Science.gov

Sample records for cerebral uma nova

  1. Doppler Tomography of the Dwarf Nova IY UMa During Quiescence

    NASA Astrophysics Data System (ADS)

    Rolfe, D. J.; Abbott, T. M. C.; Haswell, C. A.

    Quiescent Doppler tomography of the newly discovered deeply-eclipsing SU UMa system IY UMa reveals properties of the region where the accretion stream from the donor impacts the edge of the disc. A very strong bright spot is produced and the Keplerian disc emission in the impact region is disrupted or obscured. The differing properties of Hα, Hβ and He I emission will allow physical parameters of the converging flow region to be studied.

  2. SU UMa dwarf novae in the period gap showing the negative superhumps

    NASA Astrophysics Data System (ADS)

    Pavlenko, Elena

    2016-07-01

    There are only two known up to date SU UMa dwarf novae in the period gap showing the negative superhumps, namely, MN Dra and 1RXS J003828.7+250920. We present the results of X-ray and spectral investigation for 1RXS J003828.7+250920, multicolor optical investigation for 1RXS J003828.7+250920 and MN Dra at different stages of their activity in 2011-2016 years. We discuss a finding of the accretion disc radius for both dwarf novae, its variation during separated intervals between outbursts for MN Dra as well as high and low temperature regions in quiescent accretion disk for 1RXS J003828.7+250920.

  3. Curious Variables Experiment (CURVE). Superhump Period Change Pattern in KS UMa and Other Dwarf Novae

    NASA Astrophysics Data System (ADS)

    Olech, A.; Schwarzenberg-Czerny, A.; Kedzierski, P.; Zloczewski, K.; Mularczyk, K.; Wisniewski, M.

    2003-06-01

    We report extensive photometry of the dwarf nova KS UMa throughout its 2003 superoutburst till quiescence. During the superoutburst the star displayed clear superhumps with a mean period of P_sh=0.070092(23) days. In the middle stage of superoutburst the period was increasing with a rate of dot P/P=(21+/-12)*10^-5 and later was decreasing with a rate of dot P/P=-(21+/-8)*10^-5. At the end of superoutburst and during first dozen days of quiescence the star was showing late superhumps with a mean period of P_late=0.06926(2) days. This phenomenon was observed even 30 days after beginning of the superoutburst. In quiescence the star shows quasi-periodic modulations with amplitude reaching 0.5 mag. The most common structure observed during this stage was sinusoidal wave characterized by a period of about 0.1 days. Comparing KS UMa to other SU UMa stars we conclude that this group of dwarf novae shows decreasing superhump periods at the beginning and the end of superoutburst but increasing period in the middle phase.

  4. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IV. The Fourth Year (2011-2012)

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Hambsch, Franz-Josef; Maehara, Hiroyuki; Masi, Gianluca; Miller, Ian; Noguchi, Ryo; Akasaka, Chihiro; Aoki, Tomoya; Kobayashi, Hiroshi; Matsumoto, Katsura; Nakagawa, Shinichi; Nakazato, Takuma; Nomoto, Takashi; Ogura, Kazuyuki; Ono, Rikako; Taniuchi, Keisuke; Stein, William; Henden, Arne; de Miguel, Enrique Kiyota, Seiichiro; Dubovsky, Pavol A.; Kudzej, Igor; Imamura, Kazuyoshi; Akazawa, Hidehiko; Takagi, Ryosuke; Wakabayashi, Yuya; Ogi, Minako; Tanabe, Kenji; Ulowetz, Joseph; Morelle, Etienne; Pickard, Roger D.; Ohshima, Tomohito; Kasai, Kiyoshi; Pavlenko, Elena P.; Antonyuk, Oksana I.; Baklanov, Aleksei V.; Antonyuk, Kirill; Samsonov, Denis; Pit, Nikolaj; Sosnovskij, Aleksei; Littlefield, Colin; Sabo, Richard; Ruiz, Javier; Krajci, Thomas; Dvorak, Shawn; Oksanen, Arto; Hirosawa, Kenji; Goff, William N.; Monard, Berto; Shears, Jeremy; Boyd, David; Voloshina, Irina B.; Shugarov, Sergey Yu.; Chochol, Drahomir; Miyashita, Atsushi; Pietz, Jochen; Katysheva, Natalia; Itoh, Hiroshi; Bolt, Greg; Andreev, Maksim V.; Parakhin, Nikolai; Malanushenko, Viktor; Martinelli, Fabio; Denisenko, Denis; Stockdale, Chris; Starr, Peter; Simonsen, Mike; Tristram, Paul J.; Fukui, Akihiko; Tordai, Tamas; Fidrich, Robert; Paxson, Kevin B.; Itagaki, Koh-ichi; Nakashima, Youichirou; Yoshida, Seiichi; Nishimura, Hideo; Kryachko, Timur V.; Samokhvalov, Andrey V.; Korotkiy, Stanislav A.; Satovski, Boris L.; Stubbings, Rod; Poyner, Gary; Muyllaert, Eddy; Gerke, Vladimir; MacDonald, Walter, II; Linnolt, Michael; Maeda, Yutaka; Hautecler, Hubert

    2013-02-01

    Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 86 SU UMa-type dwarf novae, mainly observed during the 2011-2012 season. We confirmed general trends recorded in our previous studies, such as the relation between period derivatives and orbital periods. There are some systems showing positive period derivatives despite the long orbital period. We observed the 2011 outburst of the WZ Sge-type dwarf nova BW Scl, and recorded an O - C diagram similar to those of previously known WZ Sge-type dwarf novae. The WZ Sge-type dwarf nova OT J184228.1+483742 showed an unusual pattern of double outbursts composed of an outburst with early superhumps and one with ordinary superhumps. We propose an interpretation that a very small growth rate of the 3:1 resonance due to an extremely low mass-ratio led to quenching the superoutburst before the ordinary superhump appeared. We systematically studied ER UMa-type dwarf novae, and found that V1159 Ori showed positive superhumps similar to ER UMa in the 1990s. The recently recognized ER UMa-type object BK Lyn dominantly showed negative superhumps, and its behavior was very similar to the present-day state of ER UMa. The pattern of period variations in AM CVn-type objects was very similar to that of short-period hydrogen-rich SU UMa-type dwarf novae, making them a helium analogue of hydrogen-rich SU UMa-type dwarf novae. SBS 1108+574, a peculiar hydrogen-rich dwarf nova below the period minimum, showed a very similar pattern of period variations to those of short-period SU UMa-type dwarf novae. The mass-ratio derived from the detected orbital period suggests that this secondary is a somewhat evolved star whose hydrogen envelope was mostly stripped during the mass-exchange. CC Scl, MASTER OT J072948.66+593824.4, and OT J173516.9+154708 showed only low-amplitude superhumps with complex profiles. These superhumps are likely to be a combination of two closely separated periods.

  5. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Imada, Akira; Uemura, Makoto; Nogami, Daisaku; Maehara, Hiroyuki; Ishioka, Ryoko; Baba, Hajime; Matsumoto, Katsura; Iwamatsu, Hidetoshi; Kubota, Kaori; Sugiyasu, Kei; Soejima, Yuichi; Moritani, Yuuki; Ohshima, Tomohito; Ohashi, Hiroyuki; Tanaka, Junpei; Sasada, Mahito; Arai, Akira; Nakajima, Kazuhiro; Kiyota, Seiichiro; Tanabe, Kenji; Imamura, Kazuyoshi; Kunitomi, Nanae; Kunihiro, Kenji; Taguchi, Hiroki; Koizumi, Mitsuo; Yamada, Norimi; Nishi, Yuichi; Kida, Mayumi; Tanaka, Sawa; Ueoka, Rie; Yasui, Hideki; Maruoka, Koichi; Henden, Arne; Oksanen, Arto; Moilanen, Marko; Tikkanen, Petri; Aho, Mika; Monard, Berto; Itoh, Hiroshi; Dubovsky, Pavol A.; Kudzej, Igor; Dancikova, Radka; Vanmunster, Tonny; Pietz, Jochen; Bolt, Greg; Boyd, David; Nelson, Peter; Krajci, Thomas; Cook, Lewis M.; Torii, Ken'ichi; Starkey, Donn R.; Shears, Jeremy; Jensen, Lasse-Teist; Masi, Gianluca; Hynek, Tomáš; Nová; K, Rudolf; Kociá; N, Radek; Krá; L, Lukáš; Kučá; Ková, Hana; Kolasa, Marek; Štastný, Petr; Staels, Bart; Miller, Ian; Sano, Yasuo; de Ponthière, Pierre; Miyashita, Atsushi; Crawford, Tim; Brady, Steve; Santallo, Roland; Richards, Tom; Martin, Brian; Buczynski, Denis; Richmond, Michael; Kern, Jim; Davis, Stacey; Crabtree, Dustin; Beaulieu, Kevin; Davis, Tracy; Aggleton, Matt; Morelle, Etienne; Pavlenko, Elena P.; Andreev, Maksim; Baklanov, Alexander; Koppelman, Michael D.; Billings, Gary; Urbancok, L'ubomír; Ögmen, Yenal; Heathcote, Bernard; Gomez, Tomas L.; Voloshina, Irina; Retter, Alon; Mularczyk, Krzysztof; Zoczewski, Kamil; Olech, Arkadiasz; Kedzierski, Piotr; Pickard, Roger D.; Stockdale, Chris; Virtanen, Jani; Morikawa, Koichi; Hambsch, Franz-Josef; Garradd, Gordon; Gualdoni, Carlo; Geary, Keith; Omodaka, Toshihiro; Sakai, Nobuyuki; Michel, Raul; Cárdenas, A. A.; Gazeas, Kosmas D.; Niarchos, Panos G.; Yushchenko, Alexander V.; Mallia, Franco; Fiaschi, Marco; Good, Gerry A.; Walker, Stan; James, Nick; Douzu, Ken-Ichi; Julian, Wm Mack, II; Butterworth, Neil D.; Shugarov, Sergey Yu.; Volkov, Igor; Chochol, Drahomir; Katysheva, Natalia; Rosenbush, Alexander E.; Khramtsova, Maria; Kehusmaa, Petri; Reszelski, Maciej; Bedient, James; Liller, William; Pojmanski, Grzegorz; Simonsen, Mike; Stubbings, Rod; Schmeer, Patrick; Muyllaert, Eddy; Kinnunen, Timo; Poyner, Gary; Ripero, Jose; Kriebel, Wolfgang

    2009-12-01

    We systematically surveyed period variations of superhumps in SU UMa-type dwarf novae based on newly obtained data and past publications. In many systems, the evolution of the superhump period is found to be composed of three distinct stages: an early evolutionary stage with a longer superhump period, a middle stage with systematically varying periods, and a final stage with a shorter, stable superhump period. During the middle stage, many systems with superhump periods of less than 0.08 d show positive period derivatives. We present observational characteristics of these stages and give greatly improved statistics. Contrary to an earlier claim, we found no clear evidence for a variation of period derivatives among different superoutbursts of the same object. We present an interpretation that the lengthening of the superhump period is a result of the outward propagation of an eccentricity wave, which is limited by the radius near the tidal truncation. We interpret that late-stage superhumps are rejuvenated excitation of a 3:1 resonance when superhumps in the outer disk are effectively quenched. The general behavior of the period variation, particularly in systems with short orbital periods, appears to follow a scenario proposed in Kato, Maehara, and Monard (2008, PASJ, 60, L23). We also present an observational summary of WZ Sge-type dwarf novae. Many of them have shown long-enduring superhumps during a post-superoutburst stage having longer periods than those during the main superoutburst. The period derivatives in WZ Sge-type dwarf novae are found to be strongly correlated with the fractional superhump excess, or consequently with the mass ratio. WZ Sge-type dwarf novae with a long-lasting rebrightening or with multiple rebrightenings tend to have smaller period derivatives, and are excellent candidates for those systems around or after the period minimum of evolution of cataclysmic variables.

  6. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. II The Second Year (2009-2010)

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Maehara, Hiroyuki; Uemura, Makoto; Henden, Arne; Miguel, Enrique De; Miller, Ian; Dubovsky, Pavol A.; Kudzej, Igor; Kiyota, Seiichiro; Hambsch, Franz-Josef; Tanabe, Kenji; Imamura, Kazuyoshi; Kunitomi, Nanae; Takagi, Ryosuke; Nose, Mikiha; Akazawa, Hidehiko; Masi, Gianluca; Nakagawa, Shinichi; Iino, Eriko; Noguchi, Ryo; Matsumoto, Katsura; Fujii, Daichi; Kobayashi, Hiroshi; Ogura, Kazuyuki; Ohtomo, Sachi; Yamashita, Kousei; Yanagisawa, Hirofumi; Itoh, Hiroshi; Bolt, Greg; Monard, Berto; Ohshima, Tomohito; Shears, Jeremy; Ruiz, Javier; Imada, Akira; Oksanen, Arto; Nelson, Peter; Gomez, Tomas L.; Staels, Bart; Boyd, David; Voloshina, Irina B.; Krajci, Thomas; Crawford, Tim; Stockdale, Chris; Richmond, Michael; Morelle, Etienne; Novák, Rudolf; Nogami, Daisaku; Ishioka, Ryoko; Brady, Steve; Simonsen, Mike; Pavlenko, Elena P.; Ringwald, Frederick A.; Kuramoto, Tetsuya; Miyashita, Atsushi; Pickard, Roger D.; Hynek, Tomáš; Dvorak, Shawn; Stubbings, Rod; Muyllaert, Eddy

    2010-12-01

    Continued from Kato et al. (2009, PASJ, 61, S395), we collected the times of superhump maxima for 68 SU UMa-type dwarf novae, mainly observed during the 2009-2010 season. The newly obtained data confirmed the basic findings reported in Kato et al. (ibid.): the presence of stages A-C and the predominance of positive period derivatives during stage B in systems with superhump periods shorter than 0.07 d. There was a systematic difference in the period derivatives for the systems with superhump periods longer than 0.075 d between this study and Kato et al. (ibid.). We suggest that this difference was possibly caused by a relative lack of frequently outbursting SU UMa-type dwarf novae in this period regime in the present study. We recorded a strong beat phenomenon during the 2009 superoutburst of IY UMa. A close correlation between the beat period and the superhump period suggests that the changing angular velocity of the apsidal motion of the elliptical disk is responsible for the variation of the superhump periods. We also described three new WZ Sge-type objects with established early superhumps and one with likely early superhumps. We suggest that two systems, VX For and EL UMa, are WZ Sge-type dwarf novae with multiple rebrightenings. The O - C variation in OT J213806.6+261957 suggests that the frequent absence of rebrightenings in very short-Porb objects can be the result of a sustained superoutburst plateau at the epoch when usual SU UMa-type dwarf novae return to quiescence, preceding a rebrightening. We also present a formulation for a variety of Bayesian extensions to traditional period analyses.

  7. Survey of period variations of superhumps in SU UMa-type dwarf novae. VII. The seventh year (2014-2015)

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Hambsch, Franz-Josef; Dubovsky, Pavol A.; Kudzej, Igor; Monard, Berto; Miller, Ian; Itoh, Hiroshi; Kiyota, Seiichiro; Masumoto, Kazunari; Fukushima, Daiki; Kinoshita, Hiroki; Maeda, Kazuki; Mikami, Jyunya; Matsuda, Risa; Kojiguchi, Naoto; Kawabata, Miho; Takenaka, Megumi; Matsumoto, Katsura; de Miguel, Enrique; Maeda, Yutaka; Ohshima, Tomohito; Isogai, Keisuke; Pickard, Roger D.; Henden, Arne; Kafka, Stella; Akazawa, Hidehiko; Otani, Noritoshi; Ishibashi, Sakiko; Ogi, Minako; Tanabe, Kenji; Imamura, Kazuyoshi; Stein, William; Kasai, Kiyoshi; Vanmunster, Tonny; Starr, Peter; Oksanen, Arto; Pavlenko, Elena P.; Antonyuk, Oksana I.; Antonyuk, Kirill A.; Sosnovskij, Aleksei A.; Pit, Nikolaj V.; Babina, Julia V.; Sklyanov, Aleksandr; Novák, Rudolf; Dvorak, Shawn; Michel, Raúl; Masi, Gianluca; Littlefield, Colin; Ulowetz, Joseph; Shugarov, Sergey Yu.; Golysheva, Polina Yu.; Chochol, Drahomir; Krushevska, Viktoriia; Ruiz, Javier; Tordai, Tamás; Morelle, Etienne; Sabo, Richard; Maehara, Hiroyuki; Richmond, Michael; Katysheva, Natalia; Hirosawa, Kenji; Goff, William N.; Dubois, Franky; Logie, Ludwig; Rau, Steve; Voloshina, Irina B.; Andreev, Maksim V.; Shiokawa, Kazuhiko; Neustroev, Vitaly V.; Sjoberg, George; Zharikov, Sergey; James, Nick; Bolt, Greg; Crawford, Tim; Buczynski, Denis; Cook, Lewis M.; Kochanek, Christopher S.; Shappee, Benjamin; Stanek, Krzysztof Z.; Prieto, José L.; Denisenko, Denis; Nishimura, Hideo; Mukai, Masaru; Kaneko, Shizuo; Ueda, Seiji; Stubbings, Rod; Moriyama, Masayuki; Schmeer, Patrick; Muyllaert, Eddy; Shears, Jeremy; Modic, Robert J.; Paxson, Kevin B.

    2015-12-01

    Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 102 SU UMa-type dwarf novae, observed mainly during the 2014-2015 season, and characterized these objects. Our project has greatly improved the statistics of the distribution of orbital periods, which is a good approximation of the distribution of cataclysmic variables at the terminal evolutionary stage, and has confirmed the presence of a period minimum at a period of 0.053 d and a period spike just above this period. The number density monotonically decreased toward the longer period and there was no strong indication of a period gap. We detected possible negative superhumps in Z Cha. It is possible that normal outbursts are also suppressed by the presence of a disk tilt in this system. There was no indication of enhanced orbital humps just preceding the superoutburst, and this result favors the thermal-tidal disk instability as the origin of superoutbursts. We detected superhumps in three AM CVn-type dwarf novae. Our observations and recent other detections suggest that 8% of objects showing dwarf nova-type outbursts are AM CVn-type objects. AM CVn-type objects and EI Psc-type objects may be more abundant than previously recognized. OT J213806, a WZ Sge-type object, exhibited remarkably different features between the 2010 and 2014 superoutbursts. Although the 2014 superoutburst was much fainter, the plateau phase was shorter than the 2010 one, and the course of the rebrightening phase was similar. This object indicates that the O - C diagrams of superhumps can indeed be variable, at least in WZ Sge-type objects. Four deeply eclipsing SU UMa-type dwarf novae (ASASSN-13cx, ASASSN-14ag, ASASSN-15bu, and NSV 4618) were identified. We studied long-term trends in supercycles in MM Hya and CY UMa and found systematic variations of supercycles of ˜20%.

  8. Survey of period variations of superhumps in SU UMa-type dwarf novae. V. The fifth year (2012-2013)

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Hambsch, Franz-Josef; Maehara, Hiroyuki; Masi, Gianluca; Nocentini, Francesca; Dubovsky, Pavol A.; Kudzej, Igor; Imamura, Kazuyoshi; Ogi, Minako; Tanabe, Kenji; Akazawa, Hidehiko; Krajci, Thomas; Miller, Ian; de Miguel, Enrique; Henden, Arne; Noguchi, Ryo; Ishibashi, Takehiro; Ono, Rikako; Kawabata, Miho; Kobayashi, Hiroshi; Sakai, Daisuke; Nishino, Hirochika; Furukawa, Hisami; Masumoto, Kazunari; Matsumoto, Katsura; Littlefield, Colin; Ohshima, Tomohito; Nakata, Chikako; Honda, Satoshi; Kinugasa, Kenzo; Hashimoto, Osamu; Stein, William; Pickard, Roger D.; Kiyota, Seiichiro; Pavlenko, Elena P.; Antonyuk, Oksana I.; Baklanov, Aleksei V.; Antonyuk, Kirill; Samsonov, Denis; Pit, Nikolaj; Sosnovskij, Aleksei; Oksanen, Arto; Harlingten, Caisey; Tyyskä, Jenni; Monard, Berto; Shugarov, Sergey Yu.; Chochol, Drahomir; Kasai, Kiyoshi; Maeda, Yutaka; Hirosawa, Kenji; Itoh, Hiroshi; Sabo, Richard; Ulowetz, Joseph; Morelle, Etienne; Michel, Raúl; Suárez, Genaro; James, Nick; Dvorak, Shawn; Voloshina, Irina B.; Richmond, Michael; Staels, Bart; Boyd, David; Andreev, Maksim V.; Parakhin, Nikolai; Katysheva, Natalia; Miyashita, Atsushi; Nakajima, Kazuhiro; Bolt, Greg; Padovan, Stefano; Nelson, Peter; Starkey, Donn R.; Buczynski, Denis; Starr, Peter; Goff, William N.; Denisenko, Denis; Kochanek, Christopher S.; Shappee, Benjamin; Stanek, Krzysztof Z.; Prieto, José L.; Itagaki, Koh-ichi; Kaneko, Shizuo; Stubbings, Rod; Muyllaert, Eddy; Shears, Jeremy; Schmeer, Patrick; Poyner, Gary; Rodríguez-Marco, Miguel

    2014-04-01

    Continuing the project described in Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for SU UMa-type dwarf novae mainly observed during the 2012-2013 season. We found three objects (V444 Peg, CSS J203937, and MASTER J212624) having strongly positive period derivatives despite the long orbital period (Porb). By using the period of growing stage (stage A) superhumps, we obtained mass ratios for six objects. We characterized nine new WZ Sge-type dwarf novae. We made a pilot survey of the decline rate in the slowly fading parts of SU UMa-type and WZ Sge-type outbursts. The decline time scale was found to generally follow an expected P_orb^{1/4} dependence, and WZ Sge-type outbursts also generally follow this trend. There are some objects which show slower decline rates, and we consider these objects good candidates for period bouncers. We also studied unusual behavior in some objects, including BK Lyn which made a transition from an ER UMa-type state to a novalike (standstill) state in 2013, and unusually frequent occurrences of superoutbursts in NY Ser and CR Boo. We applied the least absolute shrinkage and selection operator (Lasso) power spectral analysis, which has been proven to be very effective in analyzing the Kepler data, to the ground-based photometry of BK Lyn, and detected a dramatic disappearance of the signal of negative superhumps in 2013. We suggested that the mass-transfer rates did not strongly vary between the ER UMa-type state and novalike state in BK Lyn, and this transition was less likely caused by a systematic variation of the mass-transfer rate.

  9. THE GEOMETRY AND IONIZATION STRUCTURE OF THE WIND IN THE ECLIPSING NOVA-LIKE VARIABLES RW TRI AND UX UMa

    SciTech Connect

    Noebauer, Ulrich M.; Long, Knox S.; Sim, Stuart A.; Knigge, Christian

    2010-08-20

    The UV spectra of nova-like variables are dominated by emission from the accretion disk, modified by scattering in a wind emanating from the disk. Here, we model the spectra of RW Tri and UX UMa, the only two eclipsing nova-like variables which have been observed with the Hubble Space Telescope in the far-ultraviolet, in an attempt to constrain the geometry and the ionization structure of their winds. Using our Monte Carlo radiative transfer code, we computed spectra for simply parameterized axisymmetric biconical outflow models and were able to find plausible models for both systems. These reproduce the primary UV resonance lines-N V, Si IV, and C IV-in the observed spectra in and out of eclipse. The distribution of these ions in the wind models is similar in both cases as is the extent of the primary scattering regions in which these lines are formed. The inferred mass-loss rates are 6%-8% of the mass accretion rates for the systems. We discuss the implication of our point models for our understanding of accretion disk winds in cataclysmic variables.

  10. Peculiarities of the SU UMa-Type Dwarf Nova V1504 Cyg Behavior in 1994 - 2012 Years

    NASA Astrophysics Data System (ADS)

    Antonyuk, O. I.; Pavlenko, E. P.

    2013-12-01

    For the SU UMa-type dwarf nova V1504 Cyg on the data base of the CrAO (1998 - 2009), space telescope "Kepler" (2009 - 2011), AAVSO and VSNET (1994 - 2012) we found as follows: 1) the supercycle length varying in average from 100 to 140 d; 2) the normal outbursts show a bimodal cycles lengths distributions with centers 8 - 9 days and 11 days within the range of 5 - 22 days; 3) for the quiescent data JD 2451737-2451745 we have detected the 0.0677-d periodicity that probably connected to the negative superhumps, and for the JD 245497 - 2454974 - these consisting either with simultaneous existing of positive and negative superhumps or with one of these periods.

  11. Survey of period variations of superhumps in SU UMa-type dwarf novae. VIII. The eighth year (2015-2016)

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Hambsch, Franz-Josef; Monard, Berto; Vanmunster, Tonny; Maeda, Yutaka; Miller, Ian; Itoh, Hiroshi; Kiyota, Seiichiro; Isogai, Keisuke; Kimura, Mariko; Imada, Akira; Tordai, Tamás; Akazawa, Hidehiko; Tanabe, Kenji; Otani, Noritoshi; Ogi, Minako; Ando, Kazuko; Takigawa, Naoki; Dubovsky, Pavol A.; Kudzej, Igor; Shugarov, Sergey Yu.; Katysheva, Natalia; Golysheva, Polina; Gladilina, Natalia; Chochol, Drahomir; Starr, Peter; Kasai, Kiyoshi; Pickard, Roger D.; Miguel, Enrique de; Kojiguchi, Naoto; Sugiura, Yuki; Fukushima, Daiki; Yamada, Eiji; Uto, Yusuke; Kamibetsunawa, Taku; Tatsumi, Taiki; Takeda, Nao; Matsumoto, Katsura; Cook, Lewis M.; Pavlenko, Elena P.; Babina, Julia V.; Pit, Nikolaj V.; Antonyuk, Oksana I.; Antonyuk, Kirill A.; Sosnovskij, Aleksei A.; Baklanov, Aleksei V.; Kafka, Stella; Stein, William; Voloshina, Irina B.; Ruiz, Javier; Sabo, Richard; Dvorak, Shawn; Stone, Geoff; Andreev, Maksim V.; Antipin, Sergey V.; Zubareva, Alexandra M.; Zaostrojnykh, Anna M.; Richmond, Michael; Shears, Jeremy; Dubois, Franky; Logie, Ludwig; Rau, Steve; Vanaverbeke, Siegfried; Simon, Andrei; Oksanen, Arto; Goff, William N.; Bolt, Greg; Dębski, Bartłomiej; Kochanek, Christopher S.; Shappee, Benjamin; Stanek, Krzysztof Z.; Prieto, José L.; Stubbings, Rod; Muyllaert, Eddy; Hiraga, Mitsutaka; Horie, Tsuneo; Schmeer, Patrick; Hirosawa, Kenji

    2016-08-01

    Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 128 SU UMa-type dwarf novae observed mainly during the 2015-2016 season and characterized these objects. The data have improved the distribution of orbital periods, the relation between the orbital period and the variation of superhumps, and the relation between period variations and the rebrightening type in WZ Sge-type objects. Coupled with new measurements of mass ratios using growing stages of superhumps, we now have a clearer and statistically greatly improved evolutionary path near the terminal stage of evolution of cataclysmic variables. Three objects (V452 Cas, KK Tel, and ASASSN-15cl) appear to have slowly growing superhumps, which is proposed to reflect the slow growth of the 3 : 1 resonance near the stability border. ASASSN-15sl, ASASSN-15ux, SDSS J074859.55+312512.6, and CRTS J200331.3-284941 are newly identified eclipsing SU UMa-type (or WZ Sge-type) dwarf novae. ASASSN-15cy has a short (˜0.050 d) superhump period and appears to belong to EI Psc-type objects with compact secondaries having an evolved core. ASASSN-15gn, ASASSN-15hn, ASASSN-15kh, and ASASSN-16bu are candidate period bouncers with superhump periods longer than 0.06 d. We have newly obtained superhump periods for 79 objects and 13 orbital periods, including periods from early superhumps. In order that future observations will be more astrophysically beneficial and rewarding to observers, we propose guidelines on how to organize observations of various superoutbursts.

  12. Increasing Supercycle Lengths of Active SU UMa-type Dwarf Novae

    NASA Astrophysics Data System (ADS)

    Otulakowska-Hypka, M.; Olech, A.

    2014-12-01

    We present observational evidence that supercycle lengths of the most active SU UMa-type stars are increasing during the past decades. We analyzed a large number of photometric measurements from available archives and found that this effect is generic for this class of stars, independently of their evolutionary status. This finding is in agreement with previous predictions and the most recent work of Patterson et al. (2012) on BK Lyn.

  13. Imagens do céu ontem e hoje - um multimídia interativo de astronomia e uma nova exposição no MAST

    NASA Astrophysics Data System (ADS)

    Caretta, C. A.; Lima, F. P.; Requeijo, F.; Vieira, G. G.; Alves, F.; Valente, M. E. A.; de Almeida, R.; de Garcia, G. C.; Quixadá, A. C.

    2003-08-01

    "Imagens do Céu Ontem e Hoje" é o título de uma nova exposição que está sendo inaugurada no Museu de Astronomia e Ciências Afins (MCT), que inclui experimentos interativos, maquetes, réplicas e 8 terminais de computador com um multimídia interativo sobre Astronomia para consulta dos visitantes. O multimídia apresenta um conteúdo bastante extenso, que engloba quase todos os temas em Astronomia, consistindo numa fonte de divulgação e pesquisa para um público que vai das crianças até estudantes universitários. O conteúdo está distribuído em mais de 500 páginas de texto divididas em 4 módulos: "O Universo", "Espectroscopia", "Telescópios" e "Observando o Céu". Cada módulo é subdividido em 5 seções, em média, cada uma iniciada por uma animação que ilustra os temas a serem abordados na seção. Ao final da animação, uma lista de temas é apresentada sob o título "Saiba Mais". Para exemplificar, o módulo "O Universo" contém as seguintes seções: "O Universo visto pelo homem", "Conhecendo o Sistema Solar", "Indo além do Sistema Solar", "Nossa Galáxia, a Via-Láctea" e "Indo mais além, a imensidão do Universo". A seção "Conhecendo o Sistema Solar", por sua vez, tem os seguintes temas: "A origem do Sistema Solar", "O Sol", "Os planetas", "Satélites, asteróides, cometas e outros bichos..." e "O Sistema Solar em números". Cada texto é repleto de imagens, quadros, desenhos, esquemas, etc, além de passatempos ao final de cada seção, incluindo jogos interativos, quadrinhos e curiosidades, que auxiliam o aprendizado de forma divertida. Apresentamos neste trabalho as idéias gerais que permearam a produção da exposição, e uma viagem pelo multimídia para exemplificar sua estrutura e conteúdo. O multimídia será posteriormente disponibilizado para o público externo pela página eletrônica do MAst e/ou por intermédio de uma publicação comercial.

  14. Classical Novae

    NASA Astrophysics Data System (ADS)

    Bode, Michael F.; Evans, Aneurin

    2012-07-01

    Preface; 1. Novae - a historical perspective Hilmar W. Duerbeck; 2. Properties of novae: an overview Brian Warner; 3. The evolution of nova-producing binary stars Icko Iben, Jr and Masayuki Y. Fujimoto; 4. Thermonuclear processes S. Starrfield, C. Iliadis and W. R. Hix; 5. Nova atmospheres and winds P. H. Hauschildt; 6. Observational mysteries and theoretical challenges Jordi Jose and Steven N. Shore; 7. Radio emission from novae E. R. Seaquist and M. F. Bode; 8. Infrared studies of classical novae Robert D. Gehrz; 9. Optical and ultraviolet evolution Steven N. Shore; 10. X-ray emission from classical novae in outburst Joachim Krautter; 11. Gamma-rays from classical novae Margarita Hernanz; 12. Resolved nova remnants T. J. O'Brien and M. F. Bode; 13. Dust and molecules in nova environments A. Evans and J. M. C. Rawlings; 14. Extragalactic novae Allen Shafter; Index.

  15. Recurrent novae

    NASA Technical Reports Server (NTRS)

    Hack, Margherita; Selvelli, Pierluigi

    1993-01-01

    Recurrent novae seem to be a rather inhomogeneous group: T CrB is a binary with a M III companion; U Sco probably has a late dwarf as companion. Three are fast novae; two are slow novae. Some of them appear to have normal chemical composition; others may present He and CNO excess. Some present a mass-loss that is lower by two orders of magnitude than classical novae. However, our sample is too small for saying whether there are several classes of recurrent novae, which may be related to the various classes of classical novae, or whether the low mass-loss is a general property of the class or just a peculiarity of one member of the larger class of classical novae and recurrent novae.

  16. Dwarf novae

    NASA Technical Reports Server (NTRS)

    Ladous, Constanze

    1993-01-01

    Dwarf novae are defined on grounds of their semi-regular brightness variations of some two to five magnitudes on time scales of typically 10 to 100 days. Historically several different classification schemes have been used. Today, dwarf novae are divided into three sub-classes: the U Geminorum stars, the SU Ursae Majoris stars, and the Z Camelopardalis stars. Outbursts of dwarf novae occur at semi-periodic intervals of time, typically every 10 to 100 days; amplitudes range from typically 2 to 5 mag. Within certain limits values are characteristic for each object. Relations between the outburst amplitude, or the total energy released during outburst, and the recurrence time have been found, as well as relations between the orbital period and the outburst decay time, the absolute magnitude during outburst maximum, and the widths of long and short outbursts, respectively. Some dwarf novae are known to have suspended their normal outburst activity altogether for a while. They later resumed it without having undergone any observable changes. The optical colors of dwarf novae all are quite similar during outburst, considerably bluer than during the quiescent state. During the outburst cycle, characteristic loops in the two color diagram are performed. At a time resolution on the order of minutes, strictly periodic photometric changes due to orbital motion become visible in the light curves of dwarf novae. These are characteristic for each system. Remarkably little is known about orbital variations during the course of an outburst. On time-scales of minutes and seconds, further more or less periodic types of variability are seen in dwarf novae. Appreciable flux is emitted by dwarf novae at all wavelengths from the X-rays to the longest IR wavelengths, and in some cases even in the radio. Most dwarf novae exhibit strong emission line spectra in the optical and UV during quiescence, although some have only very weak emissions in the optical and/or weak absorptions at UV

  17. Magnetic novae

    NASA Astrophysics Data System (ADS)

    Zemko, Polina; Orio, Marina

    2016-07-01

    We present the results of optical and X-ray observations of two quiescent novae, V2491 Cyg and V4743 Sgr. Our observations suggest the intriguing possibility of localization of hydrogen burning in magnetic novae, in which accretion is streamed to the polar caps. V2491 Cyg was observed with Suzaku more than 2 years after the outburst and V4743 Sgr was observed with XMM Newton 2 and 3.5 years after maximum. In the framework of a monitoring program of novae previously observed as super soft X-ray sources we also obtained optical spectra of V4743 Sgr with the SALT telescope 11.5 years after the eruption and of V2491 Cyg with the 6m Big Azimutal Telescope 4 and 7 years post-outburst. In order to confirm the possible white dwarf spin period of V2491 Cyg measured in the Suzaku observations we obtained photometric data using the 90cm WIYN telescope at Kitt Peak and the 1.2 m telescope in Crimea. We found that V4743 Sgr is an intermediate polar (IP) and V2491 Cyg is a strong IP candidate. Both novae show modulation of their X-ray light curves and have X-ray spectra typical of IPs. The Suzaku and XMM Newton exposures revealed that the spectra of both novae have a very soft blackbody-like component with a temperature close to that of the hydrogen burning white dwarfs in their SSS phases, but with flux by at least two orders of magnitude lower, implying a possible shrinking of emitting regions in the thin atmosphere that is heated by nuclear burning underneath it. In quiescent IPs, independently of the burning, an ultrasoft X-ray flux component originates at times in the polar regions irradiated by the accretion column, but the soft component of V4743 Sgr disappeared in 2006, indicating that the origin may be different from accretion. We suggest it may have been due to an atmospheric temperature gradient on the white dwarf surface, or to continuing localized thermonuclear burning at the bottom of the envelope, before complete turn-off. The optical spectra of V2491 Cyg and V

  18. Classical novae and recurrent novae: General properties

    NASA Technical Reports Server (NTRS)

    Hack, Margherita; Selvelli, Pierluigi; Duerbeck, Hilmar W.

    1993-01-01

    We describe the observable characteristics of classical novae and recurrent novae obtained by different techniques (photometry, spectroscopy, and imaging) in all the available spectral ranges. We consider the three stages in the life of a nova: quiescence (pre- and post-outburst), outburst, final decline and nebular phase. We describe the photometric properties during the quiescent phase. We describe the photometric properties during outburst, the classification according the rate of decline (magnitudes per day), which permits us to define very fast, fast, intermediate, slow, and very slow novae and the correlation between luminosity and speed class. We report the scanty data on the spectra of the few known prenovae and those on the spectra of old novae and those of dwarf novae and nova-like, which, however, are almost undistinguishable. We describe the typical spectra appearing from the beginning of the outburst, just before maximum, up to the nebular phase and the correlation between spectral type at maximum, expansional velocity, and speed class of the nova. We report the existing infrared observations, which permit us to explain some of the characteristics of the outburst light curve, and give evidence of the formation of a dust shell in slow and intermediate novae (with the important exception of the very slow nova HR Del 1967) and its absence or quasi-absence in fast novae. The ultraviolet and X-ray observations are described. The X ray observations of novae, mainly from the two satellites EINSTEIN and EXOSAT, are reported. Observations of the final decline and of the envelopes appearing several months after outburst are also reported.

  19. Typical examples of classical novae

    NASA Technical Reports Server (NTRS)

    Hack, Margherita; Selvelli, Pierluigi; Bianchini, Antonio; Duerbeck, Hilmar W.

    1993-01-01

    Because of the very complicated individualistic behavior of each nova, we think it necessary to review the observations of a few well-observed individuals. We have selected a few objects of different speed classes, which have been extensively observed. They are: V1500 Cygni 1975, a very fast nova; V603 Aql 1918, fast nova; CP Pup 1942, fast nova; GK Per 1901, fast nova; V 1668 Cyg 1979, moderately fast nova; FH Ser 1970, slow nova; DQ Her 1934, slow nova; T Aur 1891, slow nova; RR Pic 1925, slow nova; and HR Del 1967, very slow nova.

  20. Fermi Sees a Nova

    NASA Video Gallery

    Watch V407 Cyg go nova! A nova is a sudden, short-lived brightening of an otherwise inconspicuous star. The outburst occurs when a white dwarf in a binary system erupts in an enormous thermonuclear...

  1. Portuguese and the Computer: "uma bossa nova".

    ERIC Educational Resources Information Center

    Kelly, John R.

    This paper describes the process of preparing a computer study of Brazilian Portuguese literary texts to be used both in teaching and in the preparation of a reference text. Procedural difficulties encountered in the project point out the potential and limitations of computerized research in literary studies. Seven possible areas for computer…

  2. NOVA 201 ultrasonic thickness gage (NOVA Gage)

    NASA Technical Reports Server (NTRS)

    Garecht, Diane

    1990-01-01

    The measurement integrity of the NOVA 201 digital ultrasonic thickness gage (NOVA gage) was demonstrated by comparing the NOVA gage measurements to the thickness gage measurements, and determining the bias and uncertainty of the NOVA gage when measuring redesigned solid rocket motor (RSRM) hardware per engineering test plans (ETP). The NOVA gage was tested by three different operators on steel and aluminum RSRM hardware for wall thickness. The results show that the measurement bias is not consistent. The uncertainty of the bias is caused by the heterogeneous material properties of the RSRM components that influence the time of flight of ultrasonic waves. The measurement uncertainty inherent to the design and operation of the NOVA gage is less in comparison to the uncertainty of the bias. The total measurement uncertainty cannot be substantially reduced by taking more than one measurement. There is no correlation between bias and the surface finish range of this test unless 3-in-One oil is used as a couplant, in which case there appears to be a slight trend. There is no correlation between uncertainty and the surface finish range. The measurement uncertainty of the NOVA gage can be reduced using 3-in-One oil as a couplant.

  3. Novae as distance indicators

    NASA Technical Reports Server (NTRS)

    Ford, Holland C.; Ciardullo, Robin

    1988-01-01

    Nova shells are characteristically prolate with equatorial bands and polar caps. Failure to account for the geometry can lead to large errors in expansion parallaxes for individual novae. When simple prescriptions are used for deriving expansion parallaxes from an ensemble of randomly oriented prolate spheroids, the average distance will be too small by factors of 10 to 15 percent. The absolute magnitudes of the novae will be underestimated and the resulting distance scale will be too small by the same factors. If observations of partially resolved nova shells select for large inclinations, the systematic error in the resulting distance scale could easily be 20 to 30 percent. Extinction by dust in the bulge of M31 may broaden and shift the intrinsic distribution of maximum nova magnitudes versus decay rates. We investigated this possibility by projecting Arp's and Rosino's novae onto a composite B - 6200A color map of M31's bulge. Thirty two of the 86 novae projected onto a smooth background with no underlying structure due to the presence of a dust cloud along the line of sight. The distribution of maximum magnitudes versus fade rates for these unreddened novae is indistinguishable from the distribution for the entire set of novae. It is concluded that novae suffer very little extinction from the filamentary and patchy distribution of dust seen in the bulge of M31. Time average B and H alpha nova luminosity functions are potentially powerful new ways to use novae as standard candles. Modern CCD observations and the photographic light curves of M31 novae found during the last 60 years were analyzed to show that these functions are power laws. Consequently, unless the eruption times for novae are known, the data cannot be used to obtain distances.

  4. NOVA, A BRIEF .....

    ERIC Educational Resources Information Center

    WHITING, RICHARD; AND OTHERS

    NOVA IS AN EXPERIMENTAL, 6-YEAR JUNIOR-SENIOR HIGH SCHOOL. ASPECTS OF THE PROGRAM INCLUDE THE TRIMESTER SYSTEM, THE CONTINUOUS PROGRESS CURRICULUM, TEAM TEACHING, A CLASS SCHEDULE OF FOUR 70-MINUTE PERIODS PER WEEK, THE USE OF DATA-PROCESSING EQUIPMENT, AND MODERN INSTRUCTIONAL AIDS. NOVA IS ORGANIZED CAMPUS-STYLE WITH INDIVIDUAL BUILDINGS DEVOTED…

  5. Nova-like variables

    NASA Technical Reports Server (NTRS)

    Ladous, Constanze

    1993-01-01

    On grounds of different observable characteristics five classes of nova-like objects are distinguished: the UX Ursae Majoris stars, the antidwarf novae, the DQ Herculis stars, the AM Herculis stars, and the AM Canum Venaticorum stars. Some objects have not been classified specifically. Nova-like stars share most observable features with dwarf novae, except for the outburst behavior. The understanding is that dwarf novae, UX Ursae Majoris stars, and anti-dwarf novae are basically the same sort of objects. The difference between them is that in UX Ursae Majoris stars the mass transfer through the accretion disc always is high so the disc is stationary all the time; in anti-dwarf novae for some reason the mass transfer occasionally drops considerably for some time, and in dwarf novae it is low enough for the disc to undergo semiperiodic changes between high and low accretion events. DQ Herculis stars are believed to possess weakly magnetic white dwarfs which disrupt the inner disc at some distance from the central star; the rotation of the white dwarf can be seen as an additional photometric period. In AM Herculis stars, a strongly magnetic white dwarf entirely prevents the formation of an accretion disk and at the same time locks the rotation of the white dwarf to the binary orbit. Finally, AM Canum Venaticorum stars are believed to be cataclysmic variables that consist of two white dwarf components.

  6. Nova AQL 1918 - A nude old nova

    NASA Astrophysics Data System (ADS)

    Selvelli, P. L.; Cassatella, A.

    IUE observations at high and low resolution of Nova Aql 1918 are studied. No evidence of outflow or nebular lines is found, which indicates that the shell ejected at the time of the outburst and surrounding the system for many years has disappeared. The ejection of the shell is shown to be a transient phenomenon during the life of the nova, and due to expansion at a rate of about 2 arcsec/yr, the density of the nebula has probably decreased so much that the nebula can now be considered to have vanished.

  7. ER Ursae Majoris: A dwarf nova with surprises

    NASA Astrophysics Data System (ADS)

    de Miguel, Enrique; Patterson, Joe; Kemp, Jonathan; Stein, William; Roberts, George; Campbell, T.; Hambsch, Franz-J.; Krajci, Tom; Dvorak, Shawn; Koff, Robert A.; Morelle, Etienne; Potter, Michael; Cejudo, David; Brady, Steve; Menzies, Kenneth

    2012-05-01

    ER Ursae Majoris is a relatively bright member of the SU UMa-type dwarf novae that undergoes frequent eruptions of amplitude ~2 mag every ~4 d. In addition to these ordinary dwarf-nova outbursts, ER UMa shows brighter eruptions (superoutbursts) lasting ~20 d with a recurrence time of ~44 d. As other members of the SU UMa class, ER UMa displays a characteristic periodic modulation (superhumps) in its light curve during the course of a superoutburst, the period being a few percent longer than the orbital period of the underlying binary system. A routine photometric patrol of ER UMa during its January 2011superoutburst became much more interesting after noticing the presence of an additional modulation in its light curve, with a period slightly shorter than the orbital period. Similar photometric waves (known as negative superhumps) have already been observed in other cataclysmic variables, mainly in nova-like systems, but only in a small handful of SU UMa-type stars during quiescence, and never before during a superoutburst. We report in this communication the results of a worldwide photometric campaign that was orchestrated right after the discovery of negative superhumps in ER UMa, and provide a thorough analysis of the data obtained from more than 10 stations of the Center of Backyard Astrophysics (CBA) network, which include more than 1000 hours of photometric data over a 4-month baseline on 2011, and a similar (still in progress) dense coverage in 2012.

  8. Light echoes - Novae

    NASA Technical Reports Server (NTRS)

    Schaefer, Bradley E.

    1988-01-01

    The sudden brilliance of a nova eruption will be reflected on surrounding dust grains to create a phantom nebula. Previous searches for these light echoes have used relatively short exposures with photograhic detectors. This paper reports on a search around eight recent novae with long exposures using a CCD camera. Despite an increase of sensitivity by over an order of magnitude, no light echoes were detected. It is found that the average grain density must be less than about 10 to the -9th per cu cm for distances from 0.1 pc to 1000 pc from the novae. The light echo around Nova Persei 1901 was caused by reflection off clouds with grain densities of several times 10 to the -9th per cu cm which are at distances between 0.1 pc and 10 pc. Echoes from dust in a circumstellar shell or ejected during a previous eruption will be effectively unobservable.

  9. Nucleosynthesis in Novae

    NASA Astrophysics Data System (ADS)

    José, Jordi

    Remarkable progress in our understanding of nova outbursts has been achieved through combined efforts in photometry, spectroscopy and numerical simulations. According to the thermonuclear runaway model, novae are powered by thermonuclear explosions in the H-rich envelopes transferred from a low-mass stellar companion onto a close white dwarf star. Extensive numerical simulations have shown that the accreted envelopes attain peak temperatures ranging between 100 and 400 MK, for about several hundred seconds, hence allowing extensive nuclear processing which eventually shows up in the form of nucleosynthetic fingerprints in the ejecta. Indeed, it has been claimed that novae can play a key role in the enrichment of the interstellar medium through a number of intermediate-mass elements. This includes 17O, 15N, and 13C, plus a smaller contribution in a number of other species (A < 40), such as 7Li, 19F, or 26Al. At the turn of the XXI Century, classical novae entered the era of multidimensional models, which provide new insights into the physical mechanisms that drive mixing at the core-envelope interface. In this paper, we will present an overview on classical nova models, from the onset of accretion up to the explosion and ejection stages, with special emphasis on their gross observational properties and their associated nucleosynthesis. The impact of nuclear uncertainties on the final yields will be discussed.

  10. The Galactic Nova Rate Revisited

    NASA Astrophysics Data System (ADS)

    Shafter, A. W.

    2017-01-01

    Despite its fundamental importance, a reliable estimate of the Galactic nova rate has remained elusive. Here, the overall Galactic nova rate is estimated by extrapolating the observed rate for novae reaching m≤slant 2 to include the entire Galaxy using a two component disk plus bulge model for the distribution of stars in the Milky Way. The present analysis improves on previous work by considering important corrections for incompleteness in the observed rate of bright novae and by employing a Monte Carlo analysis to better estimate the uncertainty in the derived nova rates. Several models are considered to account for differences in the assumed properties of bulge and disk nova populations and in the absolute magnitude distribution. The simplest models, which assume uniform properties between bulge and disk novae, predict Galactic nova rates of ∼50 to in excess of 100 per year, depending on the assumed incompleteness at bright magnitudes. Models where the disk novae are assumed to be more luminous than bulge novae are explored, and predict nova rates up to 30% lower, in the range of ∼35 to ∼75 per year. An average of the most plausible models yields a rate of {50}-23+31 yr‑1, which is arguably the best estimate currently available for the nova rate in the Galaxy. Virtually all models produce rates that represent significant increases over recent estimates, and bring the Galactic nova rate into better agreement with that expected based on comparison with the latest results from extragalactic surveys.

  11. Nova in M31

    NASA Astrophysics Data System (ADS)

    Lang, F.; Lerchster, M.; Fliri, J.

    2006-05-01

    We report the discovery of a possible nova in M31 on a R band CCD image at JD 2453877.5 (2006, May 22.1 UT) with 18.7 mag (accuracy 0.1 mag). The image was obtained with the Wendelstein telescope (0.8 m, 1k x 1k CCD camera with 24mu sq. pixels). The position obtained for the nova candidate is RA(2000) = 00h 43m 11.81s, Dec(2000) = +41° 13' 44.7" with an accuracy of 0.1". At the position of the nova candidate no star brighter than 21.5 mag (1 sigma) was detected on 2006, May 12.2 UT on a Wendelstein R band image.

  12. Observations of Novae From ROAD

    NASA Astrophysics Data System (ADS)

    Hambsch, F.-J.

    2014-12-01

    The author discusses observations of galactic novae and some extragalactic supernovae from his remote observatory ROAD (Remote Observatory Atacama Desert) he commenced in August 2011 with Nova Lupi 2011 (PR Lup). The observed novae are mainly chosen according to AAVSO Alert Notices and AAVSO Special Notices as published on their website. Examples of dense observations of different novae are presented. The focus goes to the different behaviors of their light curves. It also demonstrates the capability of the remote observatory ROAD.

  13. NOVA HIGH SCHOOL--INTRODUCTION

    ERIC Educational Resources Information Center

    COGSWELL, JOHN F.

    AN OVERVIEW WAS PRESENTED OF THE ORGANIZATION AND OPERATION OF A NUMBER OF INNOVATIVE ASPECTS OF THE NOVA HIGH SCHOOL IN FORT LAUDERDALE, FLORIDA. NOVA IS PART OF A COMPLEX PLANNED TO INCLUDE GRADES K THROUGH 12. STUDENTS MUST APPLY TO ATTEND NOVA AND ARE SELECTED PRIMARILY ON THE RELATION OF STUDENT PERFORMANCE TO MEASURES OF APTITIDE. VOCATIONAL…

  14. School Psychology in Nova Scotia

    ERIC Educational Resources Information Center

    King, Sara; McGonnell, Melissa; Noyes, Amira

    2016-01-01

    Registration as a psychologist in Nova Scotia can be at the master's or doctoral level; however, the Nova Scotia Board of Examiners in Psychology has announced a move to the doctoral degree as the entry-level to practice. Many school psychologists in Nova Scotia practice at the master's level; therefore, this change could affect school psychology…

  15. SCIENCE AT NOVA.

    ERIC Educational Resources Information Center

    Broward County Schools, Fort Lauderdale, FL.

    THE SCIENCE PROGRAM AT NOVA HIGH SCHOOL IS STRUCTURED TO MEET THE NEEDS OF A SCIENTIFIC SOCIETY. THE JUNIOR HIGH PROGRAM EMPHASIZES THE ACCUMLATION, TABULATION, AND ANALYSIS OF DATA. THE SENIOR HIGH PROGRAM MAKES USE OF THESE PROCESSES IN THE INVESTIGATION OF VARIOUS SUBJECT AREAS. THE UNITS COMPOSING THE HIGH SCHOOL CURRICULUM ARE DESCRIBED. UNIT…

  16. Infrared spectroscopy of cataclysmic variables - III. Dwarf novae below the period gap and nova-like variables

    NASA Astrophysics Data System (ADS)

    Dhillon, V. S.; Littlefair, S. P.; Howell, S. B.; Ciardi, D. R.; Harrop-Allin, M. K.; Marsh, T. R.

    2000-06-01

    We present K-band spectra of the short-period dwarf novae YZ Cnc, LY Hya, BK Lyn, T Leo, SW UMa and WZ Sge, the nova-like variables DW UMa, V1315 Aql, RW Tri, VY Scl, UU Aqr and GP Com, and a series of field dwarf stars with spectral types ranging from K2 to M6. The spectra of the dwarf novae are dominated by emission lines of Hi and Hei. The large velocity and equivalent widths of these lines, in conjunction with the fact that the lines are double-peaked in the highest inclination systems, indicate an accretion disc origin. In the case of YZ Cnc and T Leo, for which we obtained time-resolved data covering a complete orbital cycle, the emission lines show modulations in their equivalent widths that are most probably associated with the bright spot (the region where the gas stream collides with the accretion disc). There are no clear detections of the secondary star in any of the dwarf novae below the period gap, yielding upper limits of 10-30per cent for the contribution of the secondary star to the observed K-band flux. In conjunction with the K-band magnitudes of the dwarf novae, we use the derived secondary star contributions to calculate lower limits to the distances to these systems. The spectra of the nova-like variables are dominated by broad, single-peaked emission lines of Hi and Hei - even the eclipsing systems we observed do not show the double-peaked profiles predicted by standard accretion disc theory. With the exception of RW Tri, which exhibits Nai, Cai and 12CO absorption features consistent with a M0V secondary contributing 65per cent of the observed K-band flux, we find no evidence for the secondary star in any of the nova-like variables. The implications of this result are discussed.

  17. Gamma Rays from Classical Novae

    NASA Technical Reports Server (NTRS)

    1997-01-01

    NASA at the University of Chicago, provided support for a program of theoretical research into the nature of the thermonuclear outbursts of the classical novae and their implications for gamma ray astronomy. In particular, problems which have been addressed include the role of convection in the earliest stages of nova runaway, the influence of opacity on the characteristics of novae, and the nucleosynthesis expected to accompany nova outbursts on massive Oxygen-Neon-Magnesium (ONeMg) white dwarfs. In the following report, I will identify several critical projects on which considerable progress has been achieved and provide brief summaries of the results obtained:(1) two dimensional simulation of nova runaway; (2) nucleosynthesis of nova modeling; and (3) a quasi-analytic study of nucleosynthesis in ONeMg novae.

  18. New Nova Candidates from the RSBE M31 Nova Survey

    NASA Astrophysics Data System (ADS)

    Lauber, Stephanie; Rector, Travis A.; Shafter, Allen W.

    2015-01-01

    Since 1995 the Kitt Peak National Observatory WIYN 0.9-m telescope has been used to monitor M31 for novae as part of the Research-Based Science Education Project (RBSE). The resulting images, which typically cover approximately the inner 20 arc min of M31, are taken through a broad-band H-alpha filter to isolate the strong H-alpha emission lines characteristic of novae shortly after eruption.We are in the process of reanalyzing the entire RBSE data set covering the period between September 1995 and August 2014 in order to produce an up-to-date list of novae from this survey. Here, we present coordinates and H-alpha magnitudes for 4 new nova discoveries not previous reported. Among the new nova discoveries, one system appears spatially coincident with M31N 1988-09a, and is thus a recurrent nova candidate.

  19. Nova Scorpii 2008

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2008-09-01

    Nova Sco 2008 was discovered by K. Nishiyama, Kurume, Fukuoka-ken, Japan, and F. Kabashima, Miyaki-cho, Saga-ken, Japan; Y. Sakurai, Mito, Ibaraki-ken, Japan; and Guoyou Sun, Qufu, Shandong, China, and Xing Gao, Urumqi, Xinjiang, China, on 2008 September 02.4594 UTC at magnitude 9.5 (unfiltered). This is a classical nova, as determined by low-resolution spectra by M. Fujii, Ibara, Okayama, Japan, and by H. Naito, Nishi-Harima Astron. Obs., on Sept 3.49 and Sept 5.47 UT, respectively. This object has been given the formal variable star designation V1309 Sco. Discovery information is from IAU Circular 8972, Daniel W.E. Green, editor. Observations should be submitted to the AAVSO International Database as V1309 SCO.

  20. Nova in Puppis

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2007-11-01

    Nova Puppis 2007 was discovered visually by Alfredo Jose Serra Pereira, Carnaxide, Portugal, on November 14.23 UT at visual magnitude 7.0. The discovery was announced in IAU Circular No. 8895 (Daniel W. E. Green, Ed.). The nova is located at 08:16:17.99 -34:15:25.0 (J2000, J. Young and H. Rhoades, Table Mountain Observatory, near Wrightwood, CA). Nothing was visible down to magnitude 8 on November 6.23, 7.22, 8.23, 10.23, and 11.22 UT. Young reports that a red image of the field from the Digitized Sky Survey contains a point source at an approximate magnitude of 20. No spectra have yet been published. Please report observations to the AAVSO International Database as N PUP 2007.

  1. Nova Lupi 2011

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2011-08-01

    Announcement of discovery of Nova Lupi 2011 = PNV J14542000-5505030. Discovered by Nicholas Brown (Quinns Rocks, Western Australia) on 2011 Aug. 4.73 UT at unfiltered mag=10.2 (tmax 400 film). Posted on the IAU Central Bureau for Astronomical Telegrams Transient Object Confirmation Page (TOCP) as PNV J14542000-5505030. Spectra obtained by Fred Walter (SUNY Stony Brook) 2011 August 9.0132 UT with the SMARTS 1.5m RC spectrograph at Cerro Tololo and reported in ATEL #3536 confirms that the object is an Fe II nova near maximum. Initially announced in [vsnet-alert 13560] (Nicholas Brown) and in AAVSO Special Notice #247 (Arne Henden). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations.

  2. Chemistry in Novae

    NASA Astrophysics Data System (ADS)

    Rawlings, J. M. C.; Williams, D. A.

    It is shown that the 5 μm excess, which is attributed to CO in the ejecta of novae, can be modelled chemically. The principle problems involved in the modelling are: (1) the high ejecta temperature (≡104K), (2) the extremely high UV flux, and (3) the marginal self-shielding capability of H2. The authors find that the condition of H2 self-shielding alone is sufficient to allow rapid chemistry to proceed. Time-dependent chemistry calculations indicate that the chemistry is steered by the physics of the system.

  3. NOVA Fall 2002 Teacher's Guide.

    ERIC Educational Resources Information Center

    Ransick, Kristina; Rosene, Dale; Sammons, James; Turck, Mary

    This NOVA teacher's guide presents activities, information, and teaching ideas from the Public Broadcasting System's (PBS) NOVA television program series. Episodes include: (1) "Mysterious Life of Caves" which investigates the role microbes play in the creation of some limestone caves; (2) "Lost Roman Treasure" which follows…

  4. Nova Mus 2008 = QY Mus

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2008-10-01

    Nova Mus 2008 = QY Mus was discovered by William Liller, Vina del Mar, Chile, on 2008 September 28.998 UT at magnitude 8.6 (Tech Pan film + orange filter). The position is RA = 13h 16m 36.44s , Dec = -67d 36m 47.8s (from P. Nelson). This object was announced as a nova in IAU Circular 8990 (Daniel W.E. Green, editor). The nova classification was determined using low-resolution spectra by W. Liller indicating the presence of broad H-alpha lines at least 2300 angstroms wide. Several observers confirmed the nova and provided photometry. The position above was provided by Peter Nelson (Ellinbank, Vic., Aus.), and is averaged from four separate exposures (rms error approx. 0.4 arcseconds). The GCVS team have formally designated Nova Mus 2008 as QY MUS. Observations should be reported to the AAVSO International Database as QY MUS.

  5. RECURRENT NOVAE IN M31

    SciTech Connect

    Shafter, A. W.; Henze, M.; Rector, T. A.; Schweizer, F.; Hornoch, K.; Orio, M.; Pietsch, W.; Darnley, M. J.; Williams, S. C.; Bode, M. F.; Bryan, J.

    2015-02-01

    The reported positions of 964 suspected nova eruptions in M31 recorded through the end of calendar year 2013 have been compared in order to identify recurrent nova (RN) candidates. To pass the initial screen and qualify as a RN candidate, two or more eruptions were required to be coincident within 0.′1, although this criterion was relaxed to 0.′15 for novae discovered on early photographic patrols. A total of 118 eruptions from 51 potential RN systems satisfied the screening criterion. To determine what fraction of these novae are indeed recurrent, the original plates and published images of the relevant eruptions have been carefully compared. This procedure has resulted in the elimination of 27 of the 51 progenitor candidates (61 eruptions) from further consideration as RNe, with another 8 systems (17 eruptions) deemed unlikely to be recurrent. Of the remaining 16 systems, 12 candidates (32 eruptions) were judged to be RNe, with an additional 4 systems (8 eruptions) being possibly recurrent. It is estimated that ∼4% of the nova eruptions seen in M31 over the past century are associated with RNe. A Monte Carlo analysis shows that the discovery efficiency for RNe may be as low as 10% that for novae in general, suggesting that as many as one in three nova eruptions observed in M31 arise from progenitor systems having recurrence times ≲100 yr. For plausible system parameters, it appears unlikely that RNe can provide a significant channel for the production of Type Ia supernovae.

  6. Recurrent Novae in M31

    NASA Astrophysics Data System (ADS)

    Shafter, A. W.; Henze, M.; Rector, T. A.; Schweizer, F.; Hornoch, K.; Orio, M.; Pietsch, W.; Darnley, M. J.; Williams, S. C.; Bode, M. F.; Bryan, J.

    2015-02-01

    The reported positions of 964 suspected nova eruptions in M31 recorded through the end of calendar year 2013 have been compared in order to identify recurrent nova (RN) candidates. To pass the initial screen and qualify as a RN candidate, two or more eruptions were required to be coincident within 0.‧1, although this criterion was relaxed to 0.‧15 for novae discovered on early photographic patrols. A total of 118 eruptions from 51 potential RN systems satisfied the screening criterion. To determine what fraction of these novae are indeed recurrent, the original plates and published images of the relevant eruptions have been carefully compared. This procedure has resulted in the elimination of 27 of the 51 progenitor candidates (61 eruptions) from further consideration as RNe, with another 8 systems (17 eruptions) deemed unlikely to be recurrent. Of the remaining 16 systems, 12 candidates (32 eruptions) were judged to be RNe, with an additional 4 systems (8 eruptions) being possibly recurrent. It is estimated that ∼4% of the nova eruptions seen in M31 over the past century are associated with RNe. A Monte Carlo analysis shows that the discovery efficiency for RNe may be as low as 10% that for novae in general, suggesting that as many as one in three nova eruptions observed in M31 arise from progenitor systems having recurrence times ≲ 100 yr. For plausible system parameters, it appears unlikely that RNe can provide a significant channel for the production of Type Ia supernovae.

  7. Olivier Chesneau's Work on Novae

    NASA Astrophysics Data System (ADS)

    Millour, F.; Lagadec, E.

    2015-12-01

    Olivier Chesneau founded a brand new field of observational astrophysics with his attempts to resolve the novae expanding fireball from the very first days of the explosion. With the images he could get, he showed that novae do indeed explode in an aspherical way, leading to a change of paradigm for the physics of these yet-poorly understood catastrophic systems. He also set the stage for a new way of estimating novae distances, by directly measuring the sky-size of the fireball and comparing it with spectroscopic scales, taking into account the tremendous effects of the fireball geometry.

  8. An observational study of quiescent novae

    NASA Astrophysics Data System (ADS)

    Dhillon, V. S.

    1990-01-01

    Quiescent novae are close binary stars which are characterised by the presence of Balmer and HeII emission lines in their optical spectra. In high-inclination systems, standard theory predicts that one should observe double-peaked emission line profiles which are eclipsed once every orbital period. However, the emission lines of eclipsing quiescent novae are single-peaked and uneclipsed, in obvious conflict with currently held beliefs on the nature of these systems. It is the purpose of this thesis to solve this long-standing problem and so arrive at a theoretical model for quiescent novae which is consistent with the observational evidence. The first part of the thesis sets the scene to the problem by presenting an overview of the conflicting observational and theoretical results. The second part then reports on a number of new observations obtained during the course of this work which have shed new light on the problem. The results of these new observations are presented in Part III of the thesis, where one chapter is devoted to each of the three objects studied (V1315 Aquilae, SW Sextantis and DW Ursae Majoris). The final part of the thesis is a discussion and comparison of the various results presented in Part III. Using these results, a series of observational constraints are defined which are then applied to a number of existing theoretical models. In the case of V1315 Aql and SW Sex, the very stringent set of constraints results in there being no single model capable of explaining the observed phenomena. DW UMa is even more enigmatic, appearing in a previously unseen low-state during which the mass transfer rate appears to have reduced dramatically and the optical spectra are dominated by Balmer emission from the inner face of the secondary star. The implications of these new observations for the wider field of cataclysmic variables are discussed, followed by a short summary of future work necessary to validate the origin, evolution and behaviour of the

  9. BK Lyncis: The Oldest Old Nova? or: Archaeo-Astronomy 101

    NASA Astrophysics Data System (ADS)

    Kemp, Jonathan; Patterson, Joe; de Miguel, Enrique; Roberts, George; Campbell, Tut; Hambsch, Franz-J.; Krajci, Tom; Dvorak, Shawn; Koff, Robert A.; Morell, Etienne; Potter, Michael; Cejudo, David; Ulowetz, Joe; Boyd, David; Sabo, Richard; Rock, John; Oksanen, Arto

    2012-05-01

    We summarize the results of a 20-year campaign to study the light curves of BK Lyncis, a nova-like star strangely located below the 2-3 hour orbital period gap in the family of cataclysmic variables. Two "superhumps" dominate the nightly light curves - with periods 4.6% longer, and 3.0% shorter, than Porb. The first appears to be associated with the star's brighter states (V~14), while the second appears to be present throughout and becomes very dominant in the low state (V~15.7). It's plausible that these arise, respectively, from a prograde apsidal precession and a retrograde nodal precession of the star's accretion disk. In 2011-2, the star's light curve became indistinguishable from that of a dwarf nova - in particular, that of the ER UMa subclass. No such transition has ever been observed in a cataclysmic variable. Reviewing all the star's oddities, we speculate: (a) BK Lyn is the remnant of the probable nova on 30 December 101, and (b) it has been fading ever since, but has taken ~2000 years for the accretion rate to drop sufficiently to permit dwarf-nova eruptions. If such behavior is common, it can explain two other puzzles of CV evolution. One: why the ER UMa class even exists (because all can be remnants of recent novae). And two: the relative space densities of short- and long-period CVs, and of known nova remnants (set by the durations of these transient phases).

  10. Argonne's Vilas Pol on NOVA!

    SciTech Connect

    2011-01-01

    Can innovations in materials science help clean up our world? Argonne's material scientist Vilas Pol guest starred on NOVA's "Making Stuff: Cleaner," where David Pogue explored the rapidly-developing science and business of clean energy.

  11. Argonne's Vilas Pol on NOVA!

    ScienceCinema

    None

    2016-07-12

    Can innovations in materials science help clean up our world? Argonne's material scientist Vilas Pol guest starred on NOVA's "Making Stuff: Cleaner," where David Pogue explored the rapidly-developing science and business of clean energy.

  12. Cerebral Palsy

    MedlinePlus

    Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

  13. RZ Leonis Minoris bridging between ER Ursae Majoris-type dwarf nova and nova-like system

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Ishioka, Ryoko; Isogai, Keisuke; Kimura, Mariko; Imada, Akira; Miller, Ian; Masumoto, Kazunari; Nishino, Hirochika; Kojiguchi, Naoto; Kawabata, Miho; Sakai, Daisuke; Sugiura, Yuki; Furukawa, Hisami; Yamamura, Kenta; Kobayashi, Hiroshi; Matsumoto, Katsura; Wang, Shiang-Yu; Chou, Yi; Ngeow, Chow-Choong; Chen, Wen-Ping; Panwar, Neelam; Lin, Chi-Sheng; Hsiao, Hsiang-Yao; Guo, Jhen-Kuei; Lin, Chien-Cheng; Omarov, Chingis; Kusakin, Anatoly; Krugov, Maxim; Starkey, Donn R.; Pavlenko, Elena P.; Antonyuk, Kirill A.; Sosnjvskij, Aleksei A.; Antonyuk, Oksana I.; Pit, Nikolai V.; Baklanov, Alex V.; Babina, Julia V.; Itoh, Hiroshi; Padovan, Stefano; Akazawa, Hidehiko; Kafka, Stella; de Miguel, Enrique; Pickard, Roger D.; Kiyota, Seiichiro; Shugarov, Sergey Yu.; Chochol, Drahomir; Krushevska, Viktoriia; Sekeráš, Matej; Pikalova, Olga; Sabo, Richard; Dubovsky, Pavol A.; Kudzej, Igor; Ulowetz, Joseph; Dvorak, Shawn; Stone, Geoff; Tordai, Tamás; Dubois, Franky; Logie, Ludwig; Rau, Steve; Vanaverbeke, Siegfried; Vanmunster, Tonny; Oksanen, Arto; Maeda, Yutaka; Kasai, Kiyoshi; Katysheva, Natalia; Morelle, Etienne; Neustroev, Vitaly V.; Sjoberg, George

    2016-12-01

    We observed RZ LMi, which is renowned for its extremely short (˜19 d) supercycle and is a member of a small, unusual class of cataclysmic variables called ER UMa-type dwarf novae, in 2013 and 2016. In 2016, the supercycles of this object substantially lengthened in comparison to the previous measurements to 35, 32, and 60 d for three consecutive superoutbursts. We consider that the object virtually experienced a transition to the nova-like state (permanent superhumper). This observed behavior reproduced the prediction of the thermal-tidal instability model extremely well. We detected a precursor in the 2016 superoutburst and detected growing (stage A) superhumps with a mean period of 0.0602(1) d in 2016 and in 2013. Combined with the period of superhumps immediately after the superoutburst, the mass ratio is not as small as in WZ Sge-type dwarf novae, having orbital periods similar to RZ LMi. By using least absolute shrinkage and selection operator (Lasso) two-dimensional power spectra, we detected possible negative superhumps with a period of 0.05710(1) d. We estimated an orbital period of 0.05792 d, which suggests a mass ratio of 0.105(5). This relatively large mass ratio is even above that of ordinary SU UMa-type dwarf novae, and it is also possible that the exceptionally high mass-transfer rate in RZ LMi may be a result of a stripped secondary with an evolved core in a system evolving toward an AM CVn-type object.

  14. BK Lyncis: the oldest old nova and a Bellwether for cataclysmic variable evolution

    NASA Astrophysics Data System (ADS)

    Patterson, Joseph; Uthas, Helena; Kemp, Jonathan; de Miguel, Enrique; Krajci, Thomas; Foote, Jerry; Hambsch, Franz-Josef; Campbell, Tut; Roberts, George; Cejudo, David; Dvorak, Shawn; Vanmunster, Tonny; Koff, Robert; Skillman, David; Harvey, David; Martin, Brian; Rock, John; Boyd, David; Oksanen, Arto; Morelle, Etienne; Ulowetz, Joseph; Kroes, Anthony; Sabo, Richard; Jensen, Lasse

    2013-09-01

    We summarize the results of a 20-yr campaign to study the light curves of BK Lyn, a nova-like star strangely located below the 2 to 3 h orbital-period gap in the family of cataclysmic variables (CVs). Two apparent superhumps dominate the nightly light curves, with periods 4.6 per cent longer, and 3.0 per cent shorter, than the orbital period. The first appears to be associated with the star's brighter states (V ˜ 14), while the second appears to be present throughout and becomes very dominant in the low state (V ˜ 15.7). It is plausible that these arise, respectively, from a prograde apsidal precession and a retrograde nodal precession of the star's accretion disc. Starting in the year 2005, the star's light curve became indistinguishable from that of a dwarf nova - in particular, that of the ER UMa subclass. No such clear transition has ever been observed in a CV before. Reviewing all the star's oddities, we speculate: (a) BK Lyn is the remnant of the probable nova on 101 December 30, and (b) it has been fading ever since, but it has taken ˜2000 yr for the accretion rate to drop sufficiently to permit dwarf-nova eruptions. If such behaviour is common, it can explain other puzzles of CV evolution. One: why the ER UMa class even exists (because all members can be remnants of recent novae). Two: why ER UMa stars and short-period nova-likes are rare (because their lifetimes, which are essentially cooling times, are short). Three: why short-period novae all decline to luminosity states far above their true quiescence (because they are just getting started in their post-nova cooling). Four: why the orbital periods, accretion rates and white dwarf temperatures of short-period CVs are somewhat too large to arise purely from the effects of gravitational radiation (because the unexpectedly long interval of enhanced post-nova brightness boosts the mean mass-transfer rate). And maybe even five: why very old, post-period-bounce CVs are hard to find (because the higher mass

  15. Nova LMC 1990 no. 1: The first extragalactic neon nova

    NASA Technical Reports Server (NTRS)

    Sonneborn, George; Shore, Steven N.; Starrfield, Sumner G.

    1990-01-01

    International Ultraviolet Explorer (IUE) observations of nova LMC (Large Magellanic Cloud) 1990 No. 1, the first neon (or ONeMg) nova observed outside the Galaxy are presented. The observations were obtained from 17 Jan. to Mar. 1990, with especially dense coverage during the first 25 days of the outburst. (The neon nova categorization is based on the detection of forbidden Ne 3-4 lines in optical spectra; the ultraviolet neon lines were not detected.) During the first 30 days of the outburst, the radiative losses were dominated by the N 5 delta 1240 and C 4 delta 1550 lines. The maximum ejection velocity was approximately 8000 km/s, based on the blue absorption edge of the C 4 P-Cygni profile. Early in the outburst of Nova LMC 1990 No. 1 the UV luminosity alone was approximately 3 times 10 to the 38th power erg/sec, implying that the bolometric luminosity was well in excess of the Eddington luminosity for a one solar mass object.

  16. THE SHAPE OF LONG OUTBURSTS IN U GEM TYPE DWARF NOVAE FROM AAVSO DATA

    SciTech Connect

    Cannizzo, John K.

    2012-10-01

    We search the American Association of Variable Star Observers (AAVSO) archives of the two best-studied dwarf novae in an attempt to find light curves for long outbursts that are extremely well characterized. The systems are U Gem and SS Cyg. Our goal is to search for embedded precursors such as those that have been found recently in the high-fidelity Kepler data for superoutbursts (SOs) of some members of the SU UMa subclass of dwarf novae. For the vast majority of AAVSO data, the combination of low data cadence and large errors associated with individual measurements precludes one from making any strong statement about the shape of the long outbursts. However, for a small number of outbursts, extensive long-term monitoring with digital photometry yields high-fidelity light curves. We report the discovery of embedded precursors in two of three candidate long outbursts. This is the first time that such embedded precursors have been found in dwarf novae above the period gap in other than kepler data, and reinforces van Paradijs' finding that long outbursts in dwarf novae above the period gap and SOs in systems below the period gap constitute a unified class. The thermal-tidal instability to account for SOs in the SU UMa stars predicts embedded precursors only for short orbital period dwarf novae, therefore the presence of embedded precursors in long orbital period systems-U Gem and SS Cyg-argues for a more general mechanism to explain long outbursts.

  17. Observations of classical novae in outburst

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Stryker, L. L.; Sonneborn, G.; Sparks, Warren M.; Ferland, Gary; Wagner, R. M.; Williams, R. E.; Gehrz, Robert D.; Ney, Edward P.; Kenyon, Scott

    1988-01-01

    The IUE obtained ultraviolet data on novae in outburst. The characteristics of every one of the outbursts are different. Optical and infrared data on many of the same novae were also obtained. Three members of the carbon-oxygen class of novae are presented.

  18. Ultraviolet studies of nova-like variables with the IUE

    NASA Technical Reports Server (NTRS)

    Guinan, E. F.

    1983-01-01

    KQ Mon is a new UX UMa-type nova-like variable. Optical spectra taken in 1978 reveal very shallow Balmer absorption lines and He I (wavelength 4471) absorption. There was no evidence of orbital variations but the appearance of the optical spectrum and the presence of low amplitude flickering suggested a strong similarity to CD-42 degrees 14462 (=V3885 Sgr) and other members of the UX UMa class. KQ Mon was observed at low dispersion with the IUE satellite. Six spectra taken with the short wavelength prime (SWP) camera are dominated by strong broad absorption lines due to N V, O I, Si III, Si IV, C IV, He II, N IV, and A1 III. There is little evidence of orbital phase modulation over the time baseline of the observations. Unlike UV observations of other UX UMa-type objects, KQ Mon exhibits no emission lines or P Cygni-type profiles and the velocity displacements appear to be smaller, suggesting the absence of a hot, high velocity wind characterizing other UX UMa stars. The relationship of KQ Mon to other UX UMa disk stars is discussed and a model is suggested to explain their observed properties and the lack of major outbursts.

  19. NOVA Fall 1998 Teacher's Guide.

    ERIC Educational Resources Information Center

    Colombo, Luann

    This teacher's guide is designed to accompany the PBS television program "NOVA." Six science activities correspond to: (1) "Lost at Sea: The Search for Longitude,, which researches and charts the shortest course to circumnavigate the globe; (2) "Chasing El Nino," which formulates a question and designs an experiment to…

  20. An observational case against nova hibernation

    NASA Technical Reports Server (NTRS)

    Naylor, T.; Charles, P. A.; Mukai, K.; Evans, A.

    1992-01-01

    We use WHT spectroscopy and imaging to show that nova Vul 1670 (= CK Vul) has been incorrectly identified, and thus its luminosity cannot be used as evidence that novae fade into a 'hibernation' phase within 300 yr of their outbursts. INT spectroscopy is used to correct the magnitude of nova Sge 1783 (= WY Sge) for inclination, this result also implying that novae do not fade significantly. We therefore suggest that, while novae decline in the first 60 yr after outburst, thereafter their luminosity remains constant, and they never undergo a 'hibernation' phase. We show that this idea is consistent with the space density of novae and novalike variables, the outburst interval of SS Cyg and the current luminosities of old novae.

  1. AT Cnc: A SECOND DWARF NOVA WITH A CLASSICAL NOVA SHELL

    SciTech Connect

    Shara, Michael M.; Mizusawa, Trisha; Zurek, David; Wehinger, Peter; Martin, Christopher D.; Neill, James D.; Forster, Karl; Seibert, Mark

    2012-10-20

    We are systematically surveying all known and suspected Z Cam-type dwarf novae for classical nova shells. This survey is motivated by the discovery of the largest known classical nova shell, which surrounds the archetypal dwarf nova Z Camelopardalis. The Z Cam shell demonstrates that at least some dwarf novae must have undergone classical nova eruptions in the past, and that at least some classical novae become dwarf novae long after their nova thermonuclear outbursts, in accord with the hibernation scenario of cataclysmic binaries. Here we report the detection of a fragmented 'shell', 3 arcmin in diameter, surrounding the dwarf nova AT Cancri. This second discovery demonstrates that nova shells surrounding Z Cam-type dwarf novae cannot be very rare. The shell geometry is suggestive of bipolar, conical ejection seen nearly pole-on. A spectrum of the brightest AT Cnc shell knot is similar to that of the ejecta of the classical nova GK Per, and of Z Cam, dominated by [N II] emission. Galaxy Evolution Explorer FUV imagery reveals a similar-sized, FUV-emitting shell. We determine a distance of 460 pc to AT Cnc, and an upper limit to its ejecta mass of {approx}5 Multiplication-Sign 10{sup -5} M {sub Sun }, typical of classical novae.

  2. Identifying and quantifying recurrent novae masquerading as classical novae

    SciTech Connect

    Pagnotta, Ashley; Schaefer, Bradley E.

    2014-06-20

    Recurrent novae (RNe) are cataclysmic variables with two or more nova eruptions within a century. Classical novae (CNe) are similar systems with only one such eruption. Many of the so-called CNe are actually RNe for which only one eruption has been discovered. Since RNe are candidate Type Ia supernova progenitors, it is important to know whether there are enough in our Galaxy to provide the supernova rate, and therefore to know how many RNe are masquerading as CNe. To quantify this, we collected all available information on the light curves and spectra of a Galactic, time-limited sample of 237 CNe and the 10 known RNe, as well as exhaustive discovery efficiency records. We recognize RNe as having (1) outburst amplitude smaller than 14.5 – 4.5 × log (t {sub 3}), (2) orbital period >0.6 days, (3) infrared colors of J – H > 0.7 mag and H – K > 0.1 mag, (4) FWHM of Hα > 2000 km s{sup –1}, (5) high excitation lines, such as Fe X or He II near peak, (6) eruption light curves with a plateau, and (7) white dwarf mass greater than 1.2 M {sub ☉}. Using these criteria, we identify V1721 Aql, DE Cir, CP Cru, KT Eri, V838 Her, V2672 Oph, V4160 Sgr, V4643 Sgr, V4739 Sgr, and V477 Sct as strong RN candidates. We evaluate the RN fraction among the known CNe using three methods to get 24% ± 4%, 12% ± 3%, and 35% ± 3%. With roughly a quarter of the 394 known Galactic novae actually being RNe, there should be approximately a hundred such systems masquerading as CNe.

  3. Nucleosynthesis and the nova outburst

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Truran, J.W.; Wiescher, M.; Sparks, W.M.

    1995-01-01

    A nova outburst is the consequence of the accretion of hydrogen rich material onto a white dwarf and it can be considered as the largest hydrogen bomb in the Universe. The fuel is supplied by a secondary star in a close binary system while the strong degeneracy of the massive white dwarf acts to contain the gas during the early stages of the explosion. The containment allows the temperature in the nuclear burning region to exceed 10(sup 8)K under all circumstances. As a result a major fraction of CNO nuclei in the envelope are transformed into (beta)(sup +)-unstable nuclei. We discuss the effects of these nuclei on the evolution. Recent observational studies have shown that there are two compositional classes of novae; one which occurs on carbon-oxygen white dwarfs, and a second class that occurs on oxygen-neon-magnesium white dwarfs. In this review we will concentrate on the latter explosions since they produce the most interesting nucleosynthesis. We report both on the results of new observational determinations of nova abundances and, in addition, new hydrodynamic calculations that examine the consequences of the accretion process on 1.0M(sub (circle dot)), 1.25M(sub (circle dot)), and 1.35M(sub (circle dot)) white dwarfs. Our results show that novae can produce (sup 22)Na, (sup 26)Al, and other intermediate mass nuclei in interesting amounts. We will present the results of new calculations, done with updated nuclear reaction rates and opacities, which exhibit quantitative differences with respect to published work.

  4. Nucleosynthesis and the nova outburst

    SciTech Connect

    Starrfield, S.; Truran, J.W.; Wiescher, M.; Sparks, W.M.

    1995-12-31

    A nova outburst is the consequence of the accretion of hydrogen rich material onto a white dwarf and it can be considered as the largest hydrogen bomb in the Universe. The fuel is supplied by a secondary star in a close binary system while the strong degeneracy of the massive white dwarf acts to contain the gas during the early stages of the explosion. The containment allows the temperature in the nuclear burning region to exceed 10{sup 8}K under all circumstances. As a result a major fraction of CNO nuclei in the envelope are transformed into {beta}{sup +}-unstable nuclei. We discuss the effects of these nuclei on the evolution. Recent observational studies have shown that there are two compositional classes of novae; one which occurs on carbon-oxygen white dwarfs, and a second class that occurs on oxygen-neon-magnesium white dwarfs. In this review we will concentrate on the latter explosions since they produce the most interesting nucleosynthesis. We report both on the results of new observational determinations of nova abundances and, in addition, new hydrodynamic calculations that examine the consequences of the accretion process on 1.0M{sub {circle_dot}}, 1.25M{sub {circle_dot}}, and 1.35M{sub {circle_dot}} white dwarfs. Our results show that novae can produce {sup 22}Na, {sup 26}Al, and other intermediate mass nuclei in interesting amounts. We will present the results of new calculations, done with updated nuclear reaction rates and opacities, which exhibit quantitative differences with respect to published work.

  5. NUCLEAR THERMOMETERS FOR CLASSICAL NOVAE

    SciTech Connect

    Downen, Lori N.; Iliadis, Christian; Jose, Jordi; Starrfield, Sumner

    2013-01-10

    Classical novae are stellar explosions occurring in binary systems, consisting of a white dwarf and a main-sequence companion. Thermonuclear runaways on the surface of massive white dwarfs, consisting of oxygen and neon, are believed to reach peak temperatures of several hundred million kelvin. These temperatures are strongly correlated with the underlying white dwarf mass. The observational counterparts of such models are likely associated with outbursts that show strong spectral lines of neon in their shells (neon novae). The goals of this work are to investigate how useful elemental abundances are for constraining the peak temperatures achieved during these outbursts and determine how robust 'nova thermometers' are with respect to uncertain nuclear physics input. We present updated observed abundances in neon novae and perform a series of hydrodynamic simulations for several white dwarf masses. We find that the most useful thermometers, N/O, N/Al, O/S, S/Al, O/Na, Na/Al, O/P, and P/Al, are those with the steepest monotonic dependence on peak temperature. The sensitivity of these thermometers to thermonuclear reaction rate variations is explored using post-processing nucleosynthesis simulations. The ratios N/O, N/Al, O/Na, and Na/Al are robust, meaning they are minimally affected by uncertain rates. However, their dependence on peak temperature is relatively weak. The ratios O/S, S/Al, O/P, and P/Al reveal strong dependences on temperature and the poorly known {sup 30}P(p, {gamma}){sup 31}S rate. We compare our model predictions to neon nova observations and obtain the following estimates for the underlying white dwarf masses: 1.34-1.35 M {sub Sun} (V838 Her), 1.18-1.21 M {sub Sun} (V382 Vel), {<=}1.3 M {sub Sun} (V693 CrA), {<=}1.2 M {sub Sun} (LMC 1990 no. 1), and {<=}1.2 M {sub Sun} (QU Vul).

  6. The NOvA Data Acquisition System

    NASA Astrophysics Data System (ADS)

    Norman, A.

    2012-12-01

    The NOvA experiment is a long baseline neutrino experiment designed to make key measures to determine the neutrino mass hierarchy, neutrino mixing and CP violation in the neutrino sector. In order to make these measurements the NOvA collaboration has designed a highly distributed, synchronized, continuous digitization and readout system that is able to acquire and correlate data from the Fermilab accelerator complex, the NOvA near detector at Fermilab and the NOvA far detector which is located 810 km away at Ash River, MN. This system has unique properties that let it fully exploit the physics capabilities of the NOvA detector. This paper discusses the design of the NOvA DAQ system and its capabilities.

  7. Observations of classical novae in outburst

    SciTech Connect

    Starrfield, S.; Stryker, L.L.; Sonneborn, G.; Sparks, W.M.; Ferland, G.; Wagner, R.M.; Williams, R.E.; Gehrz, R.D.; Ney, E.P.; Kenyon, S.

    1988-01-01

    Over the past 10 years the IUE Satellite has obtained ultraviolet data on a number of novae in outbursts and the characteristics of every one of the outbursts have been different. In addition, our group has also obtained optical and infrared data on many of the same novae. In this paper we present the data on three members of the carbon-oxygen class of novae. 6 refs., 5 figs.

  8. Searching for nova shells around cataclysmic variables

    NASA Astrophysics Data System (ADS)

    Sahman, D. I.; Dhillon, V. S.; Knigge, C.; Marsh, T. R.

    2015-08-01

    We present the results of a search for nova shells around 101 cataclysmic variables (CVs), using H α images taken with the 4.2-m William Herschel Telescope (WHT) and the 2.5-m Isaac Newton Telescope Photometric H α Survey of the Northern Galactic Plane (IPHAS). Both telescopes are located on La Palma. We concentrated our WHT search on nova-like variables, whilst our IPHAS search covered all CVs in the IPHAS footprint. We found one shell out of the 24 nova-like variables we examined. The newly discovered shell is around V1315 Aql and has a radius of ˜2.5 arcmin, indicative of a nova eruption approximately 120 yr ago. This result is consistent with the idea that the high mass-transfer rate exhibited by nova-like variables is due to enhanced irradiation of the secondary by the hot white dwarf following a recent nova eruption. The implications of our observations for the lifetime of the nova-like variable phase are discussed. We also examined four asynchronous polars, but found no new shells around any of them, so we are unable to confirm that a recent nova eruption is the cause of the asynchronicity in the white dwarf spin. We find tentative evidence of a faint shell around the dwarf nova V1363 Cyg. In addition, we find evidence for a light echo around the nova V2275 Cyg, which erupted in 2001, indicative of an earlier nova eruption ˜300 yr ago, making V2275 Cyg a possible recurrent nova.

  9. TOPICAL REVIEW: Nucleosynthesis in classical nova explosions

    NASA Astrophysics Data System (ADS)

    José, Jordi; Hernanz, Margarita

    2007-12-01

    Classical novae are fascinating stellar explosions at the crossroads of stellar astrophysics, nuclear physics, and cosmochemistry. In this review, we briefly summarize 30 years of nucleosynthesis studies, with special emphasis on recent advances in nova theory (including multidimensional models) as well as on experimental efforts to reduce nuclear uncertainties affecting critical reaction rates. Among the topics that are covered, we outline the interplay between nova outbursts and the galactic chemical abundances, the synthesis of radioactive nuclei of interest for γ-ray astronomy, such as 7Li, 22Na or 26Al, and the potential discovery of presolar meteoritic grains likely condensed in nova shells.

  10. The Shape of Long Outbursts in U Gem Type Dwarf Novae from AAVSO Data

    NASA Technical Reports Server (NTRS)

    Cannizzo, John K.

    2012-01-01

    We search the American Association of Variable Star Observers (AAVSO) archives of the two best studied dwarf novae in an attempt to find light curves for long out bursts that are extremely well-characterized. The systems are U Gem and S8 Cyg. Our goal is to search for embedded precursors such as those that have been found recently in the high fidelity Kepler data for superoutbursts of some members of the 8U UMa subclass of dwarf novae. For the vast majority of AAV80 data, the combination of low data cadence and large errors associated with individual measurements precludes one from making any strong statement about the shape of the long outbursts. However, for a small number of outbursts, extensive long term monitoring with digital photometry yields high fidelity light curves. We report the finding of embedded precursors in two of three candidate long outbursts. This reinforces van Paradijs' finding that long outbursts in dwarf novae above the period gap and superoutbursts in systems below the period gap constitute a unified class. The thermal-tidal instability to account for superoutbursts in the SU UMa stars predicts embedded precursors only for short orbital period dwarf novae, therefore the presence of embedded precursors in long orbital period systems - U Gem and SS Cyg - argues for a more general mechanism to explain long outbursts.

  11. Predicting a Luminous Red Nova

    NASA Astrophysics Data System (ADS)

    Van Noord, Daniel; Molnar, Larry; Kinemuchi, Karen; Steenwyk, Steven; Alexander, Cara; Spedden, Chris; Kobulnicky, Henry

    2016-05-01

    Luminous Red Novae (LRN) are rare transient events believed to be caused by the merger of a main sequence contact binary. Since the discovery of the prototype, V838 Mon, only a handful of LRN events have been observed. Tylenda et al. (2011) analyzed the OGLE data preceding the 2008 Novae of V1309 Sco and found that it exhibited a similar light curve to that of a contact binary with one interesting exception, the orbital period of V1309 Sco showed exponential period change going to zero. Unfortunately the system was discovered to be a binary after the merger, preventing any targeted observations to narrow down how the system entered this unusual state. However the extreme period change observed in V1309 Sco gives us a signature to look for in other contact binaries, allowing the discovery of merger candidates for follow up. We will present an analysis of light curves and spectra of KIC 9832227 (NSVS 5597755) that show it is a contact binary system with a negative period derivative that is becoming more extreme with time. These data span more than 15 years and are taken from the NSVS, ASAS, WASP, and Kepler surveys, with ongoing measurements from the Calvin College Observatory and the Apache Point Observatory. The ongoing period change observed in the system is consistent with the exponential model fit from V1309 Sco and the rate of period change has surpassed that of all other measured contact binaries with the exception of V1309 Sco. If the exponential period decay continues the system will likely merge between 2019 and 2022 resulting in a naked eye nova. If this event occurs, this star will present the unprecedented opportunity to study a LRN progenitor and to follow the evolution of the merger.

  12. Identification of Recurrent Novae in M31

    NASA Astrophysics Data System (ADS)

    Shafter, Allen W.; Rector, T. A.; Schweizer, F.; Bryan, J.

    2014-01-01

    Over roughly the past century a total of more than 900 optical transient events have been recorded in M31, the vast majority of which are believed to represent eruptions of classical novae. The impressive dataset of nova positions put together by Pietsch (http://www.mpe.mpg.de m31novae/opt/m31/) provides the opportunity to search for multiple nova outbursts from the same progenitor system, and thus to characterize the population of recurrent novae (RNe) in M31. In order to identify RNe candidates, we have searched for spatial near coincidences among the 945 recorded novae given in the Pietsch catalog through the end of August 2013. Given that the positions of many of the early novae are quite uncertain, we have set our initial screen to include nova pairs with nominal separations less than or equal to 6 arcsec. We have identified a total of 102 novae that pass this coarse screen. Of these, 78 novae form 39 pairs, 15 form five triples, four novae are part of a quad, and five novae form a quint. As demonstrated by Shafter, Rice and Daub (2009, presented at the "Wild Stars in the Old West II" conference, mintaka.sdsu.edu/faculty/shafter/extragalactic_novae/RNePoster4.pdf), the majority of the 102 novae surviving our initial screen are expected to be associated with chance positional near coincidences (especially near the nucleus), and are not RNe. To decide which candidates are indeed RNe, we have undertaken a study to locate the original discovery plates, CCD images or published finding charts, and to perform the necessary astrometry to identify which of our candidate RNe are chance positional coincidences, and which are RNe. For each candidate, we estimate the probability that the object is a chance positional coincidence as in Shafter et al. (2009). To date, we have been successful in identifying finding charts or original images for most of the candidates, and have found a total of 23 nova outbursts in M31 associated with 10 systems that are almost certainly RNe.

  13. Novae a theoretical and observational study

    NASA Astrophysics Data System (ADS)

    Soraisam, Monika D.

    2016-02-01

    In this thesis, we present studies relating to novae that include both theoretical and ob- servational aspects. Being hosted by accreting white dwarfs (WDs), they have drawn attention in the context of the supernova Ia (SN Ia) progenitor problem. In the case of the nova explosion, the WD host is not disrupted. Instead, it continues to supply energy, even after the optical outbust, via stable nuclear burning of the remnant hydrogen envelope that survived the outburst. Accordingly, nova emission progresses toward the harder part of the electromagnetic spectrum, where it lasts longer than in the optical regime. As a consequence, novae are found to constitute the majority of the observed supersoft X-ray sources (SSSs). This is particularly well established for the galaxy M31. For high mass accretion rates in the unstable nuclear burning regime (or nova regime), there is evidence that significant mass accumulation by the WD is possible. This paved the way for SN Ia progenitor models in the single degenerate (SD) scenario involving novae. Based on the statistics of novae in M31, which is the most frequently used target for nova surveys, we investigate the role that novae may play in producing SNe Ia. Using multicycle nova evolution models and the observationally inferred nova rate in M31, we estimate the maximal SN Ia rate that novae can produce, assuming that all of the involved WDs reach the Chandrasekhar mass. Comparing this rate to the observationally inferred SN Ia rate for M31 constrains the contribution of the nova channel to the SN Ia rate to 2-7%. Additionally, we demonstrate that a more powerful diagnostic can be obtained from statistics of fast novae, which are characterized by decline times t2 10 days. Most novae resulting from a typical SD SN Ia progenitor accreting in the nova regime are fast. Specifically, as the WD in the nova grows in mass, it produces novae more frequently and with decreasing decline times. We therefore investigate how efficiently fast

  14. Cerebral Paragonimiasis.

    PubMed

    Miyazaki, I

    1975-01-01

    The first case of cerebral paragonimiasis was reported by Otani in Japan in 1887. This was nine years after Kerbert's discovery of the fluke in the lungs of Bengal tigers and seven years after a human pulmonary infection by the fluke was demonstrated by Baelz and Manson. The first case was a 26-year-old man who had been suffering from cough and hemosputum for one year. The patient developed convulsive seizures with subsequent coma and died. The postmortem examination showed cystic lesions in the right frontal and occipital lobes. An adult fluke was found in the occipital lesion and another was seen in a gross specimen of normal brain tissue around the affected occipital lobe. Two years after Otani's discovery, at autopsy a 29-year-old man with a history of Jacksonian seizure was reported as having cerebral paragonimiasis. Some time later, however, it was confirmed that the case was actually cerebral schistosomiasis japonica. Subsequently, cases of cerebral paragonimiasis were reported. However, the majority of these cases were not confirmed histologically. It was pointed out that some of these early cases were probably not Paragonimus infection. After World War II, reviews as well as case reports were published. Recently, investigations have been reported from Korea, with a clinicla study on 62 cases of cerebral paragonimiasis seen at the Neurology Department of the National Medical Center, Seoul, between 1958 and 1964. In 1971 Higashi described a statistical study on 105 cases of cerebral paragonimiasis that had been treated surgically in Japan.

  15. Spectroscopy of novae -- a user's manual

    NASA Astrophysics Data System (ADS)

    Shore, Steven N.

    2012-09-01

    The spectroscopic development of classical novae is described as a narrative of the various stages of the outburst. The review highlights the multiwavelength aspects of the phenomenology and the recent developments related to structure, inhomogeneity, and dynamics of the ejecta. Special emphasis is placed on the distinct behavior of the symbiotic-like recurrent novae.

  16. Nova pulse power design and operational experience

    NASA Astrophysics Data System (ADS)

    Whitham, K.; Larson, D.; Merritt, B.; Christie, D.

    1987-01-01

    Nova is a 100 TW Nd++ solid state laser designed for experiments with laser fusion at Lawrence Livermore National Laboratory (LLNL). The pulsed power for Nova includes a 58 MJ capacitor bank driving 5336 flashlamps with millisecond pulses and subnanosecond high voltages for electro optics. This paper summarizes the pulsed power designs and the operational experience to date.

  17. Terra Nova Bay Polynya, Antarctica

    NASA Technical Reports Server (NTRS)

    2007-01-01

    In Terra Nova Bay, off the Scott Coast of Victoria Land, Antarctica, a large pocket of open water persists throughout most of the Southern Hemisphere winter, even while most of the rest of the Antarctic coastline is firmly embraced by the frozen Southern Ocean. This pocket of open water--a polynya--results from exceptionally strong winds that blow downslope from the Trans-Antarctic Mountains. These fierce katabatic winds drive the sea ice eastward. Since the dominant ice drift pattern in the area is northward, the Drygalski Ice Tongue prevents the bay from being re-populated with sea ice. This image of the Terra Nova Bay polynya was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite on October 16, 2007. Sea ice sits over the Ross Sea like a cracked and crumbling windshield. Blue-tinged glaciers flow down from the Trans-Antarctic Mountains. Although glaciers can appear blue because of melt water, they can also get that tint when the wind scours and polishes the ice surface. Given the strength of the katabatic winds along this part of the Antarctic coast, it is likely that the blue color of these glaciers is a result of their having been swept clean of snow. The large image has a spatial resolution (level of detail) of 250 meters per pixel.

  18. BVRJK observations of Northern Hemisphere old novae

    NASA Technical Reports Server (NTRS)

    Szkody, Paula

    1994-01-01

    BVR photometry has been accomplished for 65 objects in the Duerbeck atlas along with J photometry of 52 and K of 30 objects. The (B - V), (V - R), and (V - J) colors are compiled with those available in the literature to assess the color change of novae as a function of time since outburst. Using available reddening values results in a list of 42 (B - V), 28 (V - R), and 38 (V - J) dereddened colors for novae that are from 1 to 319 years past outburst. The results indicate all the colors cluster about zero, with no obvious transition to red values as would be expected for novae undergoing a hibernation scenario. This indicates the accretion disk is sustained for at least 200 years after outburst. It is also apparent that red novae with giant secondaries and/or unusual properties readily stand out from the normal novae in color.

  19. Nova laser assurance-management system

    SciTech Connect

    Levy, A.J.

    1983-07-18

    In a well managed project, Quality Assurance is an integral part of the management activities performed on a daily basis. Management assures successful performance within budget and on schedule by using all the good business, scientific, engineering, quality assurance, and safety practices available. Quality assurance and safety practices employed on Nova are put in perspective by integrating them into the overall function of good project management. The Nova assurance management system was developed using the quality assurance (QA) approach first implemented at LLNL in early 1978. The LLNL QA program is described as an introduction to the Nova assurance management system. The Nova system is described pictorially through the Nova configuration, subsystems and major components, interjecting the QA techniques which are being pragmatically used to assure the successful completion of the project.

  20. Cerebral Palsy (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Cerebral Palsy KidsHealth > For Parents > Cerebral Palsy A A A ... kids who are living with the condition. About Cerebral Palsy Cerebral palsy is one of the most common ...

  1. Cerebral palsy - resources

    MedlinePlus

    Resources - cerebral palsy ... The following organizations are good resources for information on cerebral palsy : National Institute of Neurological Disorders and Stroke -- www.ninds.nih.gov/disorders/cerebral_palsy/cerebral_palsy. ...

  2. Spectroscopy and photometry of the dwarf nova BZ Ursae Majoris and the CV linewidth/K, mass-ratio relation

    NASA Technical Reports Server (NTRS)

    Jurcevic, J. S.; Honeycutt, R. K.; Schlegel, E. M.; Webbink, R. F.

    1994-01-01

    Time-resolved spectroscopy of the dwarf nova BZ Ursae Majoris (BZ UMa) reveals periodic velocity variations in the hydrogen emission lines with P = 97.9 +/- 0.1 min and K = 73 +/- 6 km/s. CCD photometry over a 16-month interval shows three outbursts of about 4 mag with a mean separation of 181 days. The mean full width at half maximum (FWHM) for the hydrogen beta emission is large, prompting a recalibration of the FWHM/K vs. mass ratio relation, giving a mass ratio (M(sub RD)/M(sub WD)) of 0.20 for BZ UMa. The short period, long outburst interval, and small mass ratio support the suggestion of BZ UMa being in the SU Ursae Majoris subclass of dwarf novae.

  3. Cerebral palsy.

    PubMed

    Colver, Allan; Fairhurst, Charles; Pharoah, Peter O D

    2014-04-05

    The syndrome of cerebral palsy encompasses a large group of childhood movement and posture disorders. Severity, patterns of motor involvement, and associated impairments such as those of communication, intellectual ability, and epilepsy vary widely. Overall prevalence has remained stable in the past 40 years at 2-3·5 cases per 1000 livebirths, despite changes in antenatal and perinatal care. The few studies available from developing countries suggest prevalence of comparable magnitude. Cerebral palsy is a lifelong disorder; approaches to intervention, whether at an individual or environmental level, should recognise that quality of life and social participation throughout life are what individuals with cerebral palsy seek, not improved physical function for its own sake. In the past few years, the cerebral palsy community has learned that the evidence of benefit for the numerous drugs, surgery, and therapies used over previous decades is weak. Improved understanding of the role of multiple gestation in pathogenesis, of gene environment interaction, and how to influence brain plasticity could yield significant advances in treatment of the disorder. Reduction in the prevalence of post-neonatal cerebral palsy, especially in developing countries, should be possible through improved nutrition, infection control, and accident prevention.

  4. One Thousand New Dwarf Novae from the OGLE Survey

    NASA Astrophysics Data System (ADS)

    Mróz, P.; Udalski, A.; Poleski, R.; Pietrukowicz, P.; Szymański, M. K.; Soszyński, I.; Wyrzykowski, Ł.; Ulaczyk, K.; Kozłowski, S.; Skowron, J.

    2015-12-01

    We present one of the largest collections of dwarf novae (DNe) containing 1091 objects that have been discovered in the long-term photometric data from the Optical Gravitational Lensing Experiment (OGLE) survey. They were found in the OGLE fields toward the Galactic bulge and the Magellanic Clouds. We analyze basic photometric properties of all systems and tentatively find a population of DNe from the Galactic bulge. We identify several dozen of WZ Sge-type DN candidates, including two with superhump periods longer than 0.09 d. Other interesting objects include SU UMa-type stars with "early" precursor outbursts or a Z Cam-type star showing outbursts during standstills. We also provide a list of DNe which will be observed during the K2 Campaign 9 microlensing experiment in 2016. Finally, we present the new OGLE-IV real-time data analysis system: CVOM, which has been designed to provide continuous real time photometric monitoring of selected CVs.

  5. The NOvA Technical Design Report

    SciTech Connect

    Ayres, D.S.; Drake, G.R.; Goodman, M.C.; Grudzinski, J.J.; Guarino, V.J.; Talaga, R.L.; Zhao, A.; Stamoulis, P.; Stiliaris, E.; Tzanakos, G.; Zois, M.; /Athens U. /Caltech /UCLA /Fermilab /College de France /Harvard U. /Indiana U. /Lebedev Inst. /Michigan State U. /Minnesota U., Duluth /Minnesota U.

    2007-10-08

    Technical Design Report (TDR) describes the preliminary design of the NOvA accelerator upgrades, NOvA detectors, detector halls and detector sites. Compared to the March 2006 and November 2006 NOvA Conceptual Design Reports (CDR), critical value engineering studies have been completed and the alternatives still active in the CDR have been narrowed to achieve a preliminary technical design ready for a Critical Decision 2 review. Many aspects of NOvA described this TDR are complete to a level far beyond a preliminary design. In particular, the access road to the NOvA Far Detector site in Minnesota has an advanced technical design at a level appropriate for a Critical Decision 3a review. Several components of the accelerator upgrade and new neutrino detectors also have advanced technical designs appropriate for a Critical Decision 3a review. Chapter 1 is an Executive Summary with a short description of the NOvA project. Chapter 2 describes how the Fermilab NuMI beam will provide a narrow band beam of neutrinos for NOvA. Chapter 3 gives an updated overview of the scientific basis for the NOvA experiment, focusing on the primary goal to extend the search for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations and measure the sin{sup 2}(2{theta}{sub 13}) parameter. This parameter has not been measured in any previous experiment and NOvA would extend the search by about an order of magnitude beyond the current limit. A secondary goal is to measure the dominant mode oscillation parameters, sin{sup 2}(2{theta}{sub 23}) and {Delta}m{sub 32}{sup 2} to a more precise level than previous experiments. Additional physics goals for NOvA are also discussed. Chapter 4 describes the Scientific Design Criteria which the Fermilab accelerator complex, NOvA detectors and NOvA detector sites must satisfy to meet the physics goals discussed in Chapter 3. Chapter 5 is an overview of the NOvA project. The changes in the design relative to the NOvA CDR are discussed. Chapter 6 summarizes the NOvA

  6. Nova laser alignment control system

    SciTech Connect

    Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L.; Shelton, R.T.

    1984-03-29

    Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently with the computer system. Automatic alignment is accomplished by using image analysis techniques to determine beam references points from video images acquired along the laser chain. A major goal of the design is to contribute substantially to rapid experimental turnaround and consistent alignment results. This paper describes the computer-based control structure and the software methods developed for aligning this large laser system.

  7. Circumstellar Dust in Symbiotic Novae

    NASA Astrophysics Data System (ADS)

    Jurkic, T.; Kotnik-Karuza, D.

    2015-12-01

    We present a model of inner dust regions around the cool Mira component of the two symbiotic novae, RR Tel and HM Sge, based on the near-IR photometry, ISO spectra and mid-IR interferometry. The dust properties were determined using the DUSTY code. A compact circumstellar silicate dust shell with inner dust shell temperatures between 900 K and 1300 K and of moderate optical depth can explain all the observations. RR Tel shows the presence of an equatorially enhanced dust density during minimum obscuration. Obscuration events are explained by an increase in optical depth caused by the newly condensed dust. The mass loss rates are significantly higher than in intermediate-period single Miras but in agreement with longer-period O-rich AGB stars.

  8. Nova V2214 Ophiuchi 1988 - A magnetic nova inside the period gap

    NASA Technical Reports Server (NTRS)

    Baptista, R.; Jablonski, F. J.; Cieslinski, D.; Steiner, J. E.

    1993-01-01

    The discovery of a coherent photometric modulation in Nova Oph 1988 with period 0.117515 +/- 0.000002 d, which is associated with the orbital period of the underlying binary, is reported. On the basis of photometric observations, it is concluded that Nova V2214 Oph 1988 is a magnetic nova with an orbital period inside the period gap. The inclusion of this system in the statistics of novae suggests that there is no period gap for novae and that there is a clear correlation between the occurrence of novae with short orbital periods and the presence of magnetic white dwarfs. It is suggested that funneling of the accretion flow onto the magnetic poles favors the conditions for a thermonuclear runaway, increasing the frequency of eruptions for magnetic systems.

  9. BZ UMa and Var Her 04: Orphan TOADS

    NASA Astrophysics Data System (ADS)

    Price, A.; Howell, S.

    2005-05-01

    Both BZ UMa and Var Her 04 are cataclysmic variable stars without a home. Neither fit easily into current classification systems so may extend the population distribution of two unique CV types: UGWZ dwarf novae and intermediate polars. New outburst photometry and archival X-Ray data shed some new light on BZ UMa's high energy state and new spectral and IR observations from Spitzer of dust around the newly discovered cataclysmic variable Var Her 04 may help find it a home as well.

  10. Cerebral Malaria.

    PubMed

    Marsden, P D; Bruce-Chwatt, L J

    1975-01-01

    Cerebral malaria is an acute diffuse encephalopathy associated only with Plasmodium falciparum. It is probably a consequence of the rapid proliferation of the parasites in the body of man in relation to red cell invasion, and results in stagnation of blood flow in cerebralcapillaries with thromobotic occlusion of large numbers of cerebral capillaries. The subsequent cerebral pathology is cerebral infarction with haemorrhage and cerebral oedema. The wide prevalence of P. falciparum in highly endemic areas results in daily challenges to patients from several infected mosquitoes. It is thus important to understand the characteristics of P. falciparum, since this is one of the most important protozoan parasites of man and severe infection from it constitutes one of the few real clinical emergencies in tropical medicine. One of the more important aspects of the practice of medicine in the tropics is to establish a good understanding of the pattern of medical practice in that area. This applies to malaria as well as to other diseases. The neophyte might be somewhat surprised to learn, for example that an experienced colleague who lives in a holoendemic malarious area such as West Africa, sees no cerebral malaria. But the explanation is simple when the doctor concerned has a practice which involves treating adults only. Cerebral malaria is rare in adults, because in highly endemic areas, by the age of 1 year most of the infants in a group under study have already experienced their first falciparum infection. By the time they reach adult life, they have a solid immunity against severe falciparum infections. In fact, "clinical malaria" could occur in such a group under only two circumstances: 1) in pregnancy, a patent infection with P. falciparum might develop, probably due to an IgG drain across the placenta to the foetus;2) in an individual who has constantly taken antimalarials and who may have an immunity at such a low level that when antimalarial therapy is interrupted

  11. Recent progress in understanding the eruptions of classical novae

    SciTech Connect

    Shara, M.M.

    1989-01-01

    The physical processes generating nova eruptions are reviewed, along with the effects on nova eruptions of binary-system parameters such as the chemical composition or mass of the white dwarf and the mass accretion rate. Also considered are the possible metamorphosis from dwarf to classical novae and back again, X-ray and gamma-ray emission from novae, and the characteristics and distributions of novae in globular clusters and extragalactic systems. Limitations of the thermonuclear runaway model are discussed. 159 references.

  12. CCD observations of old nova fields

    NASA Technical Reports Server (NTRS)

    Downes, Ronald A.; Szkody, Paula

    1989-01-01

    The discovery of CK Vulpeculae (Nova 1670) has prompted a major review of ideas concerning the long-term development of novae. Unfortunately, there are very few recovered novae old enough to provide confirmation (or rejection) of the new 'hibernation' scenario. CCD images of seven old nova fields, and R band photometry for four fields, have been obtained in an attempt to recover these objects in quiescence. A strong candidate for U Leonis, and a possible counterpart for T Bootis, are found. For three other fields, weak candidates have been found. Finding charts and colors are presented for the seven fields observed. The R light curves of U Leo, indicating an orbital period of 192.5 or 385.0 min, are shown.

  13. CCD observations of old nova fields

    SciTech Connect

    Downes, R.A.; Szkody, P.; Washington Uni., Seattle )

    1989-06-01

    The discovery of CK Vulpeculae (Nova 1670) has prompted a major review of ideas concerning the long-term development of novae. Unfortunately, there are very few recovered novae old enough to provide confirmation (or rejection) of the new hibernation scenario. CCD images of seven old nova fields, and R band photometry for four fields, have been obtained in an attempt to recover these objects in quiescence. A strong candidate for U Leonis, and a possible counterpart for T Bootis, are found. For three other fields, weak candidates have been found. Finding charts and colors are presented for the seven fields observed. The R light curves of U Leo, indicating an orbital period of 192.5 or 385.0 min, are shown. 14 refs.

  14. Old Novae and the SW Sextantis Phenomenon

    NASA Astrophysics Data System (ADS)

    Schmidtobreick, L.; Tappert, C.

    2014-12-01

    From a large observing campaign, we found that nearly all non- or weakly magnetic cataclysmic variables (CVs) in the orbital period range between 2.8 and 4 hours are of SW Sex type and as such experience very high mass transfer rates. The exceptions seem to be some old novae that have periods around 3.5 h. Their spectra do not show the typical SW Sex characteristics but rather resemble those of dwarf novae with low mass transfer rates. The presence of old novae in this period range of SW Sex stars that do not follow the trend but show instead rather low mass transfer rates is interpreted as evidence for an effect of the nova eruption on the mass transfer rate of the underlying CV similar to the hibernation scenario.

  15. Pulse shaping on the Nova laser system

    SciTech Connect

    Lawson, J.K.; Speck, D.R.; Bibeau, C.; Weiland, T.L.

    1989-02-06

    Inertial confinement fusion requires temporally shaped pulses to achieve high gain efficiency. Recently, we demonstrated the ability to produce complex temporal pulse shapes at high power at 0.35 microns on the Nova laser system. 2 refs., 2 figs.

  16. Copernicus observations of Nova Cygni 1975

    NASA Technical Reports Server (NTRS)

    Jenkins, E. B.; Snow, T. P.; Upson, W. L.; Anderson, R.; Starrfield, S. G.; Gallagher, J. S.; Friedjung, M.; Linsky, J. L.; Henry, R. C.; Moos, H. W.

    1977-01-01

    Near-ultraviolet radiation from Nova Cygni 1975 was detected by the Copernicus satellite on five occasions from 1975 September 1 to 1975 September 9. The nova was not seen in the UV after this date. The principal result was the observation of a broad emission feature from the Mg II doublet at 2800 A. The absence of strong UV radiation at shorter wavelengths suggests that these lines are produced by collisional excitation in the outer layers of an expanding shell with electron temperature of approximately 4000 K. The absence of observed emission lines from highly ionized species indicates that the amount of material with log T between 4.4 and 5.7 is less than 0.001 times that which produces the Mg II emission. The continuum flux in the near-UV decreased as the nova evolved, showing that the total luminosity decreased as the nova faded in the visible.

  17. Rate of nova production in the Galaxy

    SciTech Connect

    Liller, W.; Mayer, B.

    1987-07-01

    The ongoing PROBLICOM program in the Southern Hemisphere now makes it possible to derive a reliable value for the overall production rate of Galactic novae. The results, 73 + or - 24/y, indicates that the Galaxy outproduces M 31 by a factor of two or three. It is estimated that the rate of supernova ejecta is one and a half orders of magnitude greater than that of novae in the Galaxy. 15 references.

  18. Circumstellar dust in symbiotic novae

    NASA Astrophysics Data System (ADS)

    Jurkic, Tomislav; Kotnik-Karuza, Dubravka

    2015-08-01

    Physical properties of the circumstellar dust and associated physical mechanisms play an important role in understanding evolution of symbiotic binaries. We present a model of inner dust regions around the cool Mira component of the two symbiotic novae, RR Tel and HM Sge, based on the long-term near-IR photometry, infrared ISO spectra and mid-IR interferometry. Pulsation properties and long-term variabilities were found from the near-IR light curves. The dust properties were determined using the DUSTY code which solves the radiative transfer. No changes in pulsational parameters were found, but a long-term variations with periods of 20-25 years have been detected which cannot be attributed to orbital motion.Circumstellar silicate dust shell with inner dust shell temperatures between 900 K and 1300 K and of moderate optical depth can explain all the observations. RR Tel showed the presence of an optically thin CS dust envelope and an optically thick dust region outside the line of sight, which was further supported by the detailed modelling using the 2D LELUYA code. Obscuration events in RR Tel were explained by an increase in optical depth caused by the newly condensed dust leading to the formation of a compact dust shell. HM Sge showed permanent obscuration and a presence of a compact dust shell with a variable optical depth. Scattering of the near-IR colours can be understood by a change in sublimation temperature caused by the Mira variability. Presence of large dust grains (up to 4 µm) suggests an increased grain growth in conditions of increased mass loss. The mass loss rates of up to 17·10-6 MSun/yr were significantly higher than in intermediate-period single Miras and in agreement with longer-period O-rich AGB stars.Despite the nova outburst, HM Sge remained enshrouded in dust with no significant dust destruction. The existence of unperturbed dust shell suggests a small influence of the hot component and strong dust shielding from the UV flux. By the use

  19. Gamma-ray novae: rare or nearby?

    NASA Astrophysics Data System (ADS)

    Morris, Paul J.; Cotter, Garret; Brown, Anthony M.; Chadwick, Paula M.

    2017-02-01

    Classical novae were revealed as a surprise source of γ-rays in Fermi Large Area Telescope (LAT) observations. During the first 8 yr since the LAT was launched, 6 novae in total have been detected to >5σ in γ-rays, in contrast to the 69 discovered optically in the same period. We attempt to resolve this discrepancy by assuming all novae are γ-ray emitters, and assigning peak 1 d fluxes based on a flat distribution of the known emitters to a simulated population. To determine optical parameters, the spatial distribution and magnitudes of bulge and disc novae in M31 are scaled to the Milky Way, which we approximate as a disc with a 20 kpc radius and elliptical bulge with semimajor axis 3 kpc and axis ratios 2:1 in the xy plane. We approximate Galactic reddening using a double exponential disc with vertical and radial scaleheights of rd = 5 kpc and zd = 0.2 kpc, and demonstrate that even such a rudimentary model can easily reproduce the observed fraction of γ-ray novae, implying that these apparently rare sources are in fact nearby and not intrinsically rare. We conclude that classical novae with mR ≤ 12 and within ≈ 8 kpc are likely to be discovered in γ-rays using the Fermi LAT.

  20. Shortest recurrence periods of novae

    SciTech Connect

    Kato, Mariko; Saio, Hideyuki; Hachisu, Izumi; Nomoto, Ken'ichi

    2014-10-01

    Stimulated by the recent discovery of the 1 yr recurrence period nova M31N 2008-12a, we examined the shortest recurrence periods of hydrogen shell flashes on mass-accreting white dwarfs (WDs). We discuss the mechanism that yields a finite minimum recurrence period for a given WD mass. Calculating the unstable flashes for various WD masses and mass accretion rates, we identified a shortest recurrence period of about two months for a non-rotating 1.38 M {sub ☉} WD with a mass accretion rate of 3.6 × 10{sup –7} M {sub ☉} yr{sup –1}. A 1 yr recurrence period is realized for very massive (≳ 1.3 M {sub ☉}) WDs with very high accretion rates (≳ 1.5 × 10{sup –7} M {sub ☉} yr{sup –1}). We revised our stability limit of hydrogen shell burning, which will be useful for binary evolution calculations toward Type Ia supernovae.

  1. Cerebral malaria

    PubMed Central

    Newton, C.; Hien, T. T.; White, N.

    2000-01-01

    Cerebral malaria may be the most common non-traumatic encephalopathy in the world. The pathogenesis is heterogenous and the neurological complications are often part of a multisystem dysfunction. The clinical presentation and pathophysiology differs between adults and children. Recent studies have elucidated the molecular mechanisms of pathogenesis and raised possible interventions. Antimalarial drugs, however, remain the only intervention that unequivocally affects outcome, although increasing resistance to the established antimalarial drugs is of grave concern. Artemisinin derivatives have made an impact on treatment, but other drugs may be required. With appropriate antimalarial drugs, the prognosis of cerebral malaria often depends on the management of other complications—for example, renal failure and acidosis. Neurological sequelae are increasingly recognised, but further research on the pathogenesis of coma and neurological damage is required to develop other ancillary treatments.

 PMID:10990500

  2. Models for various aspects of dwarf novae and nova-like stars

    NASA Technical Reports Server (NTRS)

    Ladous, Constanze

    1993-01-01

    The first attempts to explain the nature of dwarf novae were based on the assumption of single-star phenomena, in which emission lines were assumed to be caused by circumstellar gas shells. The outburst behavior was tentatively ascribed to the kind of (also not understood) mechanism leading to nova outbursts. The realization that some, and possibly all, dwarf novae and nova-like stars (and novae) are binaries eventually led to models which bore more and more similarities to the modern interpretation on the basis of the Roche model. Not all cataclysmic variables are known binaries. In fact, with respect to the entire number of known objects, the proven binaries are still the minority, but all the brightest variables are in fact known to binaries. Not a single system is known which exhibits the usual characteristics of a cataclysmic variable and at the same time can be declared with certainty to be a single star. Two systems are known, the dwarf nova EY Cyg and the recurrent nova V1017 Sgr, in which, in spite of intensive search, no radial velocity variations have been found; but they still exhibit composite spectra consisting of a bright continuum, an emission spectrum, and a cool absorption spectrum. If the Roche model is correct, it is to be expected that a small percentage of objects is viewed pole-on, so orbital motions do not make themselves felt as Doppler shifts of spectral lines. So even these two systems support the hypothesis that all cataclysmic variables (with the possible exception of symbiotic stars) are binaries. In cataclysmic variables, it seems that the brightness changes observed in dwarf novae and nova-like stars in the optical and the UV are due directly to changes in the accretion disks. The study and understanding of accretion disks in these systems can bear potentially valuable consequences for many other fields in astronomy. The observed spectra of dwarf novae and nova-like stars comprise a fairly large range: pure emission spectra, pure

  3. When does an old nova become a dwarf nova? Kinematics and age of the nova shell of the dwarf nova AT Cancri

    NASA Astrophysics Data System (ADS)

    Shara, Michael M.; Drissen, Laurent; Martin, Thomas; Alarie, Alexandre; Stephenson, F. Richard

    2017-02-01

    The Z Cam-type dwarf nova AT Cancri (AT Cnc) displays a classical nova (CN) shell, demonstrating that mass transfer in cataclysmic binaries decreases substantially after a CN eruption. The hibernation scenario of cataclysmic binaries predicts such a decrease, on a time-scale of a few centuries. In order to measure the time since AT Cnc's last CN eruption, we have measured the radial velocities of a hundred clumps in its ejecta with SITELLE, Canada-France-Hawaii Telescope's recently commissioned imaging Fourier transform spectrometer. These range from -455 to +490 km s-1. Coupled with the known distance to AT Cnc of 460 pc, the size of AT Cnc's shell, and a simple model of nova ejecta deceleration, we determine that the last CN eruption of this system occurred 330_{-90}^{+135} yr ago. This is the most rapid transition from a high mass-transfer rate, nova-like variable to a low mass-transfer rate, dwarf nova yet measured, and in accord with the hibernation scenario of cataclysmic binaries. We conclude by noting the similarity in the deduced outburst date (within a century of 1686 CE) of AT Cnc to a `guest star' reported in the constellation Cancer by Korean observers in 1645 CE.

  4. Serendipitous discovery of a dwarf Nova in the Kepler field near the G dwarf KIC 5438845

    SciTech Connect

    Brown, Alexander; Ayres, Thomas R.; Neff, James E.; Wells, Mark A.; Kowalski, Adam; Berdyugina, Svetlana; Harper, Graham M.; Korhonen, Heidi; Piskunov, Nikolai; Saar, Steven; Walkowicz, Lucianne

    2015-02-01

    The Kepler satellite provides a unique window into stellar temporal variability by observing a wide variety of stars with multi-year, near-continuous, high precision, optical photometric time series. While most Kepler targets are faint stars with poorly known physical properties, many unexpected discoveries should result from a long photometric survey of such a large area of sky. During our Kepler Guest Observer programs that monitored late-type stars for starspot and flaring variability, we discovered a previously unknown dwarf nova that lies within a few arcseconds of the mid-G dwarf star KIC 5438845. This dwarf nova underwent nine outbursts over a 4 year time span. The two largest outbursts lasted ∼17–18 days and show strong modulations with a 110.8 minute period and a declining amplitude during the outburst decay phase. These properties are characteristic of an SU UMa-type cataclysmic variable. By analogy with other dwarf nova light curves, we associate the 110.8 minute (1.847 hr) period with the superhump period, close to but slightly longer than the orbital period of the binary. No precursor outbursts are seen before the super-outbursts and the overall super-outburst morphology corresponds to Osaki and Meyer “Case B” outbursts, which are initiated when the outer edge of the disk reaches the tidal truncation radius. “Case B” outbursts are rare within the Kepler light curves of dwarf novae. The dwarf nova is undergoing relatively slow mass transfer, as evidenced by the long intervals between outbursts, but the mass transfer rate appears to be steady, because the smaller “normal” outbursts show a strong correlation between the integrated outburst energy and the elapsed time since the previous outburst. At super-outburst maximum the system was at V ∼ 18, but in quiescence it is fainter than V ∼ 22, which will make any detailed quiescent follow-up of this system difficult.

  5. Nova Discovery Efficiency 1890-2014; Only 43%±6% of the Brightest Nova Are Discovered

    NASA Astrophysics Data System (ADS)

    Schaefer, Bradley E.

    2014-06-01

    Galactic nova discovery has always been the domain of the best amateur astronomers, with the only substantial exception being the use of the Harvard plates from 1890-1947. (Modern CCD surveys have not produced any significant nova discoveries.) From 1890-1946, novae were discovered by gentlemen who deeply knew the stars in the sky and who checked for new stars on every clear night. This all changed when war surplus binoculars became commonly available, so the various organizations (e.g., AAVSO, BAA) instructed their hunters to use binoculars to regularly search small areas of the Milky Way. In the 1970s the hunters largely switched to blinking photographs, while they switched to CCD images in the 1990s, all exclusively in Milky Way regions. Currently, most hunters use 'go-to' scopes to look deeply only in the Milky Way, use weekly or monthly cadences, never go outside to look up at the light-polluted skies, and do not have the stars memorized at all. This situation is good for catching many faint novae, but is inefficient for catching the more isotropic and systematically-fast bright novae.I have made an exhaustive analysis of all known novae to isolate the effects on the relative discovery efficiency as a function of decade, the elongation from the Sun, the Moon's phase, the declination, the peak magnitude, and the duration of the peak. For example, the relative efficiency for novae south of declination -33° is 0.5 before 1953, 0.2 from 1953-1990, and 0.8 after 1990. My analysis gives the overall discovery efficiency to be 43%±6%, 30%, 22%, 12%, and 6% for novae peaking brighter than 2, 4, 6, 8, and 10 mag. Thus, the majority of first magnitude novae are being missed. The bright novae are lost because they are too close to the Sun, in the far south, and/or very fast. This is illustrated by the discovery rate for Vpeak<2 novae being once every five years before 1946, yet only one such nova (V1500 Cyg) has been seen in the last 68 years. A critical consequence of

  6. NOVA laser facility for inertial confinement fusion

    SciTech Connect

    Simmons, W.W.

    1983-11-30

    The NOVA laser consists of ten beams, capable of concentrating 100 to 150 kJ of energy (in 3 ns) and 100 to 150 TW of power (in 100 ps) on experimental targets by 1985. NOVA will also be capable of frequency converting the fundamental laser wavelength (1.05 ..mu..m) to its second (0.525 ..mu..m) or third (0.35 ..mu..m) harmonic. This additional capability (80 to 120 kJ at 0.525 ..mu..m, 40 to 70 kJ at 0.35 ..mu..m) was approved by the US Department of Energy (DOE) in April 1982. These shorter wavelengths are much more favorable for ICF target physics. Current construction status of the NOVA facility, intended for completion in the autumn of 1984, will be presented.

  7. AN EXTENDED GRID OF NOVA MODELS. III. VERY LUMINOUS, RED NOVAE

    SciTech Connect

    Shara, Michael M.; Zurek, David; Yaron, Ofer; Prialnik, Dina; Kovetz, Attay

    2010-12-10

    Extremely luminous, red eruptive variables like RV in M31 are being suggested as exemplars of a new class of astrophysical objects. Our greatly extended series of nova simulations shows that classical nova models can produce very red, luminous eruptions. In a poorly studied corner of three-dimensional nova parameter space (very cold, low-mass white dwarfs, accreting at very low rates) we find bona fide classical novae that are very luminous and red because they eject very slowly moving, massive envelopes. A crucial prediction of these nova models-in contrast to the predictions of merging star ('mergeburst') models-is that a hot remnant, the underlying white dwarf, will emerge after the massive ejected envelope has expanded enough to become optically thin. This blue remnant must fade on a timescale of decades-much faster than a 'mergeburst', which must fade on timescales of millennia or longer. Furthermore, the cooling nova white dwarf and its expanding ejecta must become redder in the years after eruption, while a contracting mergeburst must become hotter and bluer. We predict that red novae will always brighten to L {approx} 1000 L{sub sun} for about one year before rising to the maximum luminosity at L {approx} 10{sup 6}-10{sup 7} L{sub sun}. The maximum luminosity attainable by a nova is likely to be L {approx} 10{sup 7} L{sub sun}, corresponding to M {approx} -12. In an accompanying paper, we describe a fading, luminous blue candidate for the remnant of M31-RV; it is observed with the Hubble Space Telescope to be compatible only with the nova model.

  8. NUCLEAR MIXING METERS FOR CLASSICAL NOVAE

    SciTech Connect

    Kelly, Keegan J.; Iliadis, Christian; Downen, Lori; Champagne, Art; José, Jordi

    2013-11-10

    Classical novae are caused by mass transfer episodes from a main-sequence star onto a white dwarf via Roche lobe overflow. This material possesses angular momentum and forms an accretion disk around the white dwarf. Ultimately, a fraction of this material spirals in and piles up on the white dwarf surface under electron-degenerate conditions. The subsequently occurring thermonuclear runaway reaches hundreds of megakelvin and explosively ejects matter into the interstellar medium. The exact peak temperature strongly depends on the underlying white dwarf mass, the accreted mass and metallicity, and the initial white dwarf luminosity. Observations of elemental abundance enrichments in these classical nova events imply that the ejected matter consists not only of processed solar material from the main-sequence partner but also of material from the outer layers of the underlying white dwarf. This indicates that white dwarf and accreted matter mix prior to the thermonuclear runaway. The processes by which this mixing occurs require further investigation to be understood. In this work, we analyze elemental abundances ejected from hydrodynamic nova models in search of elemental abundance ratios that are useful indicators of the total amount of mixing. We identify the abundance ratios ΣCNO/H, Ne/H, Mg/H, Al/H, and Si/H as useful mixing meters in ONe novae. The impact of thermonuclear reaction rate uncertainties on the mixing meters is investigated using Monte Carlo post-processing network calculations with temperature-density evolutions of all mass zones computed by the hydrodynamic models. We find that the current uncertainties in the {sup 30}P(p, γ){sup 31}S rate influence the Si/H abundance ratio, but overall the mixing meters found here are robust against nuclear physics uncertainties. A comparison of our results with observations of ONe novae provides strong constraints for classical nova models.

  9. Alignment of the NOvA Detectors

    NASA Astrophysics Data System (ADS)

    Bending, Sebastian; NOvA Collaboration

    2017-01-01

    NOvA is a long-baseline neutrino oscillation experiment intended to probe the neutrino mass hierarchy and provide constraints on CP violation in the neutrino sector. The experiment consists of a Near Detector at Fermilab and a Far Detector 810 km away at Ash River, Minnesota, both of which receive neutrinos from the NuMI beamline. The misalignment of elements within the detectors contributes to systematic uncertainties in NOvA measurements. A procedure to determine and correct for detector misalignments through the use of cosmic ray muon tracks will be presented.

  10. Ultraviolet observations of LMC nova 1988

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Stryker, L. L.; Sonneborn, G.; Sparks, Warren M.; Sion, E. M.; Wagner, R. M.; Ferland, Gary; Gallagher, J. S.; Wade, R.; Williams, R. E.

    1988-01-01

    The IUE obtained ultraviolet spectra of a nova in an external galaxy. The spectral features do not seem unusual for a nova at maximum but it is hoped to be able to follow it for a long enough time to be able to study the high ionization lines that appear when the density drops to lower values (the nebular stage). A high dispersion spectrum was also obtained to assist in the line identification and to study the line of sight to the LMC 1 deg of arc away from SN 1987A.

  11. Ultraviolet observations of LMC nova 1988

    SciTech Connect

    Starrfield, S.; Stryker, L.L.; Sonneborn, G.; Sparks, W.M.; Sion, E.M.; Wagner, R.M.; Ferland, G.; Gallagher, J.S.; Wade, R.; Williams, R.E.; Heathcote, S.; Kenyon, S.; Shaviv, G.; Wehrse, R.; Hauschildt, P.; Truran, J.W.; Wu, C.C.; Gehrz, R.D.; Ney, E.P.

    1988-01-01

    This current bright novae was first detected in outburst on March 21, 1988. Its discovery has given us the opportunity of studying the first extragalactic nova in the ultraviolet and we have, therefore, obtained a number of LWP and SWP spectra when it was at maximum. We have also obtained a high dispersion LWP spectrum in order to study the ISM in the Large Magellanic Cloud on a slightly different line-of-sight from that analyzed using SN 1987A. 10 refs., 2 figs.

  12. The spectral evolution of dwarf nova outbursts

    NASA Technical Reports Server (NTRS)

    Cannizzo, John K.; Kenyon, Scott J.

    1987-01-01

    The disk instability model for dwarf nova eruptions is investigated by computing the spectral development of the accretion disk through a complete limit cycle. Observed stellar spectra are used to model the radiation emitted by optically thick annuli within the disc. The general findings agree with those of Smak (1984) and Pringle et al. (1986). It is suggested that the 'dwarf nova oscillations' might be a source of information concerning the evolution of the inner disk and that detailed observations of this phenomenon can be used to test various outburst mechanisms.

  13. PAH emission from Nova Cen 1986

    NASA Technical Reports Server (NTRS)

    Hyland, A. R. Harry; Mcgregor, P. J.

    1989-01-01

    The discovery of broad emission features between 3.2 and 3.6 microns were reported in the spectrum of Nova Cen 1986 (V842 Cen) some 300 days following outburst and remaining prominent for several months. The general characteristics of these features are similar to those attributed to polycyclic hydrocarbon (PAH) molecules in other dusty sources, although the relative strengths are different, and these observations provide the first clear evidence for molecular constituents other than graphite particles in the ejecta of novae.

  14. Nova Cephei 2014; Near-IR observations

    NASA Astrophysics Data System (ADS)

    Ashok, N. M.; Banerjee, D. P. K.; Venkataraman, V.; Joshi, Vishal

    2014-03-01

    Spectra of Nova Cephei 2014, discovered on 9 March 2014 (CBET 2825) were obtained on 13, 15 and 20 March at R ~ 1000 (0.85 to 2.4 micron range) with the 1.2m Mount Abu Telescope + the recently commissioned Near-Infrared Camera Spectrograph (NICS). The spectra show P Cygni features and are typical of the Fe II class of novae which in the NIR show prominent HI and OI lines but are distinguished from the He/N class by displaying numerous strong lines of Carbon (see Banerjee and Ashok, 2012, BASI, for the NIR templates of both classes).

  15. Terra Nova breaks new ground for alliances

    SciTech Connect

    Ghiselin, D.

    1996-08-01

    This paper reviews the development of alliances to help develop the Terra Nova oil and gas field in the offshore Atlantic areas of Canada. Largely attributed to BP, the strategic alliance concept got its start in the North Sea and on the North Slope of Alaska. BP saw it as the best way to take advantage of economy-of-scale, mitigate risk, and achieve outsourcing goals while retaining their core competencies. This paper reviews the methods of developing the alliances, the developing of a development plan for the Terra Nova field, and how the alliance plans to maximize the profittability of the operation for all involved.

  16. Mix experiments with the NOVA laser

    SciTech Connect

    Rupert, V.C.; Kilkenny, J.D.; Skokowski, P.G.

    1988-10-01

    The NOVA mix experiments are designed to study mix between two dissimilar materials subjected to strong (M/approximately/50) shocks and variable accelerations in a direction normal to their common boundary. The main purpose of the experiments is to provide a data base with which predictive models can be compared and normalized. Together with shock tube experiments, which explore a different regime, the current NOVA tests investigate the shock induced source terms in our model and the evolution of both Rayleigh-Taylor stable and unstable interfaces. 3 refs., 9 figs.

  17. The Long-Term Behavior of Known & Suspected Novae

    NASA Astrophysics Data System (ADS)

    Pagnotta, A.

    2017-03-01

    The long-term evolution of classical novae is poorly understood. I discuss here an in-progress project designed to better understand the post-eruption behavior of novae and test the Hibernation theory of nova evolution. The project has two main parts: (1) a modern survey of Galactic nova magnitudes, and (2) construction of long-term light curves using primarily archival photographic plates.

  18. The benefit of amateur observations for research in dwarf novae

    NASA Technical Reports Server (NTRS)

    La Dous, Constanze

    1992-01-01

    Contributions of amateur astronomers to research on dwarf novae, which are based on carefully monitoring the outburst behavior of these objects, are reviewed. These contributions range from scheduling of observations to the observational basis for research on the dwarf nova outburst mechanism. It is suggested, that, with better equipment, observations of orbital light variations in dwarf novae might be performed by amateur astronomers.

  19. First optical candidate for a recovered classical nova in a globular cluster - Nova 1938 in M14

    NASA Technical Reports Server (NTRS)

    Shara, Michael M.; Potter, Michael; Moffat, Anthony F. J.; Hogg, Helen S.; Wehlau, Amelia

    1986-01-01

    U, B, V, R, and H-alpha CCD frames of the field of the nova which appeared in the globular cluster M14 in 1938 have been compared with the nova discovery images. On the basis of positional coincidence, brightness, and blue color, a candidate nova was identified and its right ascension and declination to within 1 arcsec each. Confirmation of the candidate and detailed study of the quiescent nova will probably require Hubble Space Telescope observations.

  20. The nova-like variable KQ Mon and the nature of the UX Ursa Majoris stars

    NASA Technical Reports Server (NTRS)

    Sion, E. M.; Guinan, E. F.

    1982-01-01

    The KQ Mon is a UX UMa type nova-like variable discovered by Howard Bond. Optical spectra taken by Bond in 1978 reveal very shallow Balmer absorption lines and He I absorption. Bond also did UBV and high speed photometry in 1978 and early 1981. There has been no evidence of orbital variations but the appearance of the optical spectrum and the presence of low amplitude flickering suggested a strong similarity to CD-42-14462 (=V3885 Sgr) and other members of the UX UMa class. Low dispersion observations of KQ Mon were made with the International Ultraviolet Explorer satellite. Six spectra taken with the shot wavelength prime camera are dominated by strong broad absorption lines due to N V, O I, Si III, Si IV, C IV, He II, N IV, and Al III. There is little evidence of orbital phase modulation over the time baseline of the observations. Unlike UV observations of other UX UMa type objects, KQ Mon exhibits no emission lines or P Cygni type profiles and the velocity displacements appear to be smaller, suggesting the absence of a hot, high velocity wind characterizing other UX UMa stars. The relationship of KQ Mon to other UX UMa disk stars is discussed and a model is suggested to explain their observed properties and the lack of major outbursts.

  1. A near-infrared survey of old novae. I - The discovery of a candidate recurrent nova

    NASA Astrophysics Data System (ADS)

    Harrison, Thomas E.

    1992-12-01

    We report on a near-infrared survey of old novae in an attempt to discover previously unidentified members of the RS Oph family of recurrent novae. An RS Oph-type system contains a red giant, and is easily identified using infrared photometry. Two objects in our survey have infrared colors and luminosities that suggest that they may be recurrent novae: V723 Sco and AR Cir. We use a model of the Galaxy to rule out the possibility of source confusion in either case. The light curve of the 1952 outburst of V723 Sco was very similar to those of the other members of the RS Oph group of recurrent novae, and we conclude that it is a previously unidentified member of this family. The light curve of the 1906 outburst of AR Cir, however, more closely resembles those of the outbursts of symbiotic stars, and we classify it as such.

  2. Novae. Fermi establishes classical novae as a distinct class of gamma-ray sources.

    PubMed

    2014-08-01

    A classical nova results from runaway thermonuclear explosions on the surface of a white dwarf that accretes matter from a low-mass main-sequence stellar companion. In 2012 and 2013, three novae were detected in γ rays and stood in contrast to the first γ-ray-detected nova V407 Cygni 2010, which belongs to a rare class of symbiotic binary systems. Despite likely differences in the compositions and masses of their white dwarf progenitors, the three classical novae are similarly characterized as soft-spectrum transient γ-ray sources detected over 2- to 3-week durations. The γ-ray detections point to unexpected high-energy particle acceleration processes linked to the mass ejection from thermonuclear explosions in an unanticipated class of Galactic γ-ray sources.

  3. NOVA making stuff: Season 2

    SciTech Connect

    Leombruni, Lisa; Paulsen, Christine Andrews

    2014-12-12

    Over the course of four weeks in fall 2013, 11.7 million Americans tuned in to PBS to follow host David Pogue as he led them in search of engineering and scientific breakthroughs poised to change our world. Levitating trains, quantum computers, robotic bees, and bomb-detecting plants—these were just a few of the cutting-edge innovations brought into the living rooms of families across the country in NOVA’s four-part series, Making Stuff: Faster, Wilder, Colder, and Safer. Each of the four one-hour programs gave viewers a behind-the-scenes look at novel technologies poised to change our world—showing them how basic research and scientific discovery can hold the keys to transforming how we live. Making Stuff Season 2 (MS2) combined true entertainment with educational value, creating a popular and engaging series that brought accessible science into the homes of millions. NOVA’s goal to engage the public with such technological innovation and basic research extended beyond the broadcast series, including a variety of online, educational, and promotional activities: original online science reporting, web-only short-form videos, a new online quiz-game, social media engagement and promotion, an educational outreach “toolkit” for science educators to create their own “makerspaces,” an online community of practice, a series of nationwide Innovation Cafés, educator professional development, a suite of teacher resources, an “Idealab,” participation in national conferences, and specialized station relation and marketing. A summative evaluation of the MS2 project indicates that overall, these activities helped make a significant impact on the viewers, users, and participants that NOVA reached. The final evaluation conducted by Concord Evaluation Group (CEG) confidently concluded that the broadcast, website, and outreach activities were successful at achieving the project’s intended impacts. CEG reported that the MS2 series and website content were

  4. Numerical modelling of the classical nova outburst

    SciTech Connect

    Kutter, G.S.; Sparks, W.M.

    1987-01-01

    We describe a mechanism that promises to explain how nova outbursts take place on white dwarf of 1 Msub solar or less and for accretion rates of 4 x 10/sup -10/ Msub solar yr/sup -1/ or greater. 7 refs.

  5. The expanding fireball of Nova Delphini 2013.

    PubMed

    Schaefer, G H; ten Brummelaar, T; Gies, D R; Farrington, C D; Kloppenborg, B; Chesneau, O; Monnier, J D; Ridgway, S T; Scott, N; Tallon-Bosc, I; McAlister, H A; Boyajian, T; Maestro, V; Mourard, D; Meilland, A; Nardetto, N; Stee, P; Sturmann, J; Vargas, N; Baron, F; Ireland, M; Baines, E K; Che, X; Jones, J; Richardson, N D; Roettenbacher, R M; Sturmann, L; Turner, N H; Tuthill, P; van Belle, G; von Braun, K; Zavala, R T; Banerjee, D P K; Ashok, N M; Joshi, V; Becker, J; Muirhead, P S

    2014-11-13

    A classical nova occurs when material accreting onto the surface of a white dwarf in a close binary system ignites in a thermonuclear runaway. Complex structures observed in the ejecta at late stages could result from interactions with the companion during the common-envelope phase. Alternatively, the explosion could be intrinsically bipolar, resulting from a localized ignition on the surface of the white dwarf or as a consequence of rotational distortion. Studying the structure of novae during the earliest phases is challenging because of the high spatial resolution needed to measure their small sizes. Here we report near-infrared interferometric measurements of the angular size of Nova Delphini 2013, starting one day after the explosion and continuing with extensive time coverage during the first 43 days. Changes in the apparent expansion rate can be explained by an explosion model consisting of an optically thick core surrounded by a diffuse envelope. The optical depth of the ejected material changes as it expands. We detect an ellipticity in the light distribution, suggesting a prolate or bipolar structure that develops as early as the second day. Combining the angular expansion rate with radial velocity measurements, we derive a geometric distance to the nova of 4.54 ± 0.59 kiloparsecs from the Sun.

  6. Nova pulse power system description and status

    SciTech Connect

    Holloway, R.W.; Whitham, K.; Merritt, B.T.; Gritton, D.G.; Oicles, J.A.

    1981-06-01

    The Nova laser system is designed to produce critical data in the nation's inertial confinement fusion effort. It is the world's largest peak power laser and presents various unique pulse power problems. In this paper, pulse power systems for this laser are described, the evolutionary points from prior systems are pointed out, and the current status of the hardware is given.

  7. NOVA[R] Spring 2001 Teacher's Guide.

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    This teacher's guide is designed to accompany the PBS television program "NOVA" and features six activities. "Sultan's Lost Treasure" presents the attempts of an archaeologist and his team to salvage an ancient ship wreck. "Vanished!" investigates what happened to the Stardust airliner in 1947 which disappeared during…

  8. Supernova hydrodynamicas experiments using the Nova laser

    SciTech Connect

    Remington, B.A.; Glendinning, S.G.; Estabrook, K.

    1997-07-01

    We are developing experiments using the Nova laser to investigate (1) compressible nonlinear hydrodynamic mixing relevant to the first few hours of the supernova (SN) explosion and (2) ejecta-ambient plasma interactions relevant to the early SN remnant phase. The experiments and astrophysical implications are discussed.

  9. Models of classical and recurrent novae

    NASA Technical Reports Server (NTRS)

    Friedjung, Michael; Duerbeck, Hilmar W.

    1993-01-01

    The behavior of novae may be divided roughly into two separate stages: quiescence and outburst. However, at closer inspection, both stages cannot be separated. It should be attempted to explain features in both stages with a similar model. Various simple models to explain the observed light and spectral observations during post optical maximum activity are conceivable. In instantaneous ejection models, all or nearly all material is ejected in a time that is short compared with the duration of post optical maximum activity. Instantaneous ejection type 1 models are those where the ejected material is in a fairly thin shell, the thickness of which remains small. In the instantaneous ejection type 2 model ('Hubble Flow'), a thick envelope is ejected instantaneously. This envelope remains thick as different parts have different velocities. Continued ejection models emphasize the importance of winds from the nova after optical maximum. Ejection is supposed to occur from one of the components of the central binary, and one can imagine a general swelling of one of the components, so that something resembling a normal, almost stationary, stellar photosphere is observed after optical maximum. The observed characteristics of recurrent novae in general are rather different from those of classical novae, thus, models for these stars need not be the same.

  10. The NOvA simulation chain

    DOE PAGES

    Aurisano, A.; Backhouse, C.; Hatcher, R.; ...

    2015-12-23

    The NOvA experiment is a two-detector, long-baseline neutrino experiment operating in the recently upgraded NuMI muon neutrino beam. Simulating neutrino interactions and backgrounds requires many steps including: the simulation of the neutrino beam flux using FLUKA and the FLUGG interface, cosmic ray generation using CRY, neutrino interaction modeling using GENIE, and a simulation of the energy deposited in the detector using GEANT4. To shorten generation time, the modeling of detector-specific aspects, such as photon transport, detector and electronics noise, and readout electronics, employs custom, parameterized simulation applications. We will describe the NOvA simulation chain, and present details on the techniquesmore » used in modeling photon transport near the ends of cells, and in developing a novel data-driven noise simulation. Due to the high intensity of the NuMI beam, the Near Detector samples a high rate of muons originating in the surrounding rock. In addition, due to its location on the surface at Ash River, MN, the Far Detector collects a large rate ((˜) 140 kHz) of cosmic muons. Furthermore, we will discuss the methods used in NOvA for overlaying rock muons and cosmic ray muons with simulated neutrino interactions and show how realistically the final simulation reproduces the preliminary NOvA data.« less

  11. Status of the NOvA experiment

    SciTech Connect

    Plunkett, Robert; /Fermilab

    2007-12-01

    The NOvA experiment, using the existing NuMI beamline, is planned for construction at Ash River, Minnesota. The experiment will provide a measurement of, or strong limit on the neutrino mixing angle {theta}{sub 13}, and for sufficiently strong mixing, establish the hierarchy of the neutrino masses.

  12. Nova Scotia. Reference Series No. 32.

    ERIC Educational Resources Information Center

    Department of External Affairs, Ottawa (Ontario).

    This booklet, one of a series featuring the Canadian provinces, presents a brief overview of Nova Scotia and is suitable for teacher reference or student reading. Separate sections discuss the geography and climate, history, economic development, fishing, agriculture, forestry, mining, manufacturing, energy, education, arts and culture, and…

  13. NOVA[R] Spring 2002 Teacher's Guide.

    ERIC Educational Resources Information Center

    Armstrong, Peter; Ransick, Kristi; Rosene, Dale; Sammons, James

    The guide presents lesson plans from "NOVA" which targets middle school and junior high school students and meet the National Science Education Standards. Lessons include: (1) "Neanderthals on Trial"; (2) "Fireworks"; (3) "Secrets, Lies and Atomic Spies"; (4) "Bioterror"; (5) "The Missing…

  14. Clinical and laboratory features of Nocardia nova.

    PubMed Central

    Wallace, R J; Brown, B A; Tsukamura, M; Brown, J M; Onyi, G O

    1991-01-01

    Recent studies have shown that Nocardia asteroides isolates have five major antibiotic resistance patterns; one of these patterns identifies isolates of Nocardia farcinica. In the current study, we investigated a second pattern characterized by susceptibility to ampicillin and erythromycin. This pattern was seen in 17% of 223 clinical isolates identified by standard techniques as N. asteroides and associated with diseases typical for nocardiae. Biochemically, isolates with this drug pattern were relatively homogeneous and identical to the type strain and previous descriptions of Nocardia nova. The strains studied were unique among nocardiae in having both alpha- and beta-esterase activity (85 and 95%, respectively). However, the arylsulfatase activity at 14 days (75%) and antimicrobial susceptibility patterns, including susceptibility to erythromycin (100%), were the only routinely available methods that would separate N. nova strains from other members of N. asteroides. N. asteroides should be considered a complex because current clinical identification schemes include isolates of N. farcinica and N. nova and may well include additional species. This is the first detailed description of N. nova as a pathogen in humans. PMID:1774244

  15. NOvA: Exploring Neutrino Mysteries

    ScienceCinema

    Vahle, Tricia; Messier, Mark

    2016-07-12

    Neutrinos are a mystery to physicists. They exist in three different flavors and mass states and may be able to give hints about the origins of the matter-dominated universe. A new long-baseline experiment led by Fermilab called NOvA may provide some answers.

  16. NOVA[R] Fall 2001 Teacher's Guide.

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    This teacher guide includes activity information for the program NOVA, Fall 2001. Background for each activity is provided along with its correlation to the national science standards. Activities include: (1) "Search for a Safe Cigarette"; (2) "18 Ways To Make a Baby"; (3) "Secrets of Mind"; (4) "Neanderthals on…

  17. THE DWARF NOVA OUTBURSTS OF NOVA HER 1960 (=V446 HER)

    SciTech Connect

    Honeycutt, R. K.; Robertson, J. W.; Kafka, S. E-mail: jrobertson@atu.edu

    2011-04-15

    V446 Her is the best example of an old nova which has developed dwarf nova (DN) eruptions in the post-nova state. We report on observed properties of the long-term light curve of V446 Her, using photometry over 19 years. Yearly averages of the outburst (OB) magnitudes show a decline of {approx}0.013 mag yr{sup -1}, consistent with the decline of other post-novae that do not have DN OBs. Previous suggestions of bimodal distributions of the amplitudes and widths of the OBs are confirmed. The OBs occur at a mean spacing of 18 days but the range of spacings is large (13-30 days). From simulations of DN OBs, it has been predicted that the OB spacing in V446 Her will increase as M-dot from the red dwarf companion slowly falls following the nova; however, the large intrinsic scatter in the spacings serves to hide any evidence of this effect. We do find a systematic change in the OB pattern in which the brighter, wider type of OBs disappeared after late 2003, and this phenomenon is suggested to be due to falling M-dot following the nova.

  18. Explosive lithium production in the classical nova V339 Del (Nova Delphini 2013).

    PubMed

    Tajitsu, Akito; Sadakane, Kozo; Naito, Hiroyuki; Arai, Akira; Aoki, Wako

    2015-02-19

    The origin of lithium (Li) and its production process have long been uncertain. Li could be produced by Big Bang nucleosynthesis, interactions of energetic cosmic rays with interstellar matter, evolved low-mass stars, novae, and supernova explosions. Chemical evolution models and observed stellar Li abundances suggest that at least half the Li may have been produced in red giants, asymptotic giant branch (AGB) stars, and novae. No direct evidence, however, for the supply of Li from evolved stellar objects to the Galactic medium has hitherto been found. Here we report the detection of highly blue-shifted resonance lines of the singly ionized radioactive isotope of beryllium, (7)Be, in the near-ultraviolet spectra of the classical nova V339 Del (Nova Delphini 2013) 38 to 48 days after the explosion. (7)Be decays to form (7)Li within a short time (half-life of 53.22 days). The (7)Be was created during the nova explosion via the alpha-capture reaction (3)He(α,γ)(7)Be (ref. 5). This result supports the theoretical prediction that a significant amount of (7)Li is produced in classical nova explosions.

  19. ToO IRS Observations of Novae

    NASA Astrophysics Data System (ADS)

    Woodward, Charles; Black, John; Bode, Michael; Evans, Aneuryn; Geballe, Thomas; Gehrz, Robert; Greenhouse, Matthew; Hauschildt, Peter; Helton, Andrew; Krautter, Joachim; Liller, William; Lyke, James; Lynch, David; Rudy, Richard; Salama, Alberto; Schwarz, Greg; Shore, Steve; Starrfield, Sumner; Truran, Jim; Vanlandingham, Karen; Wagner, R. Mark

    2006-05-01

    Stars are the engines of energy production and chemical evolution in our Universe. They deposit radiative and mechanical energy into their environments and enrich the ambient interstellar medium 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. Using Spitzer (+IRS), we propose a 25.8 hrs no-impact ToO program to study (in temporal detail) the evolutionary stages of CN by targeting 4 Galactic and 2 Magellanic Cloud (MC) novae. Spitzer is a unique facility that enables us to investigate aspects of the CN phenomenon including the in situ formation and astromineralogy of nova dust, the elemental abundances resulting from thermonuclear runaway, the correlation of ejecta masses with progenitor type, the bolometric luminosities of the outburst, and the kinematics and structure of the ejected envelopes. Synoptic, high signal-to-noise IRS 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; 3) measurement of the density and masses of the ejecta; 4) characterization of the geometry and structure of ejected shells at early stages during which the initial mixing of the chemical abundances can be studied in detail; and 5) exploration of the characteristics of CN in low metallicity systems (MC) at mid- to far-IR wavelengths. Observations of CN with Spitzer will be complemented by extensive ground-based, as well as space-based (e.g., Chandra, Swift, XMM-Newton), DDT and ToO programs led by team CoIs.

  20. The NOvA software testing framework

    NASA Astrophysics Data System (ADS)

    Tamsett, M.; C Group

    2015-12-01

    The NOvA experiment at Fermilab is a long-baseline neutrino experiment designed to study vε appearance in a vμ beam. NOvA has already produced more than one million Monte Carlo and detector generated files amounting to more than 1 PB in size. This data is divided between a number of parallel streams such as far and near detector beam spills, cosmic ray backgrounds, a number of data-driven triggers and over 20 different Monte Carlo configurations. Each of these data streams must be processed through the appropriate steps of the rapidly evolving, multi-tiered, interdependent NOvA software framework. In total there are greater than 12 individual software tiers, each of which performs a different function and can be configured differently depending on the input stream. In order to regularly test and validate that all of these software stages are working correctly NOvA has designed a powerful, modular testing framework that enables detailed validation and benchmarking to be performed in a fast, efficient and accessible way with minimal expert knowledge. The core of this system is a novel series of python modules which wrap, monitor and handle the underlying C++ software framework and then report the results to a slick front-end web-based interface. This interface utilises modern, cross-platform, visualisation libraries to render the test results in a meaningful way. They are fast and flexible, allowing for the easy addition of new tests and datasets. In total upwards of 14 individual streams are regularly tested amounting to over 70 individual software processes, producing over 25 GB of output files. The rigour enforced through this flexible testing framework enables NOvA to rapidly verify configurations, results and software and thus ensure that data is available for physics analysis in a timely and robust manner.

  1. The Dwarf Novae Ty Psc and V436 Cen During Quiescence: Exposed White Dwarfs?

    NASA Astrophysics Data System (ADS)

    Nadalin, I.; Sion, E. M.

    2000-12-01

    The dwarf novae TY Psc and V436 Cen are SU UMa systems with very similar orbital periods, similar recurrence times for normal outbursts ( 23 days) and superoutbursts ( ~ 340 days) and nearly identical outburst amplitudes. We have applied the Massa-Fitzpatrick (2000) flux calibration correction to the archival IUE NEWSIPS SWP spectra of these two systems, obtained during dwarf nova quiescence. We have carried out high gravity model atmosphere using the codes TLUSTY195, SYNSPEC42, ROTIN and accretion disk synthetic spectra from the grid of Wade and Hubeny (1998). We present our results on the physical properties of the underlying white dwarf accreters, including temperature, gravity, chemical abundances estimates, and the accretion rate during quiescence. We discuss our results in the context of the overall picture of accretion physics in dwarf novae and the effects of accretion on the white dwarf. This research was supported in part by NSF grant AST 99-01955, NASA ADP grant NAG5-8388 and by summer research funding from the NASA- Delaware Space Grant Colleges Consortium.

  2. The awakening of a classical nova from hibernation

    NASA Astrophysics Data System (ADS)

    Mróz, Przemek; Udalski, Andrzej; Pietrukowicz, Paweł; Szymański, Michał K.; Soszyński, Igor; Wyrzykowski, Łukasz; Poleski, Radosław; Kozłowski, Szymon; Skowron, Jan; Ulaczyk, Krzysztof; Skowron, Dorota; Pawlak, Michał

    2016-09-01

    Cataclysmic variable stars—novae, dwarf novae, and nova-likes—are close binary systems consisting of a white dwarf star (the primary) that is accreting matter from a low-mass companion star (the secondary). From time to time such systems undergo large-amplitude brightenings. The most spectacular eruptions, with a ten-thousandfold increase in brightness, occur in classical novae and are caused by a thermonuclear runaway on the surface of the white dwarf. Such eruptions are thought to recur on timescales of ten thousand to a million years. In between, the system’s properties depend primarily on the mass-transfer rate: if it is lower than a billionth of a solar mass per year, the accretion becomes unstable and the matter is dumped onto the white dwarf during quasi-periodic dwarf nova outbursts. The hibernation hypothesis predicts that nova eruptions strongly affect the mass-transfer rate in the binary, keeping it high for centuries after the event. Subsequently, the mass-transfer rate should significantly decrease for a thousand to a million years, starting the hibernation phase. After that the nova awakes again—with accretion returning to the pre-eruption level and leading to a new nova explosion. The hibernation model predicts cyclical evolution of cataclysmic variables through phases of high and low mass-transfer. The theory gained some support from the discovery of ancient nova shells around the dwarf novae Z Camelopardalis and AT Cancri, but direct evidence for considerable mass-transfer changes prior, during and after nova eruptions has not hitherto been found. Here we report long-term observations of the classical nova V1213 Cen (Nova Centauri 2009) covering its pre- and post-eruption phases and precisely documenting its evolution. Within the six years before the explosion, the system revealed dwarf nova outbursts indicative of a low mass-transfer rate. The post-nova is two orders of magnitude brighter than the pre-nova at minimum light with no trace of

  3. The awakening of a classical nova from hibernation.

    PubMed

    Mróz, Przemek; Udalski, Andrzej; Pietrukowicz, Paweł; Szymański, Michał K; Soszyński, Igor; Wyrzykowski, Łukasz; Poleski, Radosław; Kozłowski, Szymon; Skowron, Jan; Ulaczyk, Krzysztof; Skowron, Dorota; Pawlak, Michał

    2016-09-29

    Cataclysmic variable stars-novae, dwarf novae, and nova-likes-are close binary systems consisting of a white dwarf star (the primary) that is accreting matter from a low-mass companion star (the secondary). From time to time such systems undergo large-amplitude brightenings. The most spectacular eruptions, with a ten-thousandfold increase in brightness, occur in classical novae and are caused by a thermonuclear runaway on the surface of the white dwarf. Such eruptions are thought to recur on timescales of ten thousand to a million years. In between, the system's properties depend primarily on the mass-transfer rate: if it is lower than a billionth of a solar mass per year, the accretion becomes unstable and the matter is dumped onto the white dwarf during quasi-periodic dwarf nova outbursts. The hibernation hypothesis predicts that nova eruptions strongly affect the mass-transfer rate in the binary, keeping it high for centuries after the event. Subsequently, the mass-transfer rate should significantly decrease for a thousand to a million years, starting the hibernation phase. After that the nova awakes again-with accretion returning to the pre-eruption level and leading to a new nova explosion. The hibernation model predicts cyclical evolution of cataclysmic variables through phases of high and low mass-transfer. The theory gained some support from the discovery of ancient nova shells around the dwarf novae Z Camelopardalis and AT Cancri, but direct evidence for considerable mass-transfer changes prior, during and after nova eruptions has not hitherto been found. Here we report long-term observations of the classical nova V1213 Cen (Nova Centauri 2009) covering its pre- and post-eruption phases and precisely documenting its evolution. Within the six years before the explosion, the system revealed dwarf nova outbursts indicative of a low mass-transfer rate. The post-nova is two orders of magnitude brighter than the pre-nova at minimum light with no trace of dwarf

  4. Far Ultraviolet Spectroscopy of Three Long Period Nova-Like Variables, V363 Aur, AC Cnc and RZ Gru

    NASA Astrophysics Data System (ADS)

    Bisol, Alexandra; Sion, E. M.

    2011-01-01

    We have selected three nova-like variables: V363 Aur, RZ Gru and AC Cnc, all of which are UX UMa types, having similar orbital periods well beyond the 3 to 4 hour range where most nova-likes are found. All should have very similar secondary stars given the fact that they their physical parameters are so similar. V363 Aur is a bona fide SW Sex star, and AC Cnc is a probable one, while RZ Gru is not a member of the SW Sex subclass. Our objective is to carry out the first synthetic spectral analysis of far ultraviolet spectra of the three systems using state-of-the-art models both of accretion disks and photospheres. Therefore we shall compare the distances we obtain from the best fitting synthetic spectral models to other distance estimates in the literature. We present model-derived accretion rates and distances for all three systems. The FUV flux range of RZ Gru and V363 Aur is dominated by radiation from an optically thick, steady state, accretion but for AC Cnc, we find that a hot white dwarf accounts for 70% of the FUV flux. We compare the FUV characteristics and physical properties of these three long period nova-like systems to the properties of other nova-likes at shorter periods. This work was supported in part by NSF grant AST0807892 to Villanova University.

  5. Strong earthquakes, novae and cosmic ray environment

    NASA Technical Reports Server (NTRS)

    Yu, Z. D.

    1985-01-01

    Observations about the relationship between seismic activity and astronomical phenomena are discussed. First, after investigating the seismic data (magnitude 7.0 and over) with the method of superposed epochs it is found that world seismicity evidently increased after the occurring of novae with apparent magnitude brighter than 2.2. Second, a great many earthquakes of magnitude 7.0 and over occurred in the 13th month after two of the largest ground level solar cosmic ray events (GLEs). The causes of three high level phenomena of global seismic activity in 1918-1965 can be related to these, and it is suggested that according to the information of large GLE or bright nova predictions of the times of global intense seismic activity can be made.

  6. Tycho Brahe and the Nova of 1572

    NASA Astrophysics Data System (ADS)

    Gingerich, O.

    2005-12-01

    The brilliant Nova of 1572 marked the beginning of the end of Aristotelian cosmology and provided the defining moment when the young Tycho Brahe became a professional astronomer. He received more than a ton of gold from the Danish king to build his Uraniborg Observatory. His instruments, the finest produced in the pre-telescopic age, enabled him to establish that both the nova and the Comet of 1577 lay beyond the moon, contrary to Aristotle's teaching. His major attempt to establish the distance to Mars (in order to distinguish between the Ptolemaic and Copernican cosmologies) failed, but left in its wake a magnificently accurate set of data that enabled Kepler to make the greatest advance in celestial mechanics since Copernicus himself.

  7. Discovery of an eclipsing dwarf nova in the ancient nova shell Te 11

    NASA Astrophysics Data System (ADS)

    Miszalski, Brent; Woudt, P. A.; Littlefair, S. P.; Warner, B.; Boffin, H. M. J.; Corradi, R. L. M.; Jones, D.; Motsoaledi, M.; Rodríguez-Gil, P.; Sabin, L.; Santander-García, M.

    2016-02-01

    We report on the discovery of an eclipsing dwarf nova (DN) inside the peculiar, bilobed nebula Te 11. Modelling of high-speed photometry of the eclipse finds the accreting white dwarf to have a mass 1.18 M⊙ and temperature 13 kK. The donor spectral type of M2.5 results in a distance of 330 pc, colocated with Barnard's loop at the edge of the Orion-Eridanus superbubble. The perplexing morphology and observed bow shock of the slowly expanding nebula may be explained by strong interactions with the dense interstellar medium in this region. We match the DN to the historic nova of 483 CE in Orion and postulate that the nebula is the remnant of this eruption. This connection supports the millennia time-scale of the post-nova transition from high to low mass-transfer rates. Te 11 constitutes an important benchmark system for CV and nova studies as the only eclipsing binary out of just three DNe with nova shells.

  8. A wave model for dwarf novae

    NASA Technical Reports Server (NTRS)

    Sparks, W. M.; Kutter, G. S.

    1980-01-01

    The rapid coherent oscillation during a dwarf nova outburst is attributed to an accretion-driven wave going around the white dwarf component of the binary system. The increase and decrease in the period of this oscillation is due to the change in the velocity of the wave as it is first being driven and then damped. Qualitatively, a large number of observations can be explained with such a model. The beginnings of a mathematical representation of this model are developed.

  9. Testing Coordinate Frame Transformations NOVAS vs SOFA

    DTIC Science & Technology

    2010-07-14

    2 International Earth Rotation and Reference Systems Service (IERS) Fortran modules is independent of SOFA although both software libraries include...code that is similar to two .3 The document SOFA Tools for Earth Attitude (IAU 2009b), also known as the “SOFA Cookbook,” contains several Fortran...out in both NOVAS and SOFA. NU2000A and iau2000a (Fortran and C, respectively), which evaluate the full 1,365-term IAU 2000A nutation series in

  10. Cerebral Palsy (For Kids)

    MedlinePlus

    ... de los dientes Video: Getting an X-ray Cerebral Palsy KidsHealth > For Kids > Cerebral Palsy Print A A ... the things that kids do every day. What's CP? Some kids with CP use wheelchairs and others ...

  11. Cerebral Palsy (For Kids)

    MedlinePlus

    ... Emergency Room? What Happens in the Operating Room? Cerebral Palsy KidsHealth > For Kids > Cerebral Palsy A A A ... the things that kids do every day. What's CP? Some kids with CP use wheelchairs and others ...

  12. Introduction to the Nova technical contract

    SciTech Connect

    Lindl, J.D.; Kilkenny, J.D.

    1996-06-01

    The 1990 National Academy of Sciences (NAS) final report recommended proceeding with the construction of a 1-to 2-MJ Nd-doped glass laser designed to achieve ignition in the laboratory (a laser originally called the Nova Upgrade, but now called the National Ignition Facility, or NIF, and envisioned as a national user facility). As a prerequisite, the report recommended completion of a series of target physics objectives on the Nova laser in use at the Lawrence Livermore National Laboratory (LLNL). Meeting these objectives, which were called the Nova Technical Contract (NTC), would demonstrate (the Academy committee believed) that the physics of ignition targets was understood well enough that the laser requirements could be accurately specified. Completion of the NTC objectives was given the highest priority (it was Recommendation 1.1) in the NAS report. The NAS committee also recommended a concentrated effort on advanced target design for ignition. As recommended in the report, completion of these objectives has been the joint responsibility of LLNL and the Los Alamos National Laboratory. Most of the articles in this issue of the ICF Quarterly were written jointly by scientists from both institutions. The original NTC objectives have been largely met. This Introduction summarizes those objectives and their motivation in the context of the requirements for ignition.

  13. Low Mach Number Simulations of Classical Novae

    NASA Astrophysics Data System (ADS)

    Krueger, Brendan K.; Calder, A. C.; Zingale, M.; Almgren, A. S.; Bell, J. B.; Nonaka, A.

    2012-01-01

    Classical novae are thermonuclear explosions in the accreted layer on the surface of a white dwarf star. The manner in which convective flow interacts with the underlying white dwarf plays a critical role in determining the composition of the accreted layer and the energy release in the outburst. Studies of these complex reactive flows are typically limited by the available computing technology. I am applying a new low Mach number simulation code, MAESTRO, to study classical novae. MAESTRO filters out acoustic waves, allowing much larger time steps without restricting temperature or density perturbations, which in turn enables simulations of much longer time scales. With this unique tool, I have been exploring the development of convection and subsequent mixing in classical novae and their impact on the overall evolution of the outburst. I will present results from multidimensional simulations and quantify the character of the convection and mixing. This work was supported by NASA under grant No. NNX09AD19G and LLNL under contract B59328.

  14. Aging and Cerebral Palsy.

    ERIC Educational Resources Information Center

    Networker, 1993

    1993-01-01

    This special edition of "The Networker" contains several articles focusing on aging and cerebral palsy (CP). "Aging and Cerebral Palsy: Pathways to Successful Aging" (Jenny C. Overeynder) reports on the National Invitational Colloquium on Aging and Cerebral Palsy held in April 1993. "Observations from an Observer" (Kathleen K. Barrett) describes…

  15. Integration of the Super Nova early warning system with the NOvA Trigger

    SciTech Connect

    Habig, Alec; Zirnstein, Jan

    2015-12-23

    The NOvA experiment, with a baseline of 810km, samples Fermilab’s upgraded NuMI beam with a Near Detector on-site and a Far Detector (FD) at Ash River, MN, to observe oscillations of muon neutrinos. The 344,064 liquid scintillator-filled cells of the 14 kton FD provide high granularity of a large detector mass and enable us to also study non-accelerator based neutrinos with our Data Driven Trigger framework. This paper will focus on the real time integration of the SNEWS with the NOvA Trigger where we have set up an XML-RPC based messaging system to inject the SNEWS signal directly into our trigger. In conclusion, this presents a departure from the E-Mail based notification mechanism used by SNEWS in the past and allows NOvA more control over propagation and transmission timing.

  16. Integration of the Super Nova early warning system with the NOvA Trigger

    DOE PAGES

    Habig, Alec; Zirnstein, Jan

    2015-12-23

    The NOvA experiment, with a baseline of 810km, samples Fermilab’s upgraded NuMI beam with a Near Detector on-site and a Far Detector (FD) at Ash River, MN, to observe oscillations of muon neutrinos. The 344,064 liquid scintillator-filled cells of the 14 kton FD provide high granularity of a large detector mass and enable us to also study non-accelerator based neutrinos with our Data Driven Trigger framework. This paper will focus on the real time integration of the SNEWS with the NOvA Trigger where we have set up an XML-RPC based messaging system to inject the SNEWS signal directly into ourmore » trigger. In conclusion, this presents a departure from the E-Mail based notification mechanism used by SNEWS in the past and allows NOvA more control over propagation and transmission timing.« less

  17. Integration of the Super Nova Early Warning System with the NOvA Trigger

    NASA Astrophysics Data System (ADS)

    Habig, Alec; Zirnstein, Jan

    2015-12-01

    The NOvA experiment, with a baseline of 810km, samples Fermilab's upgraded NuMI beam with a Near Detector on-site and a Far Detector (FD) at Ash River, MN, to observe oscillations of muon neutrinos. The 344,064 liquid scintillator-filled cells of the 14kton FD provide high granularity of a large detector mass and enable us to also study non-accelerator based neutrinos with our Data Driven Trigger framework. This paper will focus on the real time integration of the SNEWS with the NOvA Trigger where we have set up an XML-RPC based messaging system to inject the SNEWS signal directly into our trigger. This presents a departure from the E-Mail based notification mechanism used by SNEWS in the past and allows NOvA more control over propagation and transmission timing.

  18. Extinction, ejecta masses, and radial velocities of novae

    NASA Technical Reports Server (NTRS)

    Williams, Robert E.

    1994-01-01

    Interstellar reddening is determined for a number of recent novae based upon emission-line ratios which are generally observable using CCDs. Large values of extinction are found for most systems, possibly indicative of an intrinsic component of reddening in postoutburst novae. The unusual characteristics of the (O I) lines in novae, which are strong and optically thick, require a large population of very dense globules which are the likely sites of dust formation. These pyroclasts must be ejected from the white dwarf. The total mass of the neutral gas in the globules in some of the objects is substantially larger than the masses normally derived for the ionized ejecta of novae. The distribution of radial velocities of Galactic novae in the Tololo sample, although uncertain, shows an asymmetry in having predominantly negative values. Either high internal absorption in the expanding ejecta skews the emission lines to bluer wavelengths, or most of the novae are moving out from the center of the Galaxy.

  19. NovaNet Student Outcomes, 2001-2002.

    ERIC Educational Resources Information Center

    Harlow, Kristin; Baenen, Nancy

    NovaNet is an individualized, computer-based instruction program that is used in the Wake County Public School System (WCPSS), North Carolina, for high school course credit, remediation, and enrichment. NovaNet was first used in WCPSS in 1996, and in 1999 WCPSS received a 3-year federal grant to expand the use of NovaNET to all high schools. In…

  20. The UBV color evolution of classical novae. I. Nova-giant sequence in the color-color diagram

    SciTech Connect

    Hachisu, Izumi; Kato, Mariko E-mail: mariko@educ.cc.keio.ac.jp

    2014-04-20

    We identified a general course of classical nova outbursts in the B – V versus U – B color-color diagram. It is reported that novae show spectra similar to those of A-F supergiants near optical light maximum. However, they do not follow the supergiant sequence in the color-color diagram, neither the blackbody nor the main-sequence sequence. Instead, we found that novae evolve along a new sequence in the pre-maximum and near-maximum phases, which we call 'the nova-giant sequence'. This sequence is parallel to but Δ(U – B) ≈ –0.2 mag bluer than the supergiant sequence. This is because the mass of a nova envelope is much (∼10{sup –4} times) less than that of a normal supergiant. After optical maximum, its color quickly evolves back blueward along the same nova-giant sequence and reaches the point of free-free emission (B – V = –0.03, U – B = –0.97), which coincides with the intersection of the blackbody sequence and the nova-giant sequence, and remains there for a while. Then the color evolves leftward (blueward in B – V but almost constant in U – B), owing mainly to the development of strong emission lines. This is the general course of nova outbursts in the color-color diagram, which was deduced from eight well-observed novae in various speed classes. For a nova with unknown extinction, we can determine a reliable value of the color excess by matching the observed track of the target nova with this general course. This is a new and convenient method for obtaining the color excesses of classical novae. Using this method, we redetermined the color excesses of 20 well-observed novae. The obtained color excesses are in reasonable agreement with the previous results, which in turn support the idea of our general track of nova outbursts. Additionally, we estimated the absolute V magnitudes of about 30 novae using a method for time-stretching nova light curves to analyze the distance-reddening relations of the novae.

  1. The UBV Color Evolution of Classical Novae. I. Nova-giant Sequence in the Color-Color Diagram

    NASA Astrophysics Data System (ADS)

    Hachisu, Izumi; Kato, Mariko

    2014-04-01

    We identified a general course of classical nova outbursts in the B - V versus U - B color-color diagram. It is reported that novae show spectra similar to those of A-F supergiants near optical light maximum. However, they do not follow the supergiant sequence in the color-color diagram, neither the blackbody nor the main-sequence sequence. Instead, we found that novae evolve along a new sequence in the pre-maximum and near-maximum phases, which we call "the nova-giant sequence." This sequence is parallel to but Δ(U - B) ≈ -0.2 mag bluer than the supergiant sequence. This is because the mass of a nova envelope is much (~10-4 times) less than that of a normal supergiant. After optical maximum, its color quickly evolves back blueward along the same nova-giant sequence and reaches the point of free-free emission (B - V = -0.03, U - B = -0.97), which coincides with the intersection of the blackbody sequence and the nova-giant sequence, and remains there for a while. Then the color evolves leftward (blueward in B - V but almost constant in U - B), owing mainly to the development of strong emission lines. This is the general course of nova outbursts in the color-color diagram, which was deduced from eight well-observed novae in various speed classes. For a nova with unknown extinction, we can determine a reliable value of the color excess by matching the observed track of the target nova with this general course. This is a new and convenient method for obtaining the color excesses of classical novae. Using this method, we redetermined the color excesses of 20 well-observed novae. The obtained color excesses are in reasonable agreement with the previous results, which in turn support the idea of our general track of nova outbursts. Additionally, we estimated the absolute V magnitudes of about 30 novae using a method for time-stretching nova light curves to analyze the distance-reddening relations of the novae.

  2. Recent progress in understanding the eruptions of classical novae

    SciTech Connect

    Shara, M.M.

    1988-10-01

    Dramatic progress has occurred in the last two decades in understanding the physical processes and events leading up to, and transpiring during the eruption of a classical nova. The mechanism whereby a white dwarf accreting hydrogen-rich matter from a low-mass main-sequence companion produces a nova eruption has been understood since 1970. The mass-transferring binary stellar configuration leads inexorably to thermonuclear runaways detected at distances of megaparsecs. Summarized here are the efforts of many researchers in understanding the physical processes which generate nova eruptions; the effects upon nova eruptions of different binary-system parameters (e.g., chemical composition or mass of the white dwarf, different mass accretion rates); the possible metamorphosis from dwarf to classical novae and back again; and observational diagnostics of novae, including x ray and gamma ray emission, and the characteristics and distributions of novae in globular clusters and in extragalactic systems. While the thermonuclear-runaway model remains the successful cornerstone of nova simulation, it is now clear that a wide variety of physical processes, and three-dimensional hydrodynamic simulations, will be needed to explain the rich spectrum of behavior observed in erupting novae.

  3. Nova M33N 2012-10a

    NASA Astrophysics Data System (ADS)

    Alothman, Nourah

    In this thesis I present a study and measurement of a Nova in M33 galaxy type N 2012-10a (which is type of binary star) using data that were collected by the ROTSE IIIb robotic telescope and another observatory. I study the fundamental properties of the light curve and determined the brightness and the velocity of this type of nova. I analyzed the spectra that were measured by the Hobby-Eberly Telescope (HET) at the McDonald Observatory. In addition, I compared this type of nova to other types of Novae.

  4. Recent progress in understanding the eruptions of classical novae

    NASA Technical Reports Server (NTRS)

    Shara, Michael M.

    1988-01-01

    Dramatic progress has occurred in the last two decades in understanding the physical processes and events leading up to, and transpiring during the eruption of a classical nova. The mechanism whereby a white dwarf accreting hydrogen-rich matter from a low-mass main-sequence companion produces a nova eruption has been understood since 1970. The mass-transferring binary stellar configuration leads inexorably to thermonuclear runaways detected at distances of megaparsecs. Summarized here are the efforts of many researchers in understanding the physical processes which generate nova eruptions; the effects upon nova eruptions of different binary-system parameters (e.g., chemical composition or mass of the white dwarf, different mass accretion rates); the possible metamorphosis from dwarf to classical novae and back again; and observational diagnostics of novae, including x ray and gamma ray emission, and the characteristics and distributions of novae in globular clusters and in extragalactic systems. While the thermonuclear-runaway model remains the successful cornerstone of nova simulation, it is now clear that a wide variety of physical processes, and three-dimensional hydrodynamic simulations, will be needed to explain the rich spectrum of behavior observed in erupting novae.

  5. Search for X-ray emission from Nova Cygni 1975

    NASA Technical Reports Server (NTRS)

    Hoffman, J. A.; Lewin, W. H. G.; Brecher, K.; Buff, J.; Clark, G. W.; Joss, P. C.; Matilsky, T.

    1976-01-01

    A search for X-rays from Nova Cygni 1975 was carried out before, during, and after the time of optical maximum. No X-rays were detected over the spectral range 0.1-50 keV. On the basis of these results a strong upper limit of .0001 has been placed on the ratio of X-ray to optical luminosity for this nova, consistent with effective temperatures of about 10,000 K. If Nova Cygni 1975 is a virgin nova, its low mass exchange rate would imply that any associated X-ray emission would not be detectable by present techniques.

  6. Monitoring of Northern dwarf novae for radio jets campaign

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2014-10-01

    Ms. Deanne Coppejans (PhD candidate, Radboud University Nijmegen (Netherlands) and University of Cape Town) and colleagues have requested AAVSO observer assistance in monitoring nine Northern dwarf novae in support of their campaign to observe them in outburst with the Very Large Array (VLA) to search for radio jets. They will observe 5 targets from the following list: U Gem*, EX Dra, Z Cam*, RX And*, EM Cyg, AB Dra, SY Cnc, SU UMa*, and YZ Cnc*. Stars with an asterisk (*) will be given higher priority. The campaign will begin now, starting with monitoring of RX And and EM Cyg, and run through September 2015, or until all five VLA triggers have been used. This campaign is similar to previous AAVSO campaigns, namely the 2007 campaign to monitor a sample of 10 dwarf novae (AAVSO Alert Notice 345), which resulted in the first detection of a radio jet in a dwarf nova system (Koerding et al. 2008, Science, 320, 1318), and the ones carried out at the request of Dr. James Miller-Jones and colleagues on SS Cyg in 2010-2011 (AAVSO Special Notices #204, #206, Alert Notice 445). The latter resulted in an accurate distance determination to SS Cyg, thereby reconciling its behavior with our understanding of accretion disc theory in accreting compact objects (Miller-Jones et al. 2013, Science, 340, 950). Ms. Coppejans writes: "The relation between accretion and outflow is one of the basic problems in modern astrophysics. It has long been thought that CVs are the only accreting systems that do not produce jets, and this notion has even been used to constrain jet models. However, there are now some indications that CVs do show jets, possibly allowing a universal link between accretion and ejection. Radio observations provide the best unambiguous tracer of the corresponding jet or directed outflow, but there are only two clear detections. By observing a more extensive sample of cataclysmic variables in outburst we will determine the existence of jets or other outflows in these

  7. Discovery of a Probable Nova in M81 and Photometry of Three M81 Novae

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Errmann, R.; Carlisle, Ch.; Vaduvescu, O.

    2015-02-01

    We report the discovery of a probable nova in M81 on a co-added 1600-s narrow-band H-alpha CCD image taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~1.6" seeing on 2015 Jan.

  8. Unusual ``Stunted'' Outbursts in Old Novae and Nova-Like Cataclysmic Variables

    NASA Astrophysics Data System (ADS)

    Honeycutt, R. K.; Robertson, J. W.; Turner, G. W.

    1998-06-01

    Outbursts averaging 0.6 mag in amplitude and 10 days in width are described in five old novae and nova-like cataclysmic variables: UU Aqr, Q Cyg, CP Lac, X Ser, and RW Sex. These stars are thought to be high mass transfer rate systems for which the accretion disk is expected to be stable against the thermal instability responsible for dwarf nova outbursts. The widths and spacings of these events are similar to those of dwarf nova eruptions, but the amplitudes are significantly smaller, or ``stunted.'' The outbursts are sometimes accompanied by dips. These dips have amplitudes that are similar to the outbursts' but have shapes that scatter significantly more than the shapes of the outbursts. The outbursts and dips sometimes occur as pairs and are sometimes isolated. We are not able at this time to determine a single common mechanism for this behavior, or even to conclude that some mechanisms are preferred. Rather, we characterize these phenomena with regard to outburst shapes and frequency of occurrence and explore a range of possible causes, including truncated disks, mass transfer modulations, and Z Camelopardalis type behavior. Arguments are assembled for and against such possible mechanisms, and key observations are suggested. It appears unlikely that accretion disk instabilities are the single common cause of these phenomena, and we are left with either a combination of accretion disk and mass transfer events or a situation in which mass transfer events are somehow responsible for all these varied behaviors.

  9. Recurrent Nova U Scorpii in outburst

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.; Schaefer, Bradley E.

    2010-01-01

    The outburst is announced of the recurrent nova U Sco at magnitude V=8.05 on 2010 January 28.4385 UT, according to observations by Barbara G. Harris, New Smyrna Beach, FL, USA. The outburst was confirmed by Shawn Dvorak, Clermont, FL, USA, who estimated it at V~8.8 at Jan 28.4743. Prior to outburst, U Scorpii was measured at V=18.2 on Jan 27.4501 (Harris), and estimated at m(vis) <16.5 on January 27.6271 (Mike Linnolt, Hoolehua, HI, USA). Observations in the AAVSO International Database show that the last outburst of U Sco occurred on 1999 February 25, when the star reached visual magnitude 7.5. U Sco is an extremely fast nova, and will reach maximum and decline by one magnitude within one day. Visual, CCD, and PEP observations are urgently requested, including unfiltered CCD time series. Please obtain S/N of at least 50 for all instrumental photometry. Observers are asked to use filters when performing single-measure photometry, but unfiltered time series is also requested beginning immediately and continuing for the next month. The AAVSO has been participating in a campaign on U Sco by request of Dr. Bradley Schaefer (LSU; see AAVSO Alert Notice 367). This nova outburst will be observed by several ground- and space-based observatories world-wide, and your observations are urgently requested to provide the overall, long-term optical light curve of U Sco. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  10. V4743 Sgr, a magnetic nova?

    NASA Astrophysics Data System (ADS)

    Zemko, P.; Orio, M.; Mukai, K.; Bianchini, A.; Ciroi, S.; Cracco, V.

    2016-08-01

    Two XMM-Newton observations of Nova V4743 Sgr (Nova Sgr 2002) were performed shortly after it returned to quiescence, 2 and 3.5 yr after the explosion. The X-ray light curves revealed a modulation with a frequency of ≃0.75 mHz, indicating that V4743 Sgr is most probably an intermediate polar (IP). The X-ray spectra have characteristics in common with known IPs, with a hard thermal plasma component that can be fitted only assuming a partially covering absorber. In 2004, the X-ray spectrum had also a supersoft blackbody-like component, whose temperature was close to that of the white dwarf (WD) in the supersoft X-ray phase following the outburst, but with flux by at least two orders of magnitude lower. In quiescent IPs, a soft X-ray flux component originates at times in the polar regions irradiated by an accretion column, but the supersoft component of V4743 Sgr disappeared in 2006, indicating a possible origin different from accretion. We suggest that it may have been due to an atmospheric temperature gradient on the WD surface, or to continuing localized thermonuclear burning at the bottom of the envelope, before complete turn-off. An optical spectrum obtained with Southern African Large Telescope (SALT) 11.5 yr after the outburst showed a prominent He II λ4686 line and the Bowen blend, which reveal a very hot region, but with peak temperature shifted to the ultraviolet range. V4743 Sgr is the third post-outburst nova and IP candidate showing a low-luminosity supersoft component in the X-ray flux a few years after the outburst.

  11. Supernova hydrodynamics experiments using the Nova laser

    SciTech Connect

    Remington, B.A.; Glendinning, S.G.; Estabrook, K.; Wallace, R.J.; Rubenchik, A.; Kane, J.; Arnett, D.; Drake, R.P.; McCray, R.

    1997-04-01

    We are developing experiments using the Nova laser to investigate two areas of physics relevant to core-collapse supernovae (SN): (1) compressible nonlinear hydrodynamic mixing and (2) radiative shock hydrodynamics. In the former, we are examining the differences between the 2D and 3D evolution of the Rayleigh-Taylor instability, an issue critical to the observables emerging from SN in the first year after exploding. In the latter, we are investigating the evolution of a colliding plasma system relevant to the ejecta-stellar wind interactions of the early stages of SN remnant formation. The experiments and astrophysical implications are discussed.

  12. Review of the classical nova outburst

    SciTech Connect

    Starrfield, S.; Sparks, W.M.

    1986-06-01

    Observational studies have not only identified a new class of novae but theoretical simulations of this class have been found to be in excellent agreement with the observations. This new class consists of outbursts occurring on ONeMg white dwarfs in close binar systems in contrast to the other outbursts which are occurring on CO white dwarfs. We also review the effects of the ..beta../sup +/-unstable nuclei and show how their presence has a major effect on the evolution. 77 refs.

  13. New nova candidate in M81

    NASA Astrophysics Data System (ADS)

    Henze, M.; Sala, G.; Jose, J.; Figueira, J.; Hernanz, M.

    2016-06-01

    We report the discovery of a new nova candidate in the M81 galaxy on 16x200s stacked R filter CCD images, obtained with the 80 cm Ritchey-Chretien F/9.6 Joan Oro telescope at Observatori Astronomic del Montsec, owned by the Catalan Government and operated by the Institut d'Estudis Espacials de Catalunya, Spain, using a Finger Lakes PL4240-1-BI CCD Camera (with a Class 1 Basic Broadband coated 2k x 2k chip with 13.5 microns sq. pixels).

  14. CURious Variables Experiment (CURVE): CCD photometry of active dwarf nova DI Ursae Majoris

    NASA Astrophysics Data System (ADS)

    Rutkowski, A.; Olech, A.; Wiśniewski, M.; Pietrukowicz, P.; Pala, J.; Poleski, R.

    2009-04-01

    Context: We report an analysis of photometric behaviour of DI UMa, an extremely active dwarf nova. The observational campaign (completed in 2007) covers five superoutbursts and four normal outbursts. Aims: We examined principal parameters of the system to understand peculiarities of DI UMa, and other active cataclysmic variables. Methods: Based on precise photometric measurements, temporal light curve behaviour, O-C analysis, and power spectrum analysis, we investigated physical parameters of the system. Results: We found that the period of the supercycle now equals 31.45 ± 0.3 days. Observations during superoutbursts infer that the period of superhumps equals P_sh = 0.055318(11) days (79.66± 0.02 min). During quiescence, the light curve reveals a modulation of period P_orb = 0.054579(6) days (78.59 ± 0.01 min), which we interpret as the orbital period of the binary system. The values obtained allowed us to determine a fractional period excess of 1.35% ± 0.02%, which is surprisingly small compared to the usual value for dwarf novae (2%-5%). A detailed O-C analysis was performed for two superoutbursts with the most comprehensive coverage. In both cases, we detected an increase in the superhump period with a mean rate of dot P/P_sh = 4.4(1.0)× 10-5. Conclusions: Based on these measurements, we confirm that DI UMa is probably a period bouncer, an old system that reached its period minimum a long time ago, has a secondary that became a degenerate brown dwarf, the entire system evolving now toward longer periods. DI UMa is an extremely interesting object because we know only one more active ER UMa star with similar characteristics (IX Dra). Photometric data are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/497/437

  15. Superhumps in Cataclysmic Binaries. XXIV. Twenty More Dwarf Novae

    NASA Astrophysics Data System (ADS)

    Patterson, Joseph; Thorstensen, John R.; Kemp, Jonathan; Skillman, David R.; Vanmunster, Tonny; Harvey, David A.; Fried, Robert A.; Jensen, Lasse; Cook, Lewis M.; Rea, Robert; Monard, Berto; McCormick, Jennie; Velthuis, Fred; Walker, Stan; Martin, Brian; Bolt, Greg; Pavlenko, Elena; O'Donoghue, Darragh; Gunn, Jerry; Novák, Rudolf; Masi, Gianluca; Garradd, Gordon; Butterworth, Neil; Krajci, Thomas; Foote, Jerry; Beshore, Edward

    2003-11-01

    We report precise measures of the orbital and superhump period in 20 more dwarf novae. For 10 stars, we report new and confirmed spectroscopic periods-signifying the orbital period Po-as well as the superhump period Psh. These are GX Cas, HO Del, HS Vir, BC UMa, RZ Leo, KV Dra, KS UMa, TU Crt, QW Ser, and RZ Sge. For the remaining 10, we report a medley of Po and Psh measurements from photometry; most are new, with some confirmations of previous values. These are KV And, LL And, WX Cet, MM Hya, AO Oct, V2051 Oph, NY Ser, KK Tel, HV Vir, and RX J1155.4-5641. Periods, as usual, can be measured to high accuracy, and these are of special interest since they carry dynamical information about the binary. We still have not quite learned how to read the music, but a few things are clear. The fractional superhump excess ɛ[=(Psh-Po)/Po] varies smoothly with Po. The scatter of the points about that smooth curve is quite low, and can be used to limit the intrinsic scatter in M1, the white dwarf mass, and the mass-radius relation of the secondary. The dispersion in M1 does not exceed 24%, and the secondary-star radii scatter by no more than 11% from a fixed mass-radius relation. For the well-behaved part of ɛ(Po) space, we estimate from superhump theory that the secondaries are 18%+/-6% larger than theoretical ZAMS stars. This affects some other testable predictions about the secondaries: at a fixed Po, it suggests that the secondaries are (compared with ZAMS predictions) 40%+/-14% less massive, 12%+/-4% smaller, 19%+/-6% cooler, and less luminous by a factor of 2.5(7). The presence of a well-defined mass-radius relation, reflected in a well-defined ɛ(Po) relation, strongly limits effects of nuclear evolution in the secondaries.

  16. Independent Discovery of an Apparent Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Kucakova, H.; Vrastil, J.; Williams, S. C.; Henze, M.; Meusinger, H.; Pohl, C.; Darnley, M. J.; Kaur, A.; Hartmann, D. H.; Sala, G.; Jose, J.; Figueira, J.; Sin, P.; Hernanz, M.; Shafter, A. W.

    2017-02-01

    The M81 nova monitoring collaboration reports the independent discovery of an apparent nova in M81 on a co-added 3510-s unfiltered CCD frame taken on 2017 Feb. 24.119 UT with the 0.65-m telescope at Ondrejov.

  17. Independent Discovery of an Apparent Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Kucakova, H.; Williams, S. C.; Henze, M.; Darnley, M. J.; Kaur, A.; Hartmann, D. H.; Sala, G.; Jose, J.; Figueira, J.; Sin, P.; Hernanz, M.; Shafter, A. W.; Meusinger, H.

    2017-02-01

    The M81 nova monitoring collaboration reports the independent discovery of an apparent nova in M81 on a co-added 5400-s unfiltered CCD frame taken on 2017 Feb. 19.962 UT with the 0.65-m telescope at Ondrejov (OND).

  18. Discovery of a nova candidate in M81

    NASA Astrophysics Data System (ADS)

    Williams, S. C.; Hornoch, K.; Kucakova, H.; Henze, M.; Darnley, M. J.; Kaur, A.; Hartmann, D. H.; Sala, G.; Jose, J.; Figueira, J.; Sin, P.; Hernanz, M.; Shafter, A. W.; Meusinger, H.

    2017-02-01

    The M81 nova monitoring collaboration reports the discovery of a new nova candidate in M81. The candidate was discovered at a H & alpha; magnitude of 20.6 & pm;0.2 on 2017-02-08.05 UT, with the 2-m Liverpool Telescope.

  19. Discovery of a Probable Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Henze, M.; Vrastil, J.; Kucakova, H.; Meusinger, H.; Pohl, C.; Williams, S. C.; Darnley, M. J.; Kaur, A.; Hartmann, D. H.; Sala, G.; Jose, J.; Figueira, J.; Sin, P.; Hernanz, M.; Shafter, A. W.

    2017-02-01

    The M81 nova monitoring collaboration reports the discovery of a probable nova in M81 on a co-added 1800-s unfiltered CCD frame taken on 2017 Feb. 26.928 UT with the 0.65-m telescope at Ondrejov (OND).

  20. Results of Statewide TerraNova Testing, Fall 1998.

    ERIC Educational Resources Information Center

    La Marca, Paul M.

    This summary provides key findings about state, district, and school level performance on the TerraNova examinations (CTB/McGraw Hill) in Nevada in 1998-1999. The TerraNova tests are used to assess students in grades 4, 8, and 10 as stipulated by Nevada law. Within this summary, a description of performance as measured by national percentile…

  1. Quark nova model for fast radio bursts

    NASA Astrophysics Data System (ADS)

    Shand, Zachary; Ouyed, Amir; Koning, Nico; Ouyed, Rachid

    2016-05-01

    Fast radio bursts (FRBs) are puzzling, millisecond, energetic radio transients with no discernible source; observations show no counterparts in other frequency bands. The birth of a quark star from a parent neutron star experiencing a quark nova - previously thought undetectable when born in isolation - provides a natural explanation for the emission characteristics of FRBs. The generation of unstable r-process elements in the quark nova ejecta provides millisecond exponential injection of electrons into the surrounding strong magnetic field at the parent neutron star's light cylinder via β-decay. This radio synchrotron emission has a total duration of hundreds of milliseconds and matches the observed spectrum while reducing the inferred dispersion measure by approximately 200 cm-3 pc. The model allows indirect measurement of neutron star magnetic fields and periods in addition to providing astronomical measurements of β-decay chains of unstable neutron rich nuclei. Using this model, we can calculate expected FRB average energies (˜ 1041 erg) and spectral shapes, and provide a theoretical framework for determining distances.

  2. V390 Nor = Nova Normae 2007

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2007-06-01

    Nova Normae 2007 was discovered photographically by William Liller on June 15.086 UT at magnitude 9.4. Precise position measured by G. Bolt from his unfiltered CCD image of June 16.7 UT: 16:32:11.51 -45:09:13.4 (2000.0). Giorgio Di Scala reported to the AAVSO that a low-resolution spectrum indicates a nova a week or so after outburst, with strong H-alpha emission. E. Kazarovets, Sternberg Astronomical Institute, reports that N Nor 07 has been assigned the name V390 Nor. Discovery originally announced in IAU Central Bureau Electronic Telegram 982 (Daniel W. E. Green) and AAVSO Special Notice #49 (Arne Henden). Information in this Alert Notice was received at AAVSO from William Liller, Giorgio Di Scala, or via IAU Circular No. 8850, ed. Daniel W. E. Green. A chart for V390 Nor is available via the Variable Star Plotter (VSP). Go to: http://www.aavso.org/observing/charts/vsp/ and enter the name V390 NOR.

  3. Developing beam phasing on the Nova laser

    SciTech Connect

    Ehrlich, R.B.; Amendt, P.A.; Dixit, S.N.; Hammel, B.A.; Kalantar, D.H.; Pennington, D.M.; Weiland, T.L.

    1997-03-10

    We are presently adding the capability to irradiate indirectly-driven Nova targets with two rings of illumination inside each end of the hohlraum for studies of time-dependent second Legendre (P2) and time- integrated fourth Legendre (P4) flux asymmetry control. The rings will be formed with specially designed kinoform phase plates (KPPs), which will direct each half of each beam into two separate rings that are nearly uniform azimuthally. The timing and temporal pulse shape of the outer rings will be controlled independently from those of the inner rings, allowing for phasing of the pulse shapes to control time dependent asymmetry. Modifications to the incident beam diagnostics (IBDS) will enable us to verify that acceptable levels of power balance among the contributing segments of each ring have been achieved on each shot. Current techniques for precision beam pointing and timing are expected to be sufficiently accurate for these experiments. We present a design for an affordable retrofit to achieve beam phasing on Nova, results of a simplified demonstration, and calculations highlighting the anticipated benefits.

  4. SALT observations of southern post-novae

    NASA Astrophysics Data System (ADS)

    Tomov, T.; Swierczynski, E.; Mikolajewski, M.; Ilkiewicz, K.

    2015-04-01

    Aims: We report on recent optical observations of the stellar and the nebular remnants of 22 southern post-novae. Methods: In this study, for each of our targets, we obtained and analysed long-slit spectra in the spectral range 3500-6600 Å and in Hα+[N ii] narrow-band images. Results: The changes in the emission lines' equivalent widths with the time since the outburst agree with earlier published results of other authors. We estimated an average value α = 2.37 for the exponent of the power law fitted to the post-novae continua. Our observations clearly show the two-component structure of the V842 Cen expanding nebulae, owing to the different velocities of the ejected matter. We discovered an expanding shell around V382 Vel with an outer diameter of about 12″. Based on observations made with the Southern African Large Telescope (SALT).The spectra as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/576/A119

  5. Population of post-nova supersoft X-ray sources

    NASA Astrophysics Data System (ADS)

    Soraisam, Monika D.; Gilfanov, Marat; Wolf, William M.; Bildsten, Lars

    2016-01-01

    Novae undergo a supersoft X-ray phase of varying duration after the optical outburst. Such transient post-nova supersoft X-ray sources (SSSs) are the majority of the observed SSSs in M31. In this paper, we use the post-nova evolutionary models of Wolf et al. to compute the expected population of post-nova SSSs in M31. We predict that depending on the assumptions about the white dwarf (WD) mass distribution in novae, at any instant there are about 250-600 post-nova SSSs in M31 with (unabsorbed) 0.2-1.0 keV luminosity Lx ≥ 1036 erg s-1. Their combined unabsorbed luminosity is of the order of ˜1039 erg s-1. Their luminosity distribution shows significant steepening around log (Lx) ˜ 37.7-38 and becomes zero at Lx ≈ 2 × 1038 erg s-1, the maximum Lx achieved in the post-nova evolutionary tracks. Their effective temperature distribution has a roughly power-law shape with differential slope of ≈4-6 up to the maximum temperature of Teff ≈ 1.5 × 106 K. We compare our predictions with the results of the XMM-Newton monitoring of the central field of M31 between 2006 and 2009. The predicted number of post-nova SSSs exceeds the observed number by a factor of ≈2-5, depending on the assumed WD mass distribution in novae. This is good agreement, considering the number and magnitude of uncertainties involved in calculations of the post-nova evolutionary models and their X-ray output. Furthermore, only a moderate circumstellar absorption, with hydrogen column density of the order of ˜1021 cm-2, will remove the discrepancy.

  6. Observations and simulations of nova Vul 1984 no. 2: A nova with ejecta rich in oxygen, neon, and magnesium

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Sonneborn, G.; Stryker, L. L.; Sparks, Warren M.; Truran, James W.; Ferland, Gary; Wagner, R. M.; Gallagher, J. S.; Wade, R.; Williams, R. E.

    1988-01-01

    Nova Vul 1984 no. 2 was observed with IUE from Dec. 1984 through Nov. 1987. The spectra are characterized by strong lines from Mg, Ne, C, Si, O, N, and other elements. Data obtained in the ultraviolet, infrared, and optical show that this nova is ejecting material rich in oxygen, neon, and magnesium.

  7. Statins and cerebral hemodynamics

    PubMed Central

    Giannopoulos, Sotirios; Katsanos, Aristeidis H; Tsivgoulis, Georgios; Marshall, Randolph S

    2012-01-01

    HMG-CoA reductase inhibitors (statins) are associated with improved stroke outcome. This observation has been attributed in part to the palliative effect of statins on cerebral hemodynamics and cerebral autoregulation (CA), which are mediated mainly through the upregulation of endothelium nitric oxide synthase (eNOS). Several animal studies indicate that statin pretreatment enhances cerebral blood flow after ischemic stroke, although this finding is not further supported in clinical settings. Cerebral vasomotor reactivity, however, is significantly improved after long-term statin administration in most patients with severe small vessel disease, aneurysmal subarachnoid hemorrhage, or impaired baseline CA. PMID:22929438

  8. THE NOVA SHELL AND EVOLUTION OF THE RECURRENT NOVA T PYXIDIS

    SciTech Connect

    Schaefer, Bradley E.; Pagnotta, Ashley; Shara, Michael M.

    2010-01-01

    T Pyxidis (T Pyx) is the prototypical recurrent nova (RN), with five eruptions from 1890 to 1967 and a mysterious nova shell. We report new observations of the nova shell with the Hubble Space Telescope (HST) in the year 2007, which provides a long time baseline to compare with HST images from 1994 and 1995. We find that the knots in the nova shell are expanding with velocities ranging from roughly 500 km s{sup -1} to 715 km s{sup -1}, assuming a distance of 3500 pc. The fractional expansion of the knots is constant, which implies no significant deceleration of the knots, which must have been ejected by an eruption close to the year 1866. We see knots that have turned on after 1995; this shows that the knots are powered by shocks from the collision of the '1866' ejecta with fast ejecta from later RN eruptions. We derive that the '1866' ejecta has a total mass of approx10{sup -4.5} M {sub sun}, which with the low ejection velocity shows that the '1866' event was an ordinary nova eruption, not an RN eruption. This also implies that the accretion rate before the ordinary nova event must have been low (around the 4 x 10{sup -11} M{sub sun} yr{sup -1} expected for gravitational radiation alone), and that the matter accumulated on the surface of the white dwarf for approx750,000 years. The current accretion rate (>10{sup -8} M{sub sun} yr{sup -1}) is approx1000x higher than expected for a system below the period gap, with the plausible reason being that the '1866' event started a continuing supersoft source that drives the accretion. The accretion rate has been declining since before the 1890 eruption, with the current rate being only 3% of its earlier value. The decline in the observed accretion rate shows that the supersoft source is not self-sustaining; we calculate that the accretion in T Pyx will effectively stop in upcoming decades. With this, T Pyx will enter a state of hibernation lasting for an estimated 2,600,000 years before gravitational radiation brings the

  9. Cerebral Asymmetries and Reading Acquisition

    ERIC Educational Resources Information Center

    Pirozzolo, Francis J.

    1978-01-01

    Reviewed are historical developments regarding the concepts of cerebral localization, and analyzed are implications of current research on the role of the cerebral hemispheres in reading disorders. (CL)

  10. Dwarf nova-type cataclysmic variable stars are significant radio emitters

    NASA Astrophysics Data System (ADS)

    Coppejans, Deanne L.; Körding, Elmar G.; Miller-Jones, James C. A.; Rupen, Michael P.; Sivakoff, Gregory R.; Knigge, Christian; Groot, Paul J.; Woudt, Patrick A.; Waagen, Elizabeth O.; Templeton, Matthew

    2016-12-01

    We present 8-12 GHz radio light curves of five dwarf nova (DN) type cataclysmic variable stars (CVs) in outburst (RX And, U Gem, and Z Cam), or superoutburst (SU UMa and YZ Cnc), increasing the number of radio-detected DN by a factor of 2. The observed radio emission was variable on time-scales of minutes to days, and we argue that it is likely to be synchrotron emission. This sample shows no correlation between the radio luminosity and optical luminosity, orbital period, CV class, or outburst type; however, higher cadence observations are necessary to test this, as the measured luminosity is dependent on the timing of the observations in these variable objects. The observations show that the previously detected radio emission from SS Cyg is not unique in type, luminosity (in the plateau phase of the outburst), or variability time-scales. Our results prove that DN, as a class, are radio emitters in outburst.

  11. Curious Variables Experiment (CURVE). CCD Photometry of Dwarf Nova V660 Herculis

    NASA Astrophysics Data System (ADS)

    Olech, A.; Zloczewski, K.; Cook, L. M.; Mularczyk, K.; Kedzierski, P.; Wisniewski, M.

    2005-06-01

    We report extensive photometry of the dwarf nova V660 Her. During our campaign, lasting from August 2003 to November 2004, we recorded one bright eruption which turned out to be a superoutburst lasting about 15 days and having amplitude of approx 4.5 mag. Clear superhumps with a mean period of P_sh=0.080924(18) days (116.53+/-0.03 min) were present during all nights of the superoutburst. The period of the superhumps was not stable and in the interval covered by our observations it decreased with a rate of dot P/P_sh=-4.0(1.4) times 10^-5. Based on our data and the known orbital period of the binary we calculate the period excess of 3.4\\+/-0.1%, which is typical for an SU UMa star at this orbital period. This value indicates that the mass ratio of the system is q=0.154.

  12. An X-ray source associated with a Vista Variables Survey nova candidate nova

    NASA Astrophysics Data System (ADS)

    Orio, M.; Mukai, K.; Valle, M. Della

    2016-02-01

    We report that one of the ten Galactic transients proposed to be novae, discovered in the Vista-Variables-Via Lactea (VVV) Survey disk area by Saito et al. (ATel 8602), VVV-NOV-13, is spatially coincident with a faint, hard X-ray source observed in 2011 June 16 and 17 for 19700 s in a survey of the NORMA spiral arm with the Chandra ACIS-I camera (P.I.

  13. HYDROGEN BURNING ON ACCRETING WHITE DWARFS: STABILITY, RECURRENT NOVAE, AND THE POST-NOVA SUPERSOFT PHASE

    SciTech Connect

    Wolf, William M.; Bildsten, Lars; Brooks, Jared; Paxton, Bill

    2013-11-10

    We examine the properties of white dwarfs (WDs) accreting hydrogen-rich matter in and near the stable burning regime of accretion rates as modeled by time-dependent calculations done with Modules for Experiments in Stellar Astrophysics (MESA). We report the stability boundary for WDs of masses between 0.51 M{sub ☉} and 1.34 M{sub ☉} as found via time-dependent calculations. We also examine recurrent novae that are accreting at rates close to, but below, the stable burning limit and report their recurrence times. Our dense grid in accretion rates finds the expected minimum possible recurrence times as a function of the WD mass. This enables inferences to be made about the minimum WD mass possible to reach a specific recurrence time. We compare our computational models of post-outburst novae to the stably burning WDs and explicitly calculate the duration and effective temperature (T{sub eff}) of the post-nova WD in the supersoft phase. We agree with the measured turnoff time-T{sub eff} relation in M31 by Henze and collaborators, infer WD masses in the 1.0-1.3 M{sub ☉} range, and predict ejection masses consistent with those observed. We close by commenting on the importance of the hot helium layer generated by stable or unstable hydrogen burning for the short- and long-term evolution of accreting WDs.

  14. A FORCAST Mid-IR Study of the Classical Nova V1369 Cen (Nova Centauri 2013)

    NASA Astrophysics Data System (ADS)

    Helton, L.

    2014-10-01

    The Galactic cycle of chemical evolution depends on the redistribution into the ambient interstellar medium (ISM) of elements synthesized by thermonuclear processes. Classical novae (CNe) contribute to this cycle by deposition into the ISM of gas enriched through explosive nucleosynthesis and dust grains condensed in their ejecta providing the material from which the next generation of stars and planets grow. We propose to observe the nova V1369 Cen (Nova Centauri 2013) in the mid-IR with FORCAST to determine the ejecta mass, the degree of elemental enrichment in the ejecta, the dust grain mineralogy, and the processes of dust grain growth and destruction. FORCAST observations fulfill these goals by providing high S/N data in which we can 1.) measure H recombination, nebular, and coronal emission lines necessary to determine ejecta abundances and masses; 2.) measure prominent dust features from silicates and polycyclic aromatic hydrocarbons to track dust condensation, mass, grain size distribution, and processing; and 3.) estimate the energy budget of the eruption providing insight into the underlying white dwarf and the eruption's contribution to the energy budget of the ISM. These observations will complement our extensive, on-going Chandra, Swift, and ground based optical and near-IR observing programs.

  15. OGLE ATLAS OF CLASSICAL NOVAE. II. MAGELLANIC CLOUDS

    SciTech Connect

    Mróz, P.; Udalski, A.; Poleski, R.; Soszyński, I.; Szymański, M. K.; Pietrzyński, G.; Wyrzykowski, Ł.; Ulaczyk, K.; Kozłowski, S.; Pietrukowicz, P.; Skowron, J.

    2016-01-15

    The population of classical novae in the Magellanic Clouds was poorly known because of a lack of systematic studies. There were some suggestions that nova rates per unit mass in the Magellanic Clouds were higher than in any other galaxy. Here, we present an analysis of data collected over 16 years by the OGLE survey with the aim of characterizing the nova population in the Clouds. We found 20 eruptions of novae, half of which are new discoveries. We robustly measure nova rates of 2.4 ± 0.8 yr{sup −1} (LMC) and 0.9 ± 0.4 yr{sup −1} (SMC) and confirm that the K-band luminosity-specific nova rates in both Clouds are 2–3 times higher than in other galaxies. This can be explained by the star formation history in the Magellanic Clouds, specifically the re-ignition of the star formation rate a few Gyr ago. We also present the discovery of the intriguing system OGLE-MBR133.25.1160, which mimics recurrent nova eruptions.

  16. Non-Detection of Nova Shells Around Asynchronous Polars

    NASA Astrophysics Data System (ADS)

    Pagnotta, Ashley; Zurek, David

    2016-01-01

    Asynchronous polars (APs) are accreting white dwarfs (WDs) that have different WD and orbital angular velocities, unlike the rest of the known polars, which rotate synchronously (i.e., their WD and orbital angular velocities are the same). Past nova eruptions are the predicted cause of the asynchronicity, in part due to the fact that one of the APs, V1500 Cyg, was observed to undergo a nova eruption in 1975. We used the SALT 10m-class telescope and the MDM 2.4m Hiltner telescope to search for nova shells around three of the remaining four APs (V1432 Aql, BY Cam, and CD Ind) as well as one Intermediate Polar with a high asynchronicity (EX Hya). We found no evidence of nova shells in any of our images. We therefore cannot say that any of the systems besides V1500 Cyg had nova eruptions, but because not all post-nova systems have detectable shells, we also cannot exclude the possibility of a nova eruption occurring in any of these systems and knocking the rotation out of sync.

  17. CLIP Identifies Nova-Regulated RNA Networks in the Brain

    NASA Astrophysics Data System (ADS)

    Ule, Jernej; Jensen, Kirk B.; Ruggiu, Matteo; Mele, Aldo; Ule, Aljaž; Darnell, Robert B.

    2003-11-01

    Nova proteins are neuron-specific antigens targeted in paraneoplastic opsoclonus myoclonus ataxia (POMA), an autoimmune neurologic disease characterized by abnormal motor inhibition. Nova proteins regulate neuronal pre-messenger RNA splicing by directly binding to RNA. To identify Nova RNA targets, we developed a method to purify protein-RNA complexes from mouse brain with the use of ultraviolet cross-linking and immunoprecipitation (CLIP). Thirty-four transcripts were identified multiple times by Nova CLIP. Three-quarters of these encode proteins that function at the neuronal synapse, and one-third are involved in neuronal inhibition. Splicing targets confirmed in Nova-/- mice include c-Jun N-terminal kinase 2, neogenin, and gephyrin; the latter encodes a protein that clusters inhibitory γ-aminobutyric acid and glycine receptors, two previously identified Nova splicing targets. Thus, CLIP reveals that Nova coordinately regulates a biologically coherent set of RNAs encoding multiple components of the inhibitory synapse, an observation that may relate to the cause of abnormal motor inhibition in POMA.

  18. Nova is an old hand at big deals in Alberta

    SciTech Connect

    Sutherland, J.

    1980-09-10

    Nova, an Alberta Corporation, formerly Alberta Gas Trunk Line Co. Ltd., and Shell Canada Resources Ltd. will build a 600 million lb/yr styrene plant near Edmonton, Alberta. For feedstock, 5000 bbl/day of benzene will come from a $350 million, 100,000 bbl/day refinery that will be built by Shell at Edmonton. Husky Oil Ltd., which is controlled by Nova, will take a 40% equity in the refinery. According to Nova, which has a monopoly on gas transmission in Alberta, continued collaboration with Shell could lead to the spending of an additional $2 billion in the next few years. Dow Chemical of Canada Ltd. and Nova will put together an ethane extraction system in Alberta which will feed their jointly owned 1.2 billion lb/yr ethylene plant near Red Deer, Alberta. Dow uses the entire output of the ethylene plant at its recently completed Fort Saskatchewan, Alberta, complex. Alberta Gas Ethylene Co. Ltd., a Nova subsidiary, has begun work on a second 1.2 billion lb/yr ethylene unit scheduled for completion in early 1984, and will soon start work on a third ethylene unit at Red Deer. According to J. Sutherland (Nova, Alberta Corp.), Nova is rapidly expanding its ethylene capacity because, for at least a certain period of time, world-scale plants using Alberta natural gas will be very competitive.

  19. Laying the foundation for a digital Nova Scotia

    NASA Astrophysics Data System (ADS)

    Bond, J.

    2016-04-01

    In 2013, the Province of Nova Scotia began an effort to modernize its coordinate referencing infrastructure known as the Nova Scotia Coordinate Referencing System (NSCRS). At that time, 8, active GPS stations were installed in southwest Nova Scotia to evaluate the technology's ability to address the Province's coordinate referencing needs. The success of the test phase helped build a business case to implement the technology across the entire Province. It is anticipated that by the end of 2015, 40 active GPS stations will be in place across Nova Scotia. This infrastructure, known as the Nova Scotia Active Control Stations (NSACS) network, will allow for instantaneous, centimetre level positioning across the Province. Originally designed to address the needs of the surveying community, the technology has also proven to have applications in mapping, machine automation, agriculture, navigation, emergency response, earthquake detection and other areas. In the foreseeable future, all spatial data sets captured in Nova Scotia will be either directly or indirectly derived from the NSACS network. The technology will promote high accuracy and homogenous spatial data sets across the Province. The technology behind the NSACS and the development of the system are described. Examples of how the technology is contributing to a digital Nova Scotia are presented. Future applications of the technology are also considered.

  20. TIDAL NOVAE IN COMPACT BINARY WHITE DWARFS

    SciTech Connect

    Fuller, Jim; Lai Dong

    2012-09-01

    Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon-oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such 'tidal novae' may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 10{sup 5}-10{sup 6} years.

  1. Supernova hydrodynamics experiments using the Nova laser*

    NASA Astrophysics Data System (ADS)

    Remington, B. A.; Glendinning, S. G.; Estabrook, K. G.; London, R. A.; Wallace, R. J.; Kane, J.; Arnett, D.; Drake, R. P.; Liang, E.; McCray, R.; Rubenchik, A.

    1997-04-01

    We are developing experiments using the Nova laser [1,2] to investigate two areas of physics relevant to core-collapse supernovae (SN): compressible nonlinear hydrodynamic mixing and (2) radiative shock hydrodynamics. In the former, we are examining the differences between the 2D and 3D evolution of the Rayleigh-Taylor instability, an issue critical to the observables emerging from SN in the first year after exploding. In the latter, we are investigating the evolution of a colliding plasma system relevant to the ejecta-stellar wind interactions of the early stages of SN remnant formation. The experiments and astrophysical implications will be discussed. *Work performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under contract number W-7405-ENG-48. [1] J. Kane et al., in press, Astrophys. J. Lett. (March-April, 1997). [2] B.A. Remington et al., in press, Phys. Plasmas (May, 1997).

  2. Classical Rayleigh Taylor experiments on Nova

    SciTech Connect

    Budil, K.S.; Remington, B.A.; Peyser, T.A.

    1995-07-01

    The evolution of the Rayleigh-Taylor (RT) instability in a compressible medium was investigated both at an accelerating embedded interface and at the ablation front in a new series of experiments on Nova. The x-ray drive generated in a hohlraum ablatively accelerated a planar target consisting of a doped plastic pusher which was in some cases backed by a higher density titanium payload. Both target types were diagnosed by face-on and side-on radiography. Experiments have been done with a variety of wavelengths and initial amplitudes. In the case where the perturbed RT-unstable embedded interface is isolated from the ablation front, short wavelength perturbations are observed to grow strongly. When the perturbation is at the ablation front, the short wavelengths are observed to be severely stabilized.

  3. Event Reconstruction Techniques in NOvA

    NASA Astrophysics Data System (ADS)

    Baird, M.; Bian, J.; Messier, M.; Niner, E.; Rocco, D.; Sachdev, K.

    2015-12-01

    The NOvA experiment is a long-baseline neutrino oscillation experiment utilizing the NuMI beam generated at Fermilab. The experiment will measure the oscillations within a muon neutrino beam in a 300 ton Near Detector located underground at Fermilab and a functionally-identical 14 kiloton Far Detector placed 810 km away. The detectors are liquid scintillator tracking calorimeters with a fine-grained cellular structure that provides a wealth of information for separating the different particle track and shower topologies. Each detector has its own challenges with the Near Detector seeing multiple overlapping neutrino interactions in each event and the Far Detector having a large background of cosmic rays due to being located on the surface. A series of pattern recognition techniques have been developed to go from event records, to spatially and temporally separating individual interactions, to vertexing and tracking, and particle identification. This combination of methods to achieve the full event reconstruction will be discussed.

  4. Cerebral Palsy (CP) Quiz

    MedlinePlus

    ... Submit Button Past Emails CDC Features Pop Quiz: Cerebral Palsy Language: English Español (Spanish) Recommend on Facebook Tweet ... Sandy is the parent of a child with cerebral palsy and the Board President of Gio’s Garden , a ...

  5. Eclipse Mapping Experiments in Dwarf Novae Outbursts

    NASA Astrophysics Data System (ADS)

    Borges, B. W.; Baptista, R.

    2006-06-01

    In this work, we report the eclipse mapping analysis of CCD photometric data of two short period dwarf novae - V4140 Sgr (Borges & Baptista 2005) and HT Cas (Borges, Baptista & Catalán, in preparation) - during observed outburst events. The analysis of the observations of V4140 Sgr, done between 1991 and 2001, reveals that the object was in the decline from an outburst in 1992 and again in outburst in 2001. A distance of d = 170+/-30 pc is obtained from a method similar to that used to constrain the distance to open clusters. From this distance, disc radial brightness temperature distributions are determined, and the disc temperatures remain below the critical effective temperature T_{crit} at all disc radii during the outburst. The distributions in quiescence and in outburst are significantly different from those of other dwarf novae of similar orbital period. These results cannot be explained within the framework of the disc instability model and the small amplitude outbursts of V4140 Sgr can be due bursts of enhanced mass transfer rate from the secondary star. Our HT Cas data consist of V and R CCD photometric observations done in 2005 November with the 0.95-m James Gregory Telescope (JGT) and cover a outburst cycle. We used the entropy associated to the eclipse maps to obtain the semi-opening disc angle α evolution throught the outburst. The obtained angles are systematically lower than those obtained by Ioannou et al. (1999) and we can conclude that the outburst radial profiles must be flatter than the the T ∝ r^{-3/4} law of steady state dics, against the expectations of the disc instability model. Our intensity radial distributions presents the same ``outside-in'' outburst behavior as obtained by the referred author.

  6. 15 CFR 904.101 - Notice of violation and assessment (NOVA).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (NOVA). 904.101 Section 904.101 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign... REGULATIONS CIVIL PROCEDURES Civil Penalties § 904.101 Notice of violation and assessment (NOVA). (a) A NOVA will be issued by NOAA and served upon the respondent(s). The NOVA will contain: (1) A...

  7. 15 CFR 904.101 - Notice of violation and assessment (NOVA).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... (NOVA). 904.101 Section 904.101 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign... REGULATIONS CIVIL PROCEDURES Civil Penalties § 904.101 Notice of violation and assessment (NOVA). (a) A NOVA will be issued by NOAA and served upon the respondent(s). The NOVA will contain: (1) A...

  8. 15 CFR 904.101 - Notice of violation and assessment (NOVA).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (NOVA). 904.101 Section 904.101 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign... REGULATIONS CIVIL PROCEDURES Civil Penalties § 904.101 Notice of violation and assessment (NOVA). (a) A NOVA will be issued by NOAA and served upon the respondent(s). The NOVA will contain: (1) A...

  9. 15 CFR 904.101 - Notice of violation and assessment (NOVA).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (NOVA). 904.101 Section 904.101 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign... REGULATIONS CIVIL PROCEDURES Civil Penalties § 904.101 Notice of violation and assessment (NOVA). (a) A NOVA will be issued by NOAA and served upon the respondent(s). The NOVA will contain: (1) A...

  10. 15 CFR 904.101 - Notice of violation and assessment (NOVA).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (NOVA). 904.101 Section 904.101 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign... REGULATIONS CIVIL PROCEDURES Civil Penalties § 904.101 Notice of violation and assessment (NOVA). (a) A NOVA will be issued by NOAA and served upon the respondent(s). The NOVA will contain: (1) A...

  11. 78 FR 53493 - Presidential Permits: NOVA Chemicals Inc. Line 20 Facilities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... Presidential Permits: NOVA Chemicals Inc. Line 20 Facilities August 21, 2013. AGENCY: Department of State. ACTION: Notice of Issuance of a Presidential Permit for NOVA Chemicals Inc. Line 20 Facilities. SUMMARY: The Department of State issued a Presidential Permit to NOVA Chemicals Inc. (``NOVA Inc.'') on...

  12. Pre-Discovery Detections of the Nova Delphini Outburst

    NASA Astrophysics Data System (ADS)

    Wren, J.; Vestrand, T. W.; Wozniak, P.; Davis, H

    2013-08-01

    Three RAPTOR full-sky persistent monitors located in Los Alamos, NM, and Maui, HI, detected the emergence of Nova Delphini 2013 (CBET #3628) at magnitude 10.1 at 6:58 UT on 14 Aug, 2013. Our photometry of the nova shows a rapid rise to approximately magnitude 8.5 by 8 UT and then a more gradual rise to approximately magnitude 7.5 by 14 UT (the time of discovery by Koichi Itagaki). Our full-sky persistent monitors imaged the nova every 10s during this time period, a total of about 2500 photometric measurements before 14 UT.

  13. SOFIA: A Promising Resource for Future Nova Studies

    NASA Astrophysics Data System (ADS)

    Helton, L. A.; Sofia Science Team

    2014-12-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a 2.5-m telescope carried on board a Boeing 747-SP aircraft. Optimized for observations from infrared through sub-mm wavelengths, SOFIA observes from an altitude of 37,000 - 45,000 feet, above 99% of the atmospheric water vapor. The Observatory's complement of instruments possesses a broad range of capabilities, many of which are especially well suited for observations of classical novae, recurrent novae, and other cataclysmic variables. Here we present a selection of the instruments available on board SOFIA that may prove to be very useful for future novae studies.

  14. The analysis of spectra of novae taken near maximum

    NASA Technical Reports Server (NTRS)

    Stryker, L. L.; Hestand, J.; Starrfield, S.; Wehrse, R.; Hauschildt, P.; Spies, W.; Baschek, B.; Shaviv, G.

    1988-01-01

    A project to analyze ultraviolet spectra of novae obtained at or near maximum optical light is presented. These spectra are characterized by a relatively cool continuum with superimposed permitted emission lines from ions such as Fe II, Mg II, and Si II. Spectra obtained late in the outburst show only emission lines from highly ionized species and in many cases these are forbidden lines. The ultraviolet data will be used with calculations of spherical, expanding, stellar atmospheres for novae to determine elemental abundances by spectral line synthesis. This method is extremely sensitive to the abundances and completely independent of the nebular analyses usually used to obtain novae abundances.

  15. Microstructures of Rare Silicate Stardust from Nova and Supernovae

    NASA Technical Reports Server (NTRS)

    Nguyen, A. N.; Keller, L. P.; Rahman, Z.; Messenger, S

    2011-01-01

    Most silicate stardust analyzed in the laboratory and observed around stellar environments derives from O-rich red giant and AGB stars [1,2]. Supernova (SN) silicates and oxides are comparatively rare, and fewer than 10 grains from no-va or binary star systems have been identified to date. Very little is known about dust formation in these stellar environments. Mineralogical studies of only three O-rich SN [3-5] and no nova grains have been performed. Here we report the microstructure and chemical makeup of two SN silicates and one nova grain.

  16. Current results of the NOvA experiment

    NASA Astrophysics Data System (ADS)

    Kolupaeva, Liudmila

    2016-10-01

    NOvA is a long baseline neutrino oscillation experiment at Fermi National Accelerator Laboratory, USA. It is one of the so-called "off-beam-axis" experiments with two highly active detectors separated by 810 km of Earth's crust. Both detectors are identical and consist of PVC cells filled with a liquid scintillator. The NOvA collaboration has already published its first results for muon neutrino disappearance [1] and electron neutrino appearance [2] mode with data collected between July 2013 and March 2015. This talk is devoted to a discussion on NOvA's first results.

  17. Neutrino Physics in the NOvA Experiment

    SciTech Connect

    Sanchez, Mayly

    2016-09-19

    The objective of the experimental neutrino physics program at ISU is to contribute to the NOvA experiment in order to enable the measurement of the unknown neutrino parameters: the CP violation phase and the mass hierarchy. In the Summer of 2015, the NOvA Collaboration released results from the first year of data collected by the experiment. The ISU group played an important role in various aspects of these results including authoring one of the two resulting publications. During this project period and with the support of this grant the PI and her group made leading contributions both in data analysis and operations to the NOvA experiment.

  18. E2000 + 223 - A newly discovered old nova?

    NASA Astrophysics Data System (ADS)

    Takalo, L. O.; Nousek, J. A.

    1985-06-01

    The X-ray source, E2000 + 223, serendipitously discovered by the Einstein Observatory, has been tentatively identified with an old nova shell. Spectroscopic observations of the diffuse optical counterpart show a heavily reddened continuum with bright forbidden S II emission lines at double lambda 6716, 6732. Radio observations at the VLA show a weak (about 1.2 mJy) extended radio source, with a nonthermal spectrum, concident with the optical emission. The observations can be best explained by assuming the object is an old nova which erupted sometime in the eighteenth or nineteenth century, similar to GK Per (Nova 1901) but at a distance of 1.4 kpc.

  19. E2000 + 223 - A newly discovered old nova?

    NASA Technical Reports Server (NTRS)

    Takalo, L. O.; Nousek, J. A.

    1985-01-01

    The X-ray source, E2000 + 223, serendipitously discovered by the Einstein Observatory, has been tentatively identified with an old nova shell. Spectroscopic observations of the diffuse optical counterpart show a heavily reddened continuum with bright forbidden S II emission lines at double lambda 6716, 6732. Radio observations at the VLA show a weak (about 1.2 mJy) extended radio source, with a nonthermal spectrum, concident with the optical emission. The observations can be best explained by assuming the object is an old nova which erupted sometime in the eighteenth or nineteenth century, similar to GK Per (Nova 1901) but at a distance of 1.4 kpc.

  20. Liquid Scintillator Production for the NOvA Experiment

    DOE PAGES

    Mufson, S.; Baugh, B.; Bower, C.; ...

    2015-04-15

    The NOvA collaboration blended and delivered 8.8 kt (2.72M gal) of liquid scintillator as the active detector medium to its near and far detectors. The composition of this scintillator was specifically developed to satisfy NOvA's performance requirements. A rigorous set of quality control procedures was put in place to verify that the incoming components and the blended scintillator met these requirements. The scintillator was blended commercially in Hammond, IN. The scintillator was shipped to the NOvA detectors using dedicated stainless steel tanker trailers cleaned to food grade.

  1. Liquid scintillator production for the NOvA experiment

    NASA Astrophysics Data System (ADS)

    Mufson, S.; Baugh, B.; Bower, C.; Coan, T. E.; Cooper, J.; Corwin, L.; Karty, J. A.; Mason, P.; Messier, M. D.; Pla-Dalmau, A.; Proudfoot, M.

    2015-11-01

    The NOvA collaboration blended and delivered 8.8 kt (2.72M gal) of liquid scintillator as the active detector medium to its near and far detectors. The composition of this scintillator was specifically developed to satisfy NOvA's performance requirements. A rigorous set of quality control procedures was put in place to verify that the incoming components and the blended scintillator met these requirements. The scintillator was blended commercially in Hammond, IN. The scintillator was shipped to the NOvA detectors using dedicated stainless steel tanker trailers cleaned to food grade.

  2. THE BEHAVIOR OF NOVAE LIGHT CURVES BEFORE ERUPTION

    SciTech Connect

    Collazzi, Andrew C.; Schaefer, Bradley E.; Xiao Limin; Pagnotta, Ashley; Kroll, Peter; Loechel, Klaus; Henden, Arne A.

    2009-12-15

    In 1975, E. R. Robinson conducted the hallmark study of the behavior of classical nova light curves before eruption, and this work has now become part of the standard knowledge of novae. He made three points: 5 out of 11 novae showed pre-eruption rises in the years before eruption, one nova (V446 Her) showed drastic changes in the variability across eruptions, and all but one of the novae (excepting BT Mon) have the same quiescent magnitudes before and after the outburst. This work has not been tested since it came out. We have now tested these results by going back to the original archival photographic plates and measuring large numbers of pre-eruption magnitudes for many novae using comparison stars on a modern magnitude scale. We find in particular that four out of five claimed pre-eruption rises are due to simple mistakes in the old literature, that V446 Her has the same amplitude of variations across its 1960 eruption, and that BT Mon has essentially unchanged brightness across its 1939 eruption. Out of 22 nova eruptions, we find two confirmed cases of significant pre-eruption rises (for V533 Her and V1500 Cyg), while T CrB has a deep pre-eruption dip. These events are a challenge to theorists. We find no significant cases of changes in variability across 27 nova eruptions beyond what is expected due to the usual fluctuations seen in novae away from eruptions. For 30 classical novae plus 19 eruptions from 6 recurrent novae, we find that the average change in magnitude from before the eruption to long after the eruption is 0.0 mag. However, we do find five novae (V723 Cas, V1500 Cyg, V1974 Cyg, V4633 Sgr, and RW UMi) that have significantly large changes, in that the post-eruption quiescent brightness level is over ten times brighter than the pre-eruption level. These large post-eruption brightenings are another challenge to theorists.

  3. Distributed computer control system in the Nova Laser Fusion Test Facility

    SciTech Connect

    Not Available

    1985-09-01

    The EE Technical Review has two purposes - to inform readers of various activities within the Electronics Engineering Department and to promote the exchange of ideas. The articles, by design, are brief summaries of EE work. The articles included in this report are as follows: Overview - Nova Control System; Centralized Computer-Based Controls for the Nova Laser Facility; Nova Pulse-Power Control System; Nova Laser Alignment Control System; Nova Beam Diagnostic System; Nova Target-Diagnostics Control System; and Nova Shot Scheduler. The 7 papers are individually abstracted.

  4. A Hubble Space Telescope survey for novae in M87.I. light and color curves, spatial distributions, and the nova rate

    SciTech Connect

    Shara, Michael M.; Doyle, Trisha F.; Lauer, Tod R.; Zurek, David; Neill, J. D.; Madrid, Juan P.; Mikołajewska, Joanna; Welch, D. L.; Baltz, Edward A.

    2016-11-08

    The Hubble Space Telescope has imaged the central part of M87 over a 10 week span, leading to the discovery of 32 classical novae (CNe) and nine fainter, likely very slow, and/or symbiotic novae. In this first paper of a series, we present the M87 nova finder charts, and the light and color curves of the novae. We demonstrate that the rise and decline times, and the colors of M87 novae are uncorrelated with each other and with position in the galaxy. The spatial distribution of the M87 novae follows the light of the galaxy, suggesting that novae accreted by M87 during cannibalistic episodes are well-mixed. Conservatively using only the 32 brightest CNe we derive a nova rate for M87: ${363}_{-45}^{+33}$ novae yr–1. We also derive the luminosity-specific classical nova rate for this galaxy, which is ${7.88}_{-2.6}^{+2.3}\\,{\\mathrm{yr}}^{-1}/{10}^{10}\\,{L}_{\\odot }{,}_{K}$. Both rates are 3–4 times higher than those reported for M87 in the past, and similarly higher than those reported for all other galaxies. As a result, we suggest that most previous ground-based surveys for novae in external galaxies, including M87, miss most faint, fast novae, and almost all slow novae near the centers of galaxies.

  5. A Hubble Space Telescope survey for novae in M87.I. light and color curves, spatial distributions, and the nova rate

    DOE PAGES

    Shara, Michael M.; Doyle, Trisha F.; Lauer, Tod R.; ...

    2016-11-08

    The Hubble Space Telescope has imaged the central part of M87 over a 10 week span, leading to the discovery of 32 classical novae (CNe) and nine fainter, likely very slow, and/or symbiotic novae. In this first paper of a series, we present the M87 nova finder charts, and the light and color curves of the novae. We demonstrate that the rise and decline times, and the colors of M87 novae are uncorrelated with each other and with position in the galaxy. The spatial distribution of the M87 novae follows the light of the galaxy, suggesting that novae accreted by M87 during cannibalistic episodes are well-mixed. Conservatively using only the 32 brightest CNe we derive a nova rate for M87:more » $${363}_{-45}^{+33}$$ novae yr–1. We also derive the luminosity-specific classical nova rate for this galaxy, which is $${7.88}_{-2.6}^{+2.3}\\,{\\mathrm{yr}}^{-1}/{10}^{10}\\,{L}_{\\odot }{,}_{K}$$. Both rates are 3–4 times higher than those reported for M87 in the past, and similarly higher than those reported for all other galaxies. As a result, we suggest that most previous ground-based surveys for novae in external galaxies, including M87, miss most faint, fast novae, and almost all slow novae near the centers of galaxies.« less

  6. Summary of Stimulated Raman Scattering Experiments in the Nova Air-Path and Projected Nova and Nova II System Performance Limits

    SciTech Connect

    Henesian, M; Swift, C D; Murray, J R

    2007-07-17

    The authors present the results of high intensity beam propagation experiments conducted with the Nova laser system to investigate the occurrence of stimulated rotational Raman scattering (SRRS) from atmospheric nitrogen in the beam path. Enclosed is a preprint entitled ''Stimulated Rotational Raman Scattering in Nitrogen in Long Air Paths'' that they have published in the November issue of Optics Letters. The physics issues associated with SRRS are discussed at length in the preprint. The small signal steady-state SRRS gain coefficient that they determined from threshold measurements is in excellent agreement with recent direct SRRS gain measurements by Bischel, et al., at SRI, and is in good agreement with early gain estimates from Averbakh, et al., in the Soviet Union. Consequently, they have a high degree of confidence in the gain coefficient. In addition, threshold SRRS experiments on the long air-path Nova II system are in substantial agreement with the earlier Nova experiments. Nova and Nova II system performance limitations were not critically addressed in the publication so they shall discuss these issues in this paper.

  7. A Comprehensive Review of Nova-Like Variable Stars

    NASA Astrophysics Data System (ADS)

    Sion, Edward

    2016-07-01

    A comprehensive review of nova-like variable stars of the VY Sculptoris and UX Ursa Majoris subtypes is presented. All that has been learned, up to the present time, from observations in the X-ray, far ultraviolet, optical and infrared bandpasses will be discussed. Spectroscopic analyses of high optical brightness states and low optical brightness states of nova-like variables will be summarized. The application of standard and non-standard accretion disk models as well as boundary layer structure will be discussed. The results of searches for nova shells, the evolutionary state of nova-likes as well as new spectroscopic results on BZ Cam (the bow shock CV) and BB Dor will also be included. This work is supported by NASA ADP grants NNX13AF12G and NNX13AF11G to Villanova University.

  8. WHT, DIPOL-2 polarimetry of Nova Sgr 2015b

    NASA Astrophysics Data System (ADS)

    Harvey, Eamonn; Berdyugin, Andrei; Redman, Matt

    2015-09-01

    We report polarimetry data from three nights observing of Nova Sgr 2015b (also PNV J18365700-2855420 or V5668 Sgr) with the William Herschel Telescope in the BVR passbands using the DIPOL-2 instrument.

  9. Ultraviolet spectroscopy of the recurrent nova U Scorpii during outburst

    NASA Technical Reports Server (NTRS)

    Williams, R. E.; Sparks, W. M.; Gallagher, J. S.; Ney, E. P.; Starrfield, S. G.; Truran, J. W.

    1981-01-01

    Observations of the recurrent nova U Sco during the 1979 outburst are presented, and the spectral evolution is found to differ from that of other recurrent novas. Spectra are dominated by emission lines, and the strong forbidden-line emission characteristic is conspicuously absent. A method to determine masses of nova shells is outlined, and an analysis of the emission lines shows an enrichment in N relative to C and O, and that the nova ejecta are rich in He relative to H. Optical spectra of U Sco obtained following its return to quiescence show predominantly He II emission lines, which suggests an enrichment of the preoutburst gas in He, and thus the presence of a highly evolved companion.

  10. Ocean and Coastal Acidification off New England and Nova Scotia

    EPA Science Inventory

    New England coastal and adjacent Nova Scotia shelf waters have a reduced buffering capacity because of significant freshwater input, making the region’s waters potentially more vulnerable to coastal acidification. Nutrient loading and heavy precipitation events further acid...

  11. AAS Nova and Astrobites: Making current astronomy research accessible

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna; Astrobites Team

    2016-10-01

    AAS Nova and Astrobites are two resources available for astronomers, astronomy students, and astronomy enthusiasts to keep up with some of the most recent research published across the field of astronomy. Both supported by the AAS, these two daily astrophysical literature blogs provide accessible summaries of recent publications on the arXiv and in AAS journals. We present the goals, content, and readership of AAS Nova and Astrobites, and discuss how they might be used as tools in the undergraduate classroom.

  12. Synthesis of C-rich dust in CO nova outbursts

    NASA Astrophysics Data System (ADS)

    José, Jordi; Halabi, Ghina M.; El Eid, Mounib F.

    2016-09-01

    Context. Classical novae are thermonuclear explosions that take place in the envelopes of accreting white dwarfs in stellar binary systems. The material transferred onto the white dwarf piles up under degenerate conditions, driving a thermonuclear runaway. In these outbursts, about 10-7-10-3 M⊙, enriched in CNO and sometimes other intermediate-mass elements (e.g., Ne, Na, Mg, or Al for ONe novae) are ejected into the interstellar medium. The large concentrations of metals spectroscopically inferred in the nova ejecta reveal that the solar-like material transferred from the secondary mixes with the outermost layers of the underlying white dwarf. Aims: Most theoretical models of nova outbursts reported to date yield, on average, outflows characterized by O > C, from which, in principle, only oxidized condensates (e.g., O-rich grains) would be expected. Methods: To specifically address whether CO novae can actually produce C-rich dust, six different hydrodynamic nova models have been evolved, from accretion to the expansion and ejection stages, with different choices for the composition of the substrate with which the solar-like accreted material mixes. Updated chemical profiles inside the H-exhausted core have been used, based on stellar evolution calculations for a progenitor of 8 M⊙ through H- and He-burning phases. Results: We show that these profiles lead to C-rich ejecta after the nova outburst. This extends the possible contribution of novae to the inventory of presolar grains identified in meteorites, particularly in a number of carbonaceous phases (i.e., nanodiamonds, silicon carbides, and graphites).

  13. X-ray Grating Observations of Recent Recurrent Novae

    NASA Astrophysics Data System (ADS)

    Orio, Marina; Behar, Ehud; Gallagher, J.; Bianchini, A.; Chiosi, E.; Luna, J.; Nelson, T.; Rauch, T.

    2013-01-01

    Two recurrent novae (RNe) that do not host red giants were observed in outburst at the beginning of 2009 and 2010, respectively. The first nova was LMC 2009a, and the second one was U Scorpii. Nova LMC 2009a was a relatively slow RN, and it was quite luminous both at optical and X-ray wavelengths. U Sco is the fastest nova ever recorded. Its supersoft X-ray phase started a couple of weeks after optical maximum and lasted for about a month, while for Nova LMC 2009a this phase started four months after maximum and lasted for 5 months. For both novae, the first X-ray spectrum taken while the luminous supersoft X-ray source was beginning to emerge is remarkably similar with broad and prominent emission lines of nitrogen and carbon accounting for at least 30% of the X-ray flux. Blue-shifted absorption and red-shifted emission form apparent P-Cyg profiles. We attribute the emission features to the ejecta and show evidence that they are largely due to collisional ionization. In the case of U Sco the absorption lines were embedded in the emission features after the first observation. We find evidence that in U Scorpii we were observing the Thomson reflected spectrum at a distance of ~= 3 R⊙ from the white dwarf rather than the atmosphere itself. For both novae, the peak temperature was remarkably high, probably close to 900,000 K for U Sco, and about 600,000 K for Nova LMC 2009a. We suggest that these two objects represent different stages of RNe secular evolution.

  14. Optical observations of KT Eri = Nova Eridani 2009

    NASA Astrophysics Data System (ADS)

    Ragan, E.; Brozek, T.; Suchomska, K.; Skalbania, A.; Konorski, P.; Galan, C.; Swierczynski, E.; Tomov, T.; Mikolajewski, M.; Wychudzki, P.

    2009-12-01

    We report on optical observations of Nova Eri 2009 obtained at the Nicolaus Copernicus University Observatory (Torun, Poland) and the Olsztyn Planetarium and Astronomical Observatory. Using a 60 cm Cassegrain telescope (Torun) and a 25 cm Schmidt-Cassegrain telescope (Olsztyn) we estimated the V brightness of the Nova to ~8.30+/-0.04 mag and ~8.59+/-0.01 mag on Nov. 27.00 UT and Nov. 27.91 UT.

  15. Near-infrared photometric observations of Nova Ophiuchi 2012

    NASA Astrophysics Data System (ADS)

    Raj, Ashish; Ashok, N. M.; Banerjee, D. P. K.; Raman, V. Venkata

    2012-04-01

    Ashish Raj, N. M. Ashok, D. P. K. Banerjee and V. Venkata Raman, Physical Research Laboratory, report near-infrared J-, H-, and K-band photometry of the Nova Oph 2012 (cf. CBET 3072, 3081) obtained with the Mt. Abu 1.2-m telescope (+PRL Near-Infrared NICMOS3 Imager/Spectrometer). The preliminary reduction of these Mt. Abu observations, of Mar. 29, 31 and Apr. 2, 3 UT shows the brightening of the nova in the JHK bands.

  16. Evolution of Nova-Dependent Splicing Regulation in the Brain

    PubMed Central

    Živin, Marko; Darnell, Robert B

    2007-01-01

    A large number of alternative exons are spliced with tissue-specific patterns, but little is known about how such patterns have evolved. Here, we study the conservation of the neuron-specific splicing factors Nova1 and Nova2 and of the alternatively spliced exons they regulate in mouse brain. Whereas Nova RNA binding domains are 94% identical across vertebrate species, Nova-dependent splicing silencer and enhancer elements (YCAY clusters) show much greater divergence, as less than 50% of mouse YCAY clusters are conserved at orthologous positions in the zebrafish genome. To study the relation between the evolution of tissue-specific splicing and YCAY clusters, we compared the brain-specific splicing of Nova-regulated exons in zebrafish, chicken, and mouse. The presence of YCAY clusters in lower vertebrates invariably predicted conservation of brain-specific splicing across species, whereas their absence in lower vertebrates correlated with a loss of alternative splicing. We hypothesize that evolution of Nova-regulated splicing in higher vertebrates proceeds mainly through changes in cis-acting elements, that tissue-specific splicing might in some cases evolve in a single step corresponding to evolution of a YCAY cluster, and that the conservation level of YCAY clusters relates to the functions encoded by the regulated RNAs. PMID:17937501

  17. Novae as a Class of Transient X-ray Sources

    NASA Technical Reports Server (NTRS)

    Mukai, K.; Orio, M.; Valle, M. Della

    2007-01-01

    Motivated by the recently discovered class of faint (10(exp 34)-10(exp 35) ergs/s) X-ray transients in the Galactic Center region, we investigate the 2-10 keV properties of classical and recurrent novae. Existing data are consistent with the idea that all classical novae are transient X-ray sources with durations of months to years and peak luminosities in the 10(exp 34)-10(exp 35)ergs/s range. This makes classical novae a viable candidate class for the faint Galactic Center transients. We estimate the rate of classical novae within a 15 arcmin radius region centered on the Galactic Center (roughly the field of view of XMM-Newton observations centered on Sgr A*) to be approx.0.1 per year. Therefore, it is plausible that some of the Galactic Center transients that have been announced to date are unrecognized classical novae. The continuing monitoring of the Galactic Center region carried out by Chandra and XMM-Newton may therefore provide a new method to detect classical novae in this crowded and obscured region, an

  18. Detecting Nova Shells around known Cataclysmic Variable systems

    NASA Astrophysics Data System (ADS)

    Xhakaj, Enia; Kupfer, Thomas; Prince, Thomas A.

    2017-01-01

    Nova shells are hydrogen-rich nebulae around Cataclysmic Variables that are created when a Nova outburst takes place. Learning more about Nova shells can help us get a better understanding of the long-term evolution of white dwarfs in active Cataclysmic Variables. In this project, we present the search for Nova shells around 1700 Cataclysmic Variables, using Hα images from the Palomar Transient Factory (PTF) survey. The PTF Hα survey started in 2009 using the 48’’ Oschin telescope at Palomar Observatory and is the first of its type covering the whole northern hemisphere while reaching 18 mags in 60 seconds of exposure. We concentrated our search on the IAU catalogue of Historical Novae, as well as on the SDSS and the Ritter-Kolb catalogue of Cataclysmic Variables. We numerically analyzed radial profiles centered on the target sources to search for excess emission potentially associated with the shells. Out of 1700 Cataclysmic Variables present in these catalogues, we detected 25 Nova shells, out of which 20 are not observed before.

  19. Backyard Research on Cataclysmic Variables by a Consortium of Professional and Amateur Astronomers: DV UMa-A Case Study

    NASA Astrophysics Data System (ADS)

    Vanmunster, T.

    2006-06-01

    The Center for Backyard Astrophysics (CBA) is a multi-longitude network of small photometric telescopes, owned by talented amateurs, who study periodic phenomena in Cataclysmic Variables (CVs). The CBA is among the leading examples of successful partnerships between professional and amateur enthusiasts, producing vast amounts of high-quality variable star data. This poster paper highlights observational CBA results obtained on DV UMa, a most interesting eclipsing UGSU-type dwarf nova, that has been intensively monitored during its April 1997 superoutburst.

  20. Another neon nova - Early infrared photometry and spectroscopy of Nova Cygni 1992

    NASA Technical Reports Server (NTRS)

    Hayward, T. L.; Gehrz, R. D.; Miles, J. W.; Houck, J. R.

    1992-01-01

    Infrared photometry and spectrophotometry of Nova Cygni 1992 taken within 54 days of its eruption show a strong 12.8-micron Ne II forbidden emission line as well as hydrogen recombination lines. Spectra with lambda/Delta lambda of about 2000 resolve the Ne II forbidden and 12.37-micron Hu-alpha lines with about 2200 km/s (FWHM). The Ne II forbidden line shows multiple velocity components. The amount of forbidden Ne II required to produce the observed emission feature exceeds the solar abundance of neon by at least a factor of 4.

  1. ARAS Optical Spectroscopy of Classical Nova ASASSN-16ig (Nova Sgr 2016 no. 2)

    NASA Astrophysics Data System (ADS)

    Garde, Olivier; Charbonnel, Stephane; Du, Pascal Le

    2016-08-01

    We obtained a series of optical of the classical nova ASASSN-16ig in Sagittarius (N Sgr 2016 no. 2) (see ATels #9375, #9343, #9352, #9359, CBET 4295, 4299) with a LISA spectrograph plus ATIK414EX CCD using a C14 at Obs. Hautes Provence on Aug. 13.83 UT and 14.49 UT with total exposures of about 6000 sec each at a resolution of around 700 covering the interval 4000 - 7550 A with sufficient S/N ratio ( > 10). The spectra on both days are show the early optically thick "Fe curtain" stage of the ejecta expansion with the usual low ionization spectrum.

  2. Observations and simulations of Nova Vul 1984 No. 2: A nova with ejecta rich in oxygen, neon, and magnesium

    SciTech Connect

    Starrfield, S.; Sonneborn, G.; Stryker, L.L.; Sparks, W.M.; Truran, J.W.; Ferland, G.; Wagner, R.M.; Gallagher, J.S.; Wade, R.; Williams, R.E.; Kenyon, S.; Shaviv, G.; Wu, C.C.; Gehrz, R.D.; Ney, E.P.

    1988-01-01

    Nova Vul 1984 /number sign/2 has been observed with the IUE Satellite from December 1984 through November 1987 and we expect to be able to observe it with the IUE Satellite for at least another two years. These spectra are characterized by strong lines from Mg, Ne, C, Si, O, N, and other elements. Data obtained in the ultraviolet, infrared, and optical show that this nova is ejecting material rich in oxygen, neon, and magnesium. 16 refs., 5 figs., 1 tab.

  3. Cerebral Palsy (For Parents)

    MedlinePlus

    ... palsy — causes a problem with balance and depth perception Since cerebral palsy affects muscle control and coordination, ... fluid into the lungs) gastroesophageal reflux (spitting up) speech problems drooling tooth decay sleep disorders osteoporosis (weak, ...

  4. Cerebral Contusions and Lacerations

    MedlinePlus

    ... Sports-Related Concussion Diffuse Axonal Injury Intracranial Hematomas Skull Fracture Cerebral contusions are bruises of the brain, ... object or pushed-in bone fragment from a skull fracture. Motor vehicle crashes and blows to the ...

  5. Cerebral amyloid angiopathy

    MedlinePlus

    ... 911) if you have sudden loss of movement , sensation, vision, or speech. Alternative Names Amyloidosis - cerebral; CAA; Congophilic angiopathy Images Amyloidosis on the fingers Arteries of the brain References Kase CS, Shoamanesh A. Intracerebral hemorrhage. In: Daroff ...

  6. Supernova experiments on the Nova Laser

    SciTech Connect

    Kane, J.; Arnett, D.; Remington, B.A.; Glendinning, S.G.; Wallace, R.; Rubenchik, A.; Fryxell, B.A.

    1997-12-02

    Supernova (SN) 1987A focused attention on the critical role of hydrodynamic instabilities in the evolution of supernovae. To test the modeling of these instabilities, we are developing laboratory experiments of hydrodynamic mixing under conditions relevant to supernovae. Initial results were reported in [l]. The Nova laser is used to generate a 10-15 Mbar shock at the interface of a two-layer planar target, which triggers perturbation growth, due to the Richtmyer-Meshkov and Rayleigh-Taylor instabilities as the interface decelerates. This resembles the hydrodynamics of the He-H interface of a Type II supernova at intermediate times, up to a few x10{sup 3} s. The experiment is modeled using the hydrodynamics codes HYADES and CALE, and the supernova code PROMETHEUS. Results of the experiments and simulations are presented. New analysis of the bubble velocity is presented, as well as a study of 2D vs. 3D difference in growth at the He-H interface of SN 1987A.

  7. Supernova Experiments on the Nova Laser

    SciTech Connect

    Kane, J.; Arnett, D.; Remington, B. A.; Glendinning, S. G.; Bazan, G.; Drake, R. P.; Fryxell, B. A.

    2000-04-01

    Supernova (SN) 1987A focused attention on the critical role of hydrodynamic instabilities in the evolution of supernovae. To test the modeling of these instabilities, we are developing laboratory experiments of hydrodynamic mixing under conditions relevant to supernovae. Initial results were reported by Kane et al. in a recent paper. The Nova laser is used to generate a 10-15 Mbar shock at the interface of a two-layer planar target, which triggers perturbation growth, due to the Richtmeyer-Meshkov instability, and to the Rayleigh-Taylor instability as the interface decelerates. This resembles the hydrodynamics of the He-H interface of a Type II supernova at intermediate times, up to a few times 10{sup 3} s. The experiment is modeled using the hydrodynamics codes HYADES and CALE, and the supernova code PROMETHEUS. Results of the experiments and simulations are presented. We also present new analysis of the bubble velocity, a study of two-dimensional versus three-dimensional difference in growth at the He-H interface of SN 1987A, and designs for two-dimensional versus three-dimensional hydro experiments. (c) 2000 The American Astronomical Society.

  8. Supernova hydrodynamics experiments on the Nova laser

    NASA Astrophysics Data System (ADS)

    Kane, J.; Arnett, D.; Remington, B. A.; Glendinning, S. G.; Rubenchik, A.; Drake, R. P.; Fryxell, B. A.; Muller, E.

    1997-12-01

    The critical roles of hydrodynamic instabilities in SN 1987A and in ICF are well known; 2D-3D differences are important in both areas. In a continuing project at Lawrence Livermore National Laboratory (LLNL), the Nova Laser is being used in scaled laboratory experiments of hydrodynamic mixing under supernova-relevant conditions. Numerical simulations of the experiments are being done, using LLNL hydro codes, and astrophysics codes used to model supernovae. Initial investigations with two-layer planar packages having 2D sinusoidal interface perturbations are described in Ap.J. 478, L75 (1997). Early-time simulations done with the LLNL 1D radiation transport code HYADES are mapped into the 2D LLNL code CALE and into the multi-D supernova code PROMETHEUS. Work is underway on experiments comparing interface instability growth produced by 2D sinusoidal versus 3D cross-hatch and axisymmetric cylindrical perturbations. Results of the simulations will be presented and compared with experiment. Implications for interpreting supernova observations and for supernova modelling will be discussed. * Work performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under contract number W-7405-ENG-48.

  9. T Pyxidis: death by a thousand novae

    NASA Astrophysics Data System (ADS)

    Patterson, Joseph; Oksanen, Arto; Kemp, Jonathan; Monard, Berto; Rea, Robert; Hambsch, Franz-Josef; McCormick, Jennie; Nelson, Peter; Allen, William; Krajci, Thomas; Lowther, Simon; Dvorak, Shawn; Borgman, Jordan; Richards, Thomas; Myers, Gordon; Harlingten, Caisey; Bolt, Greg

    2017-04-01

    We report a 20-yr campaign to track the 1.8 h photometric (and orbital) wave in the recurrent nova T Pyxidis. Before and after the 2011 eruption, the period increased on a time-scale P/dot{P} = 3 × 105 yr. This suggests a mass transfer rate in quiescence of ∼10-7 M⊙ yr-1, in substantial agreement with the accretion rate based on the star's luminosity. During the eruption itself, a rapid period increase of 0.0054(7) per cent occurred. This is probably a measure of the mass ejected in the outburst. For a plausible choice of binary parameters, that mass is at least 3 × 10-5 M⊙, and probably more. This represents >300 yr of accretion at the pre-outburst rate, but the time between outbursts was only 45 yr. Thus, the erupting white dwarf (WD) seems to have ejected at least six times more mass than it accreted. If this eruption is typical, the WD must be eroding, rather than growing, in mass. Unless the present series of eruptions is a short-lived episode, the binary dynamics will evaporate the secondary in ∼105 yr. This could be a major channel by which short-period cataclysmic variables are removed from the population.

  10. Nanomedicine in cerebral palsy.

    PubMed

    Balakrishnan, Bindu; Nance, Elizabeth; Johnston, Michael V; Kannan, Rangaramanujam; Kannan, Sujatha

    2013-01-01

    Cerebral palsy is a chronic childhood disorder that can have diverse etiologies. Injury to the developing brain that occurs either in utero or soon after birth can result in the motor, sensory, and cognitive deficits seen in cerebral palsy. Although the etiologies for cerebral palsy are variable, neuroinflammation plays a key role in the pathophysiology of the brain injury irrespective of the etiology. Currently, there is no effective cure for cerebral palsy. Nanomedicine offers a new frontier in the development of therapies for prevention and treatment of brain injury resulting in cerebral palsy. Nanomaterials such as dendrimers provide opportunities for the targeted delivery of multiple drugs that can mitigate several pathways involved in injury and can be delivered specifically to the cells that are responsible for neuroinflammation and injury. These materials also offer the opportunity to deliver agents that would promote repair and regeneration in the brain, resulting not only in attenuation of injury, but also enabling normal growth. In this review, the current advances in nanotechnology for treatment of brain injury are discussed with specific relevance to cerebral palsy. Future directions that would facilitate clinical translation in neonates and children are also addressed.

  11. NOVA2-mediated RNA regulation is required for axonal pathfinding during development

    PubMed Central

    Saito, Yuhki; Miranda-Rottmann, Soledad; Ruggiu, Matteo; Park, Christopher Y; Fak, John J; Zhong, Ru; Duncan, Jeremy S; Fabella, Brian A; Junge, Harald J; Chen, Zhe; Araya, Roberto; Fritzsch, Bernd; Hudspeth, A J; Darnell, Robert B

    2016-01-01

    The neuron specific RNA-binding proteins NOVA1 and NOVA2 are highly homologous alternative splicing regulators. NOVA proteins regulate at least 700 alternative splicing events in vivo, yet relatively little is known about the biologic consequences of NOVA action and in particular about functional differences between NOVA1 and NOVA2. Transcriptome-wide searches for isoform-specific functions, using NOVA1 and NOVA2 specific HITS-CLIP and RNA-seq data from mouse cortex lacking either NOVA isoform, reveals that NOVA2 uniquely regulates alternative splicing events of a series of axon guidance related genes during cortical development. Corresponding axonal pathfinding defects were specific to NOVA2 deficiency: Nova2-/- but not Nova1-/- mice had agenesis of the corpus callosum, and axonal outgrowth defects specific to ventral motoneuron axons and efferent innervation of the cochlea. Thus we have discovered that NOVA2 uniquely regulates alternative splicing of a coordinate set of transcripts encoding key components in cortical, brainstem and spinal axon guidance/outgrowth pathways during neural differentiation, with severe functional consequences in vivo. DOI: http://dx.doi.org/10.7554/eLife.14371.001 PMID:27223325

  12. Outburst of the recurrent nova V745 Sco

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2014-02-01

    The outburst of the recurrent nova V745 Sco (Nova Sco 1937) by Rod Stubbings (Tetoora Road, VIC, Australia) at visual magnitude 9.0 on 2014 February 6.694 UT is reported. This recurrent nova is fading quickly. Follow-up observations of all types (visual, CCD, DSLR) are strongly encouraged, as is spectroscopy; fast time-series of this nova may be useful to detect possible flaring activity as was observed during the outburst of U Scorpii in 2010. Coincident time-series by multiple observers would be most useful for such a study, with a V-filter being preferred. Observations reported to the AAVSO International Database show V745 Sco at visual mag. 10.2 on 2014 Feb. 07.85833 UT (A. Pearce, Nedlands, W. Australia). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. Previous outbursts occurred in 1937 and 1989. The 1937 outburst was detected in 1958 (in decline at magnitude 11.0 on 1937 May 11.1 UT; outburst had occurred within the previous 19 days) by Lukas Plaut on plates taken by Hendrik van Gent at the Leiden Observatory; the object was announced as Nova Sco 1937 and later assigned the GCVS name V745 Sco. The 1989 outburst was detected on 1989 August 1.55 UT by Mati Morel (MMAT, Thornton, NSW, Australia) at visual magnitude 10.4 and in decline. Dr. Bradley Schaefer (Louisiana State University) reports (2010ApJS..187..275S) in his comprehensive analysis of the 10 known galactic recurrent novae (including V745 Sco) that the median interval between recurrent novae outbursts is 24 years. The interval since the 1989 outburst of V745 Sco is 24.10 years. See the Alert Notice for additional visual and multicolor photometry and for more details.

  13. KIC 9832227: a red nova precursor

    NASA Astrophysics Data System (ADS)

    Molnar, Lawrence A.; Van Noord, Daniel; Kinemuchi, Karen; Smolinski, Jason P.; Alexander, Cara E.; Kobulnicky, Henry A.; Cook, Evan M.; Jang, Byoungchan; Steenwyk, Steven D.

    2017-01-01

    Molnar et al. (2015) suggested that KIC 9832227 is a contact binary star in its final years before merging and producing a red nova eruption. Analysis of light curves spanning 1999 to 2014 showed a negative time derivative and second derivative of the orbital period. The timing data were found to be well fit by the empirical exponential formula that Tylenda et al. (2011) used to describe preoutburst data of V1309 Sco. While it could not be concluded that this was the correct interpretation of the data, the prediction made for the near future was specific and falsifiable. We will present light curve data from 2015-2016 which is consistent with the extrapolation of the previous fit. As predicted, the period derivative now exceeds the range measured for other contact systems. Reanalysis of the Kepler spacecraft timing data shows a low amplitude modulation consistent with a third star with an orbital period of 1.7 y and msin i = 0.11 solar masses. We will also present spectroscopic data that show the signature of both binary components. These data rule out the presence of any additional main sequence stars with mass greater than 0.4 solar masses. Based on an updated fit to the exponential formula, we now estimate the time of merger to be the year 2022.2 with a random uncertainty of 0.6 years. These results greatly strengthen the original suggestion. The system presents an unprecedented opportunity to study the mechanism of stellar merger through targeted observations of a precursor. Molnar, L. et al. (2015), AAS Meeting #225, id.415.05. Tylenda, R., et al. (2011), AA, 528, A114.

  14. The Nova-like star RW Sextantis

    NASA Astrophysics Data System (ADS)

    Stokes, S. J.; Evans, J. M.; Bianchini, A.; Canterna, R.

    2000-12-01

    We have analyzed 17 medium resolution spectra of RW Sex taken in 1988 at La Silla in the spectral range is 4000-5000 Å with a dispersion of 60 Å/mm and spectral resolution of about 2 Å/pixel. The mean spectrum of the object shows the continuum energy distribution slightly brighter and steeper than that observed by Beuermann, Stasiewski and Schwope (1992). In both cases the slope seems to be steeper that the λ -2.33 power law predicted for standard accretion discs (see Warner 1995). This might be due to uncertain flux calibration or to the dramatic intrinsic variability of this nova-like system (Honeycutt et al. 1998). Like in Beuerman et al.'s, the hydrogen and the HeI lines appear in absorption with superimposed central emission components. Relatively weak emissions from HeII at λ λ 4542,4686 and the blend CIII+NIII at λ4640 -50 are also seen. The peaks of the narrow emissions components of Hβ , HeIλ4471 and HeIλ4922 have been measured using Gaussian fittings. The new ephemeris are: T0(HJD) = 2446486.5061 +/- 0.0010 + 0.245064 +/- 0.000004 The radial velocity curve produced by the absorption components of the hydrogen and the HeI lines are in antiphase with respect to that produced by the emission cores. The amplitudes of all the radial velocity curves are consistent with those shown by Beuermann, Stasiewski and Schwope (1992). According to these authors the absorption lines are produced in the optically thick accretion disc while the narrow emissions arise from the heated atmosphere of the secondary. We fail however to detect the broad emission components observed by these authors and attributed to the hot disc corona. This point should deserve future investigation.

  15. Na-22 decay gamma rays from classical novae

    NASA Technical Reports Server (NTRS)

    Truran, James W.

    1993-01-01

    NASA Grant NAG 5-1565 has provided support for a program of theoretical research in nuclear astrophysics and related areas, focusing upon the possibility of detecting gamma rays from nearby novae. Particular attention has been given to the evaluation of the theoretical expectations for gamma ray emission from four possible sources: (1) the positron decays of the unstable CNO and fluorine isotopes that are transported to the surface regions of the envelope in the earliest stages of the outbursts; (2) Be-7 decay gamma rays, (3) Na-22 decay gamma rays released in the later stages of the outbursts; and (4) Al-26 decay gamma rays from novae and their possible contribution to Galactic emission. The critical questions of (1) the frequency of occurrence of ONeMg-enriched novae; (2) the expected Galactic distribution of the novae that produce 26Al; and (3) the nature of the observed soft X-ray emission from classical novae, have also been addressed. Considerable progress in research has been achieved on many of these fronts. Brief summaries of the results of several research projects are presented.

  16. Evaluating local food programs: the case of Select Nova Scotia.

    PubMed

    Knight, Andrew J

    2013-02-01

    This study evaluated the effectiveness of the buy local food program Select Nova Scotia; a government program with the goal to increase awareness and consumption of Nova Scotia produced and processed agri-food products by Nova Scotians and visitors. The evaluation methodology was based on prior evaluation resources and local food consumer research. Data were gathered through a web panel survey; 877 respondents completed the survey in June 2010. The results suggest that the program is reaching a wider audience than just those predisposed to local food initiatives. In addition, awareness of Select Nova was related to perceptions of local benefits and barriers, as well as purchase motivation and behavior. Respondents who were aware of Select Nova Scotia rated societal benefits as more important and viewed location and price as less of a barrier; they were also more likely to be highly motivated to purchase local foods. This study also informs results found in previous consumer research studies and identifies marketing opportunities to enhance the effectiveness of local food programs. The results suggest that societal benefits might be used as a way to differentiate products with similar attributes.

  17. π0 mass reconstruction in NOvA Far Detector.

    NASA Astrophysics Data System (ADS)

    Edayath, Sijith

    2017-01-01

    NOvA is a long-baseline neutrino oscillation experiment with functionally identical, segmented, tracking calorimeter Near and Far detectors. The detectors lie 14.6 mrad off-axis from the Fermilab NuMI beam, with a well-defined peak in neutrino energy at 2 GeV. The absolute calibration of the energy scale of the detectors is a major systematic uncertainty in long-baseline oscillation search in NOvA. Neutrino detectors make use of some standard candles for absolute energy calibration. Stopping muon energy distributions, Michel electron energy distributions, and invariant π0 mass are among them. In this talk, we cover NOvA's use of a new method to identify π0 with cosmic origins in the NOvA Far Detector. We employ a computer vision based particle identifier using convolutional neural networks (CVN) to identify π0s, complementing an existing strategy to identify π0 from the neutrino beam using more traditional methods in the Near Detector. Registered for PhD at Cochin University of Science and Technology, India and doing research in NOvA experiment at Fermilab.

  18. Observations and predictions of EUV emission from classical novae

    SciTech Connect

    Starrfield, S.; Truran, J.W.; Sparks, W.M.; Krautter, J.

    1989-01-01

    Theoretical modeling of novae in outburst predicts that they should be active emitters of radiation both in the EUV and soft X-ray wavelengths twice during the outburst. The first time is very early in the outburst when only an all sky survey can detect them. This period lasts only a few hours. They again become bright EUV and soft X-ray emitters late in the outburst when the remnant object becomes very hot and is still luminous. The predictions imply both that a nova can remain very hot for months to years and that the peak temperature at this time strongly depends upon the mass of the white dwarf. It is important to observe novae at these late times because a measurement of both the flux and temperature can provide information about the mass of the white dwarf, the tun-off time scale, and the energy budget of the outburst. We review the existing observations of novae in late stages of their outburst and present some newly obtained data for GQ Mus 1983. We then provide results of new hydrodynamic simulations of novae in outburst and compare the predictions to the observations. 43 refs., 6 figs.

  19. Nova outbursts in the case of mild hibernation

    SciTech Connect

    Livio, M.; Shankar, A.; Truran, J.W.

    1988-02-01

    The necessary conditions for the production of strong thermonuclear runaways in the hibernation scenario are identified and explored. It is found that a reduction in the accretion rate by a factor of about 100, for a period longer than a few thousand years, is generally sufficient to ensure nova-type outbursts, even in the presence of rather high preoutburst accretion rates. Nova outbursts can be obtained under mild hibernation conditions on 1 solar mass white dwarfs as well as on very massive ones. A reduction in the accretion rate by a factor of 10 only is insufficient to produce a nova outburst, if the preoutburst accretion rate is as high as 10 to the -8th solar mass/yr. 28 references.

  20. Discovery of Explosive Lithium Production in Classical Novae

    NASA Astrophysics Data System (ADS)

    Tajitsu, Akito; Sadakane, Kozo; Naito, Hiroyuki; Arai, Akira; Kawakita, Hideyo; Aoki, Wako

    The origin of lithium (Li) and its production process have long been an unsettled question in cosmology and astrophysics. Chemical evolution models and observed stellar Li abundances suggest that at least half of the present Li abundance may have been produced in red giants, asymptotic giant branch (AGB) stars, and novae. However, no direct evidence for the supply of Li from evolved stellar o bjects to the Galactic medium has been found until we reported the detection of a radioactive isotope of beryllium, 7Be, in the post-outburst UV spectra of the classical novae — V339 Del, V5668 Sgr, and V2944 Oph. 7Be decays to form 7Li within a short period of time. These findings strongly suggest that the explosive production of 7Li via the reaction 3He(α , γ )7Be and subsequent decay to 7Li occurs frequently among classical novae and contributes to the process of the Galactic Li enrichment.

  1. High Energy Neutrino Physics with NOvA

    SciTech Connect

    Coan, Thomas

    2016-09-09

    Knowledge of the position of energy deposition in “hit” detector cells of the NOvA neutrino detector is required by algorithms for pattern reconstruction and particle identification necessary to interpret the raw data. To increase the accuracy of this process, the majority of NOvA's 350 000 far detector cell shapes, including distortions, were measured as they were constructed. Using a special laser scanning system installed at the site of the NOvA far detector in Ash River, MN, we completed algorithmic development and measured shape parameters for the far detector. The algorithm and the measurements are “published” in NOνA’s document database (doc #10389, “Cell Center Finder for the NOνA Far Detector Modules”).

  2. Multi-Dimensional Modeling of Nova with Realistic Nuclear Physics

    SciTech Connect

    Zingale, M; Hoffman, R D

    2011-01-27

    This contract covered the period from 03/09/2010 to 09/30/2010. Over this period, we adapted the low Mach number hydrodynamics code MAESTRO to perform simulations of novae. A nova is the thermonuclear runaway of an accreted hydrogen layer on the surface of a white dwarf. As the accreted layer grows in mass, the temperature and density at the base increase to the point where hydrogen fusion can begin by the CNO cycle - a burning process that uses carbon, nitrogen, and oxygen to complete the fusion of four hydrogen nuclei into one helium-4 nucleus. At this point, we are running initial models of nova, exploring the details of the convection. In the follow-on contract to this one, we will continue this investigation.

  3. Soft x-ray emission from classical novae in outburst

    SciTech Connect

    Starrfield, S. Arizona State Univ., Tempe, AZ . Dept. of Physics and Astronomy); Truran, J.W. . Dept. of Astronomy); Sparks, W.M. ); Krautter, J. ); MacDonald, J. . Dept. of Physics and Ast

    1989-01-01

    Theoretical modeling of novae in outburst predicts that they should be active emitters of radiation at soft x-ray wavelengths twice during their outburst. The first time occurs very early in the outburst when only a very sensitive all sky survey will be able to detect them. This period lasts only a few hours for the very fastest novae. They again become bright in x-rays late in the outburst when the remnant object becomes very hot and is still luminous. Both simulations and observations show that novae can remain very hot for months to years. It is important to observe them at these late times because a measurement both of the flux and temperature can provide information about the mass of the white dwarf, the turn-off time scale, and the energy budget of the outburst. 8 refs., 2 figs.

  4. Model Atmospheres for Novae in Outburst: Summary of Research

    NASA Technical Reports Server (NTRS)

    Hauschildt, Peter H.

    1999-01-01

    This paper presents a final report and summary of research on Model Atmospheres for Novae in Outburst. Some of the topics include: 1) Detailed NLTE (non-local thermodynamic equilibrium) Model Atmospheres for Novae during Outburst: II. Modeling optical and ultraviolet observations of Nova LMC 1988 #1; 2) A Non-LTE Line-Blanketed Stellar Atmosphere Model of the Early B Giant epsilon CMa; 3) Spectroscopy of Low Metallicity Stellar atmospheres; 4) Infrared Colors at the Stellar/Substellar Boundary; 5) On the abundance of Lithium in T CrB; 6) Numerical Solution of the Expanding Stellar Atmosphere Problem; and 7) The NextGen Model Atmosphere grid for 3000 less than or equal to T (sub eff) less than or equal to 10000K.

  5. Ultrastructure of extrusomes in hypotrichous ciliate Pseudourostyla nova

    NASA Astrophysics Data System (ADS)

    Zhou, Yao; Wang, Zhengjun; Zhang, Jun; Gu, Fukang

    2011-01-01

    The ultrastructure of extrusomes of the hypotrichous ciliate Pseudourostyla nova was observed in scanning and transmission electron microscopy and enzyme-cytochemistry. The results show that the distribution, morphological characteristics, morphogenesis process, and extrusive process of the extrusomes in P. nova are different from the trichocysts in Paramecium, suggesting that the extrusomes of P. nova can respond to environmental stimuli, play an important role in the defense of this species, and cannot be regarded as "trichocysts". The results also suggest that the extrusomes might be originated from the Golgi apparatus and mature in the cytoplasm; after the extrusion of mature extrusomes, the residual substance might be reabsorbed and reused by the ciliate cell via food vacuoles, and take part in material recycling of the cell.

  6. Nova V2362 Cygni (Nova Cygni 2006): Spitzer, Swift, and Ground-Based Spectral Evolution

    NASA Technical Reports Server (NTRS)

    Lynch, David K.; Venturini, Catherine C.; Mazuk, S.; Woodward, Charles; Gehrz, Robert; Rayner, John; Helton, L.A.; Ness, Jan-Uwe; Starrfield, Sumner; Rudy, Richard J.; Russell, Ray W.; Osborne, Julian P.; Page, Kim; Pearson, Richard; Wagner, R. Mark; Puetter, Richard C.; Perry, Raleigh B.; Schwarz, Greg; Vanlandingham, Karen; Black, John; Bode, Michael; Evans, Aneurin; Geballe, Thomas; Greenhouse, Matthew; Hauschildt, Peter

    2008-01-01

    Nova V2362 Cygni has undergone a number of very unusual changes. Ground-based spectroscopy initially revealed a normal sequence of events: the object faded and its near-infrared emission lines gradually shifted to higher excitation conditions until about day 100 when the optical fading reversed and the object slowly brightened. This was accompanied by a rise in the Swift X-ray telescope flux and a sudden shift in excitation of the visible and IR spectrum back to low levels. The new lower excitation spectrum revealed broad line widths and many P-Cygni profiles, all indicative of the ejection of a second shell. Eventually, dust formed, the X-ray brightness -- apparently unaffected by dust formation -- peaked and then declined, and the object faded at all wavelengths. The Spitzer dust spectra revealed a number of solid-state emission features that, at this time, are not identified.

  7. On the decay of outbursts in dwarf novae nad X-ray novae

    NASA Technical Reports Server (NTRS)

    Cannizzo, John K.

    1994-01-01

    We perform computations using a time-dependent model for the accretion disk limit-cycle mechanism to examine the decay of the optical light following the peak of a dwarf nova outburst. We present the results of a parameter study of the physical input variables which affect the decay rate. In the model, the decay is brought about by a cooling transition front which begins at large radii in the disk and moves inward. The nature of the decay is strongly influenced by the radial dependence of the accretion disk viscosity parameter alpha. To obtain exponential decays for typical dwarf nova parameters, we require alpha proportional to r(exp epsilon(sub 0)), where epsilon(sub 0) approximately = 0.3-0.4. The exact value of epsilon(sub 0) which produces exponential decays depends on factors such as the mass of the accreting star and the inner radius of the accretion disk. Therefore, the observed ubiquity of exponential decays in two different types of systems (dwarf novae and X-ray novae) leads us to believe that alpha is an unnatural scaling for the viscosity. The physics of the cooling transition front must be self-regulating in that the timescale (-parital derivative of lnSigma(r)/partial derivative +)(exp -1) (where Sigma is the surface density) for mass extraction across the front remains constant. This may be consistent with a scaling alpha proportional to (h/r)(exp n), where h is the local disk semi-thickness and n approximately 1-2. As regards the speed of the cooling front, we find v(sub F)(r) proportional to r(exp p), where p approximately 3 at large radii, with an abrupt transition to p approximately 0 at some smaller radius. The r(exp 3) dependence is much steeper than has been found by previous workers and appears to result from the strong variation of specific heat within the cooling front when the front resides at a large radius in the disk. The outflow of disk material across the cooling front causes a significant departure of dln T(sub dff0/dln r from the

  8. Hypernatraemia in cerebral disorders

    PubMed Central

    Taylor, W. H.

    1962-01-01

    Six patients are described in whom cerebral damage was associated with raised plasma sodium and chloride concentrations and with extremely low urinary outputs of sodium and chloride. The patients were not clinically dehydrated and direct determinations showed that the blood and plasma volumes, the endogenous creatinine clearance, and the urinary output of antidiuretic hormone were normal. For these and other reasons it is concluded that the metabolic picture results not from diminished circulatory volume, water deficiency, sodium deficiency, undetected diabetes insipidus or osmotic diuresis, but from the cerebral damage itself. In these and other cited cases, the cerebral damage was localized chiefly in the frontal lobes, hypothalamus or lower brain-stem, thus suggesting a descending pathway, the relationship of which to the pineal area controlling aldosterone secretion requires clarification. Images PMID:13920001

  9. Duplicated middle cerebral artery.

    PubMed

    Perez, Jesus; Machado, Calixto; Scherle, Claudio; Hierro, Daniel

    2009-01-01

    Duplicated middle cerebral artery (DMCA) is an anomalous vessel arising from the internal carotid artery. The incidence DMCA is relatively law, and an association between this anomaly and cerebral aneurysms has been documented. There is a controversy whether DMCA may have perforating arteries. This is an important fact to consider in aneurysm surgery. We report the case of a 34-year-old black woman who suffered a subarachnoid hemorrhage and the angiography a left DMCA, and an aneurysm in an inferior branch of the main MCA. The DMCA and the MCA had perforating arteries. The aneurysm was clipped without complications. The observation of perforating arteries in our patient confirms that the DMCA may have perforating arteries. This is very important to be considered in cerebral aneurysms surgery. Moreover, the DMCA may potentially serve as a collateral blood supply to the MCA territory in cases of MCA occlusion.

  10. [Cerebral ischemia and histamine].

    PubMed

    Adachi, Naoto

    2002-10-01

    Cerebral ischemia induces excess release of glutamate and an increase in the intracellular Ca2+ concentration, which provoke catastrophic enzymatic processes leading to irreversible neuronal injury. Histamine plays the role of neurotransmitter in the central nervous system, and histaminergic fibers are widely distributed in the brain. In cerebral ischemia, release of histamine from nerve endings has been shown to be enhanced by facilitation of its activity. An inhibition of the histaminergic activity in ischemia aggravates the histologic outcome. In contrast, intracerebroventricular administration of histamine improves the aggravation, whereas blockade of histamine H2 receptors aggravates ischemic injury. Furthermore, H2 blockade enhances ischemic release of glutamate and dopamine. These findings suggest that central histamine provides beneficial effects against ischemic neuronal damage by suppressing release of excitatory neurotransmitters. However, histaminergic H2 action facilitates the permeability of the blood-brain barrier and shows deleterious effects on cerebral edema.

  11. PU Vulpeculae: an eclipsing symbiotic nova.

    NASA Astrophysics Data System (ADS)

    Nussbaumer, H.; Vogel, M.

    1996-03-01

    A series of IUE observation from 1992 to 1995 has definitely established PU Vul as an eclipsing binary. The outburst of this symbiotic nova began in 1977. An extended fading in 1980 gave rise to various interpretations, the eclipse scenario being one of them, dust formation being another. From AFOEV and AAVSO observations we find a period of 4900+/-100days, or 13.42+/-0.27years. An eclipsing object of such a long period signifies that we see the binary system at an orbital inclination close to 90deg. ESO observations in the near infrared give an orbital velocity of 4.7km/s and a mass function of m_f_=~0.05. Assuming a white dwarf mass between 0.4Msun_ and 0.5Msun_ gives for the red giant 0.7<=M/Msun_<=1.1. From the length of the eclipse the radius of the red giant is determined as R_giant_>=82Rsun_. We discuss IUE, HST and ground based observations of PU Vulpeculae before and during its second observed eclipse of the hot component by the cool giant which lasted from 1993 to 1995, mid-eclipse was in April 1994. Line profiles, particularly those taken by HST, allow a neat distinction between narrow nebular lines and broader wind lines which prove the existence of a fast wind from the hot star in the binary system of v=~1000km/s. That wind has relatively high densities (N_e_>10^12^cm^-3^) and is optically thick to radiation at λ<228A. Nebular lines have half widths corresponding to v=~70km/s. During the 1994 eclipse the more highly ionized lines were strongly eclipsed, whereas the lowly ionized nebular lines were hardly affected. This proves that the lowly ionized nebular lines are emitted in a very extended region, and not only close to the cool giant. From 1990 to 1994 relative C/N/O abundances of the nebular and wind emission regions have not changed beyond observational uncertainties.

  12. Cerebral venous sinus thrombosis with cerebral hemorrhage during early pregnancy

    PubMed Central

    Nie, Quanmin; Guo, Pin; Ge, Jianwei; Qiu, Yongming

    2015-01-01

    Cerebral venous sinus thrombosis (CVST) rarely induces cerebral hemorrhage, and CVST with cerebral hemorrhage during early pregnancy is extremely rare. Upon literature review, we are able to find only one case of CVST with cerebral hemorrhage in early pregnancy. In this paper, we report another case of a 27-year-old patient who developed CVST with cerebral hemorrhage in her fifth week of pregnancy. Although the optimal treatment for this infrequent condition remains controversial, we adopted anticoagulation as the first choice of treatment and obtained favorable results. PMID:25630781

  13. Bipolar gas outflow from the nova V458 Vul

    NASA Astrophysics Data System (ADS)

    Goranskij, V. P.; Barsukova, E. A.; Fatkhullin, T. A.

    2010-06-01

    Classical nova V458 Vul (N Vul 2007 No.1) was detected as a supersoft X-ray source by the Swift XRT (ATel#1246, #1603). This star is interesting with its spectral class change: features of Fe II class nova completely changed by features of He/N class in the SSS phase (T.N. Tarasova, IBVS No.5807). We performed spectral observations of V458 Vul with the Russian 6-m telescope BTA and spectral camera SCORPIO on 2010 June 9.84 UT.

  14. The Orbital Period of the Classical Nova V458 Vul

    NASA Astrophysics Data System (ADS)

    Goranskij, V. P.; Metlova, N. V.; Barsukova, E. A.; Burenkov, A. N.; Soloviev, V. Ya.

    2008-07-01

    Classical nova V458 Vul (N Vul 2007 No.1) was detected as a supersoft X-ray source (SSS) by the Swift XRT several times in the time range between 2007 October 18 and 2008 June 18 (J. Drake et al., ATel #1246 and #1603). Our V photometry shows the plateau in the light curve continued since January till June 2008. This feature accompanies usually the SSS phases in some classical novae. The fragmentary monitoring during plateau shows night- to-night variability with the amplitudes between 1.2 and 0.4 mag and rapid variability by 0.1 mag in the time scale of an hour.

  15. NOVA: A new multi-level logic simulator

    NASA Technical Reports Server (NTRS)

    Miles, L.; Prins, P.; Cameron, K.; Shovic, J.

    1990-01-01

    A new logic simulator that was developed at the NASA Space Engineering Research Center for VLSI Design was described. The simulator is multi-level, being able to simulate from the switch level through the functional model level. NOVA is currently in the Beta test phase and was used to simulate chips designed for the NASA Space Station and the Explorer missions. A new algorithm was devised to simulate bi-directional pass transistors and a preliminary version of the algorithm is presented. The usage of functional models in NOVA is also described and performance figures are presented.

  16. Nova Sagittarii 2012 No. 5 = PSN J18193700-1907400

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2012-07-01

    Nova Sagittarii 2012 No. 5 = PSN J18193700-1907400 was discovered by Tadashi Kojima (Tsumagoi, Agatsuma-gun, Gunma-ken, Japan) (reported by S. Nakano (Sumoto, Japan) at mag 12.6 on two frames using a Canon EOS 40D camera (+ 150-mm f/2.8 lens) on 2012 July 16.512 UT. Coordinates (2000.0) R.A. 18 19 37.0 Decl. -19 07 40. Spectra confirm it as a Fe II-type nova close to maximum brightness and as being affected by large interstellar reddening. Details are in IAU CBET 3182 and CBET 3184. Report observations to the AAVSO International Database.

  17. First Radio Detections of Nova V5588 Sgr

    NASA Astrophysics Data System (ADS)

    Krauss, M. I.; Chomiuk, L.; Sokoloski, J. L.; Rupen, M. P.; Mioduszewski, A. J.; Roy, N.; O'Brien, T. J.; Bode, M. F.; Eyres, S. P. S.

    2011-06-01

    The EVLA Nova Team reports the first radio detections of the classical nova V5588 Sgr (IAUC #9203, CBET #2707) with the EVLA. The flux densities were 49.3 ± 9.1 microJy at 5.0 GHz and 69.0 ± 7.5 microJy at 6.8 GHz on 2011 May 15.4, and 394 ± 55 microJy at 33.1 GHz on May 14.5. The spectral index α was 1.1 ± 0.1 (where Sν ∝ ν α), suggesting partially optically thick thermal emission.

  18. Optical photometry and spectroscopy of Nova Del 2013

    NASA Astrophysics Data System (ADS)

    Tomov, T.; Ilkiewicz, K.; Swierczynski, E.; Belcheva, M.; Dimitrov, D.

    2013-08-01

    We report optical BV photometry and spectroscopy of Nova Del 2013, carried out between August 14.88 UT and August 15.08 UT. Using a 60 cm Cassegrain telescope at the Nicolaus Copernicus University Observatory (Torun, Poland) we estimated the V brightness of the Nova to be 6.31+/-0.02 mag and 6.18+/-0.03 mag on Aug. 14.94 UT and Aug. 15.02 UT respectively. HD 194113 (F2, V=8.00 mag) was used as a comparison star.

  19. Nova V2467 Cyg as possible intermediate polar

    NASA Astrophysics Data System (ADS)

    Swierczynski, E.; Ragan, E.; Galan, C.; Mikolajewski, M.

    2008-09-01

    We report the results of 8 nights of unfiltered and RI band CCD photometry of the fast nova V2467Cyg (Nova Cyg 2007). The observations were carried out from 26 June to 8 July 2008 with the 60cm Cassegrain telescope of the Nicolaus Copernicus University Observatory (Torun, Poland). In total we collected 5683 frames during about 20 hours of observations. The magnitudes estimated on July 25.94 UT were B=16.10, V=14.71, R=14.19, I=13.67.

  20. Nova Scotia: late career nurse and new graduate transition.

    PubMed

    Bellefontaine, Pat; Eden, Valerie

    2012-03-01

    Addressing Canada's growing shortage of nurses requires effective strategies for their education, retention and recruitment. Although Nova Scotia produces more than 250 registered nurses and 125 licensed practical nurses each year, some 20% of these graduates leave the province to work elsewhere. The Nova Scotia Research to Action project focused on three retention and recruitment projects: (a) a new-nurse graduate orientation/transition framework, (b) guidelines for nursing mentorship and (c) an online employment tool to assist in the hiring of new nurse graduates. Project partners continue to work collaboratively to advance these provincial initiatives.

  1. A Hubble Space Telescope Survey for Novae in M87. I. Light and Color Curves, Spatial Distributions, and the Nova Rate

    NASA Astrophysics Data System (ADS)

    Shara, Michael M.; Doyle, Trisha F.; Lauer, Tod R.; Zurek, David; Neill, J. D.; Madrid, Juan P.; Mikołajewska, Joanna; Welch, D. L.; Baltz, Edward A.

    2016-11-01

    The Hubble Space Telescope has imaged the central part of M87 over a 10 week span, leading to the discovery of 32 classical novae (CNe) and nine fainter, likely very slow, and/or symbiotic novae. In this first paper of a series, we present the M87 nova finder charts, and the light and color curves of the novae. We demonstrate that the rise and decline times, and the colors of M87 novae are uncorrelated with each other and with position in the galaxy. The spatial distribution of the M87 novae follows the light of the galaxy, suggesting that novae accreted by M87 during cannibalistic episodes are well-mixed. Conservatively using only the 32 brightest CNe we derive a nova rate for M87: {363}-45+33 novae yr-1. We also derive the luminosity-specific classical nova rate for this galaxy, which is {7.88}-2.6+2.3 {{yr}}-1/{10}10 {L}⊙ {,}K. Both rates are 3-4 times higher than those reported for M87 in the past, and similarly higher than those reported for all other galaxies. We suggest that most previous ground-based surveys for novae in external galaxies, including M87, miss most faint, fast novae, and almost all slow novae near the centers of galaxies. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  2. The neon nova. II - Condensation of silicate grains in the ejecta of Nova Vulpeculae 1984 number 2

    NASA Astrophysics Data System (ADS)

    Gehrz, R. D.; Grasdalen, G. L.; Greenhouse, M.; Hackwell, J. A.; Hayward, T.; Bentley, A. F.

    1986-09-01

    Infrared photometry of Nova Vulpeculae 1984 number 2 (NV2) from 2.3 to 19.5 microns during May 14, 1985 to March 31, 1986 shows that silicate grains had condensed and grown in the nova ejecta by August 23, 1985, 240 days after the eruption. A relative overabundance of oxygen in the nova shell seems indicated. Forbidden 12.8-micron Ne II forbidden line emission was a factor of about 41 above the continuum at a spectral resolution of 67 on day 240; the line persisted through day 461. The anomalous chemical composition of NV2's ejecta supports recent suggestions that ONeMg white dwarfs (evolved from 8-12 solar-mass progenitor stars) are accreting matter in binary systems.

  3. 15 CFR 904.102 - Procedures upon receipt of a NOVA.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 3 2014-01-01 2014-01-01 false Procedures upon receipt of a NOVA. 904... PROCEDURES Civil Penalties § 904.102 Procedures upon receipt of a NOVA. (a) The respondent has 30 days from receipt of the NOVA in which to respond. During this time the respondent may: (1) Accept the penalty...

  4. 15 CFR 904.102 - Procedures upon receipt of a NOVA.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Procedures upon receipt of a NOVA. 904... PROCEDURES Civil Penalties § 904.102 Procedures upon receipt of a NOVA. (a) The respondent has 30 days from receipt of the NOVA in which to respond. During this time the respondent may: (1) Accept the penalty...

  5. 15 CFR 719.8 - Filing and service of papers other than the NOVA.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... than the NOVA. 719.8 Section 719.8 Commerce and Foreign Trade Regulations Relating to Commerce and... CONVENTION REGULATIONS ENFORCEMENT § 719.8 Filing and service of papers other than the NOVA. (a) Filing. All... address set forth in the NOVA, or such other place as the ALJ may designate. Filing by United States...

  6. 15 CFR 719.8 - Filing and service of papers other than the NOVA.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... than the NOVA. 719.8 Section 719.8 Commerce and Foreign Trade Regulations Relating to Commerce and... CONVENTION REGULATIONS ENFORCEMENT § 719.8 Filing and service of papers other than the NOVA. (a) Filing. All... address set forth in the NOVA, or such other place as the ALJ may designate. Filing by United States...

  7. 15 CFR 719.8 - Filing and service of papers other than the NOVA.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... than the NOVA. 719.8 Section 719.8 Commerce and Foreign Trade Regulations Relating to Commerce and... CONVENTION REGULATIONS ENFORCEMENT § 719.8 Filing and service of papers other than the NOVA. (a) Filing. All... address set forth in the NOVA, or such other place as the ALJ may designate. Filing by United States...

  8. 15 CFR 904.102 - Procedures upon receipt of a NOVA.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 3 2012-01-01 2012-01-01 false Procedures upon receipt of a NOVA. 904... PROCEDURES Civil Penalties § 904.102 Procedures upon receipt of a NOVA. (a) The respondent has 30 days from receipt of the NOVA in which to respond. During this time the respondent may: (1) Accept the penalty...

  9. 15 CFR 719.8 - Filing and service of papers other than the NOVA.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... than the NOVA. 719.8 Section 719.8 Commerce and Foreign Trade Regulations Relating to Commerce and... CONVENTION REGULATIONS ENFORCEMENT § 719.8 Filing and service of papers other than the NOVA. (a) Filing. All... address set forth in the NOVA, or such other place as the ALJ may designate. Filing by United States...

  10. 15 CFR 719.8 - Filing and service of papers other than the NOVA.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... than the NOVA. 719.8 Section 719.8 Commerce and Foreign Trade Regulations Relating to Commerce and... CONVENTION REGULATIONS ENFORCEMENT § 719.8 Filing and service of papers other than the NOVA. (a) Filing. All... address set forth in the NOVA, or such other place as the ALJ may designate. Filing by United States...

  11. 15 CFR 904.102 - Procedures upon receipt of a NOVA.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Procedures upon receipt of a NOVA. 904... PROCEDURES Civil Penalties § 904.102 Procedures upon receipt of a NOVA. (a) The respondent has 30 days from receipt of the NOVA in which to respond. During this time the respondent may: (1) Accept the penalty...

  12. 15 CFR 904.102 - Procedures upon receipt of a NOVA.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 3 2013-01-01 2013-01-01 false Procedures upon receipt of a NOVA. 904... PROCEDURES Civil Penalties § 904.102 Procedures upon receipt of a NOVA. (a) The respondent has 30 days from receipt of the NOVA in which to respond. During this time the respondent may: (1) Accept the penalty...

  13. NovaNET User Manual for C-Router Instructors. Second Edition Revised.

    ERIC Educational Resources Information Center

    Fortner, Monica B.; Davis, Dennis M.

    The NovaNET computer system is a mainframe system with a large network of users sharing the same computer. This manual is intended to teach instructors how to use the NovaNET system to deliver instruction to their students. The manual is divided into four main sections, each of which teaches a group of skills needed by NovaNET instructors. The…

  14. Cerebral Folate Deficiency

    ERIC Educational Resources Information Center

    Gordon, Neil

    2009-01-01

    Cerebral folate deficiency (CFD) is associated with low levels of 5-methyltetrahydrofolate in the cerebrospinal fluid (CSF) with normal folate levels in the plasma and red blood cells. The onset of symptoms caused by the deficiency of folates in the brain is at around 4 to 6 months of age. This is followed by delayed development, with deceleration…

  15. United Cerebral Palsy

    MedlinePlus

    ... be sure to follow us on Twitter ! Affiliate Network UCP affiliates provide services and support on a community-by-community basis, serving the unique needs of people with disabilities in their region. Find your ... and their networks. Individuals with cerebral palsy and other disabilities deserve ...

  16. Cerebral Palsy (For Teens)

    MedlinePlus

    ... brain is affected and which parts of the body that section of the brain controls. If CP affects both arms and both legs, ... the case of spastic CP) or to help control seizures. And some might have special surgeries to keep their arms or legs straighter and more ... Coping With Cerebral Palsy Puberty can ...

  17. Cerebral Palsy Litigation

    PubMed Central

    Sartwelle, Thomas P.

    2015-01-01

    The cardinal driver of cerebral palsy litigation is electronic fetal monitoring, which has continued unabated for 40 years. Electronic fetal monitoring, however, is based on 19th-century childbirth myths, a virtually nonexistent scientific foundation, and has a false positive rate exceeding 99%. It has not affected the incidence of cerebral palsy. Electronic fetal monitoring has, however, increased the cesarian section rate, with the expected increase in mortality and morbidity risks to mothers and babies alike. This article explains why electronic fetal monitoring remains endorsed as efficacious in the worlds’ labor rooms and courtrooms despite being such a feeble medical modality. It also reviews the reasons professional organizations have failed to condemn the use of electronic fetal monitoring in courtrooms. The failures of tort reform, special cerebral palsy courts, and damage limits to stem the escalating litigation are discussed. Finally, the authors propose using a currently available evidence rule—the Daubert doctrine that excludes “junk science” from the courtroom—as the beginning of the end to cerebral palsy litigation and electronic fetal monitoring’s 40-year masquerade as science. PMID:25183322

  18. The Present Status of the Antigonish Movement in Nova Scotia.

    ERIC Educational Resources Information Center

    Sowder, Ellie Mae

    A comprehensive case study is presented of the Antigonish Movement in eastern Nova Scotia. Originally founded to combat poverty and exploitation, it has functioned since 1929 under the extension department of St. Francis Xavier University, Antigonish. The Movement brought education into the lives of ordinary working people and introduced group…

  19. Late stages in the evolution of classical novae

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Krautter, J.; Sonneborn, G.; Shore, S. N.; Wagner, R. M.; Austin, S.; Saizar, P.; Ferland, G.; Wade, R.; Gehrz, R. D.

    1990-01-01

    We have begun a study of the long term evolution of novae in outburst in order to determine the means by which they return in quiescence when nuclear burning has ended. This project involves both IUE and optical observations and theoretical predictions. Recently, in the initial observational part of this project, we have obtained IUE Short Wavelength Prime (SWP) spectra of GQ Mus 1983 and QU Vul 1984. Each spectrum was a 16 hour exposure using a combined US1 plus Vilspa shift. No novae have been studied in the UV for as long as QU Vul and GQ Mus and observations of their spectral evolution are providing unique data on the turn-off time scale. We have also obtained the spectra of old novae from the IUE archives in order to compare and contrast the existing spectra with those of GQ Mus and Qu Vul. The theoretical prediction is that a nova should be very hot just before turnoff but x ray observations from EXOSAT do not confirm this prediction.

  20. Optical and ultraviolet observations of nova Vul 1987

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Stryker, L. L.; Sonneborn, G.; Sparks, Warren M.; Wagner, R. M.; Ferland, Gary; Gallagher, J. S.; Wade, R.; Williams, R. E.; Gehrz, Robert D.

    1988-01-01

    The outburst for a nova discovered in Nov. 1987 and followed since then is summarized. Although it was possible to observe it with the IUE at maximum, its ultraviolet energy faded rapidly, and after the first 2 weeks it was impossible to observe it at IUE wavelengths. It is observed to form a thick dust shell and is in the nebular stage.

  1. H-alpha confirmation of novae in M31

    NASA Astrophysics Data System (ADS)

    Ovcharov, E.; Nikolov, G.; Kostov, A.; Bozhilov, V.; Minev, M.; Valcheva, A.; Nedialkov, P.

    2015-08-01

    We report H-alpha and BR-band photometry of three objects in M31, suspected as novae. The objects are: PNV J00420640+4108211 = 2015-03a? (ATel# 7189), 2015-07c? (ATel# 7795, ATel #7818) and TCP J00401150+4042199 = 2015-07e? (ATel #7834).

  2. Epidemiology of Lyme Disease, Nova Scotia, Canada, 2002–2013

    PubMed Central

    Johnston, B. Lynn; Schleihauf, Emily; Mask, Angela; Haldane, David; Drebot, Michael; Baikie, Maureen; Cole, Teri J.; Fleming, Sarah; Gould, Richard; Lindsay, Robbin

    2015-01-01

    Ixodes scapularis ticks, which transmit Borrelia burgdorferi, the causative agent of Lyme disease (LD), are endemic to at least 6 regions of Nova Scotia, Canada. To assess the epidemiology and prevalence of LD in Nova Scotia, we analyzed data from 329 persons with LD reported in Nova Scotia during 2002–2013. Most patients reported symptoms of early localized infection with rash (89.7%), influenza-like illness (69.6%), or both; clinician-diagnosed erythema migrans was documented for 53.2%. In a separate serosurvey, of 1,855 serum samples screened for antibodies to B. burgdorferi, 2 were borderline positive (both with an indeterminate IgG on Western blot), resulting in an estimated seroprevalence of 0.14% (95% CI 0.02%–0.51%). Although LD incidence in Nova Scotia has risen sharply since 2002 and is the highest in Canada (16/100,000 population in 2013), the estimated number of residents with evidence of infection is low, and risk is localized to currently identified LD-endemic regions. PMID:26401788

  3. Discovery of a Probable Nova in M31

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Kucakova, H.

    2017-03-01

    We report the discovery of a probable nova in M31 on a co-added 900-s R-band CCD frame taken on 2017 Mar. 1.754 UT with the 0.65-m telescope at Ondrejov. The object designated PNV J00430201+4113190 is located at R.A. = 0h43m02s.01, Decl.

  4. High Speed Photometry and Spectroscopy of Novae at Quiescence

    NASA Astrophysics Data System (ADS)

    Egan, J. M.; Woudt, P. A.; Warner, B.; Williams, R. E.; Steeghs, D. T. H.; Ribeiro, V. A. R. M.

    2014-12-01

    We present spectroscopy of Nova Velorum 1999 (V382 Vel) and Nova Sagittarii 1936c (V630 Sgr) obtained with the Southern African Large Telescope in May and July 2012 as part of our ongoing observing campaign of old novae. The SALT spectrum of V382 Vel is dominated by broad Hα emission associated with the nova shell. The other Balmer lines in the spectrum are narrower and single-peaked, with Hβ at similar line strength as He II 4686Å. The SALT spectrum of V630 Sgr is dominated by He II 4686Å, emission lines are double-peaked (except the lines of the He II Pickering series) and show clear variations in multiple spectra obtained over one-quarter of the binary orbit. Additional high speed photometry of V382 Vel has been obtained in 2012 using the new SHOC photometer of the South African Astronomical Observatory. It shows the emergence of large amplitude quasi-periodic variability with periodicities around ˜ 30 minutes, not seen previously.

  5. 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.

  6. 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.

  7. The Formation of Cataclysmic Variables: The Influence of Nova Eruptions

    NASA Astrophysics Data System (ADS)

    Nelemans, G.; Siess, L.; Repetto, S.; Toonen, S.; Phinney, E. S.

    2016-01-01

    The theoretical and observed populations of pre-cataclysmic variables are dominated by systems with low-mass white dwarfs (WDs), while the WD masses in cataclysmic variables (CVs) are typically high. In addition, the space density of CVs is found to be significantly lower than in the theoretical models. We investigate the influence of nova outbursts on the formation and initial evolution of CVs. In particular, we calculate the stability of the mass transfer in the case where all of the material accreted on the WD is lost in classical novae and part of the energy to eject the material comes from a common-envelope-like interaction with the companion. In addition, we study the effect of an asymmetry in the mass ejection that may lead to small eccentricities in the orbit. We find that a common-envelope-like ejection significantly decreases the stability of the mass transfer, particularly for low-mass WDs. Similarly, the influence of asymmetric mass loss can be important for short-period systems and even more so for low-mass WDs; however, this influence likely disappears long before the next nova outburst due to orbital circularization. In both cases the mass-transfer rates increase, which may lead to observable (and perhaps already observed) consequences for systems that do survive to become CVs. However, a more detailed investigation of the interaction between nova ejecta and the companion and the evolution of slightly eccentric CVs is needed before definite conclusions can be drawn.

  8. Character Sets for PLATO/NovaNET: An Expository Catalog.

    ERIC Educational Resources Information Center

    Gilpin, John B.

    The PLATO and NovaNET computer-based instructional systems use a fixed system character set ("normal font") and an author-definable character set ("alternate font"). The alternate font lets the author construct his own symbols and bitmapped pictures. This expository catalog allows users to determine quickly (1) whether there is…

  9. Maria Helena Novaes--Creative Person, Creative Life

    ERIC Educational Resources Information Center

    de Alencar, Eunice M. L. Soriano

    2014-01-01

    This article describes the characteristics and accomplishments of Maria Helena Novaes, one of the most creative school psychologists of Brazil. It identifies the people who influenced her and some of the factors that may have contributed to her achievements and rise to eminence. It highlights the numerous opportunities she received during her life…

  10. Grassroots Response to HIV/AIDS in Nova Scotia

    ERIC Educational Resources Information Center

    Plumb, Donovan

    2005-01-01

    This chapter describes how by adopting a cultural theory of learning, members of a community-based research team deepened their understanding of the nature, pervasiveness, and contribution of everyday learning processes of people affected by HIV/AIDS in Nova Scotia, Canada.

  11. Hydrodynamic studies of oxygen, neon, and magnesium novae

    NASA Technical Reports Server (NTRS)

    Starrfield, Sumner; Sparks, W. M.; Truran, J. W.

    1987-01-01

    Results are presented from recent theoretical studies that have examined the properties of nova outbursts on ONeMg white dwarfs. These outbursts are much more violent and occur much more frequently than outbursts on CO white dwarfs. Hydrodynamic simulations of both kinds of outbursts are in excellent agreement with the observations.

  12. Non-LTE model atmosphere analysis of Nova Cygni 1992

    NASA Technical Reports Server (NTRS)

    Hauschildt, P. H.; Starrfield, S.; Austin, S.; Wagner, R. M.; Shore, S. N.; Sonneborn, G.

    1994-01-01

    We use spherically symmetric non-local thermodynamic equilibrium (non-LTE), line-blanketed, expanding model atmospheres to analyze the International Ultraviolet Explorer (IUE) and optical spectra of Nova Cygni 1992 during the early phases of its outburst. We find that the first IUE spectrum obtained just after discovery on 1992 February 20, is best reproduced by a model atmosphere with a steep density gradient and homologous expansion, whereas the IUE and optical spectra obtained on February 24 show an extended, optically thick, wind structure. Therefore, we distinguish two phases of the early evolution of the nova photosphere: the initial, rapid, 'fireball' phase and the subsequent, much longer, optically thick 'wind' phase. The importance of line-blanketing in nova spectra is demonstrated. Our preliminary abundance analysis implies that hydrogen is depeleted in the ejecta, corresponding to abundance enhancements of Fe by a factor of approximately 2 and of CNO by more than a factor of 10 when compared to solar abundances. The synthetic spectra reproduce both the observed pseudo-continua as well as most of the observed features from the UV to the optical spectral range and demonstrate the importance of obtaining nearly simultaneous UV and optical spectra for performing accurate analyses of expanding stellar atmospheres (for both novae and supernovae).

  13. Discovery of an Apparent Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Alfaro, M. Diaz; Ordonez-Etxeberria, I.; Vaduvescu, O.

    2015-01-01

    We report the discovery of an apparent nova in M81 on a co-added 1600-s narrow-band H-alpha CCD image taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~2.4" seeing on 2015 Jan. 15.126 UT.

  14. Discovery of a Probable Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Vaduvescu, O.; Mocnik, T.

    2014-09-01

    We report the discovery of a probable nova in M81 on a co-added 1440-s narrow-band H-alpha CCD image taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~2.2" seeing on 2014 Sep.

  15. Discovery of a Probable Nova in M33

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Vaduvescu, O.; Tudor, V.

    2014-08-01

    We report the discovery of a probable nova in M33 on co-added 960-s narrow-band H-alpha and 480-s R-band CCD images taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~1.1" seeing on 2014 July 29.206 and 29.222 UT, respectively.

  16. Discovery of a Possible Nova in M31

    NASA Astrophysics Data System (ADS)

    Maehara, Hiroyuki

    2016-11-01

    We report the discovery of a possible nova in M31 on V-band CCD images taken on 2016-11-12.372 UT with the 1.05-m Schmidt telescope and KWFC (Sako et al. 2012, SPIE, 8446, 84466L) at Kiso Observatory, the University of Tokyo.

  17. The γ-ray sources in classical novae

    NASA Astrophysics Data System (ADS)

    Sun, Weichao; Zhu, Chunhua; Wang, Zhaojun; Lü, Guoliang

    2016-08-01

    The interaction between novae ejecta and accretion disks or circumbinary (CB) disks surrounding nova systems based on the diffusive shock acceleration (DSA) mechanism are investigated. Results suggest that interaction between the novae ejecta and CB disks most probably produce γ-rays. Both leptonic and hadronic scenarios can feasibly produce γ-rays in CB disks. A grid is calculated in order to discuss the γ-ray sources in classical novae (CNe), and results indicated that the mass of a white dwarf and the orbit period in CNe can greatly affect the production of γ-rays. According to the proposed grid and synthesis population method, it is estimated that the percentage of CNe that can produce γ-rays ranges from approximately 0.17 % to 51 % for leptonic scenarios when the magnetic field strength in the shock region ranges from 0.005 G to 0.02 G. The occurrence rate of γ-ray CNe ranges from approximately 1 yr^{-1} to 27 yr^{-1} in the galaxy. The corresponding percentage ranges from approximately 64 % to 97 % in hadronic scenarios, while the occurrence rate of γ-ray CNe ranges from approximately 35 yr^{-1} to 52 yr^{-1} in the galaxy.

  18. UK Nova/Supernova Patrol - the first 25 years

    NASA Astrophysics Data System (ADS)

    Hurst, G. M.

    2003-06-01

    The text of the Presidential Address delivered at 23 Savile Row, London W1 on 2002 October 30. The challenge of this Presidential Address is to compress the events of the first 25 years of the UK Nova/Supernova Patrol into a talk lasting for about an hour. When the patrol began as a formal search programme all that time ago, I had no idea just how much would be achieved and I feel quite humble in presenting the results as the coordinator when the real work has been carried out by all those dedicated observers over the years, whether looking for novae with binoculars or those now employing the latest technology to detect extragalactic supernovae. I will describe how and why the patrol started in 1976, including earlier events that persuaded key individuals that the time had come for a team approach to searching for novae. The aims of the patrol will be discussed and how these have changed over the years, which has necessitated some rethinking of the techniques employed. Naturally the patrol discoveries will be discussed in detail, but also the vital follow-up work on novae and supernovae, such as light curve analysis, which can produce valuable scientific information for the professional community. Indeed the patrol's work has generated excellent professional-amateur liaison as each side has helped the other to increase our understanding of these somewhat elusive objects, which suddenly burst into view in the night sky.

  19. Cambridge Health's outreach earns alliance an AHA NOVA Award.

    PubMed

    Rees, Tom

    2005-01-01

    Cambridge Health Alliance, (CHA), Somerville, Mass., has been named for one of the five NOVA Awards given this year by the American Hospital Association. It is recognized for leading a program to improve community health by extending help to low-income and uninsured children and adults, as well as to the chronically ill and racial and ethnic minorities.

  20. NOvA: Building a Next Generation Neutrino Experiment

    ScienceCinema

    Perko, John; Williams, Ron; Miller, Bill

    2016-07-12

    The NOvA neutrino experiment is searching for the answers to some of the most fundamental questions of the universe. This video documents how collaboration between government research institutions like Fermilab, academia and industry can create one of the largest neutrino detectors in the world.

  1. Discovery of a Possible Nova in M31

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Wolf, M.

    2016-10-01

    We report the discovery of a possible nova in M31 on a co-added 1080-s R-band CCD frame taken on 2016 Oct. 7.758 UT with the 0.65-m telescope at Ondrejov. The object designated PNV J00420668+4105113 is located at R.A. = 0h42m06s.68, Decl.

  2. A Long Term High-Cadence Nova Survey

    NASA Astrophysics Data System (ADS)

    Castelaz, Michael W.; Rottler, L.; Barker, T.; Coker, M.

    2014-01-01

    We have initiated a nova survey that uses a previously unstudied long term high cadence archive data set covering about 1/3 of the sky to 1) improve on the number and recurrence frequency of recurrent novae (RNe), and 2) permit an investigation of the puzzling and diverse set of features in classical novae (CNe) and RNe light curves. RNe are of great astrophysical interest because they have long been considered to be the prime candidates for progenitors of Type Ia supernovae. However, the recurrence time scale is not well known, but is an essential parameter determining whether any RNe become Type Ia supernovae. Novae exhibit a wide variety of light curves with features like pre-eruption rises and dips, flat-tops at peak, and flares superimposed on decline, for example. These features are poorly understood. The answers require more and better light curves. The data set our team is using to address RNe occurrence and light curves was taken in the 1950’s over a nearly 9 year period with two Baker Super-Schmidt telescopes 80 km apart in New Mexico, resulting in 42,000 photographic images. Each telescope had a 52 degree field of view. Images to a limiting stellar magnitude of 13 were taken at a rate of 2-3 per hour sampling a total of one-third of the entire sky. A similar data set does not exist anywhere else, nor is one planned with such high cadence and field of view. We are digitizing the films and through a data pipeline plan to identify candidate RNe and new CNe enhancing the number of known RNe and creating light curves leading up to and following novae eruptions. We will describe the digitizing process and data pipeline, and initial results from the first 1,600 films that we have surveyed.

  3. The Ghostly Novae of Spirits: Candidates, Confirmations, and Classifications

    NASA Astrophysics Data System (ADS)

    Corgan, David William

    2015-08-01

    The SPIRITS (SPitzer InfraRed Intensive Transients Survey) project has surveyed 242 galaxies across multiple epochs for over a year, searching for gap transient and variable star activity. To date, a wealth of candidate objects has been discovered in the warm Spitzer data being used, with the current total at 1426 individual detections. The discovery, confirmation, follow-up, and comparison to prediction rates of these candidates is presented. Employing subjective detection methods, discussed herein, individual discovery to group confirmation rates were found to be less than 3.6%. Photometric confirmation with correlated team instruments left 53 sources of interest remaining for further study. These targets ranged across 30 different galaxies including IC2163, Messier 101, and NGC3198. Follow-up ground observations in the 1.2, 1.6, and 2.2 µm wavelengths with the legacy 2MASS instrument at MLOF (Mount Lemmon Observing Facility) are highlighted. The data reduction process which has evolved to improve detections by ~.6mag is also detailed. These results are supplemented by SPIRITS team input from a variety of world-class infrared facilities to produce overall nova candidate characteristics, which are included. In some cases this extends to light curves from confirmed and observed novae to depths of ~20mag, while in others it is restricted to limiting magnitudes of ~18 at sight of occurrence (the true “ghosts” of SPIRITS). Candidate novae have been separated into classes where data allows, including the possible discovery of a new variable type coined SMIRTS (Super Massive InfraRed TransientS), and probable members of the elusive Luminous Red Novae category. Finally, comparison of numerical survey results to nova prediction rates is undertaken and results presented. Where deviations from luminosity curve fittings occur, such as in the overly active M81 and IC0342 galaxies, possible causes are proposed.

  4. The Emission Line Spectrum of Nova Sagittarius 1993 IN the 35-DAY after Maximum

    NASA Astrophysics Data System (ADS)

    Lawson, W. A.; James, S. D.

    1994-07-01

    We report spectroscopic observations of Nova Sgr 1993, obtained between 20 and 35 d after maximum light following the outburst in 1993 September. We compile published spectra along with our observations to determine the spectroscopic evolution of the nova. On the Tololo classification system, the object appears to have evolved from a `Fe ii class' nova to an `He/N class' nova within 20 d after maximum. [Fe iii lines appeared within 34 d. The likely evolutionary sequence in the first 35 d is either Pfe,heN? or Pfe,nN?. The uncertainty in the classification is due to a lack of spectral coverage. Photometric observations indicate the nova to have faded on a time-scale t3 of 33 d, and a flux distribution increasingly dominated by Ha emission inthefirst40 d. Key words: stars: individual: Nova Sgr 1993 - novae, cataclysmic variables.

  5. Johannes Hevelius, nova CK Vulpeculae (1670) and the "hibernation" model of cataclysmic variables.

    NASA Astrophysics Data System (ADS)

    Smak, J.

    The author reviews the basic properties of cataclysmic variables and the thermonuclear runaway (TNR) theory of the outbursts of novae, including the "hibernation" model of cataclysmic variables. The TNR theory, while remarkably successful in explaining a number of observational properties of novae, met also with some difficulties related to (1) excessive mass-transfer rates in old novae, and (2) conflicting estimates of their space density. Both are estimated from absolute magnitudes of novae as observed within decades before, or after, their outbursts. Nova CK Vulpeculae (1670), the oldest recorded nova, was observed in 1670 - 1672 by Hevelius, whose observations - together with those by Anthelme and Cassini - were sufficiently numerous and accurate to permit a modern reconstruction of the light curve and its classification as a very slow nova.

  6. 78 FR 7850 - Notice of Availability of Finding of No Significant Impact for the Proposed NOVA Chemicals Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ... of Availability of Finding of No Significant Impact for the Proposed NOVA Chemicals Inc. Line 20... of the Department of State's Finding of No Significant Impact on the proposed NOVA Chemicals Inc... other non-gaseous fuels to or from a foreign country. NOVA Chemicals Inc. (NOVA) has applied to...

  7. Managing Malignant Cerebral Infarction

    PubMed Central

    Sahuquillo, Juan; Sheth, Kevin N.; Kahle, Kristopher T.; Walcott, Brian P.

    2011-01-01

    Opinion statement Managing patients with malignant cerebral infarction remains one of the foremost challenges in medicine. These patients are at high risk for progressive neurologic deterioration and death due to malignant cerebral edema, and they are best cared for in the intensive care unit of a comprehensive stroke center. Careful initial assessment of neurologic function and of findings on MRI, coupled with frequent reassessment of clinical and radiologic findings using CT or MRI are mandatory to promote the prompt initiation of treatments that will ensure the best outcome in these patients. Significant deterioration in either neurologic function or radiologic findings or both demand timely treatment using the best medical management, which may include osmotherapy (mannitol or hypertonic saline), endotracheal intubation, and mechanical ventilation. Under appropriate circumstances, decompressive craniectomy may be warranted to improve outcome or to prevent death. PMID:21190097

  8. High Altitude Cerebral Edema

    DTIC Science & Technology

    1986-03-01

    English literature and Hultgren et al (3.1) described four more cases of HAPE within the next year. In 1960, Chiodi (5) first reported on a Peruvian...altitude and treatment with steroids and diuretics, CSF pressure was 85 mm H 0. In 1960, Chiodi .(5) described a patient 2 suffering with HACE who...Biol. Chem., 157, 297-302, 1945. 5. Chiodi H: "Mal de montana a forma cerebral; possible mecanismo etiopathogenico," An. Fac. Med. Lima., 43, 437

  9. Primary cerebral malignant melanoma

    PubMed Central

    Tang, Kai; Kong, Xiangyi; Mao, Gengsheng; Qiu, Ming; Zhu, Haibo; Zhou, Lei; Nie, Qingbin; Xu, Yi; Du, Shiwei

    2017-01-01

    Abstract Primary intracranial melanomas are uncommon and constitute approximately 1% of all melanoma cases and 0.07% of all brain tumors. In nature, these primary melanomas are very aggressive and can spread to other organs. We report an uncommon case of primary cerebral malignant melanoma—a challenging diagnosis guided by clinical presentations, radiological features, and surgical biopsy results, aiming to emphasize the importance of considering primary melanoma when making differential diagnoses of intracranial lesions. We present a rare case of a primary cerebral melanoma in the left temporal lobe. The mass appeared iso-hypodense on brain computed tomography (CT), short signal on T1-weighted magnetic resonance images (T1WI) and long signal on T2WI. It was not easy to make an accurate diagnosis before surgery. We showed the patient's disease course and reviewed related literatures, for readers’ reference. Written informed consent was obtained from the patient for publication of this case report and any accompanying images. Because of this, there is no need to conduct special ethic review and the ethical approval is not necessary. After surgery, the pathological examination confirmed the diagnosis of melanoma. The patient was discharged without any complications and went on to receive adjuvant radiochemotherapy. It is difficult to diagnose primary cerebral melanoma in the absence of any cutaneous melanosis. A high index of clinical suspicion along with good pathology reporting is the key in diagnosing these extremely rare tumors. PMID:28121927

  10. Molecular pathophysiology of cerebral edema

    PubMed Central

    Gerzanich, Volodymyr; Simard, J Marc

    2015-01-01

    Advancements in molecular biology have led to a greater understanding of the individual proteins responsible for generating cerebral edema. In large part, the study of cerebral edema is the study of maladaptive ion transport. Following acute CNS injury, cells of the neurovascular unit, particularly brain endothelial cells and astrocytes, undergo a program of pre- and post-transcriptional changes in the activity of ion channels and transporters. These changes can result in maladaptive ion transport and the generation of abnormal osmotic forces that, ultimately, manifest as cerebral edema. This review discusses past models and current knowledge regarding the molecular and cellular pathophysiology of cerebral edema. PMID:26661240

  11. Molecular pathophysiology of cerebral edema.

    PubMed

    Stokum, Jesse A; Gerzanich, Volodymyr; Simard, J Marc

    2016-03-01

    Advancements in molecular biology have led to a greater understanding of the individual proteins responsible for generating cerebral edema. In large part, the study of cerebral edema is the study of maladaptive ion transport. Following acute CNS injury, cells of the neurovascular unit, particularly brain endothelial cells and astrocytes, undergo a program of pre- and post-transcriptional changes in the activity of ion channels and transporters. These changes can result in maladaptive ion transport and the generation of abnormal osmotic forces that, ultimately, manifest as cerebral edema. This review discusses past models and current knowledge regarding the molecular and cellular pathophysiology of cerebral edema.

  12. Condições físicas do disco de acréscimo da nova-anã V4140 SGR

    NASA Astrophysics Data System (ADS)

    Borges, B.; Baptista, R.

    2003-08-01

    Discos de acréscimo são aparatos cósmicos que permitem que matéria seja eficientemente acrescida sobre uma fonte compacta pela remoção de momento angular via tensões viscosas enquanto transforma a energia potencial gravitacional em calor e, posteriormente, em radiação. Sistemas binários semi-ligados, como Variáveis Cataclísmicas (VCs) não-magnéticas, são talvez os melhores ambientes encontrados para o estudo da física desses discos de acréscimo. O desenvolvimento de técnicas de imageamento indireto, como o mapeamento por eclipses (MME) e a tomografia Doppler, permitiu avanços importantes na compreensão da física dos processos de acréscimo desses sistemas. V4140 Sagitarii é uma VC eclipsante de curto período orbital (~ 90 min) que não havia sido classificada como nova-anã ou polar. Neste trabalho apresentamos a análise do mapeamento por eclipse feito com dados de fotometria CCD nas bandas B, V e R de V4140 Sgr realizada no LNA. O objeto foi observado no declínio de erupção em julho de 1992 e em erupção em julho de 2001, isso indicou a classificação do sistema como uma nova-anã. A análise, feita sobre os mapas já apresentados em trabalho anterior, apresenta (i) diagrama cor-cor, que indica uma emissão opticamente espessa nas partes internas do disco em quiescência (R < RL1); (ii) diagrama cor-magnitude, usado para inferir uma distância de 600 +/- 10 pc ao sistema; (iii) a distribuição radial de temperatura observada que concorda com a lei de disco espesso em estado estacionário TµR-3/4, com temperaturas em torno de 10000 K e 3000 K ns partes internas e externas do disco em quiescência, respectivamente; (iv) a evolução da distribuição de temperatura no declínio de erupção; (v) estimativa da transferência de massa de 109.9+/-0.1 M¤/ano em quiescência, similar àquelas observadas em novas-like. O sistema é comparado à outras novas-anãs (e.g. OY Car e Z Cha) em quiescência e erupção, mostrando-se tratar um

  13. Nova Sagittarii 2012 No. 3 = PNV J17522579-2126215

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2012-07-01

    Nova Sagittarii 2012 No. 3 = PNV J17522579-212621 was discovered independently by: Koichi Itagaki (Yamagata, Japan, reported by Hitoshi Yamaoka, Kyushu University), Yukio Sakurai (Mito, Ibaraki-ken, Japan). Discovery Magnitude: Itagaki (magnitude 10.3 on an unfiltered CCD image taken with a 0.21-m reflector), Sakurai (magnitude 9.9 on four 20-s frames taken with a Fuji FinePix S2 Digital Camera + Nikon 180-mm f/2.8 lens). Discovery date: Itagaki (2012 June 26.5494 UT), Sakurai (2012 June 26.540 UT). Coordinates (2000.0) from Itagaki (R.A. 17 52 25.79 Dec. -21 26 21.5), from Sakurai (R.A. 17 52 25.59 Dec. -21 26 22.9). Spectra confirm the object as a He/N type nova. All details and image URLs are in IAU CBET 3156. Report observations to the AAVSO International Database.

  14. Seroepidemiology of Q fever among domestic animals in Nova Scotia.

    PubMed Central

    Marrie, T J; Van Buren, J; Fraser, J; Haldane, E V; Faulkner, R S; Williams, J C; Kwan, C

    1985-01-01

    We used the indirect microimmunofluorescence test to determine the presence of antibodies in sheep, cattle, goat, cat, and dog sera to phase I and II Coxiella burnetii antigens in Nova Scotia. Only 6.7 per cent of the 329 sheep tested had antibodies to phase II antigen and none had antibodies to phase I. Of 29 goats tested, 7 per cent and 3.5 per cent had antibodies to phase II and phase I antigens, respectively. In contrast, 23.8 per cent of the 214 cattle tested had antibodies to phase II antigen, and 24.2 per cent had antibodies to phase I antigen; 24.1 per cent of 216 cats tested had antibodies to phase II antigen and 6 per cent had antibodies to phase I antigen. None of the 447 dogs tested had antibodies detected. We conclude that cattle and cats may be reservoirs for human Q fever in Nova Scotia. PMID:3890569

  15. Nova Centauri 2013 = PNV J13544700-5909080

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-12-01

    Announces the discovery of V1369 Cen = Nova Cen 2013 = PNV J13544700-5909080 by John Seach (Chatsworth Island, NSW, Australia) at unfiltered magnitude 5.5 on 2013 December 02.692 UT. Low-resolution spectra obtained by Locke on Dec. 03.3776 UT and by Kaufman on Dec. 03.621 UT show strong Ha and Hb emission lines, indicating the object is a nova. Announced on IAU CBAT Central Bureau Electronic Telegram 3732 (Daniel W. E. Green, ed.). Finder charts with sequences may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations.

  16. PW Vul: A classical nova with nearly solar abundances

    SciTech Connect

    Saizar, P.; Ferland, G.J.; Wagner, R.M. . Dept. of Astronomy); Austin, S. . Dept. of Physics); Starrfield, S. . Dept. of Physics Los Alamos National Lab., NM Colorado Univ., Boulder, CO . IUE Regional Data Analysis Facility); Truran, J.W. . Dept.

    1990-01-01

    Ultraviolet and optical spectrophotometric data were combined in order to determine the physical parameters in the expanding shell of Nova PW Vul 1984 No. 1. Ultraviolet data were obtained with the IUE satellite from August 2, 1984 (a few days after discovery) until it became too faint to study with the satellite. The last IUE exposure was obtained in June 1988 but we have continued to follow it with ground-based optical telescopes. We will present a plot that shows the variation of electron density and temperature as a function of time. Analysis of the emission line intensities show that the abundances of this very slow nova are solar for helium, carbon, and oxygen while nitrogen is 50 times solar. We have also used the CLOUDY code of Ferland to model the emission line intensities and find very good agreement with the observations. We shall display plots of representative IUE and optical spectra. 10 refs., 5 figs.

  17. A multiwavelength study of Nova QU Vulpeculae 1984

    NASA Technical Reports Server (NTRS)

    Saizar, Pedro; Starrfield, Sumner; Ferland, Gary J.; Wagner, R. M.; Truran, James W.; Kenyon, Scott J.; Sparks, Warren M.; Williams, Robert E.; Stryker, L. L.

    1992-01-01

    We have combined ground-based optical and satellite ultraviolet spectrophotometric data to study the ejected shell of Nova Vulpecula 1984 No. 2 (QU Vul). Substantial uncertainties concerning the nature of the ionizing continuum, and the role played by density inhomogeneities, now exist. Because of these uncertainties, the chemical composition is deduced from emission-line pairs chosen to minimize the effects of variations in temperature, density, and ionization. We find that the chemical composition of the ejected shell show enhancements of several elements relative to hydrogen, namely, He, N, O, Ne, Mg, Al, and Si, as is expected for an outburst occurring on an ONeMg white dwarf. It is also shown that QU Vul ejected a large amount of aluminum into the interstellar medium, and it is estimated that only a small fraction of slow novae of this type can account for the observed abundance of aluminum in the Galaxy.

  18. Observational and theoretical studies of the nova outburst

    SciTech Connect

    Starrfield, S.; Vanlandingham, K.; Schwarz, G.

    1998-04-01

    A nova outburst is one consequence of the accretion of hydrogen rich material onto a white dwarf in a close binary system. The strong electron degeneracy of a massive white dwarf drives the temperatures in the nuclear burning region to values exceeding 108K under all circumstances. As a result, a major fraction of the CNO nuclei in the envelope are transformed into e{sup +}-decay nuclei, which constrains the nuclear energy generation and yields non-solar CNO isotopic abundance ratios. In addition, the observations demonstrate that white dwarf core material is dredged up into the accreted layers and these nuclei are the catalysts for producing peak rates of energy generation that can exceed 10{sup 16} erg gm{sup -1}s{sup -1}. Observations show that there are two compositional classes of novae, one that occurs on a carbon-oxygen white dwarf and the other that occurs on an oxygen-neon-magnesium white dwarf.

  19. Black Hole X-ray Nova in M31

    NASA Astrophysics Data System (ADS)

    Murray, Steven

    2005-09-01

    During A02-6 we found more than a dozen Black Hole X-ray Novae (BHXN) in M31 using Chandra, and with HST (WF/PC2 and ACS) found >6 potential optical counterparts. We propose to continue this program, with the goals of understanding the behavior of BH and neutron star (NS) X-ray nova in our nearest neighbor galaxy. With sufficient numbers of optical counterparts we will be able to determine the orbital period distribution of BHXN in M31. Uninterrupted monitoring of M31 is necessary to investigate the duty cycles and long-term lightcurves of BHXN (and other variables) in M31, and only Chandra can provide this. By continuing the program though AO10 we will amass nearly 500ks on the bulge of M31, giving the most detailed view of a nearby galaxy possible until Gen-X.

  20. VERITAS OBSERVATIONS OF THE NOVA IN V407 CYGNI

    SciTech Connect

    Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Bouvier, A.; Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R.; Benbow, W.; Bradbury, S. M.; Byrum, K.; Cannon, A.; Collins-Hughes, E.; Cesarini, A.; Connolly, M. P.; Ciupik, L.; Cui, W.; Decerprit, G.; Duke, C. E-mail: kazuma-tsurusaki@uiowa.edu; and others

    2012-07-20

    We report on very high energy (E > 100 GeV) gamma-ray observations of V407 Cygni, a symbiotic binary that underwent a nova outburst producing 0.1-10 GeV gamma rays during 2010 March 10-26. Observations were made with the Very Energetic Radiation Imaging Telescope Array System during 2010 March 19-26 at relatively large zenith angles due to the position of V407 Cyg. An improved reconstruction technique for large zenith angle observations is presented and used to analyze the data. We do not detect V407 Cygni and place a differential upper limit on the flux at 1.6 TeV of 2.3 Multiplication-Sign 10{sup -12} erg cm{sup -2} s{sup -1} (at the 95% confidence level). When considered jointly with data from Fermi-LAT, this result places limits on the acceleration of very high energy particles in the nova.

  1. VERITAS Observations of the Nova in V407 Cygni

    NASA Technical Reports Server (NTRS)

    Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Beilicke, M.; Benbow, W.; Bouvier, A.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.; Ciupik, L.; Collins-Hughes, E.; Connolly, M. P.; Cui, W.; Decerprit, G.; Dickherber, R.; Perkins, J. S.

    2012-01-01

    We report on very high energy (E > 100 GeV) gamma-ray observations of V407 Cygni, a symbiotic binary that underwent a nova outburst producing 0.1- 10 GeV gamma rays during 2010 March 10-26. Observations were made with the Very Energetic Radiation Imaging Telescope Array System during 2010 March 19-26 at relatively large zenith angles, due to the position of V407 Cyg. An improved reconstruction technique for large zenith angle observations is presented and used to analyze the data. We do not detect V407 Cygni and place a differential upper limit on the flux at 1.6 TeV of 2.3 10(exp -12) erg/sq cm/s (at the 95% confidence level). When considered jointly with data from Fermi-LAT, this result places limits on the acceleration of very high energy particles in the nova.

  2. Life after eruption - IV. Spectroscopy of 13 old novae

    NASA Astrophysics Data System (ADS)

    Tappert, C.; Vogt, N.; Della Valle, M.; Schmidtobreick, L.; Ederoclite, A.

    2014-07-01

    We present data on 13 post-nova systems. This includes the recovery via UBVR photometry of the five post-novae X Cir, V2104 Oph, V363 Sgr, V928 Sgr and V1274 Sgr and their spectroscopic confirmation. We provide accurate coordinates and finding charts for those objects. Additional first-time or improved spectroscopic data are presented for V356 Aql, V500 Aql, V604 Aql, V1370 Aql, MT Cen, V693 CrA, V697 Sco and MU Ser. Investigating the behaviour of a few easily accessible parameters yields (limited) information on the accretion state and the system inclination. We predict that X Cir and V697 Sco are likely to reveal their orbital period via time series photometry and that long-term photometric monitoring of V356 Aql, V500 Aql, V1370 Aql and X Cir has a good chance of discovering outburst-like behaviour in these systems.

  3. A transient radio jet in an erupting dwarf nova.

    PubMed

    Körding, Elmar; Rupen, Michael; Knigge, Christian; Fender, Rob; Dhawan, Vivek; Templeton, Matthew; Muxlow, Tom

    2008-06-06

    Astrophysical jets seem to occur in nearly all types of accreting objects, from supermassive black holes to young stellar objects. On the basis of x-ray binaries, a unified scenario describing the disc/jet coupling has evolved and been extended to many accreting objects. The only major exceptions are thought to be cataclysmic variables: Dwarf novae, weakly accreting white dwarfs, show similar outburst behavior to x-ray binaries, but no jet has yet been detected. Here we present radio observations of a dwarf nova in outburst showing variable flat-spectrum radio emission that is best explained as synchrotron emission originating in a transient jet. Both the inferred jet power and the relation to the outburst cycle are analogous to those seen in x-ray binaries, suggesting that the disc/jet coupling mechanism is ubiquitous.

  4. Three-dimensional simulations of Nova capsule implosion experiments

    SciTech Connect

    Marinak, M.M.; Tipton, R.E.; Landen, O.L.

    1995-11-01

    Capsule implosion experiments carried out on the Nova laser are simulated with the three-dimensional HYDRA radiation hydrodynamics code. Simulations of ordered near single mode perturbations indicate that structures which evolve into round spikes can penetrate farthest into the hot spot. Bubble-shaped perturbations can burn through the capsule shell fastest, however, causing even more damage. Simulations of a capsule with multimode perturbations shows spike amplitudes evolving in good agreement with a saturation model during the deceleration phase. The presence of sizable low mode asymmetry, caused either by drive asymmetry or perturbations in the capsule shell, can dramatically affect the manner in which spikes approach the center of the hot spot. Three-dimensional coupling between the low mode shell perturbations intrinsic to Nova capsules and the drive asymmetry brings the simulated yields into closer agreement with the experimental values.

  5. Nova laser system at ultra high fluence levels

    SciTech Connect

    Hunt, J.T.

    1985-01-01

    The Nova experimental facility consists of a ten arm laser system and five experimental stations and was completed in December 1984. Two of these stations are used for inertial confinement fusion (ICF) experiments and the other three are dedicated to doing large aperture (30 to 74 cm) laser experiments. The laser system is deployed in a master oscillator-power amplifier architecture and uses Nd: phosphate glass for the active medium. The fundamental wavelength of the system is 1.05 microns. Frequency converters constructed from potassium dihydrogen phosphate (KDP) crystals are located at the end of each of the ten arms and are used to produce high power frequency doubled (0.53 microns) and tripled (0.35 microns) beams for either ICF or laser experiments. Thus, the Nova laser system can produce high power beams with wavelengths ranging from the infrared to the ultraviolet.

  6. A Dynamical Study of the Eclipsing Nova OY ARA

    NASA Astrophysics Data System (ADS)

    Zhao, P.; McClintock, J. E.

    1996-12-01

    We present the results of a dynamical study of the classical nova OY Ara. Photometric and spectroscopic observations of the object were carried out at CTIO. OY Ara is an eclipsing system with an orbital period of 0.155466 +/- 0.000003 days. The radial velocity semiamplitude of the H_alpha emission line is 118 +/- 9 km s(-1) . A dynamical analysis shows that the primary and the secondary have masses of M_1 ~ 0.85 Msun and M_2 ~ 0.34 Msun, respectively, assuming that the secondary is a main sequence star. We also find that the accretion disk of OY Ara is 4-7 magnitudes more luminous than the disk of X-ray novae, presumably due to the much higher rate of mass transfer occurring in OY Ara.

  7. NON-EQUIPARTITION OF ENERGY, MASSES OF NOVA EJECTA, AND TYPE Ia SUPERNOVAE

    SciTech Connect

    Shara, Michael M.; Yaron, Ofer; Prialnik, Dina; Kovetz, Attay

    2010-04-01

    The total masses ejected during classical nova (CN) eruptions are needed to answer two questions with broad astrophysical implications: can accreting white dwarfs be 'pushed over' the Chandrasekhar mass limit to yield type Ia supernovae? Are ultra-luminous red variables a new kind of astrophysical phenomenon, or merely extreme classical novae? We review the methods used to determine nova ejecta masses. Except for the unique case of BT Mon (nova 1939), all nova ejecta mass determinations depend on untested assumptions and multi-parameter modeling. The remarkably simple assumption of equipartition between kinetic and radiated energy (E {sub kin} and E {sub rad}, respectively) in nova ejecta has been invoked as a way around this conundrum for the ultra-luminous red variable in M31. The deduced mass is far larger than that produced by any CN model. Our nova eruption simulations show that radiation and kinetic energy in nova ejecta are very far from being in energy equipartition, with variations of 4 orders of magnitude in the ratio E {sub kin}/E {sub rad} being commonplace. The assumption of equipartition must not be used to deduce nova ejecta masses; any such 'determinations' can be overestimates by a factor of up to 10,000. We data-mined our extensive series of nova simulations to search for correlations that could yield nova ejecta masses. Remarkably, the mass ejected during a nova eruption is dependent only on (and is directly proportional to) E {sub rad}. If we measure the distance to an erupting nova and its bolometric light curve, then E {sub rad} and hence the mass ejected can be directly measured.

  8. A theoretical study of problems in classical nova evolution

    SciTech Connect

    Shankar, A.

    1990-01-01

    Three distinct issues in classical nova evolution are addressed with the aid of one- and two-dimensional numerical hydrodynamics. The effects of convection on nova outbursts are examined within the confines of the mixing length theory. It is found that increasing the efficiency of convection enhances the violence of the thermonuclear runaway (TNR). This also relates to the question of the feasibility of obtaining nova outbursts on magnetic white dwarfs among the AM Her systems. The effects of a strong magnetic field on the TNR are explored. The field interferes with the development of convection during the TNR, which results in lower ejection velocities. However, for field strengths typical of cataclysmic variables, the violence of strong outbursts is affected only moderately. The conditions necessary for the production of strong TNR's in the hibernation model of cataclysmic binary evolution are also examined. The feasibility of obtaining strong nova outbursts is investigated when the accretion rate during hibernation is decreased. It is found that a reduction (by a factor of 100) for periods of longer than a couple thousand years, is sufficient to ensure violent outbursts, even in the presence of large pre-outburst accretion rates. The effects of a common envelope phase (CEP) on the outburst are discussed. The motion of the secondary through an expanding common envelope is resisted by frictional drag. This dissipates both energy and angular momentum from the orbit inducing hydrodynamic motion. Significant departures are found to occur in the manner in which mass is lost when the effects of drag are taken into account. Specifically, a CEP is found to accelerate and enhance mass loss. Ejection is found to be concentrated in the orbital plane, with velocities of a few thousand km/sec.

  9. Shocks in nova outflows - II. Synchrotron radio emission

    NASA Astrophysics Data System (ADS)

    Vlasov, Andrey; Vurm, Indrek; Metzger, Brian D.

    2016-11-01

    The discovery of GeV gamma-rays from classical novae indicates that shocks and relativistic particle acceleration are energetically key in these events. Further evidence for shocks comes from thermal keV X-ray emission and an early peak in the radio light curve on a time-scale of months with a brightness temperature which is too high to result from freely expanding photoionized gas. Paper I developed a one-dimensional model for the thermal emission from nova shocks. This work concluded that the shock-powered radio peak cannot be thermal if line cooling operates in the post-shock gas at the rate determined by collisional ionization equilibrium. Here we extend this calculation to include non-thermal synchrotron emission. Applying our model to three classical novae, we constrain the amplification of the magnetic field ɛB and the efficiency ɛe of accelerating relativistic electrons of characteristic Lorentz factor γ ˜ 100. If the shocks are radiative (low velocity vsh ≲ 1000 km s-1) and cover a large solid angle of the nova outflow, as likely characterize those producing gamma-rays, then values of ɛe ˜ 0.01-0.1 are required to achieve the peak radio brightness for ɛB = 10-2. Such high efficiencies exclude secondary pairs from pion decay as the source of the radio-emitting particles, instead favouring the direct acceleration of electrons at the shock. If the radio-emitting shocks are instead adiabatic (high velocity), as likely characterize those responsible for the thermal X-rays, then much higher brightness temperatures are possible, allowing the radio-emitting shocks to cover a smaller outflow solid angle.

  10. Discovery of a possible nova in M81

    NASA Astrophysics Data System (ADS)

    Williams, S. C.; Darnley, M. J.

    2016-10-01

    We report the discovery of a new nova candidate in M81 on 3 & times; 300s H & alpha; images taken using IO:O on the 2m Liverpool Telescope (Steele et al. 2004) on 2016 Oct 8.25 UT. The position of the new transient is RA = 9h55m17.035s, Dec. = +69 & deg;06'31.69" (J2000).

  11. Compton Observatory OSSE Studies of Supernovae and Novae

    DTIC Science & Technology

    1995-01-01

    Washington DC 20024 ABSTRACT A primary objective of the Compton Observatory is the direct study of explo- sive nucleosynthesis in supernovae and classical...our best chance to detect -rays from 22Na, a unique nucleosynthesis byproduct of the explosive hydrogen burning thought to power classical novae. The...radio, x-ray), or might go into PdV work. As for the last two e ects in the list, we doubt, based on straightforward nucleosynthesis arguments,9 that

  12. Optical and ultraviolet observations of Nova Vul 1987

    SciTech Connect

    Starrfield, S.; Stryker, L.L.; Sonneborn, G.; Sparks, W.M.; Wagner, R.M.; Ferland, G.; Gallagher, J.S.; Wade, R.; Williams, R.E.; Gehrz, R.D.

    1988-01-01

    We present a brief summary of the outburst for a nova that was discovered in November 1987 and has been followed since that time. Although we were able to observe it with the IUE at maximum, its ultraviolet energy faded rapidly and after the first two weeks we were no longer able to observe it at IUE wavelengths. It was observed to form a thick dust shell and currently is in the nebular stage. 6 figs.

  13. {beta}-decay of {sup 23}Al and nova nucleosynthesis

    SciTech Connect

    Saastamoinen, A.; Jokinen, A.; Aeystoe, J.; Trache, L.; Hardy, J. C.; Iacob, V. E.; McCleskey, M.; Roeder, B.; Simmons, E.; Tabacaru, G.; Tribble, R. E.; Banu, A.; Bentley, M. A.; Jenkins, D. G.; Davinson, T.; Woods, P. J.

    2010-11-24

    We have studied the {beta}-decay of {sup 23}Al with a novel detector setup at the focal plane of the MARS separator at the Texas A and M University to resolve existing controversies about the proton intensities of the IAS in {sup 23}Mg and to determine the absolute proton branching ratios by combining our results to the latest {gamma}-decay data. Experimental technique, results and the relevance for nova nucleosynthesis are discussed.

  14. A possible pre-nova detection for ATLAS16crq

    NASA Astrophysics Data System (ADS)

    Kuin, Paul

    2016-09-01

    The optical transient ATLAS16crq (Tonry et al. ATEL #9492) was identified by Chomiuk et al. (ATEL #9511) as a fst Galactic He/N nova. In the recently released Gaia DR1 there is a source at a distance of the coordinates given by Tonry et al. (ATEL #9492) of 1.2 arcsec with a Gaia G magnitude G=20.13, six magnitudes fainter than the discovery magnitude of 14.19.

  15. Reconnection-driven oscillations in dwarf nova disks

    NASA Technical Reports Server (NTRS)

    Tajima, T.; Gilden, D.

    1987-01-01

    A class of oscillations observed during eruption of dwarf novae has been interpreted as oscillations of the accretion disks in these systems.These oscillations are quasi-periodic with coherence times typically between three and 15 cycles. It is shown that magnetic field reconnection at high magnetic Reynolds number can drive disk oscillations. The expected stochastic geometry of disk magnetic fields could naturally produce the observed phase incoherency.

  16. Optical observations of the fast nova V2491 Cyg

    NASA Astrophysics Data System (ADS)

    Tomov, T.; Mikolajewski, M.; Ragan, E.; Swierczynski, E.; Wychudzki, P.

    2008-04-01

    We report on optical spectral observations and UBVRI brightness estimations obtained with 60/90 cm Schmidt and 60 cm Cassegrain telescopes of the Nicolaus Copernicus University Observatory (Torun, Poland). The nova V2491 Cyg was discovered on Apr. 10.728 UT with about 7.7 mag on unfiltered CCD frames (IAUC#8934). Additionally, the X-ray emission was detected for the prenova several months ago (ATel#1473).

  17. CATALOG OF 93 NOVA LIGHT CURVES: CLASSIFICATION AND PROPERTIES

    SciTech Connect

    Strope, Richard J.; Schaefer, Bradley E.; Henden, Arne A.

    2010-07-15

    We present a catalog of 93 very-well-observed nova light curves. The light curves were constructed from 229,796 individual measured magnitudes, with the median coverage extending to 8.0 mag below peak and 26% of the light curves following the eruption all the way to quiescence. Our time-binned light curves are presented in figures and as complete tabulations. We also calculate and tabulate many properties about the light curves, including peak magnitudes and dates, times to decline by 2, 3, 6, and 9 mag from maximum, the time until the brightness returns to quiescence, the quiescent magnitude, power-law indices of the decline rates throughout the eruption, the break times in this decline, plus many more properties specific to each nova class. We present a classification system for nova light curves based on the shape and the time to decline by 3 mag from the peak (t{sub 3}). The designations are 'S' for smooth light curves (38% of the novae), 'P' for plateaus (21%), 'D' for dust dips (18%), 'C' for cusp-shaped secondary maxima (1%), 'O' for quasi-sinusoidal oscillations superposed on an otherwise smooth decline (4%), 'F' for flat-topped light curves (2%), and 'J' for jitters or flares superposed on the decline (16%). Our classification consists of this single letter followed by the t{sub 3} value in parentheses; so, for example, V1500 Cyg is S(4), GK Per is O(13), DQ Her is D(100), and U Sco is P(3).

  18. Hubble Space Telescope Eclipse Observations of the Nova Like Cataclysmic Variable UX Ursae Majoris

    NASA Technical Reports Server (NTRS)

    Knigge, Christian; Long, Knox S.; Wade, Richard A.; Baptista, Raymundo; Horne, Keith; Hubeny, Ivan; Rutten, Rene G. M.

    1998-01-01

    We present and analyze Hubble Space Telescope observations of the eclipsing nova-like cataclysmic variable UX UMa obtained with the Faint Object Spectrograph. Two eclipses each were observed with the G160L grating (covering the ultraviolet waveband) in 1994 August and with the PRISM (covering the near-ultraviolet to near-infrared) in November of the same year. The system was about 50% brighter in November than in August, which, if due to a change in the accretion rate, indicates a fairly substantial increase in Mass accretion by about 50%. The eclipse light curves are qualitatively consistent with the gradual occultation of an accretion disk with a radially decreasing temperature distribution. The light curves also exhibit asymmetries about mideclipse that are likely due to a bright spot at the disk edge. Bright-spot spectra have been constructed by differencing the mean spectra observed at pre- and posteclipse orbital phases. These difference spectra contain ultraviolet absorption lines and show the Balmer jump in emission. This suggests that part of the bright spot may be optically thin in the continuum and vertically extended enough to veil the inner disk and/or the outflow from UX UMa in some spectral lines. Model disk spectra constructed as ensembles of stellar atmospheres provide poor descriptions of the observed posteclipse spectra, despite the fact that UX UMa's light should be dominated by the disk at this time. Suitably scaled single temperature model stellar atmospheres with T(sub eff) approximately equals 12,500-14,500 K actually provide a better match to both the ultraviolet and optical posteclipse spectra. Evidently, great care must be taken in attempts to derive accretion rates from comparisons of disk models to observations. One way to reconcile disk models with the observed posteclipse spectra is to postulate the presence of a significant amount of optically thin material in the system. Such an optically thin component might be associated with the

  19. X-ray observations of dwarf nova outbursts

    NASA Astrophysics Data System (ADS)

    Wheatley, P.

    Dwarf novae are semi-detached binary stars in which a white dwarf accretes material lost by a red dwarf. Accretion occurs via an accretion disk which is apparently unstable, resulting in dramatic optical outbursts (systems typically brighten by a factor 100). Dwarf nova outbursts occur infrequently (weeks to years) and unpredictably, making them difficult targets for most astronomical observatories. Consequently our understanding is based largely on optical monitoring by amateur astronomers, and observations at other wavelengths are rare and usually sketchy. While optical photometry does provide a good probe of the outer accretion disk, most of the accretion luminosity is liberated in X-rays and the EUV in the inner accretion disk and at its boundary with the white dwarf. High-energy observations allow us to study the response of these inner regions to the varying accretion rate through the outburst cycle. In this talk I review recent X-ray observations of dwarf nova outbursts. RXTE has played an extremely important role in this field because it is the only X-ray observatory with sufficient scheduling flexibility to respond rapidly to outbursts and to make frequent monitoring observations.

  20. Simulations of NOVA direct-drive hydrodynamics experiments

    SciTech Connect

    Weber, S.V,; Glendinning, S.G.

    1991-04-15

    Directly driven Rayleigh-Taylor instability growth experiments being performed on NOVA have been simulated using the computer code, LASNEX. Foils with single-wavelength imposed surface perturbations have been driven with a single beam of 0.53 {mu}m light, employing smoothing by spectral dispersion (SSD). In addition to simulating foils with imposed surface perturbations, we have simulated flat foils driven by beams with time-dependent intensity modulation resulting from the NOVA implementation of SSD. These simulations show the development of large amplitude modulation of the target from residual intensity nonuniformities. Structure seeded by beam nonuniformity would overwhelm modulation resulting from imposed surface perturbations of sub-micron initial amplitude, but is predicted to develop sufficiently slowly that we expect to observe growth of perturbations with initial amplitudes of several microns. In other NOVA experiments, flat foils with an embedded brominated spectroscopic tracer layer are used in infer mass ablation rates. SSD drive is predicted to yield ablation rates in better agreement with 1-D simulations than drive from a beam with random phase plates (RPP) alone. Simulations of foils driven with RPP beams show enhanced ablation rates because modulation of the ablation front increases its surface area. Line emission from the seed is first seen at cold spots in the beam, which create protruding spikes at the ablation front. Simulation results will be compared with early experimental data. 5 refs., 14 figs.

  1. Nova Sagittarii 2014 = PNV J18250860-2236024 AND Erratum

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2014-02-01

    Details of discovery of Nova Sagittarii 2014 (PNV J18250860-2236024) and procedures for observing and reporting observations are announced. Discovered by Sigeru Furuyama (Tone-machi, Ibaraki-ken, Japan) andreported by S. Nakano (Sumoto, Japan) at unfiltered CCD magnitude 8.7 on 2014 Jan. 26.857 UT. Coordinates: R.A. 18 25 08.60 Decl. = -22 36 02.4 (2000.0). Nova Sgr 2014 is Fe II-type classical nova past maximum, per low-resolution spectra obtained by A. Arai on 2014 Jan. 30.87 UT. Announced in IAU CBAT CBET 3802 (D. W. E. Green, ed.). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations. Also, an Erratum is reported. In AAVSO Alert Notice 496, Mati Morel (MMAT, Thornton, NSW, Australia) was credited with the discovery of the 1989 outburst of V745 Sco. The discoverer was William Liller (LIW, Vina del Mar, Chile), who observed V745 Sco on 1989 July 30.08 UT at magnitude 9.7 (PROBLICOM discovery using 2415 film with orange filter).

  2. Long-term evolution of dwarf nova outbursts

    NASA Astrophysics Data System (ADS)

    Schreiber, M. R.

    We present results from fine mesh calculations of the long-term evolution of the accretion disk in the outburst cycle of dwarf novae. In order to include realistic variations of the mass transfer rate from the secondary we used the long-term light curve of AM Herculis. In this magnetic CV the luminosity of the system is directly linked to the mass transfer rate. As apart from different illumination effects there is no obvious reason for a different behaviour of the secondary in a nonmagnetic system, the binary parameter and the mass transfer rate of AM Herculis were applied to a fictitious nonmagnetic dwarf nova system. We considered masses between 1 M_odot and 0.6 M_odot because the precise value of the mass of the primary in AM Herc ulis is still unknown. The resulting light curve of the model with 1 M_odot indicates that it could be possible to reconstruct the mass transfer rate from light curves of dwarf novae. We used a combined FE-FD grid to calculate the time-evolution of the accretion disk and discuss the results of this method in the context of other f ine mesh computations that appeared in the literature.

  3. Intial performance from the NOvA surface prototype detector

    SciTech Connect

    Muether, M.; /Fermilab

    2011-09-01

    NOvA, the NuMI Off-Axis {nu}{sub e} Appearance experiment, will study {nu}{sub {mu}} {yields} {nu}{sub e} oscillations characterized by the mixing angle {Theta}{sub 13}. Provided {Theta}{sub 13} is large enough, NOvA may ultimately determine the ordering of the neutrino masses and measure CP violation in neutrino oscillations. A complementary pair of detectors will be constructed {approx}14 mrad off beam axis to optimize the energy profile of the neutrinos. This system consists of a surface based 14 kTon liquid scintillator tracking volume located 810 km from the main injector source (NuMI) in Ash River, Minnesota and a smaller underground 222 Ton near detector at the Fermilab. The first neutrino signals at the Ash River Site are expected prior to the 2012 accelerator shutdown. In the meantime, a near detector surface prototype has been completed and neutrinos from two Fermilab sources have been observed using the same highly segmented PVC and liquid scintillator detector system that will be deployed in the full scale experiment. Design and initial performance characteristics of this prototype system are being fed back into the design for the full NOvA program.

  4. Disk irradiation and light curves of x ray novae

    NASA Technical Reports Server (NTRS)

    Kim, S.-W.; Wheeler, J. C.; Mineshige, S.

    1994-01-01

    We study the disk instability and the effect of irradiation on outbursts in the black hole X-ray nova system. In both the optical and soft X-rays, the light curves of several X-ray novae, A0620-00, GH 2000+25, Nova Muscae 1991 (GS 1124-68), and GRO J0422+32, show a main peak, a phase of exponential decline, a secondary maximum or reflare, and a final bump in the late decay followed by a rapid decline. Basic disk thermal limit cycle instabilities can account for the rapid rise and overall decline, but not the reflare and final bump. The rise time of the reflare, about 10 days, is too short to represent a viscous time, so this event is unlikely to be due to increased mass flow from the companion star. We explore the possibility that irradiation by X-rays produced in the inner disk can produce these secondary effects by enhancing the mass flow rate within the disk. Two plausible mechanisms of irradiation of the disk are considered: direct irradiation from the inner hot disk and reflected radiation from a corona or other structure above the disk. Both of these processes will be time dependent in the context of the disk instability model and result in more complex time-dependent behavior of the disk structure. We test both disk instability and mass transfer burst models for the secondary flares in the presence of irradiation.

  5. SOFIA/FORCAST Grism Spectra of Classical Novae

    NASA Astrophysics Data System (ADS)

    Gehrz, Robert D.; Evans, Aneurin; Woodward, Charles E.; Helton, L. A.; SOFIA Target of Opportunity Nova Team

    2016-01-01

    Classical novae (CNe), thermonuclear runaways (TNRs) that occur on the surfaces of white dwarfs (WDs) that are accreting matter in close binary systems, participate in the cycle of Galactic chemical evolution by ejecting gas and dust into the interstellar medium (ISM) where it is incorporated into new generations of stars and planetary systems. SOFIA FORCAST infrared (IR) spectroscopy of dust emission features and metallic forbidden line emission can be used to determine metal abundances in CN ejecta. The objective of these observations is to establish the degree to which CNe can contribute to ISM abundance anomalies. We summarize existing evidence that some recent bright CNe have ejected shells that are extremely overabundant in CNO, Ne, Mg, Al, and Si. IR spectroscopy of the recent bright CNe V339 Del and Sgr 2015#2, obtained under our SOFIA CN Target of Opportunity (ToO) Program are presented. Strong hydrogen recombination lines dominated the spectrum of V339 Del 27 days after outburst. The nucleation and maximum grain growth phases of a dust formation event were observed in Nova Sgr 2105 #2. Expectations for future observations of classical novae with SOFIA are anticipated.

  6. An evaluation of Nova Scotia's alcohol ignition interlock program.

    PubMed

    Vanlaar, Ward G M; Mainegra Hing, Marisela; Robertson, Robyn D

    2017-03-01

    Alcohol ignition interlock programs for offenders aim to reduce recidivism among convicted drink drivers. This study presents an evaluation of Nova Scotia's interlock program implemented in 2008 in order to assess its effectiveness to reduce impaired driving and to help identify areas for improvement. Data used include conviction and crash records of individual participants; provincial monthly counts of alcohol-related charges, convictions and fatal and serious crashes; and interlock logged events. Methods used include descriptive statistics, survival analysis, time series and logistic regression analysis. With respect to specific deterrence (i.e., preventing recidivism) there was a 90% reduction in recidivism among voluntary participants since participation in the interlock program and a 79% reduction after these participants exited from the program. With respect to general deterrence (i.e., referring to a preventative effect on the entire population of drivers in Nova Scotia) there were temporary decreases in the numbers of alcohol-related charges (13.32%) and convictions (9.93%) and a small significant decrease in the number of fatal and serious injury alcohol-related crashes, following the implementation of the program. The evidence suggests the interlock program was better at preventing harm due to alcohol-impaired driving than the alternative of not using the interlock program. Recommendations were formulated supporting the continuation of the interlock program in Nova Scotia.

  7. Middle Cerebral Artery Calcification

    PubMed Central

    Kao, Hung-Wen; Liou, Michelle; Chung, Hsiao-Wen; Liu, Hua-Shan; Tsai, Ping-Huei; Chiang, Shih-Wei; Chou, Ming-Chung; Peng, Giia-Sheun; Huang, Guo-Shu; Hsu, Hsian-He; Chen, Cheng-Yu

    2015-01-01

    Abstract Calcification of the middle cerebral artery (MCA) is uncommon in the healthy elderly. Whether calcification of the MCA is associated with cerebral ischemic stroke remains undetermined. We intended to investigate the association using Agatston calcium scoring of the MCA. This study retrospectively included 354 subjects with ischemic stroke in the MCA territory and 1518 control subjects who underwent computed tomography (CT) of the brain. We recorded major known risk factors for ischemic stroke, including age, gender, hypertension, diabetes mellitus, smoking, hyperlipidemia, and obesity, along with the MCA calcium burden, measured with the Agatston calcium scoring method. Univariate and modified logistic regression analyses were performed to examine the association between the MCA calcification and ischemic stroke. The univariate analyses showed significant associations of ischemic stroke with age, hypertension, diabetes mellitus, smoking, total MCA Agatston score, and the presence of calcification on both or either side of the MCA. Subjects with the presence of MCA calcification on both or either side of the MCA were 8.46 times (95% confidence interval, 4.93–14.53; P < 0.001) more likely to have a cerebral infarct than subjects without MCA calcification after adjustment for the major known risk factors, including age, hypertension, diabetes mellitus, and smoking. However, a higher degree of MCA calcification reflected by the Agatston score was not associated with higher risk of MCA ischemic stroke after adjustment for the confounding factors and presence of MCA calcification. These results suggest that MCA calcification is associated with ischemic stroke in the MCA territory. Further prospective studies are required to verify the clinical implications of the MCA calcification. PMID:26683969

  8. The dusty nova V1065 centauri (nova cen 2007) : a spectroscopic analysis of abundances and dust properties.

    SciTech Connect

    Helton, L. A.; Woodward, C. E.; Walter, F. M.; Vanlandingham, K.; Schwarz, G. J.; Evans, A.; Ness, J.-U.; Geballe, T. R.; Gehrz, R. D.; Greenhouse, M.; Krautter, J.; Liller, W.; Lynch, D. K.; Rudy, R. J.; Shore, S. N.; Starrfield, S.; Truran, J.

    2010-10-14

    We examine the ejecta evolution of the classical nova V1065 Centauri, constructing a detailed picture of the system based on spectrophotometric observations obtained from 9 to approximately 900 days post-outburst with extensive coverage from optical to mid-infrared wavelengths. We estimate a reddening toward the system of E(B-V) = 0.5 {+-} 0.1, based upon the B-V color and analysis of the Balmer decrement, and derive a distance estimate of 8.7{sub -2.1}{sup +2.8} kpc. The optical spectral evolution is classified as P{sub fe}{sup o} N{sub ne}A{sub 0} according to the CTIO Nova Classification system of Williams et al. Photoionization modeling yields absolute abundance values by number, relative to solar of He/H = 1.6 {+-} 0.3, N/H = 144 {+-} 34, O/H = 58 {+-} 18, and Ne/H = 316 {+-} 58 for the ejecta. We derive an ejected gas mass of M{sub g} = (1.6 {+-} 0.2) x 10{sup -4} M{circle_dot}. The infrared excess at late epochs in the evolution of the nova arises from dust condensed in the ejecta composed primarily of silicate grains. We estimate a total dust mass, Md , of order (0.2-3.7) x 10{sup -7} M{circle_dot}, inferred from modeling the spectral energy distribution observed with the Spitzer IRS and Gemini-South GNIRS spectrometers. Based on the speed class, neon abundance, and the predominance of silicate dust, we classify V1065 Cen as an ONe-type classical nova.

  9. Resting cerebral blood flow

    PubMed Central

    Ances, B M.; Sisti, D; Vaida, F; Liang, C L.; Leontiev, O; Perthen, J E.; Buxton, R B.; Benson, D; Smith, D M.; Little, S J.; Richman, D D.; Moore, D J.; Ellis, R J.

    2009-01-01

    Objective: HIV enters the brain soon after infection causing neuronal damage and microglial/astrocyte dysfunction leading to neuropsychological impairment. We examined the impact of HIV on resting cerebral blood flow (rCBF) within the lenticular nuclei (LN) and visual cortex (VC). Methods: This cross-sectional study used arterial spin labeling MRI (ASL-MRI) to measure rCBF within 33 HIV+ and 26 HIV− subjects. Nonparametric Wilcoxon rank sum test assessed rCBF differences due to HIV serostatus. Classification and regression tree (CART) analysis determined optimal rCBF cutoffs for differentiating HIV serostatus. The effects of neuropsychological impairment and infection duration on rCBF were evaluated. Results: rCBF within the LN and VC were significantly reduced for HIV+ compared to HIV− subjects. A 2-tiered CART approach using either LN rCBF ≤50.09 mL/100 mL/min or LN rCBF >50.09 mL/100 mL/min but VC rCBF ≤37.05 mL/100 mL/min yielded an 88% (29/33) sensitivity and an 88% (23/26) specificity for differentiating by HIV serostatus. HIV+ subjects, including neuropsychologically unimpaired, had reduced rCBF within the LN (p = 0.02) and VC (p = 0.001) compared to HIV− controls. A temporal progression of brain involvement occurred with LN rCBF significantly reduced for both acute/early (<1 year of seroconversion) and chronic HIV-infected subjects, whereas rCBF in the VC was diminished for only chronic HIV-infected subjects. Conclusion: Resting cerebral blood flow (rCBF) using arterial spin labeling MRI has the potential to be a noninvasive neuroimaging biomarker for assessing HIV in the brain. rCBF reductions that occur soon after seroconversion possibly reflect neuronal or vascular injury among HIV+ individuals not yet expressing neuropsychological impairment. GLOSSARY AEH = acute/early HIV infection; ANOVA = analysis of variance; ASL-MRI = arterial spin labeling MRI; CART = classification and regression tree; CBF = cerebral blood flow; CH = chronic HIV

  10. Oligodendrogenesis after cerebral ischemia

    PubMed Central

    Zhang, Ruilan; Chopp, Michael; Zhang, Zheng Gang

    2013-01-01

    Neural stem cells in the subventricular zone (SVZ) of the lateral ventricle of adult rodent brain generate oligodendrocyte progenitor cells (OPCs) that disperse throughout the corpus callosum and striatum where some of OPCs differentiate into mature oligodendrocytes. Studies in animal models of stroke demonstrate that cerebral ischemia induces oligodendrogenesis during brain repair processes. This article will review evidence of stroke-induced proliferation and differentiation of OPCs that are either resident in white matter or are derived from SVZ neural progenitor cells and of therapies that amplify endogenous oligodendrogenesis in ischemic brain. PMID:24194700

  11. Cerebral Disorders of Calves.

    PubMed

    Dore, Vincent; Smith, Geof

    2017-03-01

    Neurologic diseases of the cerebrum are relatively common in cattle. In calves, the primary cerebral disorders are polioencephalomalacia, meningitis, and sodium toxicity. Because diagnostic testing is not always readily available, the practitioner must often decide on a course of treatment based on knowledge of the likely disease, as well as his or her own clinical experience. This is particularly true with neurologic diseases in which the prognosis is often poor and euthanasia may be the most humane outcome. This article reviews the most common diseases affecting the cerebrum of calves with a focus on pathophysiology, diagnosis, and treatment.

  12. Rapid accretion and hibernation in the preoutburst history of classical novae

    SciTech Connect

    Prialnik, D.; Shara, M.M.

    1986-12-01

    A new nova evolution model is used to resolve the apparent discrepancy between the observed mass accretion rate (MAR) in prenovae and in old novae and the theoretical upper limit to the MAR which yields a thermonuclear runaway. The model offers a plausible disguise state for very old novae as well as unifying links between old novae, novalike variables, and dwarf novae. The model predicts that mass transfer must cease in a cataclysmic binary a few centuries after eruption, remain off for millennia, and then resume. The effects of such long-term variability of MAR on a white dwarf are studied, and the implications of the results for the long-term evolution of novae and related catalysmic binaries are discussed. 32 references.

  13. The impact of IUE on studies of the nova outburst: 1986--1990

    SciTech Connect

    Starrfield, S. . Dept. of Physics Los Alamos National Lab., NM )

    1990-01-01

    In this review I will concentrate on the improvements in our understanding of the nova outburst that have occurred since the IUE meetings in London in 1986 and Goddard in 1988 and those results that have occurred as a direct result of studies with the IUE satellite. These involve the four outbursts that have occurred in the LMC, the numerous recurrent novae outbursts, and a number of archival studies. As a direct result of IUE studies done since 1986, we can now state that fast novae become super-Eddington at maximum, that many novae decline at the same rate, and that neon novae may be more numerous than thought previously. In addition, we have found that there are differences in the outburst characteristics between novae with giant secondaries and those with compact secondaries. 18 refs., 11 figs., 1 tab.

  14. UBVJHKLM photometry and low-resolution spectroscopy of Nova Delphini 2013 (V339 Del)

    NASA Astrophysics Data System (ADS)

    Burlak, M. A.; Esipov, V. F.; Komissarova, G. V.; Shenavrin, V. I.; Taranova, O. G.; Tatarnikov, A. M.; Tatarnikova, A. A.

    We present UBVJHKLM photometric observations of Nova Delphini 2013 that started several hours before maximum light and lasted for 130 nights. Using the obtained data, we derived several photometric parameters of the Nova: the time of maximum light, brightness at maximum, rate of decline, t2=11 d. This places Nova Del 2013 among fast novae according to the classification introduced by Payne-Gaposchkin. We estimated the interstellar reddening E(B-V) = 0.18 using maps of Galactic extinction and the absolute brightness in maximum light via the MMRD relation that allowed us to determine the distance D≈ 2.7 kpc and height above the Galactic plane z≈ 440 pc. Low-resolution spectroscopy shows that Nova Del 2013 belongs to the Fe II spectral type of novae. The broad emission feature near 6825 Å observed during 2013 August and September may be the Raman-scattered O VI 1032 Å line.

  15. Fermi-LAT detection of the Galactic nova TCP J18102829-2729590

    NASA Astrophysics Data System (ADS)

    Li, Kwan-Lok; Chomiuk, Laura

    2016-11-01

    Fermi-LAT detection of the Galactic nova TCP J18102829-2729590 Following the discovery of the nova in Sagittarius TCP J18102829-2729590 (CBAT 2016 10 20.383; ATel #9658), we triggered an one-week Fermi ToO (observation number: 090603-1-1; PI: Laura Chomiuk) from 2016-10-25 as part of our Fermi-LAT monitoring campaign for Galactic novae (ATel #9311).

  16. THE INTER-ERUPTION TIMESCALE OF CLASSICAL NOVAE FROM EXPANSION OF THE Z CAMELOPARDALIS SHELL

    SciTech Connect

    Shara, Michael M.; Mizusawa, Trisha; Zurek, David; Martin, Christopher D.; Neill, James D.; Seibert, Mark

    2012-09-10

    The dwarf nova Z Camelopardalis is surrounded by the largest known classical nova shell. This shell demonstrates that at least some dwarf novae must have undergone classical nova eruptions in the past, and that at least some classical novae become dwarf novae long after their nova thermonuclear outbursts. The current size of the shell, its known distance, and the largest observed nova ejection velocity set a lower limit to the time since Z Cam's last outburst of 220 years. The radius of the brightest part of Z Cam's shell is currently {approx}880 arcsec. No expansion of the radius of the brightest part of the ejecta was detected, with an upper limit of {<=}0.17 arcsec yr{sup -1}. This suggests that the last Z Cam eruption occurred {>=}5000 years ago. However, including the important effect of deceleration as the ejecta sweeps up interstellar matter in its snowplow phase reduces the lower limit to 1300 years. This is the first strong test of the prediction of nova thermonuclear runaway theory that the interoutburst times of classical novae are longer than 1000 years. The intriguing suggestion that Z Cam was a bright nova, recorded by Chinese imperial astrologers in October-November 77 B.C.E., is consistent with our measurements. If Z Cam was indeed the nova of 77 B.C.E. we predict that its ejecta are currently expanding at 85 km s{sup -1}, or 0.11 arcsec yr{sup -1}. Detection and measurement of this rate of expansion should be possible in just a few years.

  17. Voloshina I.B., Metlov V.G., Shugarov S.Yu., Golovin A.V., Antoniuk O.I. Positive and Negative Superhumps of the Dwarf Nova MN Dra

    NASA Astrophysics Data System (ADS)

    Samsonov, D. A.; Pavlenko, E. P.; Andreev, M. V.; Sklyanov, A.; Zubareva, A. M.

    2010-12-01

    We present the result of O-C analysis of the dwarf nova MN Dra. It is based on the multi-site photometric observations that were made over 77 nights in August - November, 2009. The total exposure was 433 hours. During this time binary underwent two superoutbursts and five normal outbursts. In superoutbursts the positive superhumps decreased with extremely large P = -(3 - 8) x 10-4 for SU UMa-like dwarf novae, confirming the known behavior of MN Dra in 2003. MN Dra displayed large-amplitude (up to 1.4m in quiescence and 0.1m-0.2m in normal outbursts) negative superhumps. The improved value of negative superhump period is 0.095952(4) d.

  18. Cerebral Gluconeogenesis and Diseases

    PubMed Central

    Yip, James; Geng, Xiaokun; Shen, Jiamei; Ding, Yuchuan

    2017-01-01

    The gluconeogenesis pathway, which has been known to normally present in the liver, kidney, intestine, or muscle, has four irreversible steps catalyzed by the enzymes: pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose 1,6-bisphosphatase, and glucose 6-phosphatase. Studies have also demonstrated evidence that gluconeogenesis exists in brain astrocytes but no convincing data have yet been found in neurons. Astrocytes exhibit significant 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 activity, a key mechanism for regulating glycolysis and gluconeogenesis. Astrocytes are unique in that they use glycolysis to produce lactate, which is then shuttled into neurons and used as gluconeogenic precursors for reduction. This gluconeogenesis pathway found in astrocytes is becoming more recognized as an important alternative glucose source for neurons, specifically in ischemic stroke and brain tumor. Further studies are needed to discover how the gluconeogenesis pathway is controlled in the brain, which may lead to the development of therapeutic targets to control energy levels and cellular survival in ischemic stroke patients, or inhibit gluconeogenesis in brain tumors to promote malignant cell death and tumor regression. While there are extensive studies on the mechanisms of cerebral glycolysis in ischemic stroke and brain tumors, studies on cerebral gluconeogenesis are limited. Here, we review studies done to date regarding gluconeogenesis to evaluate whether this metabolic pathway is beneficial or detrimental to the brain under these pathological conditions. PMID:28101056

  19. Cerebral cartography and connectomics

    PubMed Central

    Sporns, Olaf

    2015-01-01

    Cerebral cartography and connectomics pursue similar goals in attempting to create maps that can inform our understanding of the structural and functional organization of the cortex. Connectome maps explicitly aim at representing the brain as a complex network, a collection of nodes and their interconnecting edges. This article reflects on some of the challenges that currently arise in the intersection of cerebral cartography and connectomics. Principal challenges concern the temporal dynamics of functional brain connectivity, the definition of areal parcellations and their hierarchical organization into large-scale networks, the extension of whole-brain connectivity to cellular-scale networks, and the mapping of structure/function relations in empirical recordings and computational models. Successfully addressing these challenges will require extensions of methods and tools from network science to the mapping and analysis of human brain connectivity data. The emerging view that the brain is more than a collection of areas, but is fundamentally operating as a complex networked system, will continue to drive the creation of ever more detailed and multi-modal network maps as tools for on-going exploration and discovery in human connectomics. PMID:25823870

  20. Cerebral hyperperfusion syndrome.

    PubMed

    van Mook, Walther N K A; Rennenberg, Roger J M W; Schurink, Geert Willem; van Oostenbrugge, Robert Jan; Mess, Werner H; Hofman, Paul A M; de Leeuw, Peter W

    2005-12-01

    Cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy is characterised by ipsilateral headache, hypertension, seizures, and focal neurological deficits. If not treated properly it can result in severe brain oedema, intracerebral or subarachnoid haemorrhage, and death. Knowledge of CHS among physicians is limited. Most studies report incidences of CHS of 0-3% after carotid endarterectomy. CHS is most common in patients with increases of more than 100% in perfusion compared with baseline after carotid endarterectomy and is rare in patients with increases in perfusion less than 100% compared with baseline. The most important risk factors in CHS are diminished cerebrovascular reserve, postoperative hypertension, and hyperperfusion lasting more than several hours after carotid endarterectomy. Impaired autoregulation as a result of endothelial dysfunction mediated by generation of free oxygen radicals is implicated in the pathogenesis of CHS. Treatment strategies are directed towards regulation of blood pressure and limitation of rises in cerebral perfusion. Complete recovery happens in mild cases, but disability and death can occur in more severe cases. More information about CHS and early institution of adequate treatment are of paramount importance in order to prevent these potentially severe complications.

  1. Cerebral cartography and connectomics.

    PubMed

    Sporns, Olaf

    2015-05-19

    Cerebral cartography and connectomics pursue similar goals in attempting to create maps that can inform our understanding of the structural and functional organization of the cortex. Connectome maps explicitly aim at representing the brain as a complex network, a collection of nodes and their interconnecting edges. This article reflects on some of the challenges that currently arise in the intersection of cerebral cartography and connectomics. Principal challenges concern the temporal dynamics of functional brain connectivity, the definition of areal parcellations and their hierarchical organization into large-scale networks, the extension of whole-brain connectivity to cellular-scale networks, and the mapping of structure/function relations in empirical recordings and computational models. Successfully addressing these challenges will require extensions of methods and tools from network science to the mapping and analysis of human brain connectivity data. The emerging view that the brain is more than a collection of areas, but is fundamentally operating as a complex networked system, will continue to drive the creation of ever more detailed and multi-modal network maps as tools for on-going exploration and discovery in human connectomics.

  2. Monitoring of cerebral autoregulation.

    PubMed

    Czosnyka, Marek; Miller, Chad

    2014-12-01

    Pressure autoregulation is an important hemodynamic mechanism that protects the brain against inappropriate fluctuations in cerebral blood flow in the face of changing cerebral perfusion pressure (CPP). Static autoregulation represents how far cerebrovascular resistance changes when CPP varies, and dynamic autoregulation represents how fast these changes happen. Both have been monitored in the setting of neurocritical care to aid prognostication and contribute to individualizing CPP targets in patients. Failure of autoregulation is associated with a worse outcome in various acute neurological diseases. Several studies have used transcranial Doppler ultrasound, intracranial pressure (ICP with vascular reactivity as surrogate measure of autoregulation), and near-infrared spectroscopy to continuously monitor the impact of spontaneous fluctuations in CPP on cerebrovascular physiology and to calculate derived variables of autoregulatory efficiency. Many patients who undergo such monitoring demonstrate a range of CPP in which autoregulatory efficiency is optimal. Management of patients at or near this optimal level of CPP is associated with better outcomes in traumatic brain injury. Many of these studies have utilized the concept of the pressure reactivity index, a correlation coefficient between ICP and mean arterial pressure. While further studies are needed, these data suggest that monitoring of autoregulation could aid prognostication and may help identify optimal CPP levels in individual patients.

  3. Cerebral sinus venous thrombosis

    PubMed Central

    Alvis-Miranda, Hernando Raphael; Milena Castellar-Leones, Sandra; Alcala-Cerra, Gabriel; Rafael Moscote-Salazar, Luis

    2013-01-01

    Cerebral sinus venous thrombosis (CSVT) is a rare phenomenon that can be seen with some frequency in young patients. CSVT is a multifactorial condition with gender-related specific causes, with a wide clinical presentation, the leading causes differ between developed and developing countries, converting CSVT in a condition characterized by a highly variable clinical spectra, difficult diagnosis, variable etiologies and prognosis that requires fine medical skills and a high suspicious index. Patients who presents with CSVT should underwent to CT-scan venography (CVT) and to the proper inquiry of the generating cause. This disease can affect the cerebral venous drainage and related anatomical structure. The symptoms may appear in relation to increased intracranial pressure imitating a pseudotumorcerebri. Prognosis depends on the early detection. Correcting the cause, generally the complications can be prevented. Mortality trends have diminished, and with the new technologies, surely it will continue. This work aims to review current knowledge about CSVT including its pathogenesis, etiology, clinical manifestations, diagnosis, and treatment. PMID:24347950

  4. [Noradrenaline and cerebral aging].

    PubMed

    Jouvet, M; Albarede, J L; Lubin, S; Meyrignac, C

    1991-01-01

    The central functions of norepinephrine (NE) are a recent discovery: regulation of alertness and of the wakefulness-sleep cycle, maintenance of attention, memory and learning, cerebral plasticity and neuro-protection. The anatomical, histological, biochemical and physiological properties of the central noradrenergic system: extreme capacity for ramification and arborization; slow conduction, non-myelinized axons with extrasynaptic varicosities producing and releasing NE; frequency of co-transmission phenomena, and; neuromodulation with fiber effect responsible for improvement in the signal over background noise ratio and selection of significant stimuli form a true interface between the outside world and the central nervous system, notably for the neocortex in the context of the cognitive treatment of information. This central noradrenergic system is involved in the neurophysiology and the clinical features of cerebral aging (ideation-motor and cognitive function slowing down, loss of behavioral adjustment), neuro-degenerative disorders (SDAT, Parkinson's disease), certain aspects of depression and less obvious conditions (head injuries, sequelae of cerebrovascular accidents, sub-cortical dementia). The recent development of medications improving alertness (adrafinil, modafinil) with a pure central action and specifically noradrenergic, may contribute to an improvement in these multifactorial disorders.

  5. Binary Orbits as the Driver of Gamma-Ray Emission and Mass Ejection in Classical Novae

    NASA Technical Reports Server (NTRS)

    Chomiuk, Laura; Linford, Justin D.; Yang, Jun; O'Brien, T. J.; Paragi, Zsolt; Mioduszewski, Amy J.; Beswick, R. J.; Cheung, C. C.; Mukai, Koji; Nelson, Thomas

    2014-01-01

    Classical novae are the most common astrophysical thermonuclear explosions, occurring on the surfaces of white dwarf stars accreting gas from companions in binary star systems. Novae typically expel about 10 (sup -4) solar masses of material at velocities exceeding 1,000 kilometers per second.However, the mechanism of mass ejection in novae is poorly understood, and could be dominated by the impulsive flash of thermonuclear energy, prolonged optically thick winds or binary interaction with the nova envelope. Classical novae are now routinely detected at giga-electronvolt gamma-ray wavelengths, suggesting that relativistic particles are accelerated by strong shocks in the ejecta. Here we report high-resolution radio imaging of the gamma-ray-emitting nova V959 Mon. We find that its ejecta were shaped by the motion of the binary system: some gas was expelled rapidly along the poles as a wind from the white dwarf, while denser material drifted out along the equatorial plane, propelled by orbital motion..At the interface between the equatorial and polar regions, we observe synchrotron emission indicative of shocks and relativistic particle acceleration, thereby pinpointing the location of gamma-ray production. Binary shaping of the nova ejecta and associated internal shocks are expected to be widespread among novae, explaining why many novae are gamma-ray emitters.

  6. Discovery of a New Photometric Sub-class of Faint and Fast Classical Novae

    NASA Astrophysics Data System (ADS)

    Kasliwal, M. M.; Cenko, S. B.; Kulkarni, S. R.; Ofek, E. O.; Quimby, R.; Rau, A.

    2011-07-01

    We present photometric and spectroscopic follow-up of a sample of extragalactic novae discovered by the Palomar 60 inch telescope during a search for "Fast Transients In Nearest Galaxies" (P60-FasTING). Designed as a fast cadence (1 day) and deep (g < 21 mag) survey, P60-FasTING was particularly sensitive to short-lived and faint optical transients. The P60-FasTING nova sample includes 10 novae in M 31, 6 in M 81, 3 in M 82, 1 in NGC 2403, and 1 in NGC 891. This significantly expands the known sample of extragalactic novae beyond the Local Group, including the first discoveries in a starburst environment. Surprisingly, our photometry shows that this sample is quite inconsistent with the canonical maximum-magnitude-rate-of-decline (MMRD) relation for classical novae. Furthermore, the spectra of the P60-FasTING sample are indistinguishable from classical novae. We suggest that we have uncovered a sub-class of faint and fast classical novae in a new phase space in luminosity-timescale of optical transients. Thus, novae span two orders of magnitude in both luminosity and time. Perhaps the MMRD, which is characterized only by the white dwarf mass, was an oversimplification. Nova physics appears to be characterized by a relatively rich four-dimensional parameter space in white dwarf mass, temperature, composition, and accretion rate.

  7. CLASSICAL NOVAE IN ANDROMEDA: LIGHT CURVES FROM THE PALOMAR TRANSIENT FACTORY AND GALEX

    SciTech Connect

    Cao Yi; Lou Yuqing; Kasliwal, Mansi M.; Neill, James D.; Kulkarni, S. R.; Quimby, Robert M.; Ben-Ami, Sagi; Bloom, Joshua S.; Cenko, S. Bradley; Nugent, Peter E.; Law, Nicholas M.; Ofek, Eran O.; Poznanski, Dovi

    2012-06-20

    We present optical light curves of 29 novae in M31 during the 2009 and 2010 observing seasons of the Palomar Transient Factory (PTF). The dynamic and rapid cadences in PTF monitoring of M31, from one day to ten minutes, provide excellent temporal coverage of nova light curves, enabling us to record the photometric evolution of M31 novae in unprecedented detail. We also detect eight of these novae in the near-ultraviolet (UV) band with the Galaxy Evolution Explorer (GALEX) satellite. Novae M31N 2009-10b and M31N 2010-11a show prominent UV emission peaking a few days prior to their optical maxima, possibly implying aspherical outbursts. Additionally, our blueshifted spectrum of the recent outburst of PT And (M31N 2010-12a) indicates that it is a recurrent nova in M31 and not a dwarf nova in the Milky Way as was previously assumed. Finally, we systematically searched for novae in all confirmed globular clusters (GCs) of M31 and found only M31N 2010-10f associated with Bol 126. The specific nova rate in the M31 GC system is thus about one per year, which is not enhanced relative to the rate outside the GC system.

  8. Binary orbits as the driver of γ-ray emission and mass ejection in classical novae.

    PubMed

    Chomiuk, Laura; Linford, Justin D; Yang, Jun; O'Brien, T J; Paragi, Zsolt; Mioduszewski, Amy J; Beswick, R J; Cheung, C C; Mukai, Koji; Nelson, Thomas; Ribeiro, Valério A R M; Rupen, Michael P; Sokoloski, J L; Weston, Jennifer; Zheng, Yong; Bode, Michael F; Eyres, Stewart; Roy, Nirupam; Taylor, Gregory B

    2014-10-16

    Classical novae are the most common astrophysical thermonuclear explosions, occurring on the surfaces of white dwarf stars accreting gas from companions in binary star systems. Novae typically expel about 10(-4) solar masses of material at velocities exceeding 1,000 kilometres per second. However, the mechanism of mass ejection in novae is poorly understood, and could be dominated by the impulsive flash of thermonuclear energy, prolonged optically thick winds or binary interaction with the nova envelope. Classical novae are now routinely detected at gigaelectronvolt γ-ray wavelengths, suggesting that relativistic particles are accelerated by strong shocks in the ejecta. Here we report high-resolution radio imaging of the γ-ray-emitting nova V959 Mon. We find that its ejecta were shaped by the motion of the binary system: some gas was expelled rapidly along the poles as a wind from the white dwarf, while denser material drifted out along the equatorial plane, propelled by orbital motion. At the interface between the equatorial and polar regions, we observe synchrotron emission indicative of shocks and relativistic particle acceleration, thereby pinpointing the location of γ-ray production. Binary shaping of the nova ejecta and associated internal shocks are expected to be widespread among novae, explaining why many novae are γ-ray emitters.

  9. Coatings for high energy applications. The Nova laser

    SciTech Connect

    Wirtenson, G.R.

    1986-01-01

    The combined requirements of energy density, multiple wavelength, and aperture make the coatings for the Nova Inertial Confinement Fusion (ICF) laser unique. This ten beam neodymium glass laser system, built at the Lawrence Livermore National Laboratory (LLNL), has over a thousand major optical components; some larger than one meter in diameter and weighing 380 Kg. The laser operates at 1054 nm and can be frequency doubled to 527 nm or tripled to 351 nm by means of full aperture potassium dihydrogen phosphate (KDP) crystal arrays. The 1.0 nsec fluence varies along the laser chain, sometimes reaching values as high as 16 J/cm/sup 2/ at the input lens to one of the spatial filters. The design specifications of this massive optical system were changed several times as the state-of-the-art advanced. Each change required redesign of the optical coatings even as vendors were preparing for production runs. Frequency conversion to include shorter wavelengths mandated the first major coating redesign and was followed almost immediately by a second redesign to reduce solarization effects in borosilicate crown glass. The conventional thermal evaporation process although successful for the deposition of mirror coatings, was not able to produce antireflection coatings able to survive the locally high chain fluences. As a consequence it became necessary to develop another technique. Solution produced coatings were developed having transmissions exceeding 99% per part and damage threshold values equal to the bare substrate. The unique requirement of the Nova laser necessitated special deposition and metrology equipment. These programmatic developments will be reviewed in the context of the cooperative working relationship developed between LLNL and its vendors. It was this excellent relationship which has enabled LLNL to obtain these highly specialized coatings for the Nova laser.

  10. ICF Ablator Physics Experiments on Saturn and Nova

    NASA Astrophysics Data System (ADS)

    Olson, Rick

    1996-11-01

    In indirect drive ICF, the driver energy is absorbed in a high-Z enclosure (or "hohlraum") that surrounds a spherical shell (or "capsule") containing DT fuel. The hohlraum walls are heated by the driver and emit x-rays, which are absorbed by the capsule material (the "ablator") and drive the implosion. We have used the Saturn z-pinch at SNL and the Nova laser at LLNL to explore the behavior of ablator material in x-ray radiation environments comparable in magnitude, spectrum and duration to those that will be experienced in National Ignition Facility (NIF) hohlraums. The large x-ray outputs available from pulsed-power driven z-pinches have enabled us to drive hohlraums of full NIF ignition scale size at radiation temperatures and timescales comparable to those required for the low power "foot" pulse of an ignition capsule. The high intensity of the Nova laser has allowed us to study capsule ablator physics in smaller scale hohlraums at radiation temperatures and timescales relevant to the peak power pulse for an ignition capsule. Taken together, these experiments have allowed us test our radiation-hydrodynamics computer code predictions of ablator opacity, radiation flow, and equation of state over almost the complete range of radiation environments to be encountered in a NIF hohlraum. * in collaboration with J. Porter, G. Chandler, D. Fehl, D. Jobe, R. Leeper, K. Matzen, J. McGurn, D. Noack, L. Ruggles, P. Sawyer, J. Torres, M. Vargas, D. Zagar (SNL), and H. Kornblum, T. Orzechowski, L. Suter, R. Thiessen, R. Wallace (LLNL), and the Saturn and Nova operations and diagnostic crews at SNL and LLNL. +This work was supported by the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  11. Coatings for high energy applications. The Nova laser

    NASA Astrophysics Data System (ADS)

    Wirtenson, G. R.

    The combined requirements of energy density, multiple wavelength, and aperture make the coatings for the Nova Inertial Confinement Fusion (ICF) laser unique. This ten beam neodymium glass laser system, built at the Lawrence Livermore National Laboratory (LLNL), has over a thousand major optical components; some larger than one meter in diameter and weighing 380 Kg. The laser operates at 1054 nm and can be frequency doubled to 527 nm or tripled to 351 nm by means of full aperture potassium dihydrogen phosphate (KDP) crystal arrays. The 1.0 nsec fluence varies along the laser chain, sometimes reaching values as high as 16 J/cm(2) at the input lens to one of the spatial filters. The design specifications of this massive optical system were changed several times as the state-of-the-art advanced. Each change required redesign of the optical coatings even as vendors were preparing for production runs. Frequency conversion to include shorter wavelengths mandated the first major coating redesign and was followed almost immediately by a second redesign to reduce solarization effects in borosilicate crown glass. The conventional thermal evaporation process although successful for the deposition of mirror coatings, was not able to produce antireflection coatings able to survive the locally high chain fluences. As a consequence it became necessary to develop another technique. Solution produced coatings were developed having transmissions exceeding 99% per part and damage threshold values equal to the bare substrate. The unique requirement of the Nova laser necessitated special deposition and metrology equipment. These programmatic developments will be reviewed in the context of the cooperative working relationship developed between LLNL and its vendors. It was this excellent relationship which has enabled LLNL to obtain these highly specialized coatings for the Nova laser.

  12. LABORATORY ANALYSIS OF PRESOLAR SILICATE STARDUST FROM A NOVA

    SciTech Connect

    Leitner, J.; Kodolanyi, J.; Hoppe, P.; Floss, C.

    2012-08-01

    We report the major element as well as the oxygen, magnesium, and silicon isotope composition of a unique presolar silicate grain found in the fine-grained fraction of the Antarctic CR2 chondrite Graves Nunataks 95229. The grain is characterized by an extremely high {sup 17}O/{sup 16}O ratio (6.3 {+-} 0.2 Multiplication-Sign 10{sup -3}) relative to solar values, whereas its {sup 18}O/{sup 16}O ratio is solar within measurement uncertainty. It also shows enrichments in {sup 25,26}Mg and a significant excess in {sup 30}Si relative to solar system compositions, with {delta}{sup 25}Mg = 79 {+-} 21 per mille , {delta}{sup 26}Mg = 70 {+-} 20 per mille , and {delta}{sup 30}Si = 379 {+-} 92 per mille . This isotopic composition is consistent with an origin in the ejecta of a {approx}1.3-1.4 M{sub Sun} ONe nova with large contributions of material from a main-sequence companion star of roughly solar metallicity. However, many details of the stellar source remain undetermined, owing to the uncertainties of current nova nucleosynthesis models. Auger electron spectroscopic analyses identify O, Mg, Si, and Fe as the grain's major constituents. Its (Mg+Fe)/Si atomic ratios are lower than that of olivine and correspond on average to Fe-Mg-pyroxene. A complex texture and heterogeneous major element distribution within the grain attest to condensation under non-equilibrium conditions, which is consistent with the proposed nova origin.

  13. Novae as Tevatrons: prospects for CTA and IceCube

    NASA Astrophysics Data System (ADS)

    Metzger, B. D.; Caprioli, D.; Vurm, I.; Beloborodov, A. M.; Bartos, I.; Vlasov, A.

    2016-04-01

    The discovery of novae as sources of ˜0.1-1 GeV gamma-rays highlights the key role of shocks and relativistic particle acceleration in these transient systems. Although there is evidence for a spectral cut-off above energies ˜1-100 GeV at particular epochs in some novae, the maximum particle energy achieved in these accelerators has remained an open question. The high densities of the nova ejecta (˜10 orders of magnitude larger than in supernova remnants) render the gas far upstream of the shock neutral and shielded from ionizing radiation. The amplification of the magnetic field needed for diffusive shock acceleration requires ionized gas, thus confining the acceleration process to a narrow photoionized layer immediately ahead of the shock. Based on the growth rate of the hybrid non-resonant cosmic ray current-driven instability (considering also ion-neutral damping), we quantify the maximum particle energy, Emax, across the range of shock velocities and upstream densities of interest. We find values of Emax ˜ 10 GeV-10 TeV, which are broadly consistent with the inferred spectral cut-offs, but which could also in principle lead to emission extending to ≳ 100 GeV accessible to atmosphere Cherenkov telescopes, such as the Cherenkov Telescope Array (CTA). Detecting TeV neutrinos with IceCube is more challenging, although the prospects are improved for a nearby event (≲ kpc) or if the shock power during the earliest, densest phases of the outburst is higher than implied by the GeV light curves, due to downscattering of the gamma-rays within the ejecta.

  14. Swift Ultraviolet Detections of Four Novae in M31

    NASA Astrophysics Data System (ADS)

    Immler, S.; Pietsch, W.; Kruse, W.; Freyberg, M.; Henze, M.; Stiele, H.

    2008-08-01

    The Ultraviolet/Optical Telescope (UVOT) on board the Swift satellite started observing the central region of M31 in three ultraviolet filters on 2008-05-26.76 UT. The following UVOT magnitudes and 3-sigma upper limits are measured for novae (Henze et al., 2008, ATel #1602) that are within the UVOT field in the uvw1 (181-321nm, 1284 s exposure time), uvm2 (166-268nm, 1400 s), and uvw2 (112-264 nm, 1649 s) filter observations: Nova uvw1 uvm2 uvw2 M31N2008-03b 18.5±0.2 19.2±0.2 19.4±0.3 M31N2008-05a 17.8±0.1 18.2±0.1 17.9±0.1 M31N2008-05b 16.8±0.1 17.5±0.1 17.2±0.1 M31N2008-05c 19.9±0.2 20.4±0.5 20.3±0.4 M31N2008-06a >19.7 >20.6 >20.3 M31N2008-06b > 19.7 >20.6 >20.3 None of the novae is detected in earlier > 13.0 ks Swift UVOT uvw2 observations obtained on 2007-06-02, down to a (3- sigma) limiting magnitude of around 21.5.

  15. A LIGHT CURVE ANALYSIS OF CLASSICAL NOVAE: FREE-FREE EMISSION VERSUS PHOTOSPHERIC EMISSION

    SciTech Connect

    Hachisu, Izumi; Kato, Mariko E-mail: mariko@educ.cc.keio.ac.jp

    2015-01-10

    We analyzed light curves of seven relatively slower novae, PW Vul, V705 Cas, GQ Mus, RR Pic, V5558 Sgr, HR Del, and V723 Cas, based on an optically thick wind theory of nova outbursts. For fast novae, free-free emission dominates the spectrum in optical bands rather than photospheric emission, and nova optical light curves follow the universal decline law. Faster novae blow stronger winds with larger mass-loss rates. Because the brightness of free-free emission depends directly on the wind mass-loss rate, faster novae show brighter optical maxima. In slower novae, however, we must take into account photospheric emission because of their lower wind mass-loss rates. We calculated three model light curves of free-free emission, photospheric emission, and their sum for various white dwarf (WD) masses with various chemical compositions of their envelopes and fitted reasonably with observational data of optical, near-IR (NIR), and UV bands. From light curve fittings of the seven novae, we estimated their absolute magnitudes, distances, and WD masses. In PW Vul and V705 Cas, free-free emission still dominates the spectrum in the optical and NIR bands. In the very slow novae, RR Pic, V5558 Sgr, HR Del, and V723 Cas, photospheric emission dominates the spectrum rather than free-free emission, which makes a deviation from the universal decline law. We have confirmed that the absolute brightnesses of our model light curves are consistent with the distance moduli of four classical novae with known distances (GK Per, V603 Aql, RR Pic, and DQ Her). We also discussed the reason why the very slow novae are about ∼1 mag brighter than the proposed maximum magnitude versus rate of decline relation.

  16. NO nova in the Hyades (re: ATel #4513)

    NASA Astrophysics Data System (ADS)

    Shelton, Ian

    2012-10-01

    Following a non-confirmation by Patrick Schmeer observing from Germany, a study of the optical system used to make the observations on October 21-22 leading to the report of a possible nova in the Hyades has revealed the system produces faint (0.1%) in-focus ghost images well-displaced from the primary image. The "new" star is in fact the faint ghost image of Aldebaran 3 degrees away. My apologies for the false-alarm, and thanks for the follow-up observations that I could not do myself due to cloudy weather here since the initial observations.

  17. EUVE photometry of SS Cygni: Dwarf nova outbursts and oscillations

    SciTech Connect

    Mauche, C.W.

    1995-05-15

    The authors present EUVE Deep Survey photometry and AAVSO optical measurements of the 1993 August and 1994 June/July outbursts of the dwarf nova SS Cygni. The EUV and optical light curves are used to illustrate the different response of the accretion disk to outbursts which begin at the inner edge and propagate outward, and those which begin at the outer edge and propagate inward. Furthermore, the authors describe the properties of the quasi-coherent 7--9 s sinusoidal oscillations in the EUV flux detected during the rise and plateau stages of these outbursts.

  18. Equation of State measurements of hydrogen isotopes on Nova

    SciTech Connect

    Collins, G. W., LLNL

    1997-11-01

    High intensity lasers can be used to perform measurements of materials at extremely high pressures if certain experimental issues can be overcome. We have addressed those issues and used the Nova laser to shock-compress liquid deuterium and obtain measurements of density and pressure on the principal Hugoniot at pressures from 300 kbar to more than 2 Mbar. The data are compared with a number of equation of state models. The data indicate that the effect of molecular dissociation of the deuterium into a monatomic phase may have a significant impact on the equation of state near 1 Mbar.

  19. New optical nova candidate in the M 31 disk

    NASA Astrophysics Data System (ADS)

    Henze, M.; Sala, G.; Jose, J.; Figueira, J.; Hernanz, M.; Pietsch, W.,

    2014-07-01

    We report the discovery of a possible nova in the disk of M 31 on two 4x200s stacked R filter CCD images, obtained with the the 80 cm Ritchey-Chretien F/9.6 Joan Oro telescope at Observatori Astronomic del Montsec, owned by the Catalan Government and operated by the Institut d'Estudis Espacials de Catalunya, Spain, using a Finger Lakes PL4240-1-BI CCD Camera (with a Class 1 Basic Broadband coated 2k x 2k chip with 13.5 microns sq.

  20. Discovery of the Galactic nova VVV-NOV-020

    NASA Astrophysics Data System (ADS)

    Saito, R. K.; Minniti, D.; Drew, J. E.; Greimel, R.; Lucas, P. W.

    2017-04-01

    We report the discovery of another likely Galactic nova from the VVV survey observations in the Milky Way disk (Minniti, D., et al. 2010, NewA, 15, 433). VVV-NOV-020 is located at equatorial coordinates RA/DEC(J2000)=13:32:45.82,-62:29:59.5, corresponding to l,b=307.6821,-0.0098 deg. VVV-NOV-020 lies in the overlap region of the disk VVV tiles d085 and d047, giving twice as many observations for a total of 96 epochs.

  1. Orbital period determination in an eclipsing dwarf nova HT Cas

    NASA Astrophysics Data System (ADS)

    Bąkowska, Karolina; Olech, Arkadiusz

    2014-09-01

    HT Cassiopeiae was discovered over seventy years ago (Hoffmeister 1943). Unfortunately, for 35 years this object did not receive any attention, until the eclipses of HT Cas were observed by Bond. After a first analysis, Patterson (1981) called HT Cas "a Rosetta stone among dwarf novae". Since then, the literature on this star is still growing, reaching several dozens of publications. We present an orbital period determination of HT Cas during the November 2010 super-outburst, but also during a longer time span, to check its stability.

  2. Discovery of Five Probable Novae in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Errmann, R.; Sowicka, P.; Humphries, N.; Vaduvescu, O.

    2015-10-01

    We report the discovery of five probable novae in M81 on a co-added 2000-s narrow-band H-alpha CCD image taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~1.5" seeing on 2015 Oct. 14.198 UT. The new objects are well visible on the co-added image (see the finding charts linked below), but are not present on numerous narrow-band H-alpha archival images from the INT down to limiting magnitude as faint as H-alpha = 22.3.

  3. Geometry Optimization in NOvA with Geant4

    NASA Astrophysics Data System (ADS)

    Nguyen, Vivan; Messier, Mark; NOvA Collaboration

    2013-10-01

    NOvA is a neutrino beam experiment, designed to detect neutrino oscillations. There are two detectors, placed at distances of 1km and 810 km from the proton target. The detectors are made of PVC filled with liquid scintillator. In simulating the experiment, an important aspect is the detector geometry, which is input to Geant4 using the GDML markup language. I will present studies in which the geometry description was systematically varied to find a configuration which preserved the modeling accuracy required by the experiment while minimizing the CPU time required for the simulation. This work was supported by the REU Program of the National Science Foundation under Award PHY-1156540.

  4. The peculiar dust shell of Nova DZ Cru (2003).

    SciTech Connect

    Evans, A.; Gehrz, R. D.; Woodward, C. E.; Helton, L. A.; Rushton, M. T.; Bode, M. F.; Krautter, J.; Lyke, J.; Lynch, D. K.; Ness, J.-U.; Starrfield, S.; Truran, J. W.; Wagner, R. M.; Physics; Keele Univ.; Univ. of Minnesota; Univ. of Central Lancashire; Liverpool John Moores Univ.; Zentrum fur Astronomie der Univ. Heidelberg; M. W. Keck Observatory; The Aerospace Corp.; European Space Astronomy Centre; Arizona State Univ.; Univ. of Chicago; Large Binocular Telscope Observatory

    2010-01-01

    We present Spitzer Space Telescope observations of the 'peculiar variable' DZ Cru, identified by Rushton et al. as a classical nova. A dust shell, on which are superimposed a number of features, is prominent in the 5-35 {micro}m range some 4 yr after eruption. We suggest that the dust in DZ Cru is primarily hydrogenated amorphous carbon in which aliphatic bands currently predominate and which may become either predominantly aromatic as the dust is photoprocessed by ultraviolet radiation from the stellar remnant or more likely completely destroyed.

  5. Cerebral Arterial Fenestrations

    PubMed Central

    Cooke, Daniel L; Stout, Charles E; Kim, Warren T; Kansagra, Akash P; Yu, John Paul; Gu, Amy; Jewell, Nicholas P; Hetts, Steven W; Higashida, Randall T; Dowd, Christopher F; Halbach, Van V

    2014-01-01

    Summary Arterial fenestrations are an anatomic variant with indeterminate significance. Given the controversy surrounding fenestrations we sought their prevalence within our practice along with their association with other cerebrovascular anomalies. We retrospectively reviewed 10,927 patients undergoing digital subtraction angiography between 1992 and 2011. Dictated reports were searched for the terms “fenestration” or “fenestrated” with images reviewed for relevance, yielding 228 unique cases. A Medline database search from February 1964 to January 2013 generated 304 citations, 127 cases of which were selected for analysis. Cerebral arterial fenestrations were identified in 228 patients (2.1%). At least one aneurysm was noted in 60.5% of patients, with an aneurysm arising from the fenestration in 19.6% of patients. Aneurysmal subarachnoid hemorrhage or non-aneurysmal subarachnoid hemorrhage were present in 60.1% and 15.8%, respectively. For the subset of patients with an aneurysm arising directly from a fenestration relative to those patients with an aneurysm not immediately associated with a fenestration, the prevalence of aneurysmal subarachnoid hemorrhage was 66.7% vs. 58.6% (p = 0.58). Fenestrations were more often within the posterior circulation (73.2%) than the anterior circulation (24.6%), though there was no difference in the prevalence of aneurysms within these groups (61.1% vs. 60.7%, p = 1.0). Cerebral arterial fenestrations are an anatomic variant more often manifesting at the anterior communicating arterial complex and basilar artery and with no definite pathological relationship with aneurysms. PMID:24976087

  6. Outcomes of intraventricular hemorrhage and posthemorrhagic hydrocephalus in a population-based cohort of very preterm infants born to residents of Nova Scotia from 1993 to 2010.

    PubMed

    Radic, Julia A E; Vincer, Michael; McNeely, P Daniel

    2015-06-01

    OBJECT Intraventicular hemorrhage (IVH) is a common complication of preterm birth, and the prognosis of IVH is incompletely characterized. The objective of this study was to describe the outcomes of IVH in a population-based cohort with minimal selection bias. METHODS All very preterm (≥ 30 completed weeks) patients born in the province of Nova Scotia were included in a comprehensive database. This database was screened for infants born to residents of Nova Scotia from January 1, 1993, to December 31, 2010. Among very preterm infants successfully resuscitated at birth, the numbers of infants who died, were disabled, developed cerebral palsy, developed hydrocephalus, were blind, were deaf, or had cognitive/language scores assessed were analyzed by IVH grade. The relative risk of each outcome was calculated (relative to the risk for infants without IVH). RESULTS Grades 2, 3, and 4 IVH were significantly associated with an increased overall mortality, primarily in the neonatal period, and the risk increased with increasing grade of IVH. Grade 4 IVH was significantly associated with an increased risk of disability (RR 2.00, p < 0.001), and the disability appeared to be primarily due to cerebral palsy (RR 6.07, p < 0.001) and cognitive impairment (difference in mean MDI scores between Grade 4 IVH and no IVH: -19.7, p < 0.001). No infants with Grade 1 or 2 IVH developed hydrocephalus, and hydrocephalus and CSF shunting were not associated with poorer outcomes when controlling for IVH grade. CONCLUSIONS Grades 1 and 2 IVH have much better outcomes than Grades 3 or 4, including a 0% risk of hydrocephalus in the Grade 1 and 2 IVH cohort. Given the low risk of selection bias, the results of this study may be helpful in discussing prognosis with families of very preterm infants diagnosed with IVH.

  7. Cerebral hydatid disease in Britain

    PubMed Central

    Anderson, Milne; Bickerstaff, Edwin R.; Hamilton, J. G.

    1975-01-01

    Two cases of cerebral hydatid disease are described. This condition, acquired by Britons in Britain, is extremely rare as only two similar cases have been reported before. Details of clinical presentation, investigation and treatment are described. Images PMID:1206419

  8. Cerebral emboli of paradoxical origin.

    PubMed

    Jones, H R; Caplan, L R; Come, P C; Swinton, N W; Breslin, D J

    1983-03-01

    A diagnosis of paradoxical cerebral embolus (PCE) was made in five patients aged 31 to 62 years who sustained eight cerebral ischemic events. No patient had evidence of primary carotid system or left heart disease. A probe-patent foramen ovale was the presumed mechanism in four patients, and an unsuspected congenital atrial septal defect was found in the fifth patient. Clinically apparent pulmonary emboli or venous thrombosis preceded the cerebral event in only one instance. Review of the literature reveals a high mortality with PCE. However, careful clinical search for this lesion may be rewarding: four of our five patients survived. One should consider PCE in any patient with cerebral embolus in whom there is no demonstrable left-sided circulatory source. This principle applies particularly if there is concomitant venous thrombosis, pulmonary embolism, or enhanced potential for venous thrombosis due to, for example, morbid obesity, use of hormonal birth control pills, prolonged bed rest (especially postoperatively), or systemic carcinoma.

  9. 78 FR 16493 - ExxonMobil Canada Energy, Flint Hills Resources Canada, LP, Imperial Oil, NOVA Chemical (Canada...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ..., NOVA Chemical (Canada) Ltd., PBF Holding Company LLC, Toledo Refining Company, LLC, Pennzoil-Quaker... Resources Canada, LP, Imperial Oil, NOVA Chemical (Canada) Ltd., PBF Holding Company LLC, Toledo...

  10. > ATCA Radio Monitoring of Nova Lup 2016 (ASAS-SN 16kt)

    NASA Astrophysics Data System (ADS)

    Ryder, S. D.; Kool, E. C.; Chomiuk, L.

    2016-10-01

    The bright Galactic nova in Lupus (ATel #9538, #9539, #9550, CBET #4322) was observed two weeks after discovery using the Australia Telescope Compact Array (ATCA) at 19 GHz on 2016 Oct 9.1 UT. No radio emission was detected at the nova's location, to a 3-sigma upper limit of 0.08 milliJy.

  11. The Potential of NovaNET Communications for Education and Instruction.

    ERIC Educational Resources Information Center

    Steinberg, Esther R.

    Intended to suggest ways of implementing the potential of NovaNet beyond its current applications, this report begins with an overview of current educational applications of telecommunications systems. It is noted that NovaNET is not only a successful computer system for presenting instructional courseware, but that it also supports…

  12. Moving Mountains for the Children and Families of Eastern Nova Scotia.

    ERIC Educational Resources Information Center

    Mrazek, Charmaine

    2001-01-01

    In the rural regions of Nova Scotia, the Network for Children & Youth of Eastern Nova Scotia is attacking the problem of service fragmentation. The network addresses the multiple factors of health that contribute to the well-being of populations by coordinating the efforts of the 37 member agencies. Accomplishments and practical rules for…

  13. Impact of the Nova Scotia School Accreditation Program on Teaching and Student Learning: An Initial Study

    ERIC Educational Resources Information Center

    Wood, Christine; Meyer, Matthew J.

    2011-01-01

    School accreditation is one process currently mandated in Nova Scotia schools to facilitate school improvement efforts. This mixed methods study sought to discover and describe the impact of the Nova Scotia School Accreditation Program (NSSAP) specifically on teaching and student learning in three secondary schools in one school board. Surveys,…

  14. Library Cooperation at the NOVA University--the Nordic University in Agriculture, Forestry and Veterinary Medicine.

    ERIC Educational Resources Information Center

    Myllys, Heli

    The Nordic University in Agriculture, Forestry and Veterinary Medicine--the NOVA University-was established in 1995 to increase the cooperation between the Nordic agricultural universities. The NOVA libraries of the seven institutions and facilities involved wanted to show that they are a very useful partner in launching new ideas. They have the…

  15. Cerebral ganglioglioma. A Golgi study.

    PubMed

    Ferrer, I; Ribalta, T; Digon, E; Acebes, J

    1983-01-01

    The morphological characteristics of neurons revealed by Golgi's method are reported in a case of cerebral ganglioglioma. Spindle-shaped (leptodendritic) neurons and radiated type I neurons form the bulk of this tumour. According to Ramon-Moliner (1968) isodendritic neurons (both leptodendritic and radiate type I) are philogenetically primitive cells and differ greatly from those observed in most of the deep cerebral nuclei of the mammalian's brain.

  16. Resource Allocation in Cerebral Specialization.

    DTIC Science & Technology

    1980-01-01

    of this multiple-resources view. EXTENSION OF THE THEORY TO THE TWO CEREBRAL HEMISPHERES Since the anatomical division of the brain invites...performance differences between the hemispheres (e.g., right-handed males with no familial history of left- handedness who use a normal rather than an...G. Beaumont (Eds.), Hemisphere function in the human rain.. New York: Halstead Press, 1974. Kinsbourne, M. The cerebral basis of lateral asymmetries

  17. 1651-32 V1280 Sco = Nova Scorpii 2007

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2007-02-01

    1651-32 V1280 Sco = Nova Scorpii 2007 was discovered independently by Yuji Nakamura (Kameyama, Mie, Japan) on 2007 February 04.8624 UT at 9.9 on two unfiltered CCD images taken with a 135-mm camera lens, and by Yukio Sakurai (Mito, Ibaraki-ken, Japan) on 2007 February 04.854 UT at 9.4 on two 10-s CCD exposures taken with a Fuji FinePix S2 Digital Camera (+ Nikon 180-mm f/2.8 lens). Nothing was seen at this location to magnitude 11.0 on images taken February 02.8662 UT by Nakamura, or on a CCD frame taken on February 02.8 UT by Sakurai. Spectroscopy (H. Naito and S. Narusawa, Nishi-Harima Astronomical Observatory, February 05.87 UT) suggests V1280 Sco is a classical nova caught near maximum light. Later spectroscopy (M. Fujii, Ibara, Okayama, Japan, February 12.88 and 14.83 UT; H. Naito, February 14.86), show the spectrum has evolved. Data reported to the AAVSO may be found at www.aavso.org.

  18. PU Vulpeculae - The outburst of a symbiotic nova

    NASA Astrophysics Data System (ADS)

    Vogel, M.; Nussbaumer, H.

    1992-06-01

    We report the full history of PU Vulpeculae from outburst to 1991 as seen in its ultraviolet emission. We show that PU Vul is a symbiotic nova, which went into outburst in 1977 after a nova-like thermonuclear event. The outbursting object went first into an F supergiant phase. The spectrum evolved between 1979 and 1989 from F-type into that of Ao. In 1990 PU Vul entered the nebular phase, showing a rich emission line spectrum in the UV and in the optical. Between 1979 and 1983-1985 the luminosity of the outbursting object increased by approximately a factor of 2 against 2600 solar luminosities in 1979. It subsequently decreased to reach in 1989 approximately the same value as in 1979. During 1980 the lightcurve went through a minimum and the spectral appearance changed. We interpret this as an eclipse of the outbursting star by the M giant companion. Based on IUE observations we discuss the early nebular phase of PU Vul, and we show that the UV is still dominated by the outbursting component, which in 1991 has reached a temperature of 40,000 K.

  19. A study of the shell of Nova V2659 Cyg

    NASA Astrophysics Data System (ADS)

    Tarasova, T. N.

    2016-12-01

    Results of a study of the shell of Nova V2659 Cyg based on spectrophotometric observations carried out over a year and a half after its eruption are presented. The physical conditions in the nova shell have been studied. The electron temperature (9000 K) and density (5 × 106 cm-3) in the nebular stage have been estimated, together with the abundances of helium, oxygen, nitrogen, neon, argon, and iron. The abundances of nitrogen, oxygen, neon, and argon are enhanced relative to the solar values. The relative abundances are [N/H] = 2.26 ± 0.25 dex, [O/H] = 1.66 ± 0.35 dex, [Ne/H] = 0.78 ± 0.25 dex, and [Ar/H] = 0.32 ± 0.38 dex. The estimated mass of oxygen and total mass of the emitting shell are ≈1 × 10-4 M ⊙ and ≈3 × 10-4 M ⊙, respectively. In the period of chaotic brightness oscillations, the maximum velocity of the shell expansion derived from the radial velocities of the absorption components of the HI and FeII line profiles increased by ≈400 km/s 41 days after the maximum, and by ≈200 km/s 101 days after the maximum, reaching 1600 km/s in both cases.

  20. Nova Sagittarii 2015 = PNV J18142514-2554343

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2015-02-01

    AAVSO Alert Notice 509 announces the discovery of Nova Sagittarii 2015 = PNV J18142514-2554343 [V5667 Sgr]. Independent discoveries were made as follows: Hideo Nishimura (Shizuoka-ken, Japan) on 2015 February 12.840 UT at DSLR magnitude 11.2, using 200-mm f/3.2 lens + digital camera; Koichi Nishiyama (Kurume, Japan) and Fujio Kabashima (Miyaki, Japan) on 2015 February 12.87837 UT at unfiltered CCD magnitude 10.9, using a 105-mm f/4 camera lens (+SBIG STL6303E camera). Coordinates: R.A. 18 14 25.14 Dec. -25 54 34.3 (2000.0). Echelle spectra by Frederick Walter (Stony Brook University) taken on the night of 2015 February 15/16 UT near maximum light indicate that N Sgr 2015 is a classical Fe II nova. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  1. The NOvA νe Appearance Analysis

    NASA Astrophysics Data System (ADS)

    Colo, Marco; NOvA Collaboration

    2017-01-01

    Since neutrino oscillations were first detected, oscillation experiments have managed to measure most of the parameters that govern this phenomenon. Major unknowns remain: the mass ordering - whether ν3 is the heaviest neutrino state, or the lightest; CP Violation - whether neutrino oscillation violate CP symmetry, and, if so, how big is the CP-violating phase δCP; and, the θ23 octant - whether the value of θ23 resides in the lower octant (θ23 <45°) or upper octant (θ23 >45°) or is exactly maximal (θ23 =45°). NOvA, with its 810 km baseline, the longest of any currently running experiment, and its capability to switch between a νμ source and a νμ source, is extremely well positioned to address these questions. In this talk, I will discuss the νe appearance analysis in NOvA: I will illustrate the analysis method, discuss the results that we have obtained in the latest round of analysis, and talk about what we expect from future runs.

  2. Unbound States of 32Cl Relevant for Novae

    SciTech Connect

    Matos, M.; Blackmon, Jeff C; Linhardt, Laura; Bardayan, Daniel W; Nesaraja, Caroline D; Clark, Jason; Diebel, C.; O'Malley, Patrick; Parker, P.D.; Schmitt, Kyle

    2011-01-01

    The 31S(p,g )32Cl proton capture reaction is expected to be the dominant breakout pathway of the SiP cycle, which is important for understanding nucleosynthesis in some novae [1]. At novae temperatures, the 31S(p,g )32Cl reaction rate is dominated by 31S+p resonances. Discrepancies in the 32Cl resonance energies were reported in previous measurements [1, 2]. We used the 32S(3He,t)32Cl charge exchange reaction to produce unbound states in 32Cl and determine their excitation energies by detecting tritons at the focal plane of the Enge Spectrograph at the Yale University s Wright Nuclear Structure Laboratory. Proton branching ratios were determined by detecting the decay protons coming from the residual 32Cl states using a silicon array in the spectrometer s target chamber. The improved energy values of excited levels in 32Cl and measurements of the proton-branching ratios should significantly improve our understanding of the 31S(p,g )32Cl reaction rate.

  3. Automated Detection of Classical Novae with Neural Networks

    NASA Astrophysics Data System (ADS)

    Feeney, S. M.; Belokurov, V.; Evans, N. W.; An, J.; Hewett, P. C.; Bode, M.; Darnley, M.; Kerins, E.; Baillon, P.; Carr, B. J.; Paulin-Henriksson, S.; Gould, A.

    2005-07-01

    The POINT-AGAPE collaboration surveyed M31 with the primary goal of optical detection of microlensing events, yet its data catalog is also a prime source of light curves of variable and transient objects, including classical novae (CNe). A reliable means of identification, combined with a thorough survey of the variable objects in M31, provides an excellent opportunity to locate and study an entire galactic population of CNe. This paper presents a set of 440 neural networks, working in 44 committees, designed specifically to identify fast CNe. The networks are developed using training sets consisting of simulated novae and POINT-AGAPE light curves in a novel variation on K-fold cross validation and use the binned, normalized power spectra of the light curves as input units. The networks successfully identify 9 of the 13 previously identified M31 CNe within their optimal working range (and 11 out of 13 if the network error bars are taken into account). The networks provide a catalogue of 19 new candidate fast CNe, of which four are strongly favored.

  4. BLOBS IN SPACE: THE LEGACY OF A NOVA

    NASA Technical Reports Server (NTRS)

    2002-01-01

    TThe prolific number of eruptions by the recurrent nova T Pyxidis has attracted the attention of many telescopes. The image on the left, taken by a ground-based telescope, shows shells of gas around the star that were blown off during several eruptions. Closer inspection by the Hubble Space Telescope (right-hand image), however, reveals that the shells are not smooth at all. In fact, this high-resolution image shows that the shells are actually more than 2,000 gaseous blobs packed into an area that is 1 light-year across. Resembling shrapnel from a shotgun blast, the blobs may have been produced by the nova explosion, the subsequent expansion of gaseous debris, or collisions between fast-moving and slow- moving gas from several eruptions. False color has been applied to this image to enhance details in the blobs. The ground-based image was taken Jan. 19, 1995 by the European Southern Observatory's New Technology Telescope in La Silla, Chile. The Hubble telescope picture is a compilation of data taken on Feb. 26, 1994, and June 16, Oct. 7, and Nov. 10, 1995, by the Wide Field and Planetary Camera 2. T Pyxidis is 6,000 light-years away in the dim southern constellation Pyxis, the Mariner's Compass. Credits: Mike Shara, Bob Williams, and David Zurek (Space Telescope Science Institute); Roberto Gilmozzi (European Southern Observatory); Dina Prialnik (Tel Aviv University); and NASA.

  5. What does an erupting nova do to its red dwarf companion

    SciTech Connect

    Kovetz, A.; Prialnik, D.; Shara, M.M.

    1988-02-01

    During nova eruptions and for decades afterward, the red dwards in cataclysmic binaries are irradiated with hundreds of times more luminosity than they themselves produce. Simulations of the time-dependent irradiation of three red dwarf models (0.25, 0.50, and 0.75 solar mass) are presented. The mass transfer rates forced by irradiation after nova eruption are found to be enhanced by two orders of magnitude because of the irradiation. The time scale for irradiation to become unimportant is that of the white dwarf cooling time scale, a few centuries. These two results support the hibernation scenario of novae, which suggests that novae remain bright for a few centuries after eruption because of irradiation-induced mass transfer. After irradiation decreases mass transfer slows, and some very old novae may then become extremely faint. 26 references.

  6. Therapeutic implications of melatonin in cerebral edema.

    PubMed

    Rathnasamy, Gurugirijha; Ling, Eng-Ang; Kaur, Charanjit

    2014-12-01

    Cerebral edema/brain edema refers to the accumulation of fluid in the brain and is one of the fatal conditions that require immediate medical attention. Cerebral edema develops as a consequence of cerebral trauma, cerebral infarction, hemorrhages, abscess, tumor, hypoxia, and other toxic or metabolic factors. Based on the causative factors cerebral edema is differentiated into cytotoxic cerebral edema, vasogenic cerebral edema, osmotic and interstitial cerebral edema. Treatment of cerebral edema depends on timely diagnosis and medical assistance. Pragmatic treatment strategies such as antihypertensive medications, nonsteroidal anti-inflammatory drugs, barbiturates, steroids, glutamate and N-methyl-D-aspartate receptor antagonists and trometamol are used in clinical practice. Although the above mentioned treatment approaches are being used, owing to the complexity of the mechanisms involved in cerebral edema, a single therapeutic strategy which could ameliorate cerebral edema is yet to be identified. However, recent experimental studies have suggested that melatonin, a neurohormone produced by the pineal gland, could be an effective alternative for treating cerebral edema. In animal models of stroke, melatonin was not only shown to reduce cerebral edema but also preserved the blood brain barrier. Melatonin's beneficial effects were attributed to its properties, such as being a potent anti-oxidant, and its ability to cross the blood brain barrier within minutes after its administration. This review summarizes the beneficial effects of melatonin when used for treating cerebral edema.

  7. 15 CFR 785.6 - Filing and service of papers other than the Notice of Violation and Assessment (NOVA).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... than the Notice of Violation and Assessment (NOVA). 785.6 Section 785.6 Commerce and Foreign Trade... Notice of Violation and Assessment (NOVA). (a) Filing. All papers to be filed with the ALJ shall be... NOVA, or such other place as the ALJ may designate. Filing by United States certified mail, by...

  8. 15 CFR 785.6 - Filing and service of papers other than the Notice of Violation and Assessment (NOVA).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... than the Notice of Violation and Assessment (NOVA). 785.6 Section 785.6 Commerce and Foreign Trade... Notice of Violation and Assessment (NOVA). (a) Filing. All papers to be filed with the ALJ shall be... NOVA, or such other place as the ALJ may designate. Filing by United States certified mail, by...

  9. 15 CFR 785.6 - Filing and service of papers other than the Notice of Violation and Assessment (NOVA).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... than the Notice of Violation and Assessment (NOVA). 785.6 Section 785.6 Commerce and Foreign Trade... Notice of Violation and Assessment (NOVA). (a) Filing. All papers to be filed with the ALJ shall be... NOVA, or such other place as the ALJ may designate. Filing by United States certified mail, by...

  10. 15 CFR 785.6 - Filing and service of papers other than the Notice of Violation and Assessment (NOVA).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... than the Notice of Violation and Assessment (NOVA). 785.6 Section 785.6 Commerce and Foreign Trade... Notice of Violation and Assessment (NOVA). (a) Filing. All papers to be filed with the ALJ shall be... NOVA, or such other place as the ALJ may designate. Filing by United States certified mail, by...

  11. 15 CFR 785.6 - Filing and service of papers other than the Notice of Violation and Assessment (NOVA).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... than the Notice of Violation and Assessment (NOVA). 785.6 Section 785.6 Commerce and Foreign Trade... Notice of Violation and Assessment (NOVA). (a) Filing. All papers to be filed with the ALJ shall be... NOVA, or such other place as the ALJ may designate. Filing by United States certified mail, by...

  12. VizieR Online Data Catalog: Near-IR catalog of novae in VVV survey area (Saito+, 2013)

    NASA Astrophysics Data System (ADS)

    Saito, R. K.; Minniti, D.; Angeloni, R.; Catelan, M.; Beamin, J. C.; Borissova, J.; Dekany, I.; Kerins, E.; Kurtev, R.; Mennickent, R. E.

    2013-10-01

    We used the novae list provided by VSX/AAVSO catalogue to search for all objects within the VVV area. From the 140 novae, we were able to retrieve the JHKs colours of 93 objects. We also checked in the ongoing VVV variability campaign for the light curves of novae that erupted in the last years. (1 data file).

  13. The Accretion Disk and White Dwarf in the Short-Period Dwarf Novae TY Piscium and V436 Centauri during Quiescence

    NASA Astrophysics Data System (ADS)

    Nadalin, Ira; Sion, Edward M.

    2001-07-01

    The short-period dwarf novae TY Psc and V436 Cen are SU UMa systems with very similar orbital periods, similar recurrence times for normal outbursts (~23 days) and superoutbursts (~340 days), and nearly identical outburst amplitudes. We have carried out high-gravity model atmosphere and accretion disk synthetic spectra from the grid of Wade & Hubeny. The best-fit stellar model spectrum, from spectral slope and line fitting, is a white dwarf photosphere having Teff=25,000 K, logg=8, and essentially solar chemical abundances, while the best-fit optically thick accretion disk model, from spectral slope fitting, has Mwd=0.55 Msolar, M=10-9.5 Msolar yr-1, and an inclination i=18deg. The implied accretion rate is almost certainly too large for dwarf nova quiescence. The predicted fluxes using parameters from the photosphere and disk spectral slope fitting models reveal enormous differences compared with the observed luminosity using a reasonable distance estimate. For TY Psc, the predicted accretion disk luminosity is ~100 times too luminous, while the stellar luminosity is too luminous by a factor of ~10. For V436 Cen, the best-fit high-gravity model photosphere, from spectral slope fitting, yields Teff=24,000 K, logg=8, and essentially solar abundance, while the best-fit accretion disk models, from spectral slope fitting, yield Mwd=0.8 Msolar, M=10-10 Msolar yr-1, and i=75deg. The presence of broad absorption troughs at unusual wavelength positions suggests the presence of an absorption curtain (upper disk atmosphere) in V436 Cen. The temperatures we have for TY Psc and V436 Cen are higher than normal for the accreting white dwarfs in dwarf novae below the period gap. This could indicate that the systems were not in the deepest level of quiescence when they were observed.

  14. Monitoring Cerebral Oxygenation in Neonates: An Update

    PubMed Central

    Dix, Laura Marie Louise; van Bel, Frank; Lemmers, Petra Maria Anna

    2017-01-01

    Cerebral oxygenation is not always reflected by systemic arterial oxygenation. Therefore, regional cerebral oxygen saturation (rScO2) monitoring with near-infrared spectroscopy (NIRS) is of added value in neonatal intensive care. rScO2 represents oxygen supply to the brain, while cerebral fractional tissue oxygen extraction, which is the ratio between rScO2 and systemic arterial oxygen saturation, reflects cerebral oxygen utilization. The balance between oxygen supply and utilization provides insight in neonatal cerebral (patho-)physiology. This review highlights the potential and limitations of cerebral oxygenation monitoring with NIRS in the neonatal intensive care unit. PMID:28352624

  15. Constraining the role of novae as progenitors of type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Soraisam, Monika D.; Gilfanov, Marat

    2015-11-01

    Context. With the progenitors of type Ia supernovae (SNe Ia) still eluding direct detections, various types of accreting white dwarfs (WDs) have been proposed as prospective candidates. One of the possibilities are WDs undergoing unstable nuclear burning on their surfaces. Although observations and theoretical modeling of classical novae generally suggest that more material is ejected during the explosion than is accreted, there is growing evidence that in certain accretion regimes of novae, appreciable mass accumulation by the WD in the course of unstable nuclear burning may be possible. Aims: We propose that statistics of novae in nearby galaxies may be a powerful tool to determine the role these systems play in producing SNe Ia. Methods: We used multicycle nova evolutionary models to compute the number and temporal distribution of novae that would be produced by a typical SN Ia progenitor before it reached the Chandrasekhar mass limit (Mch) and exploded, assuming that it experienced unstable nuclear burning during its entire accretion history. We then used the observed nova rate in M 31 to constrain the maximal contribution of the nova channel to the SN Ia rate in this galaxy. Results: The M 31 nova rate measured by the POINT-AGAPE survey is ≈ 65 yr-1. Assuming that all these novae will reach Mch, we estimate the maximal SN Ia rate novae may produce, which is ≲0.1-0.5 × 10-3 yr-1. This constrains the overall contribution of the nova channel to the SN Ia rate at ≲ 2-7%. However, if all POINT-AGAPE novae do eventually reach Mch, a significant population of fast novae (t2 ≲ 10 days) originating from the most massive WDs is expected, with a rate of ~200-300 yr-1, which is significantly higher than currently observed. We point out that statistics of such fast novae can provide powerful diagnostics of the contribution of the nova channel to the final stage of mass accumulation by the single-degenerate (SD) SN Ia progenitors. To explore the prospects of their

  16. Encephaloduroarteriosynangiosis for cerebral proliferative angiopathy with cerebral ischemia.

    PubMed

    Kono, Kenichi; Terada, Tomoaki

    2014-12-01

    Cerebral proliferative angiopathy (CPA) is a rare clinical entity. This disorder is characterized by diffuse vascular abnormalities with intermingled normal brain parenchyma, and is differentiated from classic arteriovenous malformations. The management of CPA in patients presenting with nonhemorrhagic neurological deficits due to cerebral ischemia is challenging and controversial. The authors report a case of adult CPA with cerebral ischemia in which neurological deficits were improved after encephaloduroarteriosynangiosis (EDAS). A 28-year-old man presented with epilepsy. Magnetic resonance imaging and angiography showed a diffuse vascular network (CPA) in the right hemisphere. Antiepileptic medications were administered. Four years after the initial onset of epilepsy, the patient's left-hand grip strength gradually decreased over the course of 1 year. The MRI studies showed no infarcts, but technetium-99m-labeled ethyl cysteinate dimer ((99m)Tc-ECD) SPECT studies obtained with acetazolamide challenge demonstrated hypoperfusion and severely impaired cerebrovascular reactivity over the affected hemisphere. This suggested that the patient's neurological deficits were associated with cerebral ischemia. The authors performed EDAS for cerebral ischemia, and the patient's hand grip strength gradually improved after the operation. Follow-up angiography studies obtained 7 months after the operation showed profound neovascularization through the superficial temporal artery and the middle meningeal artery. A SPECT study showed slight improvement of hypoperfusion at the focal region around the right motor area, indicating clinical improvement from the operation. The authors conclude that EDAS may be a treatment option for CPA-related hypoperfusion.

  17. The panchromatic spectroscopic evolution of the classical CO nova V339 Delphini (Nova Del 2013) until X-ray turnoff

    NASA Astrophysics Data System (ADS)

    Shore, S. N.; Mason, E.; Schwarz, G. J.; Teyssier, F. M.; Buil, C.; De Gennaro Aquino, I.; Page, K. L.; Osborne, J. P.; Scaringi, S.; Starrfield, S.; van Winckel, H.; Williams, R. E.; Woodward, C. E.

    2016-05-01

    Context. Classical novae are the product of thermonuclear runaway-initiated explosions occurring on accreting white dwarfs. Aims: V339 Del (Nova Delphinus 2013) was one of the brightest classical novae of the last hundred years. Spectroscopy and photometry are available from γ-rays through infrared at stages that have frequently not been observed well. The complete data set is intended to provide a benchmark for comparison with modeling and for understanding more sparsely monitored historical classical and recurrent novae. This paper is the first in the series of reports on the development of the nova. We report here on the early stages of the outburst, through the X-ray active stage. Methods: A time sequence of optical, flux calibrated high resolution spectra was obtained with the Nordic Optical Telescope (NOT) using FIES simultaneously, or contemporaneously, with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope during the early stages of the outburst. These were supplemented with Mercator/HERMES optical spectra. High resolution IUE ultraviolet spectra of OS And 1986, taken during the Fe curtain phase, served as a template for the distance determination. We used standard plasma diagnostics (e.g., [O III] and [N II] line ratios, and the Hβ line flux) to constrain electron densities and temperatures of the ejecta. Using Monte Carlo modeling of the ejecta, we derived the structure, filling factor, and mass from comparisons of the optical and ultraviolet line profiles. Results: We derive an extinction of E(B - V) = 0.23 ± 0.05 from the spectral energy distribution, the interstellar absorption, and H I emission lines. The distance, about 4-4.5 kpc, is in agreement with the inferred distance from near infrared interferometry. The maximum velocity was about 2500 km s-1, measured from the UV resonance and optical profiles. The ejecta showed considerable fine structure in all transitions, much of which persisted as emission knots. The

  18. Meteorological impact of realistic Terra Nova Bay polynyas.

    NASA Astrophysics Data System (ADS)

    Morelli, Sandra

    2010-05-01

    The energy exchange between the ocean and the atmosphere in the Antarctic marginal sea ice zone is influenced by the extent of sea-ice cover. In areas of open water, a direct contact is established and intense energy exchanges occur, due to the large difference of temperature between the water and the air above it. This implies that the polynyas are areas where the ocean exchanges energy with the atmosphere and as a result they have an effect on the polar meteorology/climate. The work presented here concerns real polynya events in the region of Terra Nova Bay (TNB), Antarctica, where a recurring coastal polynya occurs nearby the Italian Antarctic Base. The aim is the study of the impact of polynyas on the atmosphere by three-dimensional numerical simulations. The ETA model (Mesinger et al., 2006) was used and ECMWF and NCEP data provided the initial and boundary conditions. The model had already been successfully used in the Antarctic area (Casini and Morelli, 2007) A polynya of realistic size (as observed by satellite image) was included in the initial conditions for the simulations and a study of the air circulation during the events is found in Morelli et al. (2007), Morelli and Casini (2008), Morelli et al. (2009). The Eta Model reproduced the evolution of upper and mod-level conditions in good agreement with AVHRR observations (Morelli, 2008, Morelli and Parmiggiani, 2009). Also, the simulated 10 m wind was well correlated with the observed extension of the polynya. In order to isolate the effect of the presence of the open water area on the structure of the atmospheric boundary layer and on the atmospheric circulation, further simulations were performed without the presence of the polynya, i.e. with its extent covered with sea ice. The numerical simulations show that the polynyas act to increase the speed of the air above them and generate strong heat fluxes that warm the air. The effects are found over and downwind the sea ice free area. Results from the Eta

  19. Sonification of Kepler Field SU UMa Cataclysmic Variable Stars V344 Lyr and V1504 Cyg

    NASA Technical Reports Server (NTRS)

    Tutchton, Roxanne M.; Wood, Matt A.; Still, Martin D.; Howell, Steve B.; Cannizzo, John K.; Smale, Alan P.

    2012-01-01

    Sonification is the conversion of quantitative data into sound. In this work we explain the methods used in the sonification of light curves provided by the Kepler instrument from Q2 through Q6 for the cataclysmic variable systems V344 Lyr and V1504 Cyg . Both systems are SU UMa stars showing dwarf nova outbursts and superoutbursts as well as positive and negative superhumps. Focused sonifications were done from average pulse shapes of each superhump, and separate sonifications of the full, residual light curves were done for both stars. The audio of these data reflected distinct patterns within the evolutions of supercycles and superhumps that matched pervious observations and proved to be effective aids in data analysis.

  20. [Plasma osmolarity and cerebral volume].

    PubMed

    Boulard, G

    2001-02-01

    Under normal physiological conditions, the osmolarity of extracellular fluids (ECFs) and natremia are controlled by two regulatory mechanisms modulating the water balance and sodium outflow from information collected by the osmoreceptors and baroreceptors, respectively. As well, under normal physiological conditions, water and electrolytes of brain ECFs are secreted by the endothelial cells of brain capillaries. Furthermore, isotonicity is present on both sides of the blood-brain barrier. In the event of systemic osmolarity disorders, water transport subject to osmosis laws occurs at the level of the blood-brain barrier. In the case of plasmatic hyperosmolarity cerebral dehydration is observed, while cerebral edema occurs in the contrary case. However, plasmatic osmolarity disorders have less effect on the cerebral volume when their introduction is slow. Experimentation in acute conditions shows that measured variations of the cerebral water content are lower than calculated variations, thus suggesting the existence of an adaptive mechanism, that is, the cerebral osmoregulation which limits the variation of the volume of brain cells by modulating their osmoactive molecule content. These osmoactive molecules are, on the one hand, the electrolytes, which are early and rapidly mobilized, and, on the other hand, the organic osmoles (amino acids, etc.), whose secretion is slower and delayed. This phenomenon should be taken into account in the treatment of osmolarity disorders. Thus, the related-risk of treatment for natremia disorders is therapeutic reversal of the osmotic gradient at the level of the blood-brain barrier. This reversal, which corresponds to a second osmotic stress, requires the implementation of a new procedure of cerebral osmoregulation in the opposite direction of the preceding one. As successive osmotic stresses decrease the effectiveness of brain osmoregulation, the risk for cerebral dehydration and pontine myelinolysis increases when the treatment

  1. Multidimensional Simulations of Type Ia Supernovae and Classical Novae

    NASA Astrophysics Data System (ADS)

    Krueger, Brendan Kurt

    Explosive astrophysical phenomena have historically played a significant role in understanding the universe and our place within it. Stellar explosions are important distance indicators, allowing exploration of the structure and evolution of the universe. They also form and disperse heavy elements that are recycled into new astrophysical objects. Stellar explosions are not a uniform group; the progenitors and mechanisms of stellar explosions vary tremendously. I used multidimensional simulations to study two distinct types of explosions that are believed to result from similar progenitor systems: compact white dwarf stars that accrete matter from stellar companions. The two types of explosions I studied are type Ia supernovae and classical novae. Type Ia supernovae are thought to arise from a thermonuclear explosion originating in the core of an accreting white dwarf and leave no remnant. These events are the premier distance indicators in cosmological studies, but questions remain about systematic biases and intrinsic scatter. My investigation centered on the systematic impact of the central density of the progenitor on the brightness of the supernova. Relating the progenitor's central density to its age provided a theoretical explanation of the observed trend that type Ia supernovae from older stars are dimmer. I also demonstrated the importance of a statistical study of such problems, due to the strongly nonlinear evolution during the explosion. Classical novae are important for the study of circumstellar dust formation and are significant contributors of specific isotopes found in our galaxy. They result from a thermonuclear runaway occurring in the accreted envelope on a white dwarf. Only the envelope is consumed, so the white dwarf remains and the event may recur on time scales of 104 to 10 5 years. My study made use of a new simulation code specialized for low-Mach number flows, such as convection just prior to the explosion. I developed hydrostatic initial

  2. Interstellar Material towards eta UMa

    NASA Astrophysics Data System (ADS)

    Frisch, P. C.; Jenkins, E. B.; Welty, D. E.; Johns-Krull, C.

    1999-05-01

    The star eta UMa (B3 V, vsini=205 km s(-1) , d=31 pc, l=101(o) , b=+65(o) ) samples nearby interstellar gas in a high latitude direction relatively devoid of material. IMAPS, Hubble GHRS Echelle, and ground based optical data are combined to present a comprehensive picture of the interstellar material (ISM) in this direction. Two main components dominate: the blue-shifted component which appears to be ionized, and the dominant, red-shifted, component which exhibits a low electron density ( ~ 0.2 cm(-3) ). However, the Mg(o/Mg^+) ratio and C(+) fine-structure lines yield different ionizations, depending on the adopted temperature, similar to differences found in the diffuse material towards 23 Ori (Welty et al. 1999). The IMAPS and GHRS data give C, N, O, and Fe column densities, which form the basis for calculating the gas-to-dust mass ratio for the main component using a ``missing mass'' calculation combined with an assumed reference abundance (Frisch et al. 1999). Comparing the eta UMa value with other diffuse cloud values then further constrains uncertainties in N(H(o) ) values for this sightline.

  3. The Radio Light Curve of the Gamma-Ray Nova in V407 CYG: Thermal Emission from the Ionized Symbiotic Envelope, Devoured from Within by the Nova Blast

    NASA Technical Reports Server (NTRS)

    Chomiuk, Laura; Krauss, Miriam I.; Rupen, Michael P.; Nelson, Thomas; Roy, Nirupam; Sokoloski, Jennifer L.; Mukai, Koji; Munari, Ulisse; Mioduszewski, Amy; Weston, Jeninfer; O'Brien, Tim J.; Eyres, Steward P. S.; Bode, Michael F.

    2012-01-01

    We present multi-frequency radio observations of the 2010 nova event in the symbiotic binary V407 Cygni, obtained with the Karl G. Jansky Very Large Array (VLA) and spanning 1.45 GHz and 17.770 days following discovery. This nova.the first ever detected in gamma rays.shows a radio light curve dominated by the wind of the Mira giant companion, rather than the nova ejecta themselves. The radio luminosity grewas the wind became increasingly ionized by the nova outburst, and faded as the wind was violently heated from within by the nova shock. This study marks the first time that this physical mechanism has been shown to dominate the radio light curve of an astrophysical transient. We do not observe a thermal signature from the nova ejecta or synchrotron emission from the shock, due to the fact that these components were hidden behind the absorbing screen of the Mira wind. We estimate a mass-loss rate for the Mira wind of .Mw approximately equals 10(exp -6) Solar mass yr(exp -1). We also present the only radio detection of V407 Cyg before the 2010 nova, gleaned from unpublished 1993 archival VLA data, which shows that the radio luminosity of the Mira wind varies by a factor of 20 even in quiescence. Although V407 Cyg likely hosts a massive accreting white dwarf, making it a candidate progenitor system for a Type Ia supernova, the dense and radially continuous circumbinary material surrounding V407 Cyg is inconsistent with observational constraints on the environments of most Type Ia supernovae.

  4. Determination and augmentation of RNA sequence specificity of the Nova K-homology domains.

    PubMed

    Musunuru, Kiran; Darnell, Robert B

    2004-01-01

    The Nova onconeural antigens are implicated in the pathogenesis of paraneoplastic opsoclonus-myoclonus-ataxia (POMA). The Nova antigens are neuron-specific RNA-binding proteins harboring three repeats of the K-homology (KH) motif; they have been implicated in the regulation of alternative splicing of a host of genes involved in inhibitory synaptic transmission. Although the third Nova KH domain (KH3) has been extensively characterized using biochemical and crystallographic techniques, the roles of the KH1 and KH2 domains remain unclear. Furthermore, the specificity determinants that distinguish the Nova KH domains from those of the closely related hnRNP E and hnRNP K proteins are undefined. We demonstrate through the use of RNA selection and biochemical analysis that the sequence specificity of the Nova KH1/2 domains is similar to that of Nova KH3. We also show that the mutagenesis of a Nova KH domain to render it similar to the KH domains of the heterogeneous nuclear ribonucleoprotein E (hnRNP E) and hnRNP K allow it to recognize longer RNA sequences. These data yield important insights into KH domain function and suggest a strategy by which to engineer KH domains with novel sequence preferences.

  5. V5852 Sgr: an unusual nova possibly associated with the Sagittarius stream

    NASA Astrophysics Data System (ADS)

    Aydi, E.; Mróz, P.; Whitelock, P. A.; Mohamed, S.; Wyrzykowski, Ł.; Udalski, A.; Vaisanen, P.; Nagayama, T.; Dominik, M.; Scholz, A.; Onozato, H.; Williams, R. E.; Hodgkin, S. T.; Nishiyama, S.; Yamagishi, M.; Smith, A. M. S.; Ryu, T.; Iwamatsu, A.; Kawamata, I.

    2016-09-01

    We report spectroscopic and photometric follow-up of the peculiar nova V5852 Sgr (discovered as OGLE-2015-NOVA-01), which exhibits a combination of features from different nova classes. The photometry shows a flat-topped light curve with quasi-periodic oscillations, then a smooth decline followed by two fainter recoveries in brightness. Spectroscopy with the Southern African Large Telescope shows first a classical nova with an Fe II or Fe II b spectral type. In the latter spectrum, broad emissions from helium, nitrogen and oxygen are prominent, and the iron has faded which could be an indication to the start of the nebular phase. The line widths suggest ejection velocities around 1000 km s-1. The nova is in the direction of the Galactic bulge and is heavily reddened by an uncertain amount. The V magnitude 16 days after maximum enables a distance to be estimated and this suggests that the nova may be in the extreme trailing stream of the Sagittarius dwarf spheroidal galaxy. If so it is the first nova to be detected from that, or from any dwarf spheroidal galaxy. Given the uncertainty of the method and the unusual light curve we cannot rule out the possibility that it is in the bulge or even the Galactic disk behind the bulge.

  6. First Measurement of Electron Neutrino Appearance in NOvA.

    PubMed

    Adamson, P; Ader, C; Andrews, M; Anfimov, N; Anghel, I; Arms, K; Arrieta-Diaz, E; Aurisano, A; Ayres, D S; Backhouse, C; Baird, M; Bambah, B A; Bays, K; Bernstein, R; Betancourt, M; Bhatnagar, V; Bhuyan, B; Bian, J; Biery, K; Blackburn, T; Bocean, V; Bogert, D; Bolshakova, A; Bowden, M; Bower, C; Broemmelsiek, D; Bromberg, C; Brunetti, G; Bu, X; Butkevich, A; Capista, D; Catano-Mur, E; Chase, T R; Childress, S; Choudhary, B C; Chowdhury, B; Coan, T E; Coelho, J A B; Colo, M; Cooper, J; Corwin, L; Cronin-Hennessy, D; Cunningham, A; Davies, G S; Davies, J P; Del Tutto, M; Derwent, P F; Deepthi, K N; Demuth, D; Desai, S; Deuerling, G; Devan, A; Dey, J; Dharmapalan, R; Ding, P; Dixon, S; Djurcic, Z; Dukes, E C; Duyang, H; Ehrlich, R; Feldman, G J; Felt, N; Fenyves, E J; Flumerfelt, E; Foulkes, S; Frank, M J; Freeman, W; Gabrielyan, M; Gallagher, H R; Gebhard, M; Ghosh, T; Gilbert, W; Giri, A; Goadhouse, S; Gomes, R A; Goodenough, L; Goodman, M C; Grichine, V; Grossman, N; Group, R; Grudzinski, J; Guarino, V; Guo, B; Habig, A; Handler, T; Hartnell, J; Hatcher, R; Hatzikoutelis, A; Heller, K; Howcroft, C; Huang, J; Huang, X; Hylen, J; Ishitsuka, M; Jediny, F; Jensen, C; Jensen, D; Johnson, C; Jostlein, H; Kafka, G K; Kamyshkov, Y; Kasahara, S M S; Kasetti, S; Kephart, K; Koizumi, G; Kotelnikov, S; Kourbanis, I; Krahn, Z; Kravtsov, V; Kreymer, A; Kulenberg, Ch; Kumar, A; Kutnink, T; Kwarciancy, R; Kwong, J; Lang, K; Lee, A; Lee, W M; Lee, K; Lein, S; Liu, J; Lokajicek, M; Lozier, J; Lu, Q; Lucas, P; Luchuk, S; Lukens, P; Lukhanin, G; Magill, S; Maan, K; Mann, W A; Marshak, M L; Martens, M; Martincik, J; Mason, P; Matera, K; Mathis, M; Matveev, V; Mayer, N; McCluskey, E; Mehdiyev, R; Merritt, H; Messier, M D; Meyer, H; Miao, T; Michael, D; Mikheyev, S P; Miller, W H; Mishra, S R; Mohanta, R; Moren, A; Mualem, L; Muether, M; Mufson, S; Musser, J; Newman, H B; Nelson, J K; Niner, E; Norman, A; Nowak, J; Oksuzian, Y; Olshevskiy, A; Oliver, J; Olson, T; Paley, J; Pandey, P; Para, A; Patterson, R B; Pawloski, G; Pearson, N; Perevalov, D; Pershey, D; Peterson, E; Petti, R; Phan-Budd, S; Piccoli, L; Pla-Dalmau, A; Plunkett, R K; Poling, R; Potukuchi, B; Psihas, F; Pushka, D; Qiu, X; Raddatz, N; Radovic, A; Rameika, R A; Ray, R; Rebel, B; Rechenmacher, R; Reed, B; Reilly, R; Rocco, D; Rodkin, D; Ruddick, K; Rusack, R; Ryabov, V; Sachdev, K; Sahijpal, S; Sahoo, H; Samoylov, O; Sanchez, M C; Saoulidou, N; Schlabach, P; Schneps, J; Schroeter, R; Sepulveda-Quiroz, J; Shanahan, P; Sherwood, B; Sheshukov, A; Singh, J; Singh, V; Smith, A; Smith, D; Smolik, J; Solomey, N; Sotnikov, A; Sousa, A; Soustruznik, K; Stenkin, Y; Strait, M; Suter, L; Talaga, R L; Tamsett, M C; Tariq, S; Tas, P; Tesarek, R J; Thayyullathil, R B; Thomsen, K; Tian, X; Tognini, S C; Toner, R; Trevor, J; Tzanakos, G; Urheim, J; Vahle, P; Valerio, L; Vinton, L; Vrba, T; Waldron, A V; Wang, B; Wang, Z; Weber, A; Wehmann, A; Whittington, D; Wilcer, N; Wildberger, R; Wildman, D; Williams, K; Wojcicki, S G; Wood, K; Xiao, M; Xin, T; Yadav, N; Yang, S; Zadorozhnyy, S; Zalesak, J; Zamorano, B; Zhao, A; Zirnstein, J; Zwaska, R

    2016-04-15

    We report results from the first search for ν_{μ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.

  7. High convergence, indirect drive inertial confinement fusion experiments at Nova

    SciTech Connect

    Lerche, R.A.; Cable, M.D.; Hatchett, S.P.

    1995-06-02

    High convergence, indirect drive implosion experiments have been done at the Nova Laser Facility. The targets were deuterium and deuterium/tritium filled, glass microballoons driven symmetrically by x rays produced in a surrounding uranium hohlraum. Implosions achieved convergence ratios of 24:1 with fuel densities of 19 g/cm{sup 3}; this is equivalent to the range required for the hot spot of ignition scale capsules. The implosions used a shaped drive and were well characterized by a variety of laser and target measurements. The primary measurement was the fuel density using the secondary neutron technique (neutrons from the reaction {sup 2}H({sup 3}H,n){sup 4}He in initially pure deuterium fuel). Laser measurements include power, energy and pointing. Simultaneous measurement of neutron yield, fusion reaction rate, and x-ray images provide additional information about the implosion process. Computer models are in good agreement with measured results.

  8. Nova Scorpii 2015 == PNV J17032620-3504140

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2015-02-01

    AAVSO Alert Notice 508 announces the discovery of Nova Scorpii 2015 = PNV J17032620-3504140 [V1535 Sco] by Tadashi Kojima (Gunma-ken, Japan) at unfiltered DSLR magnitude 8.1, using a 150-mm f/2.8 lens and digital camera, on 2015 February 11.837 UT. Coordinates: RA: 17 03 26.18 , Decl: -35 04 17.6 (2000.0). Echelle spectra by Frederick Walter (Stony Brook University) taken on 2015 February 13.40 UT and reported in Astronomer's Telegram #7060 indicate the presence of strong H-alpha with FWHM of 2000 km/s, along with several other emission features. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  9. Attenuation Calibration in the NOvA Detectors

    NASA Astrophysics Data System (ADS)

    Campbell, Medbh; NOvA Collaboration

    2017-01-01

    NOvA is a long baseline neutrino experiment which is constructed from long extruded PVC cells filled with liquid scintillator. When charged particles move through the scintillator, they produce scintillation light. A loop of wavelength shifting optical fibre in each cell transports the scintillation light to the electronic readout. Light is attenuated as it passes through this fibre - this must be calibrated for using cosmic muons. However, cosmic muons do not deposit equal amounts of energy throughout the detector due to threshold effects, detector self-shielding, and variation in individual fibres' transmittance of light. In this talk, we discuss corrections for all three of these effects, and their impact on the accuracy of reconstructed energy.

  10. NOVA-NREL Optimal Vehicle Acquisition Analysis (Brochure)

    SciTech Connect

    Blakley, H.

    2011-03-01

    Federal fleet managers face unique challenges in accomplishing their mission - meeting agency transportation needs while complying with Federal goals and mandates. Included in these challenges are a variety of statutory requirements, executive orders, and internal goals and objectives that typically focus on petroleum consumption and greenhouse gas (GHG) emissions reductions, alternative fuel vehicle (AFV) acquisitions, and alternative fuel use increases. Given the large number of mandates affecting Federal fleets and the challenges faced by all fleet managers in executing day-to-day operations, a primary challenge for agencies and other organizations is ensuring that they are as efficient as possible in using constrained fleet budgets. An NREL Optimal Vehicle Acquisition (NOVA) analysis makes use of a mathematical model with a variety of fleet-related data to create an optimal vehicle acquisition strategy for a given goal, such as petroleum or GHG reduction. The analysis can helps fleets develop a vehicle acquisition strategy that maximizes petroleum and greenhouse gas reductions.

  11. NOvA (Fermilab E929) Official Plots and Figures

    DOE Data Explorer

    The NOvA collaboration, consisting of 180 researchers across 28 institutions and managed by the Fermi National Accelerator Laboratory (FNAL), is developing instruments for a neutrino-focused experiment that will attempt to answer three fundamental questions in neutrino physics: 1) Can we observe the oscillation of muon neutrinos to electron neutrinos; 2) What is the ordering of the neutrino masses; and 3) What is the symmetry between matter and antimatter? The collaboration makes various data plots and figures available. These are grouped under five headings, with brief descriptions included for each individual figure: Neutrino Spectra, Detector Overview, Theta12 Mass Hierarchy CP phase, Theta 23 Delta Msqr23, and NuSterile.

  12. Using the Nova target chamber for high-yield targets

    SciTech Connect

    Pitts, J.H.

    1987-09-28

    The existing 2.2-m-radius Nova aluminum target chamber, coated and lined with boron-seeded carbon shields, is proposed for use with 1000-MJ-yield targets in the next laser facility. The laser beam and diagnostic holes in the target chamber are left open and the desired 10/sup -2/ Torr vacuum is maintained both inside and outside the target chamber; a larger target chamber room is the vacuum barrier to the atmosphere. The hole area available is three times that necessary to maintain a maximum fluence below 12 J/cm/sup 2/ on optics placed at a radius of 10 m. Maximum stress in the target chamber wall is 73 MPa, which complies with the intent of the ASME Pressure Vessel Code. However, shock waves passing through the inner carbon shield could cause it to comminute. We propose tests and analyses to ensure that the inner carbon shield survives the environment. 13 refs.

  13. First Measurement of Electron Neutrino Appearance in NOvA

    NASA Astrophysics Data System (ADS)

    Adamson, P.; Ader, C.; Andrews, M.; Anfimov, N.; Anghel, I.; Arms, K.; Arrieta-Diaz, E.; Aurisano, A.; Ayres, D. S.; Backhouse, C.; Baird, M.; Bambah, B. A.; Bays, K.; Bernstein, R.; Betancourt, M.; Bhatnagar, V.; Bhuyan, B.; Bian, J.; Biery, K.; Blackburn, T.; Bocean, V.; Bogert, D.; Bolshakova, A.; Bowden, M.; Bower, C.; Broemmelsiek, D.; Bromberg, C.; Brunetti, G.; Bu, X.; Butkevich, A.; Capista, D.; Catano-Mur, E.; Chase, T. R.; Childress, S.; Choudhary, B. C.; Chowdhury, B.; Coan, T. E.; Coelho, J. A. B.; Colo, M.; Cooper, J.; Corwin, L.; Cronin-Hennessy, D.; Cunningham, A.; Davies, G. S.; Davies, J. P.; Del Tutto, M.; Derwent, P. F.; Deepthi, K. N.; Demuth, D.; Desai, S.; Deuerling, G.; Devan, A.; Dey, J.; Dharmapalan, R.; Ding, P.; Dixon, S.; Djurcic, Z.; Dukes, E. C.; Duyang, H.; Ehrlich, R.; Feldman, G. J.; Felt, N.; Fenyves, E. J.; Flumerfelt, E.; Foulkes, S.; Frank, M. J.; Freeman, W.; Gabrielyan, M.; Gallagher, H. R.; Gebhard, M.; Ghosh, T.; Gilbert, W.; Giri, A.; Goadhouse, S.; Gomes, R. A.; Goodenough, L.; Goodman, M. C.; Grichine, V.; Grossman, N.; Group, R.; Grudzinski, J.; Guarino, V.; Guo, B.; Habig, A.; Handler, T.; Hartnell, J.; Hatcher, R.; Hatzikoutelis, A.; Heller, K.; Howcroft, C.; Huang, J.; Huang, X.; Hylen, J.; Ishitsuka, M.; Jediny, F.; Jensen, C.; Jensen, D.; Johnson, C.; Jostlein, H.; Kafka, G. K.; Kamyshkov, Y.; Kasahara, S. M. S.; Kasetti, S.; Kephart, K.; Koizumi, G.; Kotelnikov, S.; Kourbanis, I.; Krahn, Z.; Kravtsov, V.; Kreymer, A.; Kulenberg, Ch.; Kumar, A.; Kutnink, T.; Kwarciancy, R.; Kwong, J.; Lang, K.; Lee, A.; Lee, W. M.; Lee, K.; Lein, S.; Liu, J.; Lokajicek, M.; Lozier, J.; Lu, Q.; Lucas, P.; Luchuk, S.; Lukens, P.; Lukhanin, G.; Magill, S.; Maan, K.; Mann, W. A.; Marshak, M. L.; Martens, M.; Martincik, J.; Mason, P.; Matera, K.; Mathis, M.; Matveev, V.; Mayer, N.; McCluskey, E.; Mehdiyev, R.; Merritt, H.; Messier, M. D.; Meyer, H.; Miao, T.; Michael, D.; Mikheyev, S. P.; Miller, W. H.; Mishra, S. R.; Mohanta, R.; Moren, A.; Mualem, L.; Muether, M.; Mufson, S.; Musser, J.; Newman, H. B.; Nelson, J. K.; Niner, E.; Norman, A.; Nowak, J.; Oksuzian, Y.; Olshevskiy, A.; Oliver, J.; Olson, T.; Paley, J.; Pandey, P.; Para, A.; Patterson, R. B.; Pawloski, G.; Pearson, N.; Perevalov, D.; Pershey, D.; Peterson, E.; Petti, R.; Phan-Budd, S.; Piccoli, L.; Pla-Dalmau, A.; Plunkett, R. K.; Poling, R.; Potukuchi, B.; Psihas, F.; Pushka, D.; Qiu, X.; Raddatz, N.; Radovic, A.; Rameika, R. A.; Ray, R.; Rebel, B.; Rechenmacher, R.; Reed, B.; Reilly, R.; Rocco, D.; Rodkin, D.; Ruddick, K.; Rusack, R.; Ryabov, V.; Sachdev, K.; Sahijpal, S.; Sahoo, H.; Samoylov, O.; Sanchez, M. C.; Saoulidou, N.; Schlabach, P.; Schneps, J.; Schroeter, R.; Sepulveda-Quiroz, J.; Shanahan, P.; Sherwood, B.; Sheshukov, A.; Singh, J.; Singh, V.; Smith, A.; Smith, D.; Smolik, J.; Solomey, N.; Sotnikov, A.; Sousa, A.; Soustruznik, K.; Stenkin, Y.; Strait, M.; Suter, L.; Talaga, R. L.; Tamsett, M. C.; Tariq, S.; Tas, P.; Tesarek, R. J.; Thayyullathil, R. B.; Thomsen, K.; Tian, X.; Tognini, S. C.; Toner, R.; Trevor, J.; Tzanakos, G.; Urheim, J.; Vahle, P.; Valerio, L.; Vinton, L.; Vrba, T.; Waldron, A. V.; Wang, B.; Wang, Z.; Weber, A.; Wehmann, A.; Whittington, D.; Wilcer, N.; Wildberger, R.; Wildman, D.; Williams, K.; Wojcicki, S. G.; Wood, K.; Xiao, M.; Xin, T.; Yadav, N.; Yang, S.; Zadorozhnyy, S.; Zalesak, J.; Zamorano, B.; Zhao, A.; Zirnstein, J.; Zwaska, R.; NOvA Collaboration

    2016-04-01

    We report results from the first search for νμ→νe transitions by the NOvA experiment. In an exposure equivalent to 2.74 ×1020 protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99 ±0.11 (syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07 ±0.14 (syst) . The 3.3 σ excess of events observed in the primary analysis disfavors 0.1 π <δC P<0.5 π in the inverted mass hierarchy at the 90% C.L.

  14. Quiescent accretion disks in black hole X-ray novae

    NASA Technical Reports Server (NTRS)

    Orosz, Jerome A.; Bailyn, Charles D.; Remillard, Ronald A.; Mcclintock, Jeffrey E.; Foltz, Craig B.

    1994-01-01

    We present detailed time-resolved spectroscopy of the Balmer emission lines from two black hole binary systems in quiescence, A0620-00 and Nova Muscae 1991. We find extraordinary similarities between the two systems. There are 30-40 km/s velocity variations of the emission lines over the orbital period, the phases of which are not aligned with the expected phase of the motion of the compact primary. Detailed modeling of both systems is complicated by variable hot spot components, regions of optical thickness, and intermittent excess emission in the blue line wings of the H-alpha lines. Both sources also display low velocities at the outer edge of the accretion disk, implying a large primary Roche lobe and extreme mass ratios. These complications suggest that although simple optically thin, Keplerian alpha-disk models provide a useful parameterization of emission lines from these systems, the straightforward physical models they imply should be treated with great caution.

  15. Nova DAQ, System Architecture, Data Combiner and Timing System

    SciTech Connect

    Biery, K.A.; Cooper, R.G.; Foulkes, S.C.; Guglielmo, G.M.; Haynes, B.W.; Kwarciany, R.; Pavlicek, F.V.; Piccoli, L.P.; Votava, M.E.V.; /Fermilab

    2007-04-01

    NOvA (E929) is a long baseline experiment that will search for neutrino oscillations. There will be one detector near the beam source at Fermilab, and one detector in northern Minnesota. The DAQ system for the far detector collects over-threshold hits from over 450,000 channels of scintillator readouts, sorts the time-stamped data packets and archives selected time periods of data for transmission and processing. While a simple point-to-point protocol is used for the first level of data collection, Ethernet was chosen as the fabric for the rest of the DAQ. The packet time-stamp and overall system synchronization is based on two common-view GPS trained clock oscillators, one at each site. The present design cost-effectively satisfies the experiment's moderate speed and data volume requirements.

  16. Simulations of NOVA direct-drive Rayleigh-Taylor experiments

    SciTech Connect

    Weber, S.V.

    1990-11-03

    Directly driven Rayleigh-Taylor instability growth experiments being performed on NOVA have been simulated using the computer code, LASNEX. These experiments employ beams smoothed with random phase plates (RPP), and will later include smoothing by spectral dispersion (SSD). Samples are CH foils with or without imposed sinusoidal surface perturbations. Perturbation growth is diagnosed by means of x-ray backlighting. Calculated growth rates are fairly flat across the wavelength range of 20--80 {mu}m which can be accessed experimentally, and are moderately suppressed below classical growth rates. Perturbations of large enough initial amplitude that the contrast in the x-ray image is measurable from the start of the experiment quickly grow into the nonlinear regime. Smaller initial amplitudes result in a longer interval of linear growth, but the initial perturbation will not be detectable in the data. Structure which is predicted to develop from speckles in the RPP beam pattern, with and without SSD, is also presented.

  17. Holocene transgressive stratigraphy and sediment dispersal, eastern shore, Nova Scotia

    SciTech Connect

    Hall, R.K.; Boyd, R.

    1985-02-01

    Coastal sedimentation along Nova Scotia's eastern shore is dominated by a rising sea level, restricted drumlin sediment supply, and inherited glacial topography. Evolution of barrier systems follows a 500-1000 year cyclic sequence of: (1) generation from marine erosion of glacial deposits, (2) transgression resulting from ongoing sea level rise and depletion of original sediment sources, and (3) landward removal following an estuarine retreat path to new sites of reconstruction. The dominant sediment transfer mechanism operating during this transgressive cycle is landward dispersal by tidal inlet, overwash, and eolian process. Vibrocore, surface sampling, marine geophysics, and underwater photography were used to investigate the potential for eastern shore coastal deposits to be incorporated into the shelf stratigraphic record. High-resolution seismic profiles from the inner continental shelf reveal a lower acoustic unit interpreted as Wisconsin glacial deposits. Overlying the lower unit is a discontinuous upper unit 1-2 m thick, which occupies topographic depressions and is composed of sand, silty sand, and a coarse gravel lag. Side-scan sonar and underwater photographs show large gravel ripples covering the upper acoustic unit in water up to 30 m deep. The upper acoustic unit is interpreted as the remnants of reworked coastal barriers, drumlins, and till. Transgressive sedimentation on the eastern shore of Nova Scotia, therefore, conforms to the concept of shoreface retreat. Coastal sediments here are poorly preserved, except in linear shelf valleys, because of a high-energy wavy climate and prior landward transfer into tidal deltas, washovers, and associated back-barriers deposits.

  18. Inertial confinement fusion ablator physics experiments on Saturn and Nova

    SciTech Connect

    Olson, R.E.; Porter, J.L.; Chandler, G.A.; Fehl, D.L.; Jobe, D.O.; Leeper, R.J.; Matzen, M.K.; McGurn, J.S.; Noack, D.D.; Ruggles, L.E.; Sawyer, P.; Torres, J.A.; Vargas, M.; Zagar, D.M.; Kornblum, H.N.; Orzechowski, T.J.; Phillion, D.W.; Suter, L.J.; Thiessen, A.R.; Wallace, R.J.

    1997-05-01

    The Saturn pulsed power accelerator [R. B. Spielman {ital et al.}, in {ital Proceedings of the 2nd International Conference on Dense} Z-{ital pinches}, Laguna Beach, CA, 1989, edited by N. R. Pereira, J. Davis, and N. Rostoker (American Institute of Physics, New York, 1989), p. 3] at Sandia National Laboratories (SNL) and the Nova laser [J. T. Hunt and D. R. Speck, Opt. Eng. {bold 28}, 461 (1989)] at Lawrence Livermore National Laboratory (LLNL) have been used to explore techniques for studying the behavior of ablator material in x-ray radiation environments comparable in magnitude, spectrum, and duration to those that would be experienced in National Ignition Facility (NIF) hohlraums [J. D. Lindl, Phys. Plasmas {bold 2}, 3933 (1995)]. The large x-ray outputs available from the Saturn pulsed-power-driven z pinch have enabled us to drive hohlraums of full NIF ignition scale size at radiation temperatures and time scales comparable to those required for the low-power foot pulse of an ignition capsule. The high-intensity drives available in the Nova laser have allowed us to study capsule ablator physics in smaller-scale hohlraums at radiation temperatures and time scales relevant to the peak power pulse for an ignition capsule. Taken together, these experiments have pointed the way to possible techniques for testing radiation-hydrodynamics code predictions of radiation flow, opacity, equation of state, and ablator shock velocity over the range of radiation environments that will be encountered in a NIF hohlraum. {copyright} {ital 1997 American Institute of Physics.}

  19. Constraining nova observables: Direct measurements of resonance strengths in 33S(p,γ)34Cl

    NASA Astrophysics Data System (ADS)

    Fallis, J.; Parikh, A.; Bertone, P. F.; Bishop, S.; Buchmann, L.; Chen, A. A.; Christian, G.; Clark, J. A.; D'Auria, J. M.; Davids, B.; Deibel, C. M.; Fulton, B. R.; Greife, U.; Guo, B.; Hager, U.; Herlitzius, C.; Hutcheon, D. A.; José, J.; Laird, A. M.; Li, E. T.; Li, Z. H.; Lian, G.; Liu, W. P.; Martin, L.; Nelson, K.; Ottewell, D.; Parker, P. D.; Reeve, S.; Rojas, A.; Ruiz, C.; Setoodehnia, K.; Sjue, S.; Vockenhuber, C.; Wang, Y. B.; Wrede, C.

    2013-10-01

    The 33S(p,γ)34Cl reaction is important for constraining predictions of certain isotopic abundances in oxygen-neon novae. Models currently predict as much as 150 times the solar abundance of 33S in oxygen-neon nova ejecta. This overproduction factor may vary by orders of magnitude due to uncertainties in the 33S(p,γ)34Cl reaction rate at nova peak temperatures. Depending on this rate, 33S could potentially be used as a diagnostic tool for classifying certain types of presolar grains. Better knowledge of the 33S(p,γ)34Cl rate would also aid in interpreting nova observations over the S-Ca mass region and contribute to the firm establishment of the maximum endpoint of nova nucleosynthesis. Additionally, the total S elemental abundance which is affected by this reaction has been proposed as a thermometer to study the peak temperatures of novae. Previously, the 33S(p,γ)34Cl reaction rate had only been studied directly down to resonance energies of 432 keV. However, for nova peak temperatures of 0.2-0.4 GK there are seven known states in 34Cl both below the 432-keV resonance and within the Gamow window that could play a dominant role. Direct measurements of the resonance strengths of these states were performed using the DRAGON (Detector of Recoils And Gammas of Nuclear reactions) recoil separator at TRIUMF. Additionally two new states within this energy region are reported. Several hydrodynamic simulations have been performed, using all available experimental information for the 33S(p,γ)34Cl rate, to explore the impact of the remaining uncertainty in this rate on nucleosynthesis in nova explosions. These calculations give a range of ≈20-150 for the expected 33S overproduction factor, and a range of ≈100-450 for the 32S/33S ratio expected in ONe novae.

  20. Experience with a high order programming language on the development of the Nova distributed control system

    SciTech Connect

    Suski, G.J.; Holloway, F.W.; Duffy, J.M.

    1983-05-10

    This paper explores the impact of an HOL on the development of the distributed computer control system for Nova laser fusion facility. As the world's most powerful glass laser, Nova will generate 150 trillion watt pulses of infrared light focused onto fusion targets a few millimeters in diameter. It will perform experiments designed to explore the feasibility of fusion as an energy source of the future. Nova will utilize fifty microcomputers and four VAX-11/780's in a distributed process control computer system architecture.

  1. Accretion disk evolution in dwarf novae through outbursts: disk instability and mass-transfer instability cases

    NASA Astrophysics Data System (ADS)

    Baptista, R.

    I discuss a set of observations of eclipsing dwarf novae through outbursts which allow fundamental tests of the predictions of the two models proposed to explain their outbursts. The observational picture which emerges from these tests indicate that there are two distinct groups of dwarf novae. While the outbursts of one group can be understood in the framework of the thermal-viscous disc instability model, those of the other group can only be explained in terms of the mass-transfer instability model. I also show that morphological differences in the orbital light curves of eclipsing dwarf novae can be useful to distinguish members of each group.

  2. A near-infrared catalogue of the Galactic novae in the VVV survey area

    NASA Astrophysics Data System (ADS)

    Saito, R. K.; Minniti, D.; Angeloni, R.; Catelan, M.; Beamin, J. C.; Borissova, J.; Dékány, I.; Kerins, E.; Kurtev, R.; Mennickent, R. E.

    2013-06-01

    Context. Near-infrared data on classical novae contain useful information about the ejected gas mass and the thermal emission by dust formed during eruption, and provide independent methods to classify the objects according to the colour of their progenitors, and the fading rate and features seen after eruption. The VISTA Variables in the Vía Láctea survey (VVV) is a near-IR ESO Public Survey mapping the Milky Way bulge and southern plane. Data taken during 2010-2011 covered the entire area in the JHKs bands plus some epochs in Ks-band of the ongoing VVV variability campaign. Aims: We used the VVV data to create a near-IR catalogue of the known Galactic novae in the 562 sq. deg. area covered by VVV. We also compiled the information about novae from the variability tables of the VVV variability campaign. Methods: We used the novae list provided by VSX/AAVSO catalogue to search for all objects within the VVV area. From the 140 novae, we were able to retrieve the JHKs colours of 93 objects. We also checked in the ongoing VVV variability campaign for the light curves of novae that erupted in the last years. Results: The VVV near-IR catalogue of novae contains JHKs photometry of 93 objects completed as of December 2012. VVV allows to monitor objects within up to ΔKs ~ 10 mag range. VVV images can also be used to discover and study novae by searching for the expanding shell. Since objects are seen at different distances and reddening levels, the colour-magnitude and colour-colour diagrams show the novae spread in magnitude as well as in colour. Dereddened colours and reddening-free indices were used with caution and cannot be a good approach in all cases since the distance and spectral features prevent more conclusive results for some extreme objects. Light curves for some recent novae are presented. Conclusions: Thanks to its high spatial resolution in the near IR and wide Ks-range, the VVV survey can be a major contributor to the search for and study of novae in the

  3. Neuroevolutional Approach to Cerebral Palsy and Speech.

    ERIC Educational Resources Information Center

    Mysak, Edward D.

    Intended for cerebral palsy specialists, the book emphasizes the contribution that a neuroevolutional approach to therapy can make to habilitation goals of the child with cerebral palsy and applies the basic principles of the Bobath approach to therapy. The first section discusses cerebral palsy as a reflection of disturbed neuro-ontogenisis and…

  4. Cerebral vasculitis associated with cocaine abuse

    SciTech Connect

    Kaye, B.R.; Fainstat, M.

    1987-10-16

    A case of cerebral vasculitis in a previously healthy 22-year-old man with a history of cocaine abuse is described. Cerebral angiograms showed evidence of vasculitis. A search for possible causes other than cocaine produced no results. The authors include cocaine with methamphetamines, heroin, and ephedrine as illicit drugs that can cause cerebral vasculitis.

  5. Behaviour Problems Amongst Children With Cerebral Palsy.

    ERIC Educational Resources Information Center

    Oswin, Maureen

    Based on 6 years of work with cerebral palsied children, the thesis considers types and causes of cerebral palsy, the life pattern of the child with cerebral palsy from early years to adolescence, and the effect of the handicapped child on his parents and family. Literature on behavior disorders is reviewed, and kinds of behavior problems are…

  6. Effects of hyperglycemia and effects of ketosis on cerebral perfusion, cerebral water distribution, and cerebral metabolism.

    PubMed

    Glaser, Nicole; Ngo, Catherine; Anderson, Steven; Yuen, Natalie; Trifu, Alexandra; O'Donnell, Martha

    2012-07-01

    Diabetic ketoacidosis (DKA) may cause brain injuries in children. The mechanisms responsible are difficult to elucidate because DKA involves multiple metabolic derangements. We aimed to determine the independent effects of hyperglycemia and ketosis on cerebral metabolism, blood flow, and water distribution. We used magnetic resonance spectroscopy to measure ratios of cerebral metabolites (ATP to inorganic phosphate [Pi], phosphocreatine [PCr] to Pi, N-acetyl aspartate [NAA] to creatine [Cr], and lactate to Cr) and diffusion-weighted imaging and perfusion-weighted imaging to assess cerebral water distribution (apparent diffusion coefficient [ADC] values) and cerebral blood flow (CBF) in three groups of juvenile rats (hyperglycemic, ketotic, and normal control). ATP-to-Pi ratio was reduced in both hyperglycemic and ketotic rats in comparison with controls. PCr-to-Pi ratio was reduced in the ketotic group, and there was a trend toward reduction in the hyperglycemic group. No significant differences were observed in NAA-to-Cr or lactate-to-Cr ratio. Cortical ADC was reduced in both groups (indicating brain cell swelling). Cortical CBF was also reduced in both groups. We conclude that both hyperglycemia and ketosis independently cause reductions in cerebral high-energy phosphates, CBF, and cortical ADC values. These effects may play a role in the pathophysiology of DKA-related brain injury.

  7. Cerebral Palsy: A Dental Update

    PubMed Central

    Sehrawat, Nidhi; Bansal, Kalpana; Chopra, Radhika

    2014-01-01

    ABSTRACT Special and medically compromised patients present a unique population that challenges the dentist’s skill and knowledge. Providing oral care to people with cerebral palsy (CP) requires adaptation of the skills we use everyday. In fact, most people with mild or moderate forms of CP can be treated successfully in the general practice setting. This article is to review various dental considerations and management of a CP patient. How to cite this article: Sehrawat N, Marwaha M, Bansal K, Chopra R. Cerebral Palsy: A Dental Update. Int J Clin Pediatr Dent 2014;7(2):109-118. PMID:25356010

  8. Caffeine induced changes in cerebral circulation

    SciTech Connect

    Mathew, R.J.; Wilson, W.H.

    1985-09-01

    While the caffeine induced cerebral vasoconstriction is well documented, the effects of oral ingestion of the drug in a dose range comparable to the quantities in which it is usually consumed and the intensity and duration of the associated reduction in cerebral circulation are unknown. Cerebral blood flow was measured via the TTXenon inhalation technique before and thirty and ninety minutes after the oral administration of 250 mg of caffeine or a placebo, under double-blind conditions. Caffeine ingestion was found to be associated with significant reductions in cerebral perfusion thirty and ninety minutes later. The placebo group showed no differences between the three sets of cerebral blood flow values.

  9. Evidence for hibernation from a statistical analysis of nova eruption amplitudes

    SciTech Connect

    Vogt, N. )

    1990-06-01

    This study is based on a sample of 97 well-observed galactic novae. First, a linear relation between eruption amplitude and decay time was determined. The residuals from this relation were analyzed for variations of the luminosities of old novae as a function of the time interval between eruption and observation in quiescence. Between 35 and 10 yr before eruption, a marginal increase in brightness may be present. However, in the last decade, four novae were found in an extremely faint low state. During the first 130 yr after the eruption, galactic novae show a slow decrease in brightness with a slope of 2.1 + or - 0.6 mag per century. The results are interpreted in terms of secular variations of the mass transfer rate as expected from the hibernation model. 20 refs.

  10. Fermi Establishes Classical Novae as a Distinct Class of Gamma-ray Sources

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Albert, A.; Baldini, L.; Ballet, J.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Ferrara, E. C.; Harding, A. K.; Hays, E.; Perkins, J. S.; Thompson, D. J.

    2014-01-01

    A classical nova results from runaway thermonuclear explosions on the surface of a white dwarf that accretes matter from a low-mass main-sequence stellar companion. In 2012 and 2013, three novae were detected in gamma rays and stood in contrast to the first gamma-ray detected nova V407 Cygni 2010, which belongs to a rare class of symbiotic binary systems. Despite likely differences in the compositions and masses of their white dwarf progenitors, the three classical novae are similarly characterized as soft spectrum transient gamma-ray sources detected over 2-3 week durations. The gamma-ray detections point to unexpected high-energy particle acceleration processes linked to the mass ejection from thermonuclear explosions in an unanticipated class of Galactic gamma-ray sources.

  11. Near-Infrared spectroscopy of the possible nova candidate PNV J17355050-2934240

    NASA Astrophysics Data System (ADS)

    Srivastava, Mudit; Joshi, Vishal; Banerjee, D. P. K.; Ashok, N. M.

    2016-03-01

    We report near-infrared observations of PNV J17355050-2934240 which has been reported as a possible nova candidate in the CBAT TOCP site (http://www.cbat.eps.harvard.edu/unconf/followups/J17355050-2934240.html).

  12. Confirmation of nova M31N 2017-01a with Swift/UVOT

    NASA Astrophysics Data System (ADS)

    Henze, M.; Middleton, M. J.

    2017-01-01

    We report the detection of the nova candidate M31N 2017-01a (ATel #9958; alternate designation PNV J00424525+4116108) in three recent observations obtained with the ultraviolet/optical telescope (UVOT) aboard the Swift satellite.

  13. Formation of Novae and Coronae on Venus. Tectonophysical Modeling Using Gravity Models

    NASA Astrophysics Data System (ADS)

    Krassilnikov, A. S.

    2001-03-01

    Novae and coronae formation was simulated using caoutchouc as a model of lower ductile part of lithosphere and dry flour as a model of upper brittle part of it. Distribution and character of the deformational structures is described.

  14. The spectral evolution of nebular phase from Nova V5668 Sgr

    NASA Astrophysics Data System (ADS)

    Muztaba, Robiatul; Malasan, Hakim L.; Arai, Akira

    2016-11-01

    The spectral evolution of the Nova V5668 Sgr has been observed on 12 June, 23 June, and 15 August 2015 using NEO-R1000 spectrograph attached to the C-11 telescope at Bosscha Observatory, Lembang, Indonesia. The observed spectra indicate that the nova has been entering the nebular phase. The spectra during this phase showed strong forbidden lines of [O I] λ6300, 6364, [O II] λ7320, and [O III] λ5007, [N II] λ5755. The spectra also showed emission line of Fe II λ4924, 5169, 5317, 6149. We classify Nova V5668 Sgr into the Fe II type. We present and discuss the variation of nebular abundance N(X)/N(H) of the Nova V5668 Sgr in the light of its evolutionary stages.

  15. Factors Impacting the Successful Implementation of Comprehensive Guidance and Counseling Programs in Nova Scotia.

    ERIC Educational Resources Information Center

    Lehr, Ron; Sumarah, John

    2002-01-01

    Assesses factors that contribute to the successful implementation of comprehensive guidance and counseling programs at the elementary, junior, and senior high school levels in Nova Scotia. Examines counselors' perceptions of what helps or hinders successful implementation. (Contains 15 references.) (GCP)

  16. Optical and Near-infrared Study of Nova V2676 Oph 2012

    NASA Astrophysics Data System (ADS)

    Raj, A.; Das, R. K.; Walter, F. M.

    2017-02-01

    We present optical spectrophotometric and near-infrared (NIR) photometric observations of the nova V2676 Oph covering the period from 2012 March 29 through 2015 May 8. The optical spectra and photometry of the nova have been taken from SMARTS and Asiago; the NIR photometry was obtained from SMARTS and Mt. Abu. The spectra were dominated by strong H i lines from the Balmer series, Fe ii, N i, and [O i] lines in the initial days, typical of an Fe ii type nova. The measured FWHM for the Hβ and Hα lines was 800–1200 km s‑1. There was pronounced dust formation starting 90 days after the outburst. The J ‑ K color was the largest among recent dust-forming novae.

  17. MINOR MALFORMATIONS AND PHYSICAL MEASURES IN AUTISM: DATA FROM NOVA SCOTIA. (R824758)

    EPA Science Inventory

    In the context of an epidemiological study of autism in Nova Scotia, subjects were evaluated for minor physical anomalies and physical measurements. Normal control children, children with autism and their siblings, and children with developmental disabilities and their siblings w...

  18. A Method for Telluric Line Removal from Supernova and Nova Spectra

    NASA Astrophysics Data System (ADS)

    Jack, D.

    2017-04-01

    We present a new method for removing telluric lines from high resolution supernova and nova spectra. This simple and quick method has the advantage of also eliminating any interstellar and intergalactic absorption features, and it smoothens the spectra removing noise and any possible cosmic-ray hits. The method identifies narrow lines in the very broad features of supernova and nova spectra and removes all of them. We applied the method to observed high resolution (R≍20,000) spectra of the type Ia supernova SN 2014J and performed a study of the effects of telluric lines in low resolution spectra of this supernova. The differences in flux can be around 25% in some wavelength ranges with broad telluric bands. In addition, we demonstrate that this method can also be applied to high resolution spectra of novae and present as an example the telluric line removal in the spectra of Nova V5668 Sgr.

  19. Cerebral ventricular volume during hyponatraemia.

    PubMed Central

    Decaux, G; Szyper, M; Grivegnée, A

    1983-01-01

    In order to determine if the neurologic manifestations in chronic hyponatraemia result partly from brain oedema, we measured the cerebral ventricular volume before and after correction of hyponatraemia in eight patients with central nervous system manifestations. Only the three patients with seizures showed a clear change in the ventricular size and probably had brain oedema. PMID:6101182

  20. Investigating cerebral oedema using poroelasticity.

    PubMed

    Vardakis, John C; Chou, Dean; Tully, Brett J; Hung, Chang C; Lee, Tsong H; Tsui, Po-Hsiang; Ventikos, Yiannis

    2016-01-01

    Cerebral oedema can be classified as the tangible swelling produced by expansion of the interstitial fluid volume. Hydrocephalus can be succinctly described as the abnormal accumulation of cerebrospinal fluid (CSF) within the brain which ultimately leads to oedema within specific sites of parenchymal tissue. Using hydrocephalus as a test bed, one is able to account for the necessary mechanisms involved in the interaction between oedema formation and cerebral fluid production, transport and drainage. The current state of knowledge about integrative cerebral dynamics and transport phenomena indicates that poroelastic theory may provide a suitable framework to better understand various diseases. In this work, Multiple-Network Poroelastic Theory (MPET) is used to develop a novel spatio-temporal model of fluid regulation and tissue displacement within the various scales of the cerebral environment. The model is applied through two formats, a one-dimensional finite difference - Computational Fluid Dynamics (CFD) coupling framework, as well as a two-dimensional Finite Element Method (FEM) formulation. These are used to investigate the role of endoscopic fourth ventriculostomy in alleviating oedema formation due to fourth ventricle outlet obstruction (1D coupled model) in addition to observing the capability of the FEM template in capturing important characteristics allied to oedema formation, like for instance in the periventricular region (2D model).

  1. Graft selection in cerebral revascularization.

    PubMed

    Baaj, Ali A; Agazzi, Siviero; van Loveren, Harry

    2009-05-01

    Cerebral revascularization constitutes an important treatment modality in the management of complex aneurysms, carotid occlusion, tumor, and moyamoya disease. Graft selection is a critical step in the planning of revascularization surgery, and depends on an understanding of graft and regional hemodynamics, accessibility, and patency rates. The goal of this review is to highlight some of these properties.

  2. Neuropathology of Acquired Cerebral Trauma.

    ERIC Educational Resources Information Center

    Bigler, Erin D.

    1987-01-01

    To help educators understand the cognitive and behavioral sequelae of cerebral injury, the neuropathology of traumatic brain injury and the main neuropathological features resulting from trauma-related brain damage are reviewed. A glossary with definitions of 37 neurological terms is appended. (Author/DB)

  3. Anxiety and Lateral Cerebral Function

    ERIC Educational Resources Information Center

    Tucker, Don M.; And Others

    1978-01-01

    Examines the effect of stressful and nonstressful experimental situations upon the processing capacity of each cerebral hemisphere, through observing the differential performance tasks presented to right and left visual half-fields (VHFs). Also examines attentional bias and lateral eye movements. (Author/RK)

  4. Sirt1 in cerebral ischemia

    PubMed Central

    Koronowski, Kevin B.; Perez-Pinzon, Miguel A.

    2015-01-01

    Cerebral ischemia is among the leading causes of death worldwide. It is characterized by a lack of blood flow to the brain that results in cell death and damage, ultimately causing motor, sensory, and cognitive impairments. Today, clinical treatment of cerebral ischemia, mostly stroke and cardiac arrest, is limited and new neuroprotective therapies are desperately needed. The Sirtuin family of oxidized nicotinamide adenine dinucleotide (NAD+)-dependent deacylases has been shown to govern several processes within the central nervous system as well as to possess neuroprotective properties in a variety of pathological conditions such as Alzheimer’s Disease, Parkinson’s Disease, and Huntington’s Disease, among others. Recently, Sirt1 in particular has been identified as a mediator of cerebral ischemia, with potential as a possible therapeutic target. To gather studies relevant to this topic, we used PubMed and previous reviews to locate, select, and resynthesize the lines of evidence presented here. In this review, we will first describe some functions of Sirt1 in the brain, mainly neurodevelopment, learning and memory, and metabolic regulation. Second, we will discuss the experimental evidence that has implicated Sirt1 as a key protein in the regulation of cerebral ischemia as well as a potential target for the induction of ischemic tolerance. PMID:26819971

  5. Confusional state and cerebral infarcts.

    PubMed Central

    García-Albea, E.

    1989-01-01

    Thirteen patients with confusional state and cerebral infarction were studied. Seven patients had optic pathway alterations. On computed tomographic scan, 2 patients had multiple infarctions and 10 had single infarctions, predominantly located in the temporo-occipital associative cortex. One patient had a normal scan. Reduction of 'selective attention', 'release' hallucinations, amnesic syndrome and secondary individual adjustment could explain the confusional state. PMID:2608563

  6. Cerebral gigantism with West syndrome.

    PubMed

    Ray, Munni; Malhi, P; Bhalla, A K; Singhi, P D

    2003-07-01

    A case of cerebral gigantism (Sotos syndrome) with West syndrome in a one-year-old male child is reported. The case had a large stature, typical facies and neurodevelopmental delay along with infantile spasms, which were refractory to treatment with valproate and clonazepam.

  7. The Orbital Periods and Variability of the Nova-Like BK Lyncis (PG 0917+342) and the Dwarf Nova WW Ceti

    NASA Astrophysics Data System (ADS)

    Ringwald, F. A.; Thorstensen, J. R.; Honeycutt, R. K.; Robertson, J. W.; Smith, Robert Connon

    1995-12-01

    Long-term light curves of the cataclysmic variable BK Lyn (PG 0917+342) from the Indiana Automated CCD photometric telescope (``RoboScope'') and the Harvard College Observatory plate archive reveal no dwarf nova outbursts. Two radial velocity studies show its orbital period to be 107.97 +/- 0.07 minutes, confirming that it does have an orbital period shorter than the 2 -- 3-hour orbital period gap for cataclysmic variables. Whether this is a nova-like below the period gap or a dwarf nova with rare outbursts resembling WZ Sge is still unclear, but anomalously high angular momentum loss below the period gap may imply that magnetic stellar-wind braking still works below the period gap---but mass-losing secondary stars there are thought to be fully convective, and therefore should not have magnetic braking. If BK Lyn is a genuine nova-like beneath the period gap, it may provide evidence of magnetic activity occurring in the faintest M dwarfs, here in an interacting binary. A radial velocity study resolves a long-standing aliasing problem and shows that the orbital period of the dwarf nova WW Cet is 0.17578 +/- 0.00013 d (4.22 hours). Its long-term light curves from RoboScope, AAVSO, Harvard archive, and VSS, RASNZ observations are examined. WW Cet does not have the characteristic standstills of the Z Cam stars, but does wander in quiescence by well over one magnitude. This and the orbital period become of interest in the context of recent speculation (Livio M., Pringle J. E., 1994, ApJ, 427, 956) that the low states of the VY Scl stars may be produced by star spots moving over L_1, choking off the mass flow, and that dwarf novae with orbital periods between 3 and 4 hours may be rare because of this.

  8. Distribution of novae and supernova remnants in the Large Magellanic Cloud

    SciTech Connect

    Van den Bergh, S.

    1988-12-01

    Novae in the LMC appear to be distributred like an old disk population. The fact that no concentration of novae is seen within the Bar of the Large Cloud suggests that this feature is of relatively recent origin. Supernova remnants are seen to exhibit concentrations in the 30 Dor region, in the Bar of the Large Cloud, and in Constellation III. This distribution supports the idea that most of the supernova remnants in the LMC had young massive progenitors. 11 references.

  9. Spectroscopy and photometry of HR Lyr (Nova Lyr 1919) during one of its mysterious dimming episodes

    NASA Astrophysics Data System (ADS)

    Munari, U.; Siviero, A.; Ochner, P.; Dallaporta, S.

    2016-08-01

    An alert posted to the BAA-VSS newsgroup on Aug 24 by J. Shears informs about a new excursion down to V~17 of old nova HR Lyr (Nova Lyr 1919). A few other such episodes were catch by Honeycutt et al (2014, AJ 147, 105) in their intensive 1991-2012 V-band monitoring of HR Lyr, usually between V=15.5 and 16.0.

  10. Strategies of design, development and activation of the Nova control system

    SciTech Connect

    Holloway, F.W.

    1983-06-30

    Nova and Novette are large complex experimental laser facilities which require extensive and sophisticated control systems for their successful operation. Often, in major controls projects, certain invisible aspects of the project, such as overall strategy, management, resources and historical constraints, have a more profound effect upon success than any specific hardware/software design. The design and performance of the Nova/Novette laser control system will be presented with special emphasis upon these often controversial aspects.

  11. Discovery of ten galactic Nova candidates in the VVV disk area

    NASA Astrophysics Data System (ADS)

    Saito, R. K.; Minniti, D.; Catelan, M.; Angeloni, R.; Beamin, J. C.; Palma, T.; Gutierrez, L. A.; Montenegro, K.

    2016-01-01

    We report the discovery of ten likely Galactic novae by the VVV Survey in its disk area (vvvsurvey.org; Minniti et al. 2010, New Astronomy, 15, 433). A search for high-amplitude transients on the VVV disk data taken during the 2010-2013 seasons detected the presence of ten stellar sources fading in brightness by at least Delta_Ks=3 mag with their light curves following the expected behavior of a nova outburst.

  12. Regulation of cerebral autoregulation by carbon dioxide.

    PubMed

    Meng, Lingzhong; Gelb, Adrian W

    2015-01-01

    Cerebral autoregulation describes a mechanism that maintains cerebral blood flow stable despite fluctuating perfusion pressure. Multiple nonperfusion pressure processes also regulate cerebral perfusion. These mechanisms are integrated. The effect of the interplay between carbon dioxide and perfusion pressure on cerebral circulation has not been specifically reviewed. On the basis of the published data and speculation on the aspects that are without supportive data, the authors offer a conceptualization delineating the regulation of cerebral autoregulation by carbon dioxide. The authors conclude that hypercapnia causes the plateau to progressively ascend, a rightward shift of the lower limit, and a leftward shift of the upper limit. Conversely, hypocapnia results in the plateau shifting to lower cerebral blood flows, unremarkable change of the lower limit, and unclear change of the upper limit. It is emphasized that a sound understanding of both the limitations and the dynamic and integrated nature of cerebral autoregulation fosters a safer clinical practice.

  13. 97-ERD-022 final report: Supernova on Nova

    SciTech Connect

    Remington, B A

    1999-03-11

    This is the final year of the 3-year LDRD-ERD involving Lasers, D&NT, Physics, and ILSA to develope astrophysics experiments on intense lasers such as the Nova and Gekko lasers. During this 3 year period, we have developed a highly successful experiment probing the hydrodynamics of the explosion phase of core-collapse supernovae, which occurs during the first ~3 hours after core collapse. This was in collaboration with the Univ. of Arizona and CEA/Saclay. We also developed a very successful experiment to probe the hydrodynamics of the later time, young remnant phase, meaning the first ~10-20 years after core collapse. This was in collaboration with the Univ. of Michigan and Univ. of Colorado. Finally, we developed during the final year an exquisite experiment to probe the dynamics of radiative, high Mach number astrophysical jets, in collaboration with the Univ. of Maryland and Osaka Univ. Each experiment has received very high visibility, with a multitude of publications, both in the technical journals (most importantly, the astrophysical journals) and in the popular press. The attached publication list shows 25 papers published or submitted to technical journals, 5 articles appearing in the popular press (including a cover story of Sky and Telescope), and 65 conference presentations, ~10 of which were invited talks. The most important papers to come out of this effort was a comprehensive theory paper for Ap. J. establishing the rigorous scaling between laboratory laser experiments and the astrophysical subjects of interest: supernovae, supernova remnants, and jets; and a review article for Science covering this emerging subfield of Astrophysics on Intense Lasers. Since there are so many publications that have resulted from this LDRD project, only these two most important papers are attached. The rest are properly referenced, and can be found online or in the library. In anticipation of the closing of the Nova laser, we have successfully proposed transferring the

  14. Pulsed power supply for Nova Upgrade. Final report, August 1, 1991 to March 31, 1992

    SciTech Connect

    Bacon, J.L.; Kajs, J.P.; Walls, A.; Weldon, W.F.; Zowarka, R.C.

    1992-12-31

    This report describes work carried out at the Center for Electromechanics at The University of Texas at Austin (CEM-UT). A baseline design of the Nova Upgrade has been completed by Lawrence Livermore National Laboratory. The Nova Upgrade is an 18 beamline Nd: glass laser design utilizing fully relayed 4x4 30 cm aperture segmented optical components. The laser thus consists of 288 independent beamlets nominally producing 1.5 to 2.0 MJ of 0.35 {mu}m light in a 3 to 5 ns pulse. The laser design is extremely flexible and will allow a wide range of pulses to irradiate ICF targets. This facility will demonstrate ignition/gain and the scientific feasibility of ICF for energy and defense applications. The pulsed power requirements for the Nova Upgrade are given. CEM-UT was contracted to study and develop a design for a homopolar generator/inductor (HPG/inductor) opening switch system which would satisfy the pulsed power supply requirements of the Nova Upgrade. The Nd:glass laser amplifiers used in the Nova Upgrade will be powered by light from xenon flashlamps. The pulsed power supply for the Nova Upgrade powers the xenon flashlamps. This design and study was for a power supply to drive flashlamps.

  15. [Prevalence of Pre-Obesity/Obesity in Pre and Basic School Children at Vila Nova de Gaia, Portugal].

    PubMed

    Camarinha, Bárbara; Graça, Pedro; Nogueira, Paulo Jorge

    2016-01-01

    Introdução: Mais de 30% das crianças portuguesas apresentam excesso de peso. Sendo um grave problema de saúde pública com múltiplas causas, só uma ação intersectorial e concertada poderá contribuir para a sua resolução. As autarquias possuem um conjunto de competências que as tornam ideais para uma intervenção eficaz na luta contra este problema. Para essa ação ser efetiva é necessária uma avaliação local da dimensão do problema e sua distribuição espacial. O objetivo deste estudo foi caracterizar, do ponto de vista da prevalência de excesso de peso, a população do pré-escolar e primeiro ciclo do ensino básico sob responsabilidade da autarquia de Vila Nova de Gaia, o terceiro município mais populoso do país. Material e Métodos: Avaliaram-se 8 974 crianças do pré-escolar e primeiro ciclo do ensino básico do município, no ano letivo 2013/14. A avaliação do estado nutricional da amostra foi feita com recurso às medidas antropométricas peso e altura. Na classificação do estado nutricional considerou-se os percentis ou z-scores do índice de massa corporal para a idade de acordo com os critérios definidos pela Organização Mundial de Saúde, Centers for Disease Control and Prevention e pela International Obesity Task Force. Resultados: A prevalência de excesso de peso pelo critério da Organização Mundial da Saúde foi de 37,4%. Identificaram-se disparidades na distribuição do excesso de peso nas escolas do concelho. Discussão: Os resultados encontrados foram ligeiramente superiores aos de outros estudos nacionais e internacionais, podendo a abrangência amostral justificar as diferenças encontradas. Conclusão: A prevalência encontrada é elevada e de distribuição aparentemente distinta a nível espacial, o que poderá contribuir para a identificação dos principais determinantes do problema a nível local.

  16. Chandra Observations of Nova V382 Vel (1999)

    NASA Astrophysics Data System (ADS)

    Krautter, Joachim; Burwitz, Vadim; Ness, Jan-Uwe; Starrfield, Sumner; Butt, Yousaf; Drake, Jeremy; Shore, Steve; Wagner, Mark R.

    The results of the analysis of the Chandra ACIS-I and LETGS observations carried out over a period of 8 months starting 7 months after the outburst of Nova V382 Velorum (1999) will be presented here. The flux of the soft X-ray component (0.4-0.8 keV) is found to decrease be factor ~200 within a period of less than 6 weeks. Following this sharp decrease the long-term X-ray lightcurves show that the soft component seems to become fainter following a steeper power-law than the hard component. The high spectral resolution Chandra LETGS spectrum shows a great wealth of broadened lines with a FWHM ~2000 km/s which is compatible with the velocity of the expanding shell. With the help of the He-like triplets of O VII and N VI we are able to put a constraints on the plasma temperature of 4.5-5.0 106 K. A puzzling fact is that the Fe lines that should be detected at these temperatures are not seen.

  17. Weather impacts on leisure activities in Halifax, Nova Scotia

    NASA Astrophysics Data System (ADS)

    Spinney, Jamie E. L.; Millward, Hugh

    2011-03-01

    The aim of this study was to investigate the impact of daily atmospheric weather conditions on daily leisure activity engagement, with a focus on physically active leisure. The methods capitalize on time diary data that were collected in Halifax, Nova Scotia to calculate objective measures of leisure activity engagement. Daily meteorological data from Environment Canada and daily sunrise and sunset times from the National Research Council of Canada are used to develop objective measures of the natural atmospheric environment. The time diary data were merged with the meteorological data in order to quantify the statistical association between daily weather conditions and the type, participation rate, frequency, and duration of leisure activity engagement. The results indicate that inclement and uncomfortable weather conditions, especially relating to thermal comfort and mechanical comfort, pose barriers to physically active leisure engagement, while promoting sedentary and home-based leisure activities. Overall, daily weather conditions exhibit modest, but significant, effects on leisure activity engagement; the strongest associations being for outdoor active sports and outdoor active leisure time budgets. In conclusion, weather conditions influence the type, participation rate, frequency, and duration of leisure activity engagement, which is an important consideration for health-promotion programming.

  18. Supernova-relevant hydrodynamic instability experiments on the Nova Laser

    SciTech Connect

    Kane, J.; arnett, D.; Remington, B.A.; Glendinning, S.G.; wallace, R.; Mangan, R.; Rubenchik, A.; Fryxell, B.A.

    1997-04-18

    Supernova 1987A focused attention on the critical role of hydrodynamic instabilities in the evolution of supernovae. To test the modeling of these instabilities we are developing laboratory experiments of hydrodynamic mixing under conditions relevant to supernovae. The target consists of two-layer planar package composed on 85 micron Cu backed by 500 micron CH2, having a single mode sinusoidal perturbation at the interface, with gamma = 200 microns, nuo + 20 microns. The Nova laser is used to generate a 10-15 Mbar (10- 15x10{sup 12} dynes/cm2) shock at the interface, which triggers perturbation growth, due to the Richtmyer-Meshov instability followed by the Raleigh-Taylor instability as the interface decelerates. This resembles the hydrodynamics of the He-H interface of a Type II supernova at the intermediate times, up to a few x10{sup 3} s. The experiment is modeled using the hydrodynamic codes HYADES and CALE, and the supernova code PROMETHEUS. We are designing experiments to test the differences in the growth of 2D vs 3D single mode perturbations; such differences may help explain the high observed velocities of radioactive core material in SN1987A. Results of the experiments and simulations are presented.

  19. Supernova-relevant hydrodynamic instability experiment on the Nova laser

    SciTech Connect

    Kane, J.; Arnett, D.; Remington, B.A.; Glendinning, S.G.; Castor, J.; Rubenchik, A.; Berning, M.

    1996-02-12

    Supernova 1987A focused attention on the critical role of hydrodynamic instabilities in the evolution of supernovae. On quite a separate front, the detrimental effect of hydrodynamic instabilities in inertial confinement fusion (ICF) has long been known. Tools from both areas are being tested on a common project. At Lawrence Livermore National Laboratory (LLNL), the Nova Laser is being used in scaled laboratory experiments of hydrodynamic mixing under supernova-relevant conditions. Numerical simulations of the experiments are being done, using hydrodynamics codes at the Laboratory, and astrophysical codes successfully used to model the hydrodynamics of supernovae. A two-layer package composed of Cu and CH{sub 2} with a single mode sinusoidal 1D perturbation at the interface, shocked by indirect laser drive from the Cu side of the package, produced significant Rayleigh-Taylor (RT) growth in the nonlinear regime. The scale and gross structure of the growth was successfully modeled, by mapping an early-time simulation done with 1D HYADES, a radiation transport code, into 2D CALE, a LLNL hydrodynamics code. The HYADES result was also mapped in 2D into the supernova code PROMETHEUS, which was also able to reproduce the scale and gross structure of the growth.

  20. Supernova-relevant hydrodynamic instability experiment on the Nova laser

    NASA Astrophysics Data System (ADS)

    Kane, J.; Arnett, D.; Remington, B. A.; Glendinning, S. G.; Castor, J.; Rubenchik, A.

    1996-02-01

    Supernova 1987A focused attention on the critical role of hydrodynamic instabilities in the evolution of supernovae. On quite a separate front, the detrimental effect of hydrodynamic instabilities in Inertial Confinement Fusion (ICF) has long been known. Tools from both areas are being tested on a common project. At Lawrence Livermore National Laboratory (LLNL), the Nova Laser is being used in scaled laboratory experiments of hydrodynamic mixing under supernova-relevant conditions. Numerical simulations of the experiments are being done, using hydrodynamics codes at the Laboratory, and astrophysical codes successfully used to model the hydrodynamics of supernovae. A two-layer package composed of Cu and CH2 with a single mode sinusoidal 1D perturbation at the interface, shocked by indirect laser drive from the Cu side of the package, produced significant Rayleigh-Taylor (RT) growth in the nonlinear regime. The scale and gross structure of the growth was successfully modeled, by mapping an early-time simulation done with 1D HYADES, a radiation transport code, into 2D CALE, a LLNL hydrodynamics code. The HYADES result was also mapped in 2D into the supernova code PROMETHEUS, which was also able to reproduce the scale and gross structure of the growth.