array cases. I have been running with as many configurations as I can and with thousands of parameters in the Hamiltonian. The computer runs take much longer to set up and produce than I had expected. I have concentrated on redoing the low iron group spectra, especially to get data for supernova modelers. I have done only Ca I -- Zn I, Ca II -- Zn II, CU I -- Cu XXIX, Zn I - Zn XXX, for practice at high stages of ionization, C I, C II, S I, and CL I and Ag I for people who were working on the laboratory spectra. Check my web site kurucz.harvard.edu for current additions. My latest calculations have been for carbon I and sulphur I, and silicon I is under way using the same elaborate approach as for C I, which took many months to do. These line lists greatly increase the number of lines in the ultraviolet, in the visible, and especially in the infrared. They will increase the opacity in A, F, and G stars. They will account for many unidentified lines in the sun.
Millisecond newly born pulsars as efficient accelerators of electrons
NASA Astrophysics Data System (ADS)
Osmanov, Zaza; Mahajan, Swadesh; Machabeli, George; Chkheidze, Nino
2015-09-01
The newly born millisecond pulsars are investigated as possible energy sources for creating ultra-high energy electrons. The transfer of energy from the star rotation to high energy electrons takes place through the Landau damping of centrifugally driven (via a two stream instability) electrostatic Langmuir waves. Generated in the bulk magnetosphere plasma, such waves grow to high amplitudes, and then damp, very effectively, on relativistic electrons driving them to even higher energies. We show that the rate of transfer of energy is so efficient that no energy losses might affect the mechanism of particle acceleration; the electrons might achieve energies of the order of 1018 eV for parameters characteristic of a young star.
A study of the stellar population in the Chamaeleon dark clouds
NASA Technical Reports Server (NTRS)
Gauvin, Lisa S.; Strom, Karen M.
1992-01-01
The properties of the stellar population in the Chamaeleon dark clouds are discussed. Spectral energy distributions, based on the extant photometric and spectroscopic data base and IRAS fluxes measured from coadded data taken at the position of each star, and spectral types allow placement of the stars in an H-R diagram. The age and mass distributions and the luminosity function for the Chamaeleon stars are compared to those in the Taurus-Auriga dark clouds and are found to be similar. A small subsample (eight of 36) of the Chamaeleon stars show unusual spectral energy distributions which seem best interpreted as arising from circumstellar disks whose inner regions (R(in)) is less than 30-50 stellar radii) area devoid of material. The X-ray properties of this sample of premain-sequence objects are compared to those of other premain-sequence samples, as well as to the Hyades and the Pleiades main-sequence stars.
Unlocking_Secrets_of_Neutron_Stars_with_NICER
2017-05-25
Though we know neutron stars are small and extremely dense, there are still many aspects of these remnants of explosive deaths of other stars that we have yet to understand. NICER, a facility to be mounted on the outside of the International Space Station, seeks to find the answers to some of the questions still being asked about neutron stars. By capturing the arrival time and energy of the x-ray photons produced by pulsars emitted by neutron stars, NICER seeks answer decades-old questions about extreme forms of matter and energy. Data from NICER will also be used in Sextant, an on-board demonstration of pulsar-based navigation. Learn more about: https://www.nasa.gov/mission_pages/station/research/experiments/1966.html and keep up with all the science being conducted aboard your orbiting laboratory by visiting: https://www.nasa.gov/iss-science/ISS Research Overview on nasa.gov http://www.twitter.com/ISS_Research on Twitter.
Overview of NASA's Space Solar Power Technology Advanced Research and Development Program
NASA Technical Reports Server (NTRS)
Howell, Joe; Mankins, John C.; Davis, N. Jan (Technical Monitor)
2001-01-01
Large solar power satellite (SPS) systems that might provide base load power into terrestrial markets were examined extensively in the 1970s by the US Department of Energy (DOE) and the National Aeronautics and Space Administration (NASA). Following a hiatus of about 15 years, the subject of space solar power (SSP) was reexamined by NASA from 1995-1997 in the 'fresh look' study, and during 1998 in an SSP 'concept definition study', and during 1999-2000 in the SSP Exploratory Research and Technology (SERT) program. As a result of these efforts, during 2001, NASA has initiated the SSP Technology Advanced Research and Development (STAR-Dev) program based on informed decisions. The goal of the STAR-Dev program is to conduct preliminary strategic technology research and development to enable large, multi-megawatt to gigawatt-class space solar power (SSP) systems and wireless power transmission (WPT) for government missions and commercial markets (in-space and terrestrial). Specific objectives include: (1) Release a NASA Research Announcement (NRA) for SSP Projects; (2) Conduct systems studies; (3) Develop Component Technologies; (4) Develop Ground and Flight demonstration systems; and (5) Assess and/or Initiate Partnerships. Accomplishing these objectives will allow informed future decisions regarding further SSP and related research and development investments by both NASA management and prospective external partners. In particular, accomplishing these objectives will also guide further definition of SSP and related technology roadmaps including performance objectives, resources and schedules; including 'multi-purpose' applications (commercial, science, and other government).
Stellar winds and coronae of low-mass Population II/III stars
NASA Astrophysics Data System (ADS)
Suzuki, Takeru K.
2018-06-01
We investigated stellar winds from zero-/low-metallicity low-mass stars by magnetohydrodynamical simulations for stellar winds driven by Alfvén waves from stars with mass M = (0.6-0.8) M⊙ and metallicity Z = (0-1) Z⊙, where M⊙ and Z⊙ are the solar mass and metallicity, respectively. Alfvénic waves, which are excited by the surface convection, travel upward from the photosphere and heat up the corona by their dissipation. For lower Z, denser gas can be heated up to the coronal temperature because of the inefficient radiation cooling. The coronal density of Population II/III stars with Z ≤ 0.01 Z⊙ is one to two orders of magnitude larger than that of a solar-metallicity star with the same mass, and as a result, the mass loss rate, \\dot{M}, is 4.5-20 times larger. This indicates that metal accretion on low-mass Pop. III stars is negligible. The soft X-ray flux of the Pop. II/III stars is also expected to be ˜1-30 times larger than that of a solar-metallicity counterpart owing to the larger coronal density, even though the radiation cooling efficiency is smaller. A larger fraction of the input Alfvénic wave energy is transmitted to the corona in low-Z stars because they avoid severe reflection owing to the smaller density difference between the photosphere and the corona. Therefore, a larger fraction is converted to the thermal energy of the corona and the kinetic energy of the stellar wind. From this energetics argument, we finally derived a scaling of \\dot{M} as \\dot{M}∝ L R_{\\star }^{11/9} M_{\\star }^{-10/9} T_eff^{11/2}[\\max (Z/Z_{⊙},0.01)]^{-1/5}, where L, R⋆, and Teff are the stellar luminosity, radius, and effective temperature, respectively.
Stellar winds and coronae of low-mass Population II/III stars
NASA Astrophysics Data System (ADS)
Suzuki, Takeru K.
2018-04-01
We investigated stellar winds from zero-/low-metallicity low-mass stars by magnetohydrodynamical simulations for stellar winds driven by Alfvén waves from stars with mass M = (0.6-0.8) M⊙ and metallicity Z = (0-1) Z⊙, where M⊙ and Z⊙ are the solar mass and metallicity, respectively. Alfvénic waves, which are excited by the surface convection, travel upward from the photosphere and heat up the corona by their dissipation. For lower Z, denser gas can be heated up to the coronal temperature because of the inefficient radiation cooling. The coronal density of Population II/III stars with Z ≤ 0.01 Z⊙ is one to two orders of magnitude larger than that of a solar-metallicity star with the same mass, and as a result, the mass loss rate, \\dot{M}, is 4.5-20 times larger. This indicates that metal accretion on low-mass Pop. III stars is negligible. The soft X-ray flux of the Pop. II/III stars is also expected to be ˜1-30 times larger than that of a solar-metallicity counterpart owing to the larger coronal density, even though the radiation cooling efficiency is smaller. A larger fraction of the input Alfvénic wave energy is transmitted to the corona in low-Z stars because they avoid severe reflection owing to the smaller density difference between the photosphere and the corona. Therefore, a larger fraction is converted to the thermal energy of the corona and the kinetic energy of the stellar wind. From this energetics argument, we finally derived a scaling of \\dot{M} as \\dot{M}∝ L R_{\\star }^{11/9} M_{\\star }^{-10/9} T_eff^{11/2}[\\max (Z/Z_{⊙},0.01)]^{-1/5}, where L, R⋆, and Teff are the stellar luminosity, radius, and effective temperature, respectively.
NASA Technical Reports Server (NTRS)
Johnson, Roy R.; Russell, P.; Dunagan, S.; Redemann, J.; Shinozuka, Y.; Segal-Rosenheimer, M.; LeBlanc, S.; Flynn, C.; Schmid, B.; Livingston, J.
2014-01-01
The objectives of this task in the AITT (Airborne Instrument Technology Transition) Program are to (1) upgrade the NASA 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument to its full science capability of measuring (a) direct-beam sun transmission to derive aerosol optical depth spectra, (b) sky radiance vs scattering angle to retrieve aerosol absorption and type (via complex refractive index spectra, shape, and mode-resolved size distribution), (c) zenith radiance for cloud properties, and (d) hyperspectral signals for trace gas retrievals, and (2) demonstrate its suitability for deployment in challenging NASA airborne multiinstrument campaigns. 4STAR combines airborne sun tracking, sky scanning, and zenith pointing with diffraction spectroscopy to improve knowledge of atmospheric constituents and their links to air pollution, radiant energy budgets (hence climate), and remote measurements of Earth's surfaces. Direct beam hyperspectral measurement of optical depth improves retrievals of gas constituents and determination of aerosol properties. Sky scanning enhances retrievals of aerosol type and size distribution. 4STAR measurements are intended to tighten the closure between satellite and ground-based measurements. 4STAR incorporates a modular sun-tracking/sky-scanning optical head with fiber optic signal transmission to rack mounted spectrometers, permitting miniaturization of the external optical head, and future detector evolution. 4STAR test flights, as well as science flights in the 2012-13 TCAP (Two-Column Aerosol Project) and 2013 SEAC4RS (Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) have demonstrated that the following are essential for 4STAR to achieve its full science potential: (1) Calibration stability for both direct-beam irradiance and sky radiance, (2) Improved light collection and usage, and (3) Improved flight operability and reliability. A particular challenge for the AITT-4STAR project has been conducting it simultaneously with preparations for, and execution of, ARISE (Arctic Radiation - IceBridge Sea&Ice Experiment), a NASA airborne science deployment (unplanned when AITT-4STAR was selected for funding) in which 4STAR will deploy to Thule, Greenland, and Fairbanks, Alaska, on the NASA C- 130. This presentation describes progress to date in accomplishing AITT-4STAR goals, and plans for project completion.
Near-Simultaneous Spectroscopic and Broadband Polarimetric Observations of Be Stars
NASA Technical Reports Server (NTRS)
Ghosh, K.; Iyengar, K. V. K.; Ramsey, B. D.; Austin, R. A.
1999-01-01
Near simultaneous optical spectroscopic (on four nights) and broadband linear continuum (B, V, R, and I bands) polarimetric (on seven nights) observations of 29 Be stars were carried out during 1993 November-December. The program Be stars displayed wavelength dependence of intrinsic polarizations with no frequency dependence of polarimetric position angles. Some of the Be stars displayed long-term polarization variability. The Be and Be-shell stars could not be distinguished from one another solely on the basis of their polarization values. Full widths at half-maximum of the H.alpha profiles and the intrinsic linear continuum polarizations are closely correlated with the projected rotational velocities of the program stars. Photospheric-absorption-corrected equivalent widths of H.alpha profiles [W(alpha)] and the radii of H.alpha-emitting or -absorbing envelopes (R(sub e) or R(sub a)) are nonlinearly correlated with the intrinsic continuum polarizations of these stars. However, W(alpha) and R(sub e) are linearly correlated. With large uncertainties, there is a trend of spectral dependence of polarization. Detailed discussion of these results is presented in this paper.
Variable Star and Exoplanet Section of the Czech Astronomical Society
NASA Astrophysics Data System (ADS)
Brát, L.; Zejda, M.
2010-12-01
We present activities of Czech variable star observers organized in the Variable Star and Exoplanet Section of the Czech Astronomical Society. We work in four observing projects: B.R.N.O. - eclipsing binaries, MEDUZA - intrinsic variable stars, TRESCA - transiting exoplanets and candidates, HERO - objects of high energy astrophysics. Detailed information together with O-C gate (database of eclipsing binaries minima timings) and OEJV (Open European Journal on Variable stars) are available on our internet portal http://var.astro.cz.
Liebling, Steven L; Palenzuela, Carlos
2017-01-01
The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s, John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called geons , but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name boson stars . Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single Killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.
Physics in strong magnetic fields near neutron stars
NASA Technical Reports Server (NTRS)
Harding, Alice K.
1991-01-01
Electromagnetic phenomena occurring in the strong magnetic fields of neutron stars are currently of great interest in high-energy astrophysics. Observations of rotation rate changes and cyclotron lines in pulsars and gamma-ray bursts indicate that surface magnetic fields of neutron stars often exceed a trillion gauss. In fields this strong, where electrons behave much as if they were in bound atomic states, familiar processes undergo profound changes, and exotic processes become important. Strong magnetic fields affect the physics in several fundamental ways: energies perpendicular to the field are quantized, transverse momentum is not conserved, and electron-positron spin is important. Neutron stars therefore provide a unique laboratory for the study of physics in extremely high fields that cannot be generated on earth.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kyutoku, Koutarou; Ioka, Kunihito, E-mail: koutarou.kyutoku@riken.jp
We reach the robust conclusion that, by combining the observed cosmic rays of r -process elements with the fact that the velocity of the neutron-star-merger ejecta is much higher than that of the supernova ejecta, either (1) the reverse shock in the neutron-star-merger ejecta is a very inefficient accelerator that converts less than 0.003% of the ejecta kinetic energy to the cosmic-ray energy or (2) the neutron star merger is not the origin of the Galactic r -process elements. We also find that the acceleration efficiency should be less than 0.1% for the reverse shock of the supernova ejecta withmore » observed cosmic rays lighter than the iron.« less
Magic star puzzle for educational mathematics
NASA Astrophysics Data System (ADS)
Gan, Yee Siang; Fong, Wan Heng; Sarmin, Nor Haniza
2013-04-01
One of the interesting fields in recreational mathematics is the magic number arrangement. There are different kinds of arrays in the arrangement for a group of numbers. In particular, one of the arrays in magic number arrangement is called magic star. In fact, magic star involves combinatorics that contributes to geometrical analysis and number theory. Hence, magic star is suitable to be introduced as educational mathematics to cultivate interest in different area of mathematics. To obtain the solutions of normal magic stars of order six, the possible sets of numbers for every line in a magic star have been considered. Previously, the calculation for obtaining the solutions has been done manually which is time-consuming. Therefore, a programming code to generate all the fundamental solutions for normal magic star of order six without including the properties of rotation and reflection has been done. In this puzzle, a magic star puzzle is created by using Matlab software, which enables a user to verify the entries for the cells of magic star of order six. Moreover, it is also user-friendly as it provides interactive commands on the inputs given by the user, which enables the user to detect the incorrect inputs. In addition, user can also choose to view all the fundamental solutions as generated by the programming code.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
The objective of this Energy Engineering Analysis (EEA) for LSAAP is threefold: Develop a systematic plan of projects which will result in reducing energy consumption. Consider renewable energy sources with the objective of establishing an orderly procedure for reducing use of non-renewable energy sources. Determine the feasibility of Total Energy (TE), Selective Energy (SE), and Central Heating Plant (CHP) concepts using alternative fuels. In essence, an assessment of the entire energy picture at LSAAP was undertaken. This report is a summary of that effort. LSAAP was originally built during 1941 and 1942 as a shell loading plant for the Army.more » After World War II, the facility was deactivated until 1951 when it was reactivated as a Government Owned, Contractor Operated (GOCO) facility. Day and Zimmerman was selected as the operator in 1951 and has been the operating contractor ever since. Located just west of Texarkana, Texas, LSAAP encompasses an area of approximately 15,546 acres. The primary mission of LSAAP is to load, assemble and pack ammunition and ammunition components for the Army.« less
Dark Skies Awareness through the GLOBE at Night Citizen-Science Campaign
NASA Astrophysics Data System (ADS)
Walker, C. E.
2011-10-01
The emphasis in the international citizen-science, star-hunting campaign, GLOBE at Night, is in bringing awareness to the public on issues of light pollution. Light pollution threatens not only observatory sites and our "right to starlight", but can affect energy consumption, wildlife and health. GLOBE at Night has successfully reached a few hundred thousand citizen-scientists during the annual 2-week campaign over the past 6 years. Provided is an overview, update and discussion of what steps can be taken to improve programs like GLOBE at Night.
Magnetic Inclination E Ects In Star-Planet Magnetic Interactions
NASA Astrophysics Data System (ADS)
Strugarek, Antoine
2017-10-01
A large fraction of the exoplanets discovered today are in a close-in orbit around their host star. This proximity allows them to be magnetically connected to their host, which lead to e cient energy and angular momentum exchanges between the star and the planet. We carry out three-dimensional magneto-hydrodynamic simulations of close-in star-planet systems to characterize the e ect of the inclination of the planetary magnetic eld on the star-planet magnetic interaction. We parametrize this e ect in scaling laws depending on the star, planet, and stellar wind properties that can be applied to any exoplanetary systems around cool stars.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Belzer, D.; Mosey, G.; Dagher, L.
2008-01-01
Home Performance with ENERGY STAR (HPwES) is a jointly managed program of the U.S. Department of Energy (DOE) and the U.S. Environmental Protection Agency (EPA). This program focuses on improving energy efficiency in existing homes via a whole-house approach to assessing and improving a home's energy performance, and helping to protect the environment. As a local sponsor for HPwES, Austin Energy's HPwES program offers a complete home energy assessment and a list of recommendations for efficiency improvements, along with cost estimates. The owner can choose to implement only one or the complete set of energy conservation measures. Austin Energy facilitatesmore » the process by providing economic incentives to the homeowner through its HPwES Loan program and its HPwES Rebate program. In 2005, the total number of participants in both programs was approximately 1,400. Both programs are only available for improvements made by a participating HPwES contractor. The individual household billing data - encompassing more than 7,000 households - provided by Austin Energy provides a rich data set to estimate the impacts of its HPwES program. The length of the billing histories is sufficient to develop PRISM-type models of electricity use based on several years of monthly bills before and after the installation of the conservation measures. Individual household savings were estimated from a restricted version of a PRISM-type regression model where the reference temperature to define cooling (or heating degree days) was estimated along with other parameters. Because the statistical quality of the regression models varies across individual households, three separate samples were used to measure the aggregate results. The samples were distinguished on the basis of the statistical significance of the estimated (normalized) cooling consumption. A normalized measure of cooling consumption was based on average temperatures observed over the most recent nine-year period ending in 2006. This study provided a statistically rigorous approach to incorporating the variability of expected savings across the households in the sample together with the uncertainty inherent in the regression models used to estimate those savings. While the impact of the regression errors was found to be relatively small in these particular samples, this approach may be useful in future studies using individual household billing data. The median percentage savings for the largest sample of 6,000 households in the analysis was 32%, while the mean savings was 28%. Because the number of households in the sample is very large, the standard error associated with the mean percentage savings are very small, less than 1%. A conservative statement of the average savings is that is falls in the range of 25% to 30% with a high level of certainty. This preliminary analysis provides robust estimates of average program savings, but offers no insight into how savings may vary by type of conservation measure or whether savings vary by the amount of cooling electricity used prior to undertaking the measure. Follow-up researchers may want to analyze the impacts of specific ECMs. Households that use electricity for heating might also be separately analyzed. In potential future work several methodological improvements could also be explored. As mentioned in Section 2, there was no formal attempt to clean the data set of outliers and other abnormal patterns of billing data prior to the statistical analysis. The restriction of a constant reference temperature might also be relaxed. This approach may provide evidence as to whether any 'take-back' efforts are present, whereby thermostat settings are lowered during the summer months after the measures are undertaken (reflected in lower reference temperatures in the post-ECM period). A more extended analysis may also justify the investment in and use of the PRISM software package, which may provide more diagnostic measures with respect to the reference temperature. PRISM also appears to contain some built-in capability to detect outliers and other anomalous data points.« less
How Bell Labs creates star performers.
Kelley, R; Caplan, J
1993-01-01
How can managers increase the productivity of professionals when most of their work goes on inside their heads? Robert Kelley and Janet Caplan believe that defining the difference between star performers and average workers is the answer. Many managers assume that top performers are just smarter. But the authors' research at the Bell Laboratories Switching Systems Business Unit (SSBU) has revealed that the real difference between stars and average workers is not IQ but the ways top performers do their jobs. Their study has led to a training program based on the strategies of star performers. The SSBU training program, known as the Productivity Enhancement Group (PEG), uses an expert model to demystify productivity. The star engineers selected to develop the expert model identified and ranked nine work strategies, such as taking initiative, networking, and self-management. Middle performers were also asked what makes for top-quality work, but their definitions and ranking of the strategies differed significantly from those of the top performers. Taking initiative, for example, meant something very different to an average worker than it did to a star. And for the middle performers, the ability to give good presentations was a core strategy, while it was peripheral for the top engineers. Once PEG got underway, respected engineers ran the training sessions, which included case studies, work-related exercises, and frank discussion. The benefits of the program were striking: participants and managers reported substantial productivity increases in both star and average performers. The PEG program may not be a blueprint for other companies, but its message is clear: managers must focus on people, not on technology, to increase productivity in the knowledge economy.
Next Generation Scientists, Next Opportunities: EPA's Science To Achieve Results (STAR) Program
NASA Astrophysics Data System (ADS)
Jones, M.
2004-12-01
Scientific research is one of the most powerful tools we have for understanding and protecting our environment. It provides the foundation for what we know about our planet, how it has changed, and how it could be altered in the future. The National Center for Environmental Research (NCER) in the U.S. Environmental Protection Agency's (EPA) Office of Research and Development (ORD) supports high-quality, extramural research by the nation's leading scientists and engineers to strengthen the basis for decisions about local and national environmental issues. NCER works with academia, state and local governments, other federal agencies, and scientists in EPA to increase human knowledge of how to protect our health and natural resources through its three major programs: · Science to Achieve Results (STAR) Grants · Small Business Innovative Research (SBIR) · Science to Achieve Results (STAR) Fellowships STAR, NCER's primary program, funds research grants and graduate fellowships in environmental science and engineering. Developing the next generation of environmental scientists and engineers is one of NCER's most important objectives. Each year, NCER helps between 80 and 160 students achieve Master's or Ph.D. degrees in environmental science and engineering through its STAR and Greater Research Opportunities (GRO) fellowships. Some of these students have moved on to careers in government while others are now full-time professors and researchers. Still others are working for state environmental agencies or furthering their studies through postdoctoral positions at universities. Since the inception of the NCER program, STAR fellowships (along with grants and SBIR projects) have been awarded in every state in the country. With the help of STAR, current and future scientists and engineers have been able to explore ways to preserve and protect human health and our precious resources.
Space Motions of Low-Mass Stars. II: Radial Velocities
NASA Astrophysics Data System (ADS)
Upgren, A. R.; Harlow, J. J. B.
1996-01-01
Radial velocities are presented for 53 dwarf K and M stars, eight of which are radial velocity standards. This is the second list in a program to determine space motions for all of the stars in the McCormick lists of dwarf stars. The observations reported here differ from those of the first list in that they were made using the 1.88m David Dunlap reflector. One of the stars varies in radial velocity, consistent with a spectroscopic binary with a period of about 48 days. (SECTION: Stars)
NASA Technical Reports Server (NTRS)
1974-01-01
The feasibility is evaluated of an evolutionary development for use of a single-axis gimbal star tracker from prior two-axis gimbal star tracker based system applications. Detailed evaluation of the star tracker gimbal encoder is considered. A brief system description is given including the aspects of tracker evolution and encoder evaluation. System analysis includes evaluation of star availability and mounting constraints for the geosynchronous orbit application, and a covariance simulation analysis to evaluate performance potential. Star availability and covariance analysis digital computer programs are included.
A spectrum synthesis program for binary stars
NASA Technical Reports Server (NTRS)
Linnell, Albert P.; Hubeny, Ivan
1994-01-01
A new program produces synthetic spectra of binary stars at arbitrary values of orbital longitude, including longitudes of partial or complete eclipse. The stellar components may be distorted, either tidally or rotationally, or both. Either or both components may be rotating nonsynchronously. We illustrate the program performance with two cases: EE Peg, an eclipsing binary with small distortion, and SX Aur, an eclipsing binary that is close to contact.
The Great Observatories Origins Deep Survey Spitzer Legacy Science Program
NASA Astrophysics Data System (ADS)
Dickinson, M.; GOODS Team
2005-12-01
The Great Observatories Origins Deep Survey (GOODS) is a multiwavelength anthology of deep field programs using NASA's Great Observatories and the most powerful ground-based facilities to create a public data resource for studying the formation and evolution of galaxies and active galactic nuclei (AGN) throughout cosmic history. GOODS incorporates a Spitzer Legacy Program, which has obtained the deepest observations with that telescope at 3.6 to 24 microns. The Spitzer/IRAC data detect the rest-frame near-infrared light from galaxies out to z ˜ 6, providing valuable information on their stellar populations and masses. The MIPS 24μ m data are a sensitive probe of re-emitted energy from dust-obscured star formation and AGN out to z ˜ 3. I will very briefly introduce the survey and summarize science highlights from the Spitzer data.
Coronal Structures in Cool Stars: XMM-NEWTON Hybrid Stars and Coronal Evolution
NASA Technical Reports Server (NTRS)
Dupree, Andrea K.; Mushotzky, Richard (Technical Monitor)
2003-01-01
This program addresses the evolution of stellar coronas by comparing a solar-like corona in the supergiant Beta Dra (G2 Ib-IIa) to the corona in the allegedly more evolved state of a hybrid star, alpha TrA (K2 II-III). Because the hybrid star has a massive wind, it appears likely that the corona will be cooler and less dense as the magnetic loop structures are no longer closed. By analogy with solar coronal holes, when the topology of the magnetic field is configured with open magnetic structures, both the coronal temperature and density are lower than in atmospheres dominated by closed loops. The hybrid stars assume a pivotal role in the definition of coronal evolution, atmospheric heating processes and mechanisms to drive winds of cool stars. We are attempting to determine if this model of coronal evolution is correct by using XMM-NEWTON RGS spectra for the 2 targets we were allocated through the Guest Observer program.
VizieR Online Data Catalog: Very metal-poor stars in the Milky Way's halo (Carollo+, 2014)
NASA Astrophysics Data System (ADS)
Carollo, D.; Freeman, K.; Beers, T. C.; Placco, V. M.; Tumlinson, J.; Martell, S. L.
2017-07-01
The Aoki et al. (2013, J/AJ/145/13) sample comprises 137 stars observed at high spectral resolution (R~30000), in the course of four observing runs between 2008 March and October, using the High Dispersion Spectrograph (Noguchi et al. 2002PASJ...54..855N) at the Subaru Telescope. We also include 190 stars from the Yong et al. (2013, J/ApJ/762/26) sample - the 38 stars from their "program sample," and 152 stars in their literature compilation. High-resolution spectra (22000
78 FR 17651 - Combined Notice of Filings #1
Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-22
...-002; ER11-46-005; ER11-47-002; ER10-2975-005; ER10-2981-002. Applicants: BlueStar Energy Services Inc... rate authority for AEP West by BlueStar Energy Services Inc., et al. Filed Date: 3/14/13. Accession...: Wisconsin Power and Light Company. Description: Wisconsin Power and Light Company submits WPL's Changes in...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-13
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR13-16-000; Docket No. PR13-17-000; Not Consolidated] TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Baseline Filings Take notice that on December 6, 2012, the applicants listed above submitted a baseline...
78 FR 22872 - TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Filings
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-17
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR13-16-001; Docket No. PR13-17-001; Not Consolidated] TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Filings Take notice that on April 5, 2013, the applicants listed above submitted an amendment to the...
Building Green: Construction for the 21st Century
ERIC Educational Resources Information Center
Phillipson, Todd
2012-01-01
At Jefferson County Vocational School (JCVS) in Bloomingdale, Ohio, students get a lesson on building green with the construction of a home in the school's subdivision. The home is being built using Energy Star guidelines so that it may be identified as an Energy Star home. The goal for the Jefferson County Vocational Schools Board of Education…
Absolute far-ultraviolet spectrophotometry of hot subluminous stars from Voyager
NASA Technical Reports Server (NTRS)
Holberg, J. B.; Ali, B.; Carone, T. E.; Polidan, R. S.
1991-01-01
Observations, obtained with the Voyager ultraviolet spectrometers, are presented of absolute fluxes for two well-known hot subluminous stars: BD + 28 deg 4211, an sdO, and G191 - B2B, a hot DA white dwarf. Complete absolute energy distributions for these two stars, from the Lyman limit at 912 A to 1 micron, are given. For BD + 28 deg 4211, a single power law closely represents the entire observed energy distribution. For G191 - B2B, a pure hydrogen model atmosphere provides an excellent match to the entire absolute energy distribution. Voyager absolute fluxes are discussed in relation to those reported from various sounding rocket experiments, including a recent rocket observation of BD + 28 deg 4211.
NASA Astrophysics Data System (ADS)
Wielanek, D.
2017-08-01
Femtoscopy is a tool to study the space-time evolution of hot and dense matter during high energy collision by using two-particle correlations. The femtoscopic and flow measurements at RHIC and LHC energies are well reproduced by the hydrodynamics models that contains equation of state (EoS) with crossover type transition from Quark-Gluon Plasma to hadron gas phase. Similar studies where performed at AGS and SPS accelerators and was performed in Beam Energy Scan (BES) program at Relativistic Heavy Ion Collider for exploring phase diagram of QCD matter. I present the femtoscopic observables calculated for Au-Au collisions at √sNN = 7:7 - 62:4 GeV calculated from viscous hydro + cascade model vHLLE+UrQMD with two types of EoSs - one that correspond to 1st order phase transition (PT) and second that correspond to crossover PT. I also discuss perspectives of femtoscopic measurements at NICA energy scale √sNN = 4 - 11 GeV.1
NASA Astrophysics Data System (ADS)
Smith, Nathan
2008-03-01
SN 2006gy radiated far more energy in visual light than any other supernova so far, and potential explanations for its energy demands have implications for galactic chemical evolution and the deaths of the first stars. It remained bright for over 200 days, longer than any normal supernova, and it radiated more than 1051 ergs of luminous energy at visual wavelengths. I argue that this Type IIn supernova was probably the explosion of an extremely massive star like Eta Carinae that retained its hydrogen envelope when it exploded, having suffered relatively little mass loss during its lifetime. That this occurred at roughly Solar metallicity challenges current paradigms for mass loss in massive-star evolution. I explore a few potential explanations for SN2006gy's power source, involving either circumstellar interaction, or instead, the decay of 56Ni to 56Co to 56Fe. If SN 2006gy was powered by the conversion of shock energy into light, then the conditions must be truly extraordinary and traditional interaction models don't work. If SN 2006gy was powered by radioactive decay, then the uncomfortably huge 56Ni mass requires that the star exploded as a pair instability supernova. The mere possibility of this makes SN 2006gy interesting, especially at this meeting, because it is the first good candidate for a genuine pair instability supernova.