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Sample records for ebus uma nova

  1. Discovery of a New Deeply Eclipsing SU UMa-Type Dwarf Nova, IY UMa (= TmzV 85)

    NASA Astrophysics Data System (ADS)

    Uemura, Makoto; Kato, Taichi; Matsumoto, Katsura; Takamizawa, Kesao; Schmeer, Patrick; Jensen, Lasse Teist; Vanmunster, Tonny; Novák, Rudolf; Martin, Brian; Pietz, Jochen; Buczynski, Denis; Kinnunen, Timo; Moilanen, Marko; Oksanen, Arto; Cook, Lewis M.; Watanabe, Tsutomu; Maehara, Hiroyuki; Itoh, Hiroshi

    2000-04-01

    We discovered a new deeply eclipsing SU UMa-type dwarf nova, IY UMa, which experienced a superoutburst in 2000 January. Our monitoring revealed two distinct outbursts, which suggest a superoutburst interval of ~ 800 d, or its half, and an outburst amplitude of 5.4 mag. From time-series photometry during the superoutburst, we determined a superhump and orbital period of 0.07588 d and 0.0739132 d, respectively.

  2. FUSE Observations of the Bright, Eclipsing Nova-like Cataclysmic Variable, UX UMa (FUSE 2000)

    NASA Technical Reports Server (NTRS)

    Long, Knox; Froning, Cynthia

    2004-01-01

    This was a project to study the disk and wind of the eclipsing nova-like variable UX UMa, in order to better define the wind geometry of the system, including the nature of the transition region between the disk photosphere and the supersonic wind. We proposed to use phase resolved spectroscopy of the system, taking advantage of the fact that UX UMa is an eclipsing system, to isolate different regions of the wind and to use a Monte Carlo radiative transfer code to simulate the spectra through the eclipse.

  3. Discovery of a New SU UMa-Type Dwarf Nova, V 1028 Cygni

    NASA Astrophysics Data System (ADS)

    Baba, Hajime; Kato, Taichi; Nogami, Daisaku; Hirata, Ryuko; Matsumoto, Katsura; Sadakane, Kozo

    2000-06-01

    V-band high-speed CCD photometry of V 1028 Cyg revealed that hump structures existed in the early stage of its 1995 July outburst. We obtained 0.06154 (+/- 0.00002) d as the best estimated period of superhumps. We confirmed that this dwarf nova belongs to the SU UMa stars. A re-brightening occurred after the superoutburst, and may be associated with a normal outburst. An analysis of the timings of superhump maxima showed clear evidence for an increase of the superhump period (P_dot = .P/P) with 7.54 x 10-6. Only a few stars (AL Com, T Leo, SW UMa, etc.) are reported to have such an increase of the superhump period. At the end of the superoutburst, we detected that the amplitude of the superhumps increased considerably. Both of these properties are not typical features of ordinary SU UMa stars. The connection between the WZ Sge-type and the SU UMa-type dwarf novae is briefly discussed.

  4. 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.

  5. 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.

  6. 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.

  7. KIC 7524178 - an SU UMa-Type Dwarf Nova Predominantly Showing Negative Superhumps throughout Supercycle

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Osaki, Yoji

    2013-12-01

    We analyzed Kepler long-cadence data of KIC 7524178 (= KIS J192254.92+430905.4), and found that it is an SU UMa-type dwarf nova with frequent normal outbursts. The signal of the negative superhump has always been the dominant one, even during the superoutburst, in contrast to our common knowledge about superhumps in dwarf novae. The signal of the positive superhump was only transiently seen during the superoutburst, and it quickly decayed afterward. The frequency variation of the negative superhump was similar to the two previously studied dwarf novae in the Kepler field, V1504 Cyg and V344 Lyr. This is the first object in which the negative superhumps dominate throughout the supercycle. Nevertheless, the superoutburst was faithfully accompanied by the positive superhump, indicating that the tidal eccentric instability is essential for triggering a superoutburst. All the pieces of evidence strengthen the thermal-tidal instability as being the origin of the superoutburst and supercycle, which makes this object the third example in the Kepler field. This object had an unusually small (˜1.0 mag) outburst amplitude, and we considered that this object has a high mass-transfer rate close to the thermal-stability limit of the accretion disk. The average periods of the negative and positive superhumps, and the candidate period of the orbital motion were 0.07288 d (variable in the range 0.0723-0.0731 d), 0.0785 d (variable in the range 0.0772-0.0788 d), and 0.074606(1) d, respectively.

  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. 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

    2016-07-01

    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.

  10. 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.

  11. 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.

  12. [Endobronchial ultrasound (EBUS): the state of the art].

    PubMed

    Douadi, Y; Dayen, C; Lachkar, S; Fournier, C; Thiberville, L; Ramon, P; François, G; Jounieaux, V

    2012-04-01

    Endobronchial ultrasound (EBUS) is a technique which allows the endoscopist to sample mediastinal and/or hilar lymph nodes for complete staging of thoracic malignancy without recourse to surgery. Originally developed at the beginning of the 21st century, EBUS has become a well developed practice within France in recent years. As the technique requires high tech, expensive and fragile equipment, it has been important to develop an approach that is appropriate for the specific features and constraints of the French health system, including access to anaesthesia, imaging modalities and costing. The first centers to adopt EBUS had to adapt quickly and develop their own practices for its use. Training seminars were carried out in order to pass on this experience. After the passage of several years, it seems helpful to give a progress report on this technique through the stages of its development, taking account of the specificities of the French system and thus to transmit this accumulated experience. In this article, the authors review the literature concerning all the essential aspects needed to apply this technique under the best conditions in the French health system. PMID:22542406

  13. Detection of the white dwarf and the secondary star in the new SU UMa dwarf nova HS 2219+1824

    NASA Astrophysics Data System (ADS)

    Rodríguez-Gil, P.; Gänsicke, B. T.; Hagen, H.-J.; Marsh, T. R.; Harlaftis, E. T.; Kitsionas, S.; Engels, D.

    2005-02-01

    We report the discovery of a new, non-eclipsing SU UMa-type dwarf nova, HS 2219+1824. Photometry obtained in quiescence (V≈17.5) reveals a double-humped light curve from which we derive an orbital period of ≃86.2 min. Additional photometry obtained during a superoutburst reaching V≃12.0 clearly shows superhumps with a period of ≃89.05 min. The optical spectrum contains double-peaked Balmer and He I emission lines from the accretion disc as well as broad absorption troughs of Hβ, Hγ, and Hδ from the white dwarf primary star. Modelling of the optical spectrum implies a white dwarf temperature of 13 000 K⪉Teff⪉17 000 K, a distance of 180 pc⪉ d⪉230 pc, and suggests that the spectral type of the donor star is later than M 5. Phase-resolved spectroscopy obtained during quiescence reveals a narrow Hα emission line component which has a radial velocity amplitude and phase consistent with an origin on the secondary star, possibly on the irradiated hemisphere facing the white dwarf. This constitutes the first detection of line emission from the secondary star in a quiescent SU UMa star. Based in part on observations obtained at the German-Spanish Astronomical Center, Calar Alto, operated by the Max-Planck-Institut für Astronomie, Heidelberg, jointly with the Spanish National Commission for Astronomy; on observations made with the IAC80 and OGS telescopes, operated on the island of Tenerife by the Instituto de Astrofísica de Canarias (IAC) and the European Space Agency (ESA), respectively, in the Spanish Observatorio del Teide of the IAC; on observations made at the 1.2 m telescope, located at Kryoneri Korinthias, and owned by the National Observatory of Athens, Greece; and on observations made with the William Herschel Telescope, which is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the IAC.

  14. EBUS-guided mediastinal lung cancer staging: monitoring of quality standards improves performance.

    PubMed

    Evison, Matthew; Crosbie, Philip; Martin, Julie; Shah, Rajesh; Doran, Helen; Borrill, Zoe; Hoyle, Jennifer; Rana, Durgesh; Bailey, Simon; Booton, Richard

    2016-08-01

    This audit examined key performance indices related to endobronchial ultrasound (EBUS)-guided mediastinal lung cancer staging before and after the introduction of defined quality standards, at four independent EBUS centres in one cancer network. Data from 642 procedures were prospectively collected and analysed. The introduction of standards was associated with a significant increase (p<0.001) in sampling of key mediastinal lymph node stations (4R, 4L and 7) and a reduction in the variability of staging sensitivity between centres. These data reinforce the requirement for an appropriate regulatory framework for EBUS-transbronchial needle aspiration provision that includes quality assurance and performance monitoring. PMID:27146201

  15. Endobronchial ultrasound EBUS--a new method for the diagnosis and staging of lung cancer.

    PubMed

    Simon, Marioara; Baldea, Luminiţa; Pop, Bogdan; Crişan, Doiniţa

    2015-01-01

    In this paper we present a new method, endobronchial ultrasound (EBUS), which appeared recently among the tools of the pulmonologist for the diagnosis and staging of lung cancer. Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) provides the opportunity for obtaining tissue samples required for the histologic and cytologic diagnosis of lung cancer. The advantages of EBUS have to be made popular as it is a minimally invasive method, safe, simple, fast, also with a superior cost/benefit ratio compared to any previously used methods. PMID:26506670

  16. 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.

  17. Yield of EBUS-TBNA for the diagnosis of sarcoidosis: impact of operator and cytopathologist experience

    PubMed Central

    Navasakulpong, Asma; Auger, Manon; Gonzalez, Anne V

    2016-01-01

    Background Studies have reported a high diagnostic yield of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the diagnosis of sarcoidosis. We sought to review the yield of EBUS-TBNA for the diagnosis of sarcoidosis at our institution over time, and examine factors that may influence this yield. Methods Patients who underwent EBUS-TBNA for suspected sarcoidosis between December 2008 and November 2011 were identified. EBUS was performed without rapid on-site evaluation (ROSE) of samples. The final diagnosis was based on the results of all invasive diagnostic procedures and/or clinical follow-up. Logistic regression analysis was used to examine the effect of various factors on yield. Results 43 patients underwent 45 EBUS-TBNA procedures for suspected sarcoidosis. A total of 115 lymph nodes were sampled. The 21 G needle was used in 51% of procedures. The mean number of lymph node stations sampled was 2.6 (SD 0.7) and the mean number of needle passes per procedure was 7.8 (SD 2.0). Non-necrotising granulomatous inflammation was detected in EBUS-TBNA samples from 34/45 (76%) procedures. The overall diagnostic yield increased to 36/45 (80%) following a cytopathology review for this study. Needle gauge, number of lymph node stations sampled and number of needle passes were not associated with diagnostic yield. The yield of EBUS-TBNA increased significantly after the first 15 procedures performed for suspected sarcoidosis; the 2 additional cases diagnosed after the cytopathology review were part of this early experience. Conclusions EBUS-TBNA is a valuable technique for the diagnosis of sarcoidosis when performed without ROSE. The yield of the procedure improved significantly over time, based on operator and cytopathologist experience. PMID:27547408

  18. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA): applications in chest disease.

    PubMed

    Medford, Andrew R L; Bennett, Jonathan A; Free, Catherine M; Agrawal, Sanjay

    2010-01-01

    Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) offers a minimally invasive option for staging the mediastinum in suspect lung cancer but also in the diagnosis of mediastinal lesions accessible from the airway. This review is aimed at centres considering establishing an EBUS service that may not be so familiar with the technique. It focuses primarily on technical aspects of EBUS-TBNA, training issues, cost considerations, indications, advantages and disadvantages compared with other mediastinal sampling techniques as well as some reference to its performance in clinical studies. In summary, EBUS-TBNA is primarily used for staging non-small cell lung cancer, especially for bulky mediastinal disease and discrete N2 or N3 disease on CT, but also used for the diagnosis of unexplained mediastinal lymphadenopathy. For radical treatment staging, mediastinoscopy is still used at many centres and negative EBUS-TBNA results should be corroborated by mediastinoscopy. In the future, EBUS-TBNA may be used for staging the radiologically normal mediastinum and in re-staging. It is a procedure that can be taught with ease by an experienced operator, has numerous advantages over mediastinoscopy and is potentially cost saving by reducing the number of mediastinoscopies and associated peri-operative support required. PMID:19895387

  19. Radial Endobronchial Ultrasound (EBUS) Guided Suction Catheter-Biopsy in Histological Diagnosis of Peripheral Pulmonary Lesions

    PubMed Central

    Zaric, Bojan; Stojsic, Vladimir; Carapic, Vladimir; Kovacevic, Tomi; Stojanovic, Goran; Panjkovic, Milana; Kioumis, Ioannis; Darwiche, Kaid; Zarogoulidis, Konstantinos; Stratakos, Grigoris; Tsavlis, Drosos; Hohenforst-Schmidt, Wolfgang; Pitsiou, Georgia; Zissimopoulos, Athanasios; Sachpekidis, Nikos; Karapantzos, Ilias; Karapantzou, Chrysanthi; Zarogoulidis, Paul; Perin, Branislav

    2016-01-01

    Background: EBUS guided trans-bronchial biopsy became routine in diagnosis of peripheral pulmonary lesions (PPL). Suction catheter-biopsy is a technique for obtaining a tissue sample from peripheral lung parenchyma. Aim of this study was to evaluate diagnostic efficiency, feasibility and safety of EBUS guided suction catheter-biopsy (SCB) in comparison to trans-bronchial biopsy (TBB) in diagnosis of PPL. The main intention was to demonstrate non-inferiority of the technique over trans-bronchial biopsy, especially when used under navigation of the EBUS. Methods: Radial EBUS probe (UM-3R, Olympus Co, Japan.) without guiding sheath was used to navigate suction catheter and TBB forceps to the PPL. The catheter was connected to the collection canister via vacuum pump. The SCB specimens were fixed with 10% buffered formalin. Results: There were 168 patients enrolled in this study; 69.9% males and 30.1% females. Main lesion diameter was 4.1±1.9 cm. Majority of patients, 131(77.9%) were diagnosed with lung cancer. Per-biopsy calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for EBUS-SCB were 92.4%, 100%, 100% and 67.7%, respectively. Corresponding values for EBUS-TBB were 92.3%, 100%, 100% and 69.7%. Only the size of the lesion significantly influenced (p=0.005) diagnostic performance. Complications occurred in 2 patients; one pneumothorax and one excessive bleeding. Conclusion: EBUS guided SCB is efficient, feasible and safe in diagnosis of peripheral lung cancer. The technique is complementary to trans-bronchial biopsy. PMID:26722354

  20. A clue in a colour? EBUS-TBNA in the analysis of isolated mediastinal lymphadenopathy

    PubMed Central

    Ryan, Daniel John; McPhillips, Dympna; Bruzzi, John; Breen, David

    2014-01-01

    A 52-year-old female patient with a background history of malignant melanoma was referred to the interventional pulmonology unit at Galway University Hospital for the investigation of possible intrathoracic recurrence. A CT of the thorax (CT thorax) demonstrated mediastinal lymphadenopathy at position 4R, right paratracheal region. An endobronchial ultrasound (EBUS) revealed multiple enlarged lymph nodes at station 4R. The nodes were heterogeneous with solid and cystic elements. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) obtained a black material consistent with malignant melanoma. Multiple TBNA samples were obtained and the diagnosis was confirmed pathologically by the presence of multiple epithelioid pigmented cells on cell block analysis. This case report emphasises the value of EBUS in the assessment of metastatic disease and, in particular, how the gross appearance of the sample can be suggestive of the diagnosis. PMID:24567182

  1. Accidental fracture of EBUS-TBNA needle during sampling of an enlarged mediastinal lymph node

    PubMed Central

    Tariq, Syed Mohammad

    2016-01-01

    Endobronchial ultrasounded-guided transbronchial needle aspiration (EBUS-TBNA) for sampling enlarged hilar and mediastinal lymph nodes, and mediastinal tumours is a safe procedure and can be performed under sedation and local anaesthesia. Rare complications of this procedure include haemorrhage, pneumothorax, pneumonia, mediastinitis and pericarditis (Asano F et al., Complications associated with endobronchial ultrasound-guided transbronchial needle aspiration: a nationwide survey by the Japan Society for Respiratory Endoscopy. Respir Res 2013;14:50). I report an unexpected fracture of the tip of the EBUS-TBNA needle as it hit a bronchial cartilage ring during attempted insertion into a subcarinal node. PMID:27099769

  2. Retrospective analysis of radial EBUS outcome for the diagnosis of peripheral pulmonary lesion: sensitivity and complications

    PubMed Central

    Durakovic, Amal; Andersen, Henrik; Christiansen, Anders; Hammen, Irena

    2015-01-01

    Background The purpose of the current study was to clarify the sensitivity and complication rate of the radial (endobronchial ultrasound, EBUS) without the use of guide-sheath (GS) and fluoroscopy for lung cancer (LC), by measuring the distance from the orifice of the bronchus to the pulmonary lesion, as well as to analyze factors that can predict the diagnostic outcome. Materials and methods A total of 147 patients with peripheral pulmonary lesions (PPL) underwent radial EBUS-guided transbronchial biopsy (TBB) in between August 1, 2013, and August 31, 2014. We analyzed retrospectively radiological data, diagnostic work-up in everyday clinical settings, final diagnosis and complication rates, as well as factors influencing the diagnostic outcome. Results Around 63.9% of PPLs were visualized by ultrasound. A definitive malignant diagnosis was established in 39 patients (26.5%) using radial EBUS. In the remaining 108 patients, additional procedures were performed. We missed LC diagnosis in 40 cases that results in a sensitivity of 49%. For malignant lesions visualized by radial EBUS, the sensitivity was 60%, compared with 24% for not visualized lesions. For malignant lesions, logistic regression was performed to identify the factors that had significant influence on visualization of the lesion and on diagnostic yield. Logistic regression analysis showed significant odds ratios (OR) for visualization depending on location of the lesion; upper lobe lesions were identified more frequent with OR of 3.85 (95% CI 1.42 – 10.98, p=0.009). Size above 30 mm had a non-significant OR of 2.11 (95% CI 0.80−5.73, p=0.134) for visualization. Diagnostic yield was only significantly influenced by visualization with the radial EBUS, OR 3.70 (95% CI 1.35−11.02, p=0.014). Location (p=0.745) and size above 30 mm (p=0.308) showed no significant increase in diagnostic yield. Other lesion characteristics defined on computed tomography, such as distance to carina and pleura, did not

  3. 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.

  4. Assessment of methylation status of locoregional lymph nodes in lung cancer using EBUS-NA.

    PubMed

    Millares, Laura; Serra, Mireia; Andreo, Felipe; Sanz-Santos, Jose; Montón, Concepción; Grimau, Carles; Gallego, Miguel; Setó, Laia; Combalia, Neus; Llatjos, Mariona; Escoda, Rosa; Castellà, Eva; Monsó, Eduard

    2015-10-01

    Hypermethylation of the promoter region of tumor suppressor genes is associated with carcinogenesis in lung cancer (LC). Endobronchial ultrasound with needle aspiration (EBUS-NA) is a semi-invasive method for obtaining cell blocks from lymph nodes, which can be used for epigenetic analyses. To establish the relationship between methylation status of p16, DAPK, RASSF1a, APC and CDH13 genes in lymph nodes sampled by EBUS-NA, tumor staging and prognosis. Methylation status of DAPK, p16, RASSF1a, APC and CDH13 genes was assessed in EBUS-NA cell blocks from LC patients and related to stage and survival. Eighty-five consecutive patients [mean age 67 (SD 8)] were included. Methylation of ≥1 gene was found in 43 malignant nodes (67 %). A higher prevalence of RASSF1a methylation was observed in small cell lung cancer patients [9/10 (90 %) vs. 15/53 (28 %); p < 0.001 χ(2) test]. Methylation of APC and/or p16 was related to advanced staging in non-small cell lung cancer (NSCLC) [15/29 (52 %) vs. 6/24 (25 %), p = 0.048, χ(2) test]. Patients with NSCLC showing methylation of APC and/or p16 had also lower 6-month survival (p = 0.019, log rank test), which persisted after adjustment for age and subtyping (HR = 6, 95 % CI [1.8-19.5], p = 0.003, Cox regression). Epigenetic analyses are feasible in EBUS-NA cell blocks and may identify methylation patterns associated with worse prognosis. Methylation of p16 and APC genes in NSCLC patients was associated with advanced staging and lower 6-month survival. PMID:26119430

  5. A rare case of mediastinal metastasis of ovarian carcinoma diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA).

    PubMed

    Carbonari, Augusto; Camunha, Marco; Binato, Marcelo; Saieg, Mauro; Marioni, Fabio; Rossini, Lucio

    2015-10-01

    Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has become a minimally invasive tool with excellent diagnostic accuracy and low risk of complications in the diagnosis of thoracic diseases, including lung cancers and primary mediastinal lesions. Occasionally, EBUS-TBNA may be useful in identifying thoracic metastasis from distant tumors. Here we report an interesting and rare case of mediastinal metastasis of ovarian carcinoma diagnosed by EBUS-TBNA. PMID:26623131

  6. Recurrent novae, classical novae, symbiotic novae, and population II novae

    NASA Astrophysics Data System (ADS)

    Kato, M.

    2002-01-01

    Light curve analyses of the decay phase of nova outbursts are summarized. The nova duration is determined by the strong wind mass-loss which depends only on the white dwarf mass. Fast novae correspond to very massive white dwarfs and very slow novae correspond almost to the lower mass limit of white dwarfs. This relation is shown in both classical novae and recurrent novae. Light curves are theoretically reproduced for recurrent novae, U Sco, V394 CrA, CI Aql, V2487 Oph, RS Oph, T CrB, V745 Sco and V3890 Sgr, using a binary model composed of a white dwarf, an irradiated accretion disk, and a partly irradiated companion which is shadowed by the accretion disk. From the light curve fitting, we conclude that most of these objects contain a very massive white dwarf close to the Chandrasekhar mass limit (1.37 Modot for U Sco, V394 CrA T CrB and RS Oph, 1.35 Modot for V2487 Oph, V3890 Sgr and V745 Sco). They are strong candidates of type Ia SN progenitors. Population II novae have trends of slow evolution and small expanding velocity compared with disk novae.

  7. Eclipsing SU UMa-Type Dwarf Nova 1RXS J003828.7+250920 During thE "Period Gap". I. Multiperiodicity and Color Features in 2011-2012

    NASA Astrophysics Data System (ADS)

    Pavlenko, E. P.; Sosnovskij, A. A.; Katysheva, N. A.; Kato, T.; Littlefield, K.

    2016-09-01

    Results are reported from multicolor photometric observations of the SU UMa-type dwarf nova 1RXS J003828.7+250920 in 2011, roughly a year after the super-outburst of 2010, and in 2012, when the object was in a quiescent state and underwent an outburst. Partial eclipses were observed in the system with depths of about 0m.6 in all color bands, both in the quiescent state and during the outburst. The orbital period of the system, 0.09451001(4) days, was determined for the first time and identifies the object as a dwarf nova in the "gap" in the orbital-period distribution of the cataclysmic variables. The ephemerides for the middle of the eclipse are determined. The average light curve profile resembles the "classical" light curve of U Gem. The orbital periodicity in the brightness variations of 1RXS J003828.7+250920 coexists with another signal with a period of 0.092 days, which we interpret as a period of negative superhumps. The color temperatures derived from the color indices may indicate multicomponent emission from 1RXS J003828.7+250920 by sources which appear to be hot and cold parts of the accretion disk and a hot spot on the accretion disk.

  8. 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

  9. The orbital period of the dwarf nova HS Virginis, the revised Po-Ps relation and the ``superhump" mass ratio distribution of SU UMa stars

    NASA Astrophysics Data System (ADS)

    Mennickent, R. E.; Matsumoto, K.; Arenas, J.

    1999-08-01

    A spectroscopic study of the SU UMa star HS Vir is presented. From the analysis of the radial velocities of the Hα emission line the most likely orbital period is 0\\fd07692(3), although we cannot discard two aliases at 0\\fd07678 and 0\\fd07709. The Balmer lines follow the orbital period with a radial velocity semiamplitude K = 96 +/- 9 km s(-1) , but the He I lambda 5875 emission line shows a double wave during the orbital cycle. We found that the mean Balmer, He I and He II 4686 lines can be roughly modeled with a disk radial emissivity ~ r(-2) . A revised version of the Po-Ps relation for SU UMa stars is also given, which is relevant for discriminating between +/- 1 c/d aliases of the orbital period. We calculated the mass ratio, derived from the tidal resonance model, of HS Vir (qsh = 0.22 +/- 0.04) and 43 additional SU UMa stars. The qsh distribution has a roughly gaussian shape with a mean 0.14, in sharp contrast with the orbital period distribution. Finally, a discussion of the possible stellar masses and inclination of HS Vir is given. We observe that the mass ratio derived from the dynamic solution is in disagreement with that derived from the tidal resonance model. This fact probably indicates that K does not represent the white dwarf binary motion. Based on observations obtained at ESO La Silla Observatory (ESO Proposal 61.D-0395).

  10. "Dry" pleural mesothelioma successfully diagnosed on endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA).

    PubMed

    Lococo, Filippo; Rossi, Giulio; Agostini, Lorenzo; Filice, Angelina; Paci, Massimiliano; Rapicetta, Cristian; Ricchetti, Tommaso; Tenconi, Sara; Piro, Roberto; Sgarbi, Giorgio

    2014-01-01

    The acquisition of histologic material is obligatory in order to establish the diagnosis of malignant pleural mesothelioma (MPM). In particular, tissue acquisition in cases of "dry" MPM (focal pleural thickening without pleural effusion or mediastinal lymph node involvement) is usually performed via a thoracoscopic pleural biopsy. In contrast, the techniques for performing echoendoscopic (transbronchial or transesophageal) needle aspiration of pleural lesions have only rarely been reported due to the theoretical limitations of tissue acquisition in such cases. We herein report the first case of "dry" MPM successfully diagnosed via endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in a 73-year-old man presenting with a pleural mass in the right costovertebral recess, adjacent to the carina. The patient underwent radical resection, and a definitive pathological examination confirmed the diagnosis of epithelioid MPM. PMID:24583437

  11. Nova Scotia.

    ERIC Educational Resources Information Center

    Timmons, Vianne; Power, Anne

    2003-01-01

    This article profiles the educational system of Nova Scotia and discusses initiatives for students who are at-risk. It describes programs and services for students who are at-risk, relevant educational legislation, areas of strength, challenges that need to be overcome, and areas of action. (Contains references.) (CR)

  12. Impact of Endobronchial Ultrasound (EBUS) Training on the Diagnostic Yield of Conventional Transbronchial Needle Aspiration for Lymph Node Stations 4R and 7

    PubMed Central

    Sehgal, Inderpaul Singh; Dhooria, Sahajal; Gupta, Nalini; Bal, Amanjit; Ram, Babu; Aggarwal, Ashutosh Nath; Behera, Digambar; Agarwal, Ritesh

    2016-01-01

    Background There is sparse literature on whether training in endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) improves the diagnostic yield of conventional TBNA (cTBNA). Objectives The aim of this study was to evaluate the diagnostic yield of cTBNA before and after the introduction of EBUS. Methods This was a retrospective analysis of patients who underwent cTBNA at our center. The study was divided into two periods, before and after the introduction of EBUS at our facility. The diagnostic yield of cTBNA was compared between the study periods. Rapid on-site cytological examination was not available. Results A total of 1,050 patients (61.6% men; mean age 45.6 years) underwent cTBNA during the study period (849 before EBUS; 201 after EBUS). Sarcoidosis (n = 527) followed by bronchogenic carcinoma (n = 222) formed the most common indications for performing cTBNA. There was a significant increase in both the success of obtaining a representative sample (from 71% to 85%), and the diagnostic yield (from 33% to 49.5%) of cTBNA, after the introduction of EBUS. The increase in the diagnostic yield of cTBNA after introduction of EBUS remained significant even after adjusting for years of performing cTBNA and the type of anesthesia (topical vs. sedation and topical) on a multivariate analysis. Conclusion The diagnostic yield of cTBNA at our facility increased after the introduction of EBUS-TBNA. However, given the retrospective nature of the study, prospective studies are required to confirm our findings. PMID:27083009

  13. 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

  14. Ultrasound techniques in the evaluation of the mediastinum, part I: endoscopic ultrasound (EUS), endobronchial ultrasound (EBUS) and transcutaneous mediastinal ultrasound (TMUS), introduction into ultrasound techniques

    PubMed Central

    Annema, Jouke Tabe; Clementsen, Paul; Cui, Xin Wu; Borst, Mathias Maximilian; Jenssen, Christian

    2015-01-01

    Ultrasound imaging has gained importance in pulmonary medicine over the last decades including conventional transcutaneous ultrasound (TUS), endoscopic ultrasound (EUS), and endobronchial ultrasound (EBUS). Mediastinal lymph node staging affects the management of patients with both operable and inoperable lung cancer (e.g., surgery vs. combined chemoradiation therapy). Tissue sampling is often indicated for accurate nodal staging. Recent international lung cancer staging guidelines clearly state that endosonography (EUS and EBUS) should be the initial tissue sampling test over surgical staging. Mediastinal nodes can be sampled from the airways [EBUS combined with transbronchial needle aspiration (EBUS-TBNA)] or the esophagus [EUS fine needle aspiration (EUS-FNA)]. EBUS and EUS have a complementary diagnostic yield and in combination virtually all mediastinal lymph nodes can be biopsied. Additionally endosonography has an excellent yield in assessing granulomas in patients suspected of sarcoidosis. The aim of this review, in two integrative parts, is to discuss the current role and future perspectives of all ultrasound techniques available for the evaluation of mediastinal lymphadenopathy and mediastinal staging of lung cancer. A specific emphasis will be on learning mediastinal endosonography. Part I is dealing with an introduction into ultrasound techniques, mediastinal lymph node anatomy and diagnostic reach of ultrasound techniques and part II with the clinical work up of neoplastic and inflammatory mediastinal lymphadenopathy using ultrasound techniques and how to learn mediastinal endosonography. PMID:26543620

  15. The utility of ROSE (rapid on-site evaluation) in endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA): Is the picture rosy?

    PubMed Central

    Mallya, Varuna; Kumar, Sandeep P; Meganathan, Prabhu; Shivkumar, Swarna; Mehta, Ravindra

    2015-01-01

    Background: Mediastinal lymphadenopathy (ML) presents a diagnostic challenge. The technique to sample the lymph nodes has evolved from conventional “blind” transbronchial needle aspiration (TBNA) to the present day endobronchial ultrasound (EBUS)-guided procedure that improves the accuracy of sampling. Objective: This study was undertaken to evaluate the utility of “rapid on-site evaluation” (ROSE) in EBUS-guided TBNA (EBUS-TBNA) for the diagnosis of ML. Patients and Methods: This prospective study included 80 patients who underwent EBUS-TBNA for computed tomography/positron emission tomography (CT/PET) diagnosed ML over a 4-month period at a single tertiary care center. All 80 of these patients underwent histopathological evaluation (HPE) in addition to cytology. Three out of these 80 (3.7%) patients were excluded in view of inadequate material on EBUS-TBNA. After the sampling of nodes was done, the slides were stained with rapid hematoxylin and eosin (H&E) and then on-site evaluation was done. The tissue derived was also processed for HPE in all cases. Results: ROSE revealed granuloma in 27 patients and malignancy in 14 patients, and the remaining patients showed nonspecific inflammation. Concomitant histopathology revealed granuloma in 34 patients and malignancy in 14 patients. Considering HPE as gold standard, the overall sensitivity and specificity of EBUS-TBNA for diagnosis were 85.4% and 89.6%, respectively. For malignancy alone, the sensitivity and specificity were 100% and 98.4%, respectively. Conclusion: This novel approach is safe, has good diagnostic yield, and has an excellent potential in assisting safe and accurate diagnostic interventional bronchoscope. PMID:26811569

  16. 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.

  17. 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.

  18. 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...

  19. Utility of conventional transbronchial needle aspiration with rapid on-site evaluation (c-TBNA-ROSE) at a tertiary care center with endobronchial ultrasound (EBUS) facility

    PubMed Central

    Madan, Neha Kawatra; Madan, Karan; Jain, Deepali; Walia, Ritika; Mohan, Anant; Hadda, Vijay; Mathur, Sandeep; Iyer, Venkateswaran K; Khilnani, Gopi C; Guleria, Randeep

    2016-01-01

    Background: Conventional transbronchial needle aspiration (c-TBNA) is an underutilized bronchoscopic modality. Endobronchial ultrasound (EBUS) guided-TBNA though efficacious is an expensive modality, facilities of which are available at only limited centers. c-TBNA is cost-effective and has potential for wide utilization especially in resource-limited settings. Rapid on-site evaluation (ROSE) improves the yield of c-TBNA. Materials and Methods: A retrospective review of the bronchoscopy records (May 2012 to July 2014) was performed. The patients who underwent c-TBNA with ROSE were included in the study and their clinical details were extracted. Convex probe EBUS-TBNA was being regularly performed during the study period by the operators performing c-TBNA. Results: c-TBNA with ROSE was performed in 41 patients with mean age of 42.4 (16.2) years. The most frequently sampled node stations (>90% patients) were the subcarinal and lower right paratracheal. Representative samples could be obtained in 33 out of the 41 patients (80.4%). c-TBNA was diagnostic in 32 [tuberculosis (TB)-8, sarcoidosis-9, and malignancy-15] patients out of the 41 patients. The overall diagnostic yield (sensitivity) of c-TBNA with ROSE was 78%. Mean procedure duration was 18.4 (3.1) min and there were no procedural complications. Conclusion: c-TBNA with ROSE is a safe, efficacious, and cost-effective bronchoscopic modality. When it was performed by operators routinely performing EBUS-TBNA, diagnostic yields similar to that of EBUS-TBNA can be obtained. Even at the centers where EBUS facilities are available, c-TBNA should be routinely performed. PMID:27011437

  20. 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.

  1. 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.

  2. 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.

  3. Novae in globular clusters

    SciTech Connect

    Kato, Mariko; Hachisu, Izumi; Henze, Martin

    2013-12-10

    We present the first light-curve analysis of Population II novae that appeared in M31 globular clusters. Our light-curve models, based on the optically thick wind theory, reproduce well both the X-ray turn-on and turnoff times with the white dwarf (WD) mass of about 1.2 M {sub ☉} for M31N 2007-06b in Bol 111 and about 1.37 M {sub ☉} for M31N 2010-10f in Bol 126. The transient supersoft X-ray source CXO J004345 in Bol 194 is highly likely a nova remnant of 1.2-1.3 M {sub ☉} WD. These WD masses are quite consistent with the temperatures deduced from X-ray spectra. We also present the dependence of nova light curves on the metallicity in the range from [Fe/H] = 0.4 to –2.7. Whereas strong optically thick winds are accelerated in Galactic disk novae owing to a large Fe opacity peak, only weak winds occur in Population II novae with low Fe abundance. Thus, nova light curves are systematically slow in low Fe environment. For an extremely low Fe abundance normal nova outbursts may not occur unless the WD is very massive. We encourage V or y filter observation rather than R as well as high cadence X-ray monitorings to open quantitative studies of extragalactic novae.

  4. 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.

  5. Novae as Thermonuclear Laboratories

    NASA Astrophysics Data System (ADS)

    Clayton, D. D.

    2003-07-01

    Fred Hoyle undertook a study of observational consequences of the thermonuclear paradigm for the nova event in the years following his 1972 resignation from Cambridge University. The most fruitful of these have been in the areas of gamma-ray astronomy, by which one attempts to measure the level of radioactivity in the nova envelope, and of presolar grain studies in laboratories, by which one measures anomalous isotopic ratios that fingerprint condensation in the thermonuclear event. This work summarizes progress with these two astronomical measures of the novae.

  6. 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.

  7. 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.

  8. Observations of Novae from ROAD

    NASA Astrophysics Data System (ADS)

    Hambsch, Franz-Josef

    2014-05-01

    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 alert notices and special notices of the AAVSO 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.

  9. Precision Nova operations

    NASA Astrophysics Data System (ADS)

    Ehrlich, Robert B.; Miller, John L.; Saunders, Rodney L.; Thompson, Calvin E.; Weiland, Timothy L.; Laumann, Curt W.

    1995-12-01

    To improve the symmetry of x-ray drive on indirectly driven ICF capsules, we have increased the accuracy of operating procedures and diagnostics on the Nova laser. Precision Nova operations include routine precision power balance to within 10% rms in the 'foot' and 5% rms in the peak of shaped pulses, beam synchronization to within 10 ps rms, and pointing of the beams onto targets to within 35 micrometer rms. We have also added a 'fail-safe chirp' system to avoid stimulated Brillouin scattering (SBS) in optical components during high energy shots.

  10. Precision Nova operations

    SciTech Connect

    Ehrlich, R.B.; Miller, J.L.; Saunders, R.L.; Thompson, C.E.; Weiland, T.L.; Laumann, C.W.

    1995-09-01

    To improve the symmetry of x-ray drive on indirectly driven ICF capsules, we have increased the accuracy of operating procedures and diagnostics on the Nova laser. Precision Nova operations includes routine precision power balance to within 10% rms in the ``foot`` and 5% nns in the peak of shaped pulses, beam synchronization to within 10 ps rms, and pointing of the beams onto targets to within 35 {mu}m rms. We have also added a ``fail-safe chirp`` system to avoid Stimulated Brillouin Scattering (SBS) in optical components during high energy shots.

  11. 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…

  12. 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…

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Analyses of the LMC Novae

    NASA Astrophysics Data System (ADS)

    Vanlandingham, K. M.; Schwarz, G. J.; Starrfield, S.; Hauschildt, P. H.; Shore, S. N.; Sonneborn, G.

    In the past 10 years, 6 classical novae have been observed in the Large Magellanic Cloud (LMC). We have begun a study of these objects using ultraviolet spectra obtained by IUE and optical spectra from nova surveys. We are using the results of this study to further our understanding of novae and stellar evolution. Our study includes analysis of both the early, optically thick spectra using model atmospheres, and the later nebular spectra using optimization of photoionization codes. By analysing of all the LMC novae in a consistent manner, we can compare their individual results and use their combined properties to calibrate Galactic novae. In addition, our studies can be used to determine the elemental abundances of the nova ejecta, the amount of mass ejected, and the contribution of novae to the ISM abundances. To date we have analyzed Nova LMC 1988#1 and Nova LMC 1990#1, and have obtained preliminary results for Nova LMC 1991. The results of this work are presented in this poster. The metal content of the LMC is known to be sub-solar and varies as a function of location within the cloud. A detailed abundance analysis of the ejecta of the LMC novae provides important information concerning the effect of initial metal abundances on energetics of the nova outburst. Since the distance to the LMC is well known, many important parameters of the outburst, such as the luminosity, can be absolutely determined. Both galactic and extragalactic novae have been proposed as potential standard candles. Recent work by Della Valle & Livio (1995) has improved on the standard relations (e.g., Schmidt 1957; Pfau 1976; Cohen 1985; Livio 1992) by including novae from the LMC and M31. Unfortunately, the dependence of the nova outburst on metallicity has not been well-studied. Recent theoretical work by Starrfield et al. (1998) indicates that the luminosity of the outburst increases with decreasing metal abundances. If there is a dependence of luminosity on metallicity, it will have to

  18. Modelling nova populations in galaxies

    NASA Astrophysics Data System (ADS)

    Chen, Hai-Liang; Woods, T. E.; Yungelson, L. R.; Gilfanov, M.; Han, Zhanwen

    2016-05-01

    Theoretical modelling of the evolution of classical and recurrent novae plays an important role in studies of binary evolution, nucleosynthesis and accretion physics. However, from a theoretical perspective the observed statistical properties of novae remain poorly understood. In this paper, we have produced model populations of novae using a hybrid binary population synthesis approach for differing star formation histories (SFHs): a starburst case (elliptical-like galaxies), a constant star formation rate case (spiral-like galaxies) and a composite case (in line with the inferred SFH for M31). We found that the nova rate at 10 Gyr in an elliptical-like galaxy is ˜10-20 times smaller than a spiral-like galaxy with the same mass. The majority of novae in elliptical-like galaxies at the present epoch are characterized by low-mass white dwarfs (WDs), long decay times, relatively faint absolute magnitudes and long recurrence periods. In contrast, the majority of novae in spiral-like galaxies at 10 Gyr have massive WDs, short decay times, are relatively bright and have short recurrence periods. The mass-loss time distribution for novae in our M31-like galaxy is in agreement with observational data for Andromeda. However, it is possible that we underestimate the number of bright novae in our model. This may arise in part due to the present uncertainties in the appropriate bolometric correction for novae.

  19. HET Spectroscopy of Extragalactic Novae

    NASA Astrophysics Data System (ADS)

    Shafter, Allen W.; Coelho, E. A.; Misselt, K. A.; Bode, M. F.; Darnley, M. J.

    2006-12-01

    We are currently involved in a multifaceted campaign to study extragalactic novae in the optical and IR using a variety of instruments: The Mount Laguna 1m, the Steward 2.3m, and the Liverpool 2m telescopes for optical imaging, the Hobbey-Eberly Telescope (HET) for optical spectroscopy, and the Spitzer Space Telescope for IR photometry and spectroscopy. Here, we report the initial results from our program of spectroscopic observations obtained with the LRS on the HET. Thus far, we have obtained spectra of three novae: Nova M31-2006#9 (ATEL 887), Nova M32-2006#1 (CBET 591), and Nova M33-2006#1 (CBET 655), which were taken on 24-Sep-2006 UT, 30-Sep-2006 UT, and 02-Oct-2006 UT, approximately 6, 65, and 4 days post discovery, for the three novae respectively. The spectra of Nova M31-2006#9 and Nova M33-2006#1 revealed prominent Balmer (FWHM 1600 km/s) and Fe II emission lines typical of the "Fe II" class in the classification system of Williams (1992 AJ, 104, 725). The spectrum of Nova M32-2006#1, which was obtained much longer after eruption, showed strong H-alpha (FWHM 1300 km/s), along with weaker H-beta, Fe II, and [N II] 5755, indicating that this nova is also a member of the Fe II class, and that it had entered the nebular phase at the time of our observations. In addition to these three novae, we also attempted to obtain a spectrum of Nova M31-2006#7 (CBET 615) on 23-Sep-2006 UT, approximately three weeks after discovery. However, by the time of our observations, the nova had faded to invisibility. An 1800s integration at the reported position reveled no trace of the nova. It is likely that this optical transient was an unusually fast nova, possibly of the "He/N" class. This work is being supported in part by NSF grant AST-0607682.

  20. 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 archaeologists working…

  1. Nova Delphini 2013: Backyard Analysis of a Classical Nova

    NASA Astrophysics Data System (ADS)

    Reid, Piper

    2014-01-01

    On August 14, 2013, Nova Delphini was discovered by Koichi Itagaki. This nova erupted to a maximum brightness of magnitude 4.4 by August 16, 2013. The extraordinary brightness of this event has allowed many amateur astronomers to have the chance to study it. More than 750 amateur astronomers have contributed to the AAVSO photometry database of Nova Delphini.1 The amount and quality of spectroscopic data gathered is unprecedented as well, as over 700 individual spectra have been collected so far in the ARAS database.2 A nova is a class of variable star that undergoes a cataclysmic eruption, which can be observed through a sudden increase in brightness that declines over a series of months or years. At the center of a nova is an accreting white dwarf star which is collecting hydrogen from its surroundings. The accreting mass causes a nuclear reaction on the surface of the white dwarf and as the pressure increases the reaction becomes super-critical and a thermonuclear runaway is ignited causing the brightness increase as well as triggering the ejection of a shell of material form the star. The stages of a classical nova outburst are outlined along with techniques available to amateur astronomers for study of these phenomena. The author’s equipment and software setup are detailed. Results obtained using a low resolution grating, Schmidt-cassegrain telescope and CCD camera that were acquired while Nova Delphini was in the “fireball stage” 3 and subsequent “iron curtain phase”3 are compared and discussed. Results obtained using a high resolution spectroscope, Schmidt-cassegrain telescope and CCD camera that were acquired during the “lifting of the iron curtain phase”3 are also presented. References 1. Turner, Rebecca. “AAVSO - Nova Del 2013” 20 Aug 2013 Web. 8 Sep 2013 nova-del-2013> 2. Tessier, Francois. “ARAS Spectral Database - Nova-Del-2013” 22 Sep 2013 Web. 22 Sep 2013 Novae/Nova

  2. Fritz Zwicky: Novae Become Supernovae

    NASA Astrophysics Data System (ADS)

    Koenig, T.

    2005-12-01

    The Swiss physicist Fritz Zwicky (1898-1974) dabbled in a plethora of disciplines, including astronomy and astrophysics. His dabblings were with vested interest and he has left quite an impact. His first great success was his nova research. In the early 1930s, while supermarkets and Superman were flying, he labelled the distinctly brighter nova Supernova. It had been believed that novae were the collision of two stars, but Zwicky came to recognize supernovae as a phenomenon quite distinct from novae. He and Walter Baade explained supernova by melding astronomy and physics and in this aim they created neutron stars, explained the origin of cosmic rays, initiated the first sky survey, and confirmed that a number of historical novae were indeed supernovae. This was truly an important work in the history of astrophysics.

  3. 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.

  4. The Hunt for Old Novae

    NASA Astrophysics Data System (ADS)

    Tappert, C.; Vogt, N.; Schmidtobreick, L.; Ederoclite, A.

    2014-12-01

    We inform on the progress of our on-going project to identify and classify old classical novae, using deep UBVR photometry and subsequent spectroscopy for a proper candidate confirmation, and time-resolved observations in order to find the orbital period and other physical properties of the identified old novae. This way, we have already increased the number of confirmed southern and equatorial post-novae from 33 to 50, and determined new orbital periods of eight objects. As an example, we sumarize the results on V728 Sco (Nova Sco 1862) which we found to be an eclipsing system with a 3.32 h orbital period, displaying high and low states similar to dwarf-nova outbursts. Analysis of the low-state eclipse indicates the presence of a small hot inner disk around the white dwarf component.

  5. 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).

  6. 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.

  7. 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.

  8. Emission line flaring in the SW Sex old nova V533 Herculis

    NASA Astrophysics Data System (ADS)

    Rodríguez-Gil, Pablo; Martínez-Pais, Ignacio G.

    2002-11-01

    We present high time resolution spectroscopy of the non-eclipsing old nova V533 Herculis (N Her 1963). It is the second nova remnant affected by the `SW Sex syndrome'. A modulation of the equivalent width of the emission lines with a period of 23.33 min has been detected. This, together with the strong He II λ4686 emission characteristic of magnetic systems, leads us to link this period to the spin of a magnetic white dwarf. Similar flaring activity has been recorded in other SW Sex stars, namely, the old nova BT Mon, LS Peg and DW UMa, supporting the idea of these systems being magnetic accretors. Stationary emission features are also observed in the Balmer lines, which we attribute to the ejected nova shell.

  9. V533 Herculis: the second SW Sex old nova displaying emission-line flaring

    NASA Astrophysics Data System (ADS)

    Rodríguez-Gil, P.; Martínez-Pais, I. G.

    2002-11-01

    We present high-time-resolution spectroscopy of the non-eclipsing old nova V533 Herculis (N Her 1963). It is the second nova remnant affected by the `SW Sex syndrome'. A modulation of the equivalent width of the emission lines with a period of 23.33 min has been detected. This, together with the strong He IIλ4686 emission characteristic of magnetic systems, leads us to link this period to the spin of a magnetic white dwarf. Similar flaring activity has been recorded in other SW Sex stars, namely, the old nova BT Mon, LS Peg and DW UMa, supporting the idea of these systems being magnetic accretors. Stationary emission features are also observed in the Balmer lines, which we attribute to the ejected nova shell.

  10. Nova Survey participation requested

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-03-01

    The AAVSO solicits participation in an online nova survey from our member and observer communities. The survey is being conducted in advance of an upcoming long-term observing campaign that will be launched in mid-April 2013. We are seeking participation in this survey from as broad a sample of the AAVSO community as possible, and your responses will help us gauge the effectiveness of the campaign and serve the observer community better. The survey may be completed anonymously, but you will have the option of providing us with your name and AAVSO observer code if you choose. Please visit the following website to complete the survey: https://www.surveymonkey.com/s/ZQHDYWB. The survey should take no more than five minutes to complete. We ask that you complete the survey by Monday, April 15, 2013.

  11. 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.

  12. HET Spectra of Three Recent Extragalactic Novae

    NASA Astrophysics Data System (ADS)

    Shafter, A. W.; Coelho, E. A.; Misselt, K. A.; Bode, M. F.; Darnley, M. J.; Quimby, R.

    2006-10-01

    We report optical spectroscopic observations (4280Å - 7280Å) obtained with the HET of three extragalactic novae: Nova M31 2006 No. 9 (ATEL #887), Nova M32 2006 No. 1 (CBET #591), and Nova M33 2006 No. 1 (CBET #655). The spectra were obtained on 24 Sep 2006 UT, 30 Sep 2006 UT, and 02 Oct 2006 UT, corresponding to approximately 6, 65, and 4 days post discovery, for the three novae respectively.

  13. Argonne's Vilas Pol on NOVA!

    ScienceCinema

    None

    2013-04-19

    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.

  14. 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.

  15. Nova reaction rates and experiments

    NASA Astrophysics Data System (ADS)

    Bishop, S.; Herlitzius, C.; Fiehl, J.

    2011-04-01

    Oxygen-neon novae form a subset of classical novae events known to freshly synthesize nuclei up to mass number A≲40. Because several gamma-ray emitters lie in this mass range, these novae are also interesting candidates for gamma-ray astronomy. The properties of excited states within those nuclei in this mass region play a critical role in determining the resonant (p,γ) reaction rates, themselves, largely unknown for the unstable nuclei. We describe herein a new Doppler shift lifetime facility at the Maier-Leibnitz tandem laboratory, Technische Universität München, with which we will map out important resonant (p,γ) nova reaction rates.

  16. Novae in γ-rays

    NASA Astrophysics Data System (ADS)

    Hernanz, M.

    2012-09-01

    Classical novae produce radioactive nuclei which are emitters of γ-rays in the MeV range. Some examples are the lines at 478 and 1275 keV (from ^7Be and ^{22}Na) and the positron-electron annihilation emission (511 keV line and a continuum below this energy, with a cut-off at 20-30 keV). The analysis of γ-ray spectra and light curves is potentially a unique and powerful tool both to trace the corresponding isotopes and to give insights on the properties of the expanding envelope determining its transparency. Another possible origin of γ-rays is the acceleration of particles up to very high energies, so that either neutral pions or inverse Compton processes produce γ-rays of energies larger than 100 MeV. MeV photons during nova explosions have not been detected yet, although several attempts have been made in the last decades; on the other hand, GeV photons from novae have been detected in some particular novae, in symbiotic binaries, where the companion is a red giant with a wind, instead of a main sequence star as in the cataclysmic variables hosting classical novae. Both mechanisms of γ-ray production in novae are reviewed, with more emphasis on the one related to radioactivities.

  17. 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

  18. 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.

  19. Classical and Recurrent Nova Models

    NASA Astrophysics Data System (ADS)

    José, Jordi; Casanova, Jordi; García-Berro, Enrique; Hernanz, Margarita; Shore, Steven N.; Calder, Alan C.

    2013-01-01

    Remarkable progress in the 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 hydrogen-rich envelopes transferred from a low-mass stellar companion onto a close white dwarf star. Extensive numerical simulations in 1-D have shown that the accreted envelopes attain peak temperatures ranging between 108 and 4 × 108 K, 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 certain role in the enrichment of the interstellar medium through a number of intermediate-mass elements. This includes 17O, 15N, and 13C, systematically overproduced with respect to solar abundances, plus a lower contribution in a number of other species (A < 40), such as 7Li, 19F, or 26Al. At the turn of the XXI Century, classical novae have entered the era of multidimensional models, which provide a new insight into the physical mechanisms that drive mixing at the core-envelope interface. In this review, we will present hydrodynamic models of classical novae, from the onset of accretion up to the explosion and ejection stages, both for classical and recurrent novae, with special emphasis on their gross observational properties and their associated nucleosynthesis. The impact of nuclear uncertainties on the final yields will be discussed. Recent results from 2-D models of mixing during classical nova outbursts will also be presented.

  20. 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.

  1. Disc structure and variability in dwarf novae

    NASA Astrophysics Data System (ADS)

    Harlaftis, Emilios Theofanus

    An introduction is given to dwarf novae reviewing the current research status in the field. We present IUE observations of Z Cha which support the mass transfer instability as the cause of the superoutbursts observed in SU UMa type dwarf novae. Comparison between the superoutburst and a normal outburst of Z Cha shows that the disc is flatter and has significantly less azimuthal structure than during superoutburst. Z Cha exhibits a soft x-ray deficit during superoutburst compared to OY Car. We find that the secondary star of Z Cha contributes approximately 30 percent of the infrared flux at peak of outburst. The second part of the thesis presents results from the 1988 International Time Project at the Observatorio del Roque de los Muchachos. Investigation of the behavior of SU UMa and YZ Cnc is carried out through the outburst cycle. The secular changes of the equivalent widths of both systems shows an increasing trend even during quiescence and are caused by the continuum decrease. Both systems show a low-velocity emission component which contaminates the wings of the H(alpha) profile. In addition to doppler broadening, the Stark effect is found to cause significant broadening to the line profile. The radial dependence of the emission lines is discussed in relation to other cataclysmic variables. H(alpha) emission from the secondary star of YZ Cnc is found during superoutburst, during outburst and during quiescence after outburst. Photometry during late decline of outburst shows a sinusoidal, weak variation peaking at 0.5 orbital phase and which is related to heating of the red star or to a transient disc event. During quiescence, the flickering is found to be caused by the bright spot. This modulation increases with time and is maximum before the outburst. Doppler tomography of IP Peg during quiescence reveals an emission line distribution not consistent to the standard model. We find Balmer emission from the secondary star, at a level of only 2.5 percent of the

  2. Spitzer observations of adolescent novae

    NASA Astrophysics Data System (ADS)

    Evans, Aneurin; Gehrz, Robert; Helton, Andrew; Krautter, Joachim; Lyke, James; Polomsky, Elisha; Rushton, Mark; Salama, Alberto; Shore, Steven; Starrfield, Sumner; Truran, James; Wagner, R. Mark; Woodward, Charles

    2006-05-01

    Classical novae (CNe) offer the best opportunity to observe many astrophysical processes (such as dust formation and processing, shaping of nebulae, gas cooling by IR fine structure lines) in `fast forward'. The CN eruption arises following a thermonuclear runaway on the surface of a white dwarf in a semi-detached binary system, following which some 10^-4 Msun of material, enriched in metals, is explosively ejected at ~1000km/s. Following the eruption, CNe vary rapidly, on a timescale ~months, and this necessitates continuous monitoring. Several novae were observed in GO1 as targets-of-opportunity (ToO). We propose to use the Spitzer IRS to observe a sample of novae, including GO1 ToO and several recent (<20years) CNe, to provide us with a well-populated CN parameter space. We aim to determine (i) the ejecta masses, (ii) abundances in the ejected material, (iii) evolution and processing of the CN dust.

  3. Transient classification and novae ejecta

    NASA Astrophysics Data System (ADS)

    Williams, Robert

    2016-07-01

    A third parameter, in addition to luminosity and rate of brightness decline, derived from the spectra of transients is suggested as a means of more accurately classifying objects in outburst. Principal component analysis of the spectra of transients is suggested as the best way to determine the third parameter. A model is suggested for novae ejecta that is based on the ballistic ejection of an ensemble of clouds having a wide range of sizes. Short term brightness fluctuations of novae, the formation of dust, and the production of X-ray emission follow naturally from such a picture of the evolving clouds.

  4. 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.

  5. 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.

  6. 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 evaluate the accuracy of…

  7. Far Ultraviolet Spectroscopy of Seven Nova-Like Variables

    NASA Astrophysics Data System (ADS)

    Mizusawa, Trisha; Merritt, Jason; Ballouz, Ronald-Louis; Bonaro, Michael; Foran, Sean; Plumberg, Christopher; Stewart, Heather; Wiley, Trayer; Sion, Edward M.

    2010-03-01

    We present the results of a multicomponent synthetic spectral analysis of the archival far ultraviolet spectra of several key nova-like variables including members of the SW Sex, RW Tri, UX UMa, and VY Scl subclasses: KR Aur, RW Tri, V825 Her, V795 Her, BP Lyn, V425 Cas, and HL Aqr. Accretion rates as well as the possible flux contribution of the accreting white dwarf are included in our analysis. Except for RW Tri, which has a reliable trigonometric parallax, we computed the distances to the nova-like systems using the method of Knigge. Our analysis of seven archival IUE spectra of RW Tri at its parallax distance of 341 pc consistently indicates a low mass (~0.4 Msolar) white dwarf and an average accretion rate, {\\overset{.}{M}} = 6.3 × 10-9 Msolar yr-1. For KR Aur, we estimate that the white dwarf has Teff = 29,000 ± 2000 K, log g = 8.4, and contributes 18% of the far-UV flux, while an accretion disk with accretion rate {\\overset{.}{M}} = 3 × 10-10 Msolar yr-1 at an inclination of 41° contributes the remainder. We find that an accretion disk dominates the far-UV spectrum of V425 Cas but a white dwarf contributes nonnegligibly with approximately 18% of the far-UV flux. For the two high state nova-likes, HL Aqr and V825 Her, their accretion disks totally dominate with {\\overset{.}{M}} = 1 × 10-9 Msolar yr-1 and 3 × 10-9 Msolar yr-1, respectively. For BP Lyn we find {\\overset{.}{M}} = 1 × 10-8 Msolar yr-1 while for V795 Her, we find an accretion rate of {\\overset{.}{M}} = 1 × 10-10 Msolar yr-1. We discuss the implications of our results for the evolutionary status of nova-like variables.

  8. THE NOVA RATE IN NGC 2403

    SciTech Connect

    Franck, J. R.; Shafter, A. W.; Hornoch, K.; Misselt, K. A.

    2012-11-20

    A multi-epoch H{alpha} survey of the late-type spiral galaxy NGC 2403 has been completed in order to determine its nova rate. A total of nine nova candidates were discovered in 48 nights of observation with two different telescopes over the period from 2001 February to 2012 April. After making corrections for temporal coverage and spatial completeness, a nova rate of 2.0{sup +0.5} {sub -0.3} yr{sup -1} was determined. This rate corresponds to a luminosity-specific nova rate of 2.5 {+-} 0.7 novae per year per 10{sup 10} L {sub Sun ,K}. This value is consistent with that of the similar Hubble-type galaxy, M33, and is typical of those of other galaxies with measured nova rates, which range from 1 to 3 novae per year per 10{sup 10} L {sub Sun ,K}.

  9. 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.

  10. AT Cnc: A Second Dwarf Nova with a Classical Nova Shell

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    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 ~5 × 10-5 M ⊙, typical of classical novae.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Hot Spot in Eclipsing Dwarf Nova IY Ursae Majoris during Quiescence and Normal Outburst

    NASA Astrophysics Data System (ADS)

    Bąkowska, K.; Olech, A.

    2015-12-01

    We present the analysis of hot spot brightness in light curves of the eclipsing dwarf nova IY UMa during its normal outburst in March 2013 and in quiescence in April 2012 and in October 2015. Examination of four reconstructed light curves of the hot spot eclipses showed directly that the brightness of the hot spot changed significantly only during the outburst. The brightness of the hot spot, before and after the outburst, was on the same level. Thus, based on the behavior of the hot spot, IY UMa during its normal outburst follows the disk-instability model.

  16. Hydrodynamic simulations of recurrent novae

    NASA Astrophysics Data System (ADS)

    Starrfield, S.; Sparks, W. M.; Truran, J. W.; Sion, E. M.

    1984-12-01

    Simulations of the 1979 outburst of the recurrent nova U Scorpii using a Lagrangian, hydrodynamic computer code which incorporates accretion in the evolution to the outburst are discussed. Three evolutionary sequences were computed in an attempt to understand the very rapid outburst and short recurrence time of this most unusual nova. It is now possible to reproduce the CNO composition of the ejected material, the light curve, the amount of ejected material, and the kinetic energy of the ejecta. The best sequence studied involved accretion of solar rich material onto a 1.38 solar magnatude white dwarf at a rate of 1.6 x 10 to the minus 8 solar magnatude per year.

  17. The NOvA experiment

    SciTech Connect

    Ray, Ronald E.

    2008-01-01

    The NOvA Project will construct a 15 kt Far Detector 835 km from Fermilab at Ash River Minnesota, a 220 ton Near Detector on the Fermilab site and upgrade the existing NuMI beamline from 400 kW to 700 kW. The detector technology is liquid scintillator captured in reflective rigid PVC cells. The light is captured using WLS fibre and routed to avalanche photo diodes. NO?A is designed to observe the appearance of electron neutrinos, determine the value of sin{sup 2}(2{theta}{sub 13}) and begin the study of CP violation in the neutrino sector. NO?A is the only currently approved experiment with the ability to determine the neutrino mass ordering. The NOvA physics program and projected sensitivities are described in this report.

  18. Possible Nova in M31

    NASA Astrophysics Data System (ADS)

    Burwitz, V.; Pietsch, W.; Updike, A.; Hartmann, D.; Milne, P.; Williams, G.

    2007-10-01

    We report the discovery of an optical nova candidate in M 31 on two 4*60sec stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) Livermore Optical Transient Imaging System (Super- LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA) on 2007 Oct 13.255, 13.259 with respective magnitudes of 18.0, 17.8. The position for the nova candidate is RA = 00h43m29.48s, Dec(2000) = +41d17'13.5" (J2000, accuracy of 0.2"), which is 8' 29" east and 1' 5" north of the core of M 31.

  19. "Huruhata's Variable" Revealed: The WZ Sge-Type Dwarf Nova EG CANCRI

    NASA Astrophysics Data System (ADS)

    Matsumoto, Katsura; Nogami, Daisaku; Kato, Taichi; Baba, Hajime

    1998-08-01

    Time-resolved CCD photometric observations of a dwarf nova EG Cnc were carried out during an outburst which occurred after a 19-year quiescent interval, since 1977 November. Our observations between 1996 December 2 and 14 revealed this outburst to be a definite superoutburst, eventually enabling a definite classification of this object as an SU UMa-type dwarf nova. This outburst was characterized by its long duration of more than two weeks and a large amplitude of at least 6.7 mag. The object showed two distinct types of superhumps: double-peaked modulations attributable to ``early superhumps'' with a period of 0.0582+/-0.00025 d in the earlier stage of the current outburst, followed by fully grown typical superhumps with a period of 0.0603+/-0.00006 d. We regard the period of 0.0582 d as being the orbital period of the object with a 3.7% superhump excess ratio. These characteristics suggest a strong resemblance to an extreme rare class of dwarf novae including WZ Sge, HV Vir, and AL Com with some other similarities between EG Cnc and the WZ Sge-type dwarf novae. The existence of double-peaked ``early superhumps'' in the early stage of superoutbursts may be a new defining criterion for the WZ Sge-type dwarf novae.

  20. 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.

  1. 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.

  2. AST3: dwarf nova outbursts

    NASA Astrophysics Data System (ADS)

    Ma, Bin; Hu, Yi; Shang, Zhaohui; Wang, Lifan

    2016-05-01

    AST3#2 OT J024453.11-580940.1 discovery - new dwarf nova outburst with ampl > 5.8 The 2nd Antarctic Survey Telescope (AST3#2) discovered OT source at (RA, Dec) = 02:44:53.11 -58:09:40.1 on 2016-05-06.071 UT with Sloan-g magnitude of 15.5m (limit 18.6m).

  3. Nova chain design and performance

    SciTech Connect

    Simmons, W.W.; Glaze, J.A.; Trenholme, J.B.; Hagen, W.F.

    1980-09-04

    During the past year design of the Nova laser has undergone significant change as a result of developments in our laser glass and optical coating evaluation programs. Two notable aspects of the glass development program deserve emphasis. First, vendor qualification for production of fluorophosphate laser glass is progressing satisfactorily. There is a reasonable expectation that vendors can meet fluorophosphate glass specifications within Nova schedule constraints. Secondly, recent gain saturation measurements have shown that the saturation fluence of the fluorophosphate glass is larger than previously supposed (approx. 5.5 J/cm/sup 2/) and in fact is somewhat larger than Shiva silicate glasses. Hence, performance of Nova for pulses in the 3 ns and longer range should be satisfactory. For pulses in the 1 ns regime, of course, the fluorophosphate chain will have superior performance to that of silicate because of its low nonlinear index of refraction (approx. 30% that of silicate). These and other considerations have led us to choose a chain design based upon the use of fluorophosphate glass in our amplifiers.

  4. 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.

  5. Positron annihilation gamma rays from novae

    NASA Technical Reports Server (NTRS)

    Leising, Mark D.; Clayton, Donald D.

    1987-01-01

    The potential for observing annihilation gamma rays from novae is investigated. These gamma rays, a unique signature of the thermonuclear runaway models of novae, would result from the annihilation of positrons emitted by beta(+)-unstable nuclei produced near the peak of the runaway and carried by rapid convection to the surface of the nova envelope. Simple models, which are extensions of detailed published models, of the expansion of the nova atmospheres are evolved. These models serve as input into investigations of the fate of nearby Galactic fast novae could yield detectable fluxes of electron-positron annihilation gamma rays produced by the decay of N-13 and F-18. Although nuclear gamma-ray lines are produced by other nuclei, it is unlikely that the fluxes at typical nova distances would be detectable to present and near-future instruments.

  6. 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.

  7. 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).

  8. Element abundances of classical novae

    NASA Astrophysics Data System (ADS)

    Andrea, J.; Drechsel, H.; Starrfield, S.

    1994-11-01

    Physical conditions and element abundances in the optically thin shells of 11 classical novae with outbursts between 1978 and 1989 were determined from an analysis of UV and optical spectra obtained during the nebular stage. Eight novae were studied on the basis of new optical and UV spectra. The accuracy of the element abundances depends on whether or not simultaneous UV spectra were available to determine individual ionization stage dependent gas temperatures. Generally, slightly higher than solar abundances of helium and pronounced overabundances of the heavier elements were found. QU Vul turned out to be an ONeMg nova, while the other objects belong to the class of CO novae. The nature of V2214 Oph could not be completely clarified. The novae V1668 Cyg (1978), V693 CrA (1981), and V1370 Aql (1982), for which published element abundances exist, were reanalyzed to check the consistency of our spectral analysis approach. Satisfactory agreement of the results was found. Photoionization calculations were carried out for PW Vul using the code of Aldrovandi, Pequignot, and Stasinska. A synthetic spectrum was generated for the parameters derived from the analysis of the UV and optical spectra, which is in very good agreement with the observations. The spectral analysis technique was then applied to the model spectrum and reproduced the model parameters well. Electron temperatures for the C(2+) and C(3+) ions between 7 500 and 12,000 K and for N(4+) betwen 12,000 and 16,000 K were derived. For PW Vul these temperatures remained relatively constant over several months. The decline in density of the ejected shells with time could be investigated for V842 Cen, QV Vul, V977 Sco, and V443 Sct, and was found to deviate from the relation Ne proportional to t-2 for free expansion of a shell in a different way for each object. A possible explanation may be the complex density structure of the shells. This suspicion is supported by high resolution spectra (ESO 3.6m telescope

  9. 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.

  10. 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.

  11. IUE observations of the dwarf novae OY Car in superoutburst

    NASA Technical Reports Server (NTRS)

    Hassall, B. J. M.; Naylor, T.; Charles, P. A.; Bath, G. T.; Sonneborn, G.

    1986-01-01

    The May 1985 superoutburst of OY Car, an eclipsing member of the SU UMa subclass of dwarf novae, was observed extensively with IUE to obtain phase-resolved spectra throughout several orbital cycles, when the superhump was well developed and lay close in phase to the eclipse. The UV lines and continuum vary with orbital phase and show a strong UV eclipse coincident with the optical eclipse. This implies that the superhump source at eclipse is not a strong contributor in the ultraviolet. The UV emission line spectrum and lack of X-ray eclipse suggest the presence of an extended coronal region. The flux evolution observed is unusual in that gross changes occur during the decline from superoutburst. The later spectra actually appear hotter than spectra earlier in the decline, and suggest that, early on, the inner disk is obscured from view.

  12. 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.

  13. The Incidence of Dwarf Novae in Large Area Transient Searches

    NASA Astrophysics Data System (ADS)

    Rau, A.; Schwarz, R.; Kulkarni, S. R.; Ofek, E. O.; Kasliwal, M. M.; Brinkworth, C.; Cenko, S. B.; Lipkin, Y.; Soderberg, A. M.

    2007-07-01

    Understanding and quantifying the contribution of known classes of transient and variable sources is an important lesson to be learned from the manifold of precursor programs of the near-future large synoptic sky survey programs such as SkyMapper, Pan-STARRS, and LSST. With this goal in mind, we undertook photometric and spectroscopic follow-up observations of four recently reported unidentified transients. For two sources, WFI J132813.7-214237 and WFI J161953.3+031909, we show that unfortunate coincidences led to their previous designation as transients. While the former is now interpreted as the spatial coincidence of a solar system object with a faint background star, the latter is merely a cataclysmic variable unfortunately caught in and out of eclipse. The third candidate, ROTSE3 J160213.1-021311.7, is identified as an SU UMa type dwarf nova with quiescent brightness of R~22.7 and an outburst amplitude of ~5 mag. The fourth event, SDSS-SN 15207, similarly shows evidence for a dwarf nova origin. Our main conclusion is that cataclysmic variables in their various avatars will contribute moderately to the population of transient objects.

  14. On the Progenitors of Local Group Novae. II. The Red Giant Nova Rate of M31

    NASA Astrophysics Data System (ADS)

    Williams, S. C.; Darnley, M. J.; Bode, M. F.; Shafter, A. W.

    2016-02-01

    In our preceding paper, Liverpool Telescope data of M31 novae in eruption were used to facilitate a search for their progenitor systems within archival Hubble Space Telescope data, with the aim of detecting systems with red giant secondaries (RG-novae) or luminous accretion disks. From an input catalog of 38 spectroscopically confirmed novae with archival quiescent observations, likely progenitors were recovered for 11 systems. Here we present the results of the subsequent statistical analysis of the original survey, including possible biases associated with the survey and the M31 nova population in general. As part of this analysis, we examine the distribution of optical decline times (t2) of M31 novae, how the likely bulge and disk nova distributions compare, and how the M31 t2 distribution compares to that of the Milky Way. Using a detailed Monte Carlo simulation, we determine that {30}-10+13% of all M31 nova eruptions can be attributed to RG-nova systems, and at the 99% confidence level, \\gt 10% of all M31 novae are RG-novae. This is the first estimate of a RG-nova rate of an entire galaxy. Our results also imply that RG-novae in M31 are more likely to be associated with the M31 disk population than the bulge; indeed, the results are consistent with all RG-novae residing in the disk. If this result is confirmed in other galaxies, it suggests that any Type Ia supernovae that originate from RG-nova systems are more likely to be associated with younger populations and may be rare in old stellar populations, such as early-type galaxies.

  15. 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.

  16. ON THE PROGENITORS OF GALACTIC NOVAE

    SciTech Connect

    Darnley, M. J.; Bode, M. F.; Hounsell, R. A.; Ribeiro, V. A. R. M.; Williams, R. P.

    2012-02-10

    Of the approximately 400 known Galactic classical novae, only 10 of them, the recurrent novae, have been seen to erupt more than once. At least eight of these recurrents are known to harbor evolved secondary stars, rather than the main-sequence secondaries typical in classical novae. In this paper, we propose a new nova classification system, based solely on the evolutionary state of the secondary and not (like the current schemes) based on the properties of the outbursts. Using archival optical and near-infrared photometric observations of a sample of 38 quiescent Galactic novae we show that the evolutionary state of the secondary star in a quiescent system can be predicted and several objects are identified for follow-up observations: CI Aql, V2487 Oph, DI Lac, and EU Sct.

  17. 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.

  18. Nova shell observation of V2275 Cyg

    NASA Astrophysics Data System (ADS)

    Esenoglu, Hasan H.; Balman, Solen; Saygac, A. Talat

    2016-07-01

    We present a recent search for nova shell of V2275 Cyg after its eruption of 9 years, using narrow bands of H-alpha, OIII and H-alpha-continuum images taken with RTT150 telescope at TUG. They were taken in November 2nd, 2010 with exposures of 600sec. There is uncertain in the literature whether the nova shell is visible in H-alpha. In this work the nova disappears on frame of OIII (wavelengt of 500.7nm with band width of 5nm) when it is faint apparent on the frames of both H-alpha and H-alpha continuum. We will calculate a new angular diameter of the nova shell by using the nebular expantion method if the data allow to measure seeing values of the nova and neighbor stars.

  19. The origin of presolar nova grains

    NASA Astrophysics Data System (ADS)

    José, Jordi; Hernanz, Margarita

    2007-08-01

    Infrared observations reveal that classical novae often form dust in their expanding shells ejected into the interstellar medium as a consequence of violent outbursts. Recent experimental efforts have led to the identification of presolar nova candidate grains from the Acfer 094 and Murchison meteorites. Recently, however, concerns have been raised about the stellar paternity of these grains by new measurements on another sample of SiC grains: these grains are characterized by 12C/13C and 14N/15N ratios similar to the ones reported for the nova grains, but a number of different imprints suggest that a possible supernova origin cannot be excluded. Here we review the predicted nucleosynthetic imprints accompanying nova explosions and discuss the chances to synthesize heavier species, such as titanium, in nova-like events.

  20. 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.

  1. Automated Searches for Extragalactic Novae

    NASA Astrophysics Data System (ADS)

    Darnley, M. J.

    2005-06-01

    Classical novae (CNe) are interacting binary systems in which the white dwarf undergoes unpredictable explosive outbursts. The energy of a nova outburst is only surpassed by that of gamma-ray bursts, supernovae and a small number of luminous blue variables. However, the outbursts of CNe are far more common than any of these other stars. Due to their brightness and occurrence in both Population I and Population II systems, novae are potentially important as extragalactic distance indicators and tools in the exploration of binary star evolution in galaxies. The POINT-AGAPE survey is an optical search for gravitational micro-lensing events towards the Andromeda galaxy (M31). As well as micro-lensing, the survey is sensitive to many different classes of variable stars and transients, including CNe. In this work we describe the automated detection and selection pipeline used to identify M31 CNe and we present the resulting catalogue of 20 strong CN candidates observed over three seasons. The CNe we discover are observed both in the M31 bulge region as well as over a wide area of the M31 disc. Nine of the CNe are caught during the final rise phase (which is often missed in Galactic novae) and all are well sampled in at least two colours. The excellent light-curve coverage has allowed us to detect and classify CNe over a wide range of speed classes, from very fast to very slow. Among the light curves is, for example, a moderately fast CN exhibiting entry into a deep transition minimum, followed by its final decline. We have also observed in detail a very slow CN which faded by only 0.01 mag day^{-1} over a 150 day period. The CN catalogue constitutes a uniquely well-sampled and objectively-selected data set with which to study the statistical properties of CNe in M31. As a by-product, we have detected other interesting variable objects, including one of the longest period and most luminous Mira variables. An analysis of the MMRD relationship in M31 was performed using the

  2. 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

  3. Shortest Recurrence Periods of Forced Novae

    NASA Astrophysics Data System (ADS)

    Hachisu, Izumi; Saio, Hideyuki; Kato, Mariko

    2016-06-01

    We revisit hydrogen shell burning on white dwarfs (WDs) with higher mass accretion rates than the stability limit, {\\dot{M}}{{stable}}, above which hydrogen burning is stable. Novae occur with mass accretion rates below the limit. For an accretion rate >{\\dot{M}}{{stable}}, a first hydrogen shell flash occurs followed by steady nuclear burning, so the shell burning will not be quenched as long as the WD continuously accretes matter. On the basis of this picture, some persistent supersoft X-ray sources can be explained by binary models with high accretion rates. In some recent studies, however, the claim has been made that no steady hydrogen shell burning exists even for accretion rates >{\\dot{M}}{{stable}}. We demonstrate that, in such cases, repetitive flashes occurred because mass accretion was artificially controlled. If we stop mass accretion during the outburst, no new nuclear fuel is supplied, so the shell burning will eventually stop. If we resume mass accretion after some time, the next outburst eventually occurs. In this way, we can design the duration of outburst and interpulse time with manipulated mass accretion. We call such a controlled nova a “forced nova.” These forced novae, if they exist, could have much shorter recurrence periods than “natural novae.” We have obtained the shortest recurrence periods for forced novae for various WD masses. Based on the results, we revisit WD masses of some recurrent novae, including T Pyx.

  4. Possible Nova in M31

    NASA Astrophysics Data System (ADS)

    Pietsch, W.; Burwitz, V.; Stoss, R.; Updike, A.; Hartmann, D.; Milne, P.; Williams, G.

    2007-10-01

    We report the discovery of an optical nova candidate in M 31 on 5 stacked white light images (each with 60 sec exposure) on 2007 Oct 6.104 with a magnitude of 17.1. The images were obtained with the REMO2 telescope of the Observatori Astronomic de Mallorca OAM (620), Costitx, Spain (30cm f/9 Schmidt-Cassegrain telescope with an SBIG STL-1001E CCD camera). The object is confirmed on R filter CCD images with the robotic 60cm telescope with an E2V CCD (2kx2k) Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA) on (two 8*60 s stacked, 17.1 and 17.2 mag) on 2007 Oct 6.336 and 6.429, respectively.

  5. 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.

  6. Similarities between Stunted Outbursts in Nova-like Cataclysmic Variables and Outbursts in Ordinary Dwarf Novae

    NASA Astrophysics Data System (ADS)

    Honeycutt, R. K.

    2001-04-01

    Stunted outbursts have been reported in old novae and nova-like cataclysmic variables by Honeycutt, Robertson, and Turner. These 0.4-1 mag outbursts were concluded to be either mass transfer events or disk outbursts similar to dwarf nova eruptions, but seen under unusual conditions. Honeycutt, Robertson, and Turner did not have enough evidence to favor either of these possibilities. This paper uses additional long-term photometry and analysis to argue that the similarities of these stunted outbursts to dwarf nova eruptions are now so numerous that the dwarf nova outburst choice is strongly favored. The similarities discussed here include the range of outburst spacings, the coherence and stability of the outbursts, and the presence of isolated outburst/dip pairs. As part of this discussion we note the presence of unexpectedly stable clocks over 9 years for the repetition interval of dwarf nova outbursts in SY Cnc and of stunted outbursts in FY Per.

  7. Multiwavelength Modeling of Nova Atmospheres

    NASA Technical Reports Server (NTRS)

    Hauschildt, P. H.; Starrfield, S.

    1997-01-01

    We have analyzed the early optically thick ultraviolet spectra of Nova OS And 1986 using a grid of spherically symmetric, non-LTE, line-blanketed, expanding model atmospheres and synthetic spectra with the following set of parameters: 5,000 less than or equal to T(sub model) less than or equal to 60,000K, solar abundances, (rho)(alpha) r(sup -3), v(sub max) = 2000 km/s, L = 6 x 10(exp 4) solar luminosity, and a statistical or microturbulent velocity of 50 km/s. We used the synthetic spectra to estimate the model parameters corresponding to the observed IUE spectra. The fits to the observations were then iteratively improved by changing the parameters of the model atmospheres, in particular T(sub model) and the abundances, to arrive at the best fits to the optically thick pseudo-continuum and the features found in the IUE spectra. The IUE spectra show two different optically thick subphases. The earliest spectra, taken a few days after maximum optical light, show a pseudo-continuum created by overlapping absorption lines. The later observations, taken approximately 3 weeks after maximum light, show the simultaneous presence of allowed, semi-forbidden, and forbidden lines in the observed spectra. Analysis of these phases indicate that OS And 86 had solar metallicities except for Mg which showed evidence of being underabundant by as much as a factor of 10. We determine a distance of 5.1 kpc to OS And 86 and derive a peak bolometric luminosity of approximately 5 x 10(exp 4) solar luminosity. The computed nova parameters provide insights into the physics of the early outburst and explain the spectra seen by IUE. Lastly, we find evidence in the later observations for large non-LTE effects of Fe II which, when included, lead to much better agreement with the observations.

  8. Recent developments on SU UMa stars - theory vs. observation

    NASA Astrophysics Data System (ADS)

    Cannizzo, John K.

    2015-01-01

    Kepler light curves of short period dwarf novae have resparked interest in the nature of superoutbursts and led to the question: Is the thermal-tidal instability needed, or can the plain vanilla version of the accretion disk limit cycle do the job all by itself? A detailed time-resolved study of an eclipsing SU UMa system during superoutburst onset should settle the question - if there is a dramatic contraction of the disk at superoutburst onset, Osaki's thermal-tidal model would be preferred; if not, the plain disk instability model would be sufficient. I will present recent results that support the contention by Osaki & Kato that the time varying negative superhump frequencies can be taken as a surrogate for the outer disk radius variations. Finally, it may be necessaryto look beyond the short period dwarf novae to gain perspective on the nature of embedded precursors in long outbursts.

  9. 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.

  10. Time-resolved optical studies and Doppler imaging of the eclipsing dwarf nova V893 Scorpii

    NASA Astrophysics Data System (ADS)

    Matsumoto, K.; Mennickent, R. E.; Kato, T.

    2000-11-01

    We present time-resolved optical spectroscopic and photometric observations of the re-discovered dwarf nova V893 Sco. The orbital period of 0fd07610 (3) derived from the radial velocity and equivalent width variations of the Hα emission line is confirmed. The photometric light curves clearly show the eclipse of the accretion disk. A mass of the white dwarf ~ 0.5-0.6 Msun is derived from the orbital amplitude K1 = 86 +/- 11 km s-1 and the eclipse constraint. The mass ratio is likely small enough to make V893 Sco an SU UMa-type dwarf nova, though this object has shown only normal outbursts in its light curve. Time-resolved Doppler maps for the emission lines show two isolated Hα emission regions, which are associated with a strong hot spot and the irradiated secondary star. Based on observations obtained at ESO La Silla Observatory (ESO Proposal 61.D-0395)

  11. 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.

  12. Photometric Periods of Recent Southern Novae

    NASA Astrophysics Data System (ADS)

    Walter, Frederick M.; Pagnotta, Ashley; Kafka, Stella

    2013-02-01

    We initiated a program to follow the temporal evolution of novae using the SMARTS facilities in 2003. Since then we have followed the evolution of the 68 galactic novae, resulting in the ``Stony Brook/SMARTS Atlas of mostly Southern Novae", a spectroscopic and photometric database. The next step is to undertake a systematic search for orbital periods. We propose here for a week of classical time on the 0.9m to search for photometric periods in the range of a few hours to a few days; we have identified two systems with periods of 1.1 and 5.2 hours. Our targets are recent novae visible in the A semester, mostly in the galactic center region. This complements our continuing longer-term SMARTS monitoring of these systems as they approach quiescence.

  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. 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.

  15. 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.

  16. Planets orbiting Quark Nova compact remnants

    NASA Astrophysics Data System (ADS)

    Keränen, P.; Ouyed, R.

    2003-08-01

    We explore planet formation in the Quark Nova scenario. If a millisecond pulsar explodes as a Quark Nova, a protoplanetary disk can be formed out of the metal rich fall-back material. The propeller mechanism transfers angular momentum from the born quark star to the disk that will go through viscous evolution with later plausible grain condensation and planet formation. As a result, earth-size planets on circular orbits may form within short radii from the central quark star. The planets in the PSR 1257+12 system can be explained by our model if the Quark Nova compact remnant is born with a period of ~ 0.5 ms following the explosion. We suggest that a good portion of the Quark Nova remnants may harbour planetary systems.

  17. 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.

  18. CNO nucleosynthesis and the nova outburst

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    Predictions for CNO nucleosynthesis by the classical nova outburst are presented. Properties of the nova phenomenon pertinent to the production of CNO isotopes are discussed, the effect of beta(+) unstable nuclei on outburst evolution is examined, and the need for enhanced CNO nuclei in the envelope is described. Possible mechanisms for producing such enhancement are considered, and recent observations of enhanced CNO nuclei in nova ejecta are reviewed. Results of model evolutionary calculations are outlined which show that a thermonuclear runaway in the hydrogen envelope of a carbon-oxygen white dwarf can reproduce the gross features of the classical nova outburst, that the behavior of the outburst depends at least on the hydrogen-envelope mass and the degree of CNO enhancement, and that all degrees of isotopic enhancement result in an outburst that may be compared with observed events. Two enhancement mechanisms are identified, both of which involve mixing in the envelope.

  19. 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.

  20. 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

  1. 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.

  2. Serendipitous Discovery of a Dwarf Nova in the Kepler Field Near the G Dwarf KIC 5438845

    NASA Astrophysics Data System (ADS)

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

    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 & 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. Seven Galactic classical novae from the OGLE-IV Survey

    NASA Astrophysics Data System (ADS)

    Mroz, P.; Udalski, A.

    2016-07-01

    We report the discovery of seven classical novae located in the Galactic bulge and disk fields. Novae were found during a search for bright transients in data from the OGLE-IV sky survey from observing seasons 2014-2016.

  8. 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.

  9. The distances of the Galactic Novae

    NASA Astrophysics Data System (ADS)

    Ozdonmez, Aykut; Guver, Tolga; Cabrera-Lavers, Antonio; Ak, Tansel

    2016-07-01

    Using location of the RC stars on the CMDs obtained from the UKIDSS, VISTA and 2MASS photometry, we have derived the reddening-distance relations towards each Galactic nova for which at least one independent reddening measurement exists. We were able to determine the distances of 72 Galactic novae and set lower limits on the distances of 45 systems. The reddening curves of the systems are presented. These curves can be also used to estimate reddening or the distance of any source, whose location is close to the position of the nova in our sample. The distance measurement method in our study can be easily applicable to any source, especially for ones that concentrated along the Galactic plane.

  10. The Distances of the Galactic Novae

    NASA Astrophysics Data System (ADS)

    Özdönmez, Aykut; Güver, Tolga; Cabrera-Lavers, Antonio; Ak, Tansel

    2016-06-01

    Utilising the unique location of red clump giants on colour-magnitude diagrams obtained from various near-IR surveys, we derived specific reddening-distance relations towards 119 Galactic novae for which independent reddening measurements are available. Using the derived distance-extinction relation and the independent measurements of reddening we calculated the most likely distances for each system. We present the details of our distance measurement technique and the results of this analysis, which yielded the distances of 73 Galactic novae and allowed us to set lower limits on the distances of 46 systems. We also present the data of reddening-distance relations derived for each nova, which may be useful to analyze the different Galactic components present in the line of sight.

  11. The distances of the Galactic novae

    NASA Astrophysics Data System (ADS)

    Özdönmez, Aykut; Güver, Tolga; Cabrera-Lavers, Antonio; Ak, Tansel

    2016-09-01

    Utilizing the unique location of red clump giants on colour-magnitude diagrams obtained from various near-infrared surveys, we derived specific reddening-distance relations towards 119 Galactic novae for which independent reddening measurements are available. Using the derived distance-extinction relation and the independent measurements of reddening we calculated the most likely distances for each system. We present the details of our distance measurement technique and the results of this analysis, which yielded the distances of 73 Galactic novae and allowed us to set lower limits on the distances of 46 systems. We also present the reddening-distance relations derived for each nova, which may be useful to analyse the different Galactic components present in the line of sight.

  12. 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.

  13. 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.

  14. Dynamic testing of NOVA laser switchyard tower

    SciTech Connect

    Weaver, H.J.; Pastrnak, J.W.; Fields, D.E.

    1984-06-01

    NOVA is the latest in a series of powerful laser systems designed to study the feasibility of initiating a controlled fusion reaction by concentrating several laser beams on a small fuel target. The laser components, turning mirrors and target chamber are all mounted on large steel frame structures. These structures were first analyzed via finite element models to access their seismic integrity as well as their overall vibrational stability. When construction was completed, a modal analysis was performed on the structures to verify and improve the finite element models. This report discusses the linking of the analytical and experimental studies for the NOVA switchyard tower structure.

  15. Infrared observations of nova V5588 Sagittarii

    NASA Astrophysics Data System (ADS)

    Banerjee, D. P. K.; Ashok, N. M.

    2011-05-01

    We report near-IR 1.08 to 2.3 micron spectroscopy of the nova V5588 Sgr using the NICMOS3 imager/spectrograph and the 1.2m Mount Abu telescope of the Physical Research Laboratory. The spectra were taken on 26 April and 4 May 2011, after the large second rebrightening of the nova reported on 25.11 April (Munari et al., CBET 2707) when it reached V = 11.7, a brightness level comparable to that of the primary maximum of V = 11.2 reached on 7 April 2011.

  16. Dust formation in Nova Cephei 2013

    NASA Astrophysics Data System (ADS)

    Ninan, J. P.; Ojha, D. K.; Ghosh, S. K.; Anupama, G. C.; Prabhu, T. P.; Bhatt, B. C.

    2013-08-01

    We report near-infrared K band photometry and spectroscopy of Nova Cephei 2013, discovered by K. Nishiyama and F. Kabashima on 2013 Feb 2.4 UT (cf. CBET #3397, ATel #4950, #4893, #5026). The observations were made using the 2-m Himalayan Chandra telescope (+TIFR Near Infrared Imager and Spectrometer, TIRSPEC) at the Indian Astronomical Observatory (IAO), Hanle (Ladakh). The estimated K band magnitudes of nova were: 2013 June 23 UT, 7.40 +/-0.02 and 2013 July 8 UT 7.84 +/- 0.02; the source brightness has therefore dimmed by 0.44 mag in K band during 16 days.

  17. 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.

  18. New optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Burwitz, V.; Pietsch, W.; Henze, M.; Rodriguez, J.; Haswell, C. A.; Holmes, S.; Kolb, U.; Lucas, R.

    2010-06-01

    We report the discovery of a possible nova in M 31 on a 5x120s stacked unfiltered CCD image obtained with the 0.35-m f/11 OU/OAM PIRATE Schmidt-Cassegrain telescope (+ SBIG STL-1001E CCD camera) at Costitx, Mallorca, Spain on 2010 June 26.084 UT with a corresponding R magnitude of 17.8. The position for the nova candidate is RA = 00h44m04.48s, Dec = +41d28'34.2" (J2000, accuracy of 0.3"), which is 902" east and 746" north of the core of M 31.

  19. 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.

  20. SN 2010U: A LUMINOUS NOVA IN NGC 4214

    SciTech Connect

    Humphreys, Roberta M.; Helton, L. Andrew; Prieto, Jose L.; Rosenfield, Philip; Williams, Benjamin; Murphy, Jeremiah; Dalcanton, Julianne; Gilbert, Karoline; Kochanek, Christopher S.; Stanek, K. Z.; Khan, Rubab; Szczygiel, Dorota; Mogren, Karen; Fesen, Robert A.; Milisavljevic, Dan

    2010-07-20

    The luminosity, light curve, post-maximum spectrum, and lack of a progenitor on deep pre-outburst images suggest that SN 2010U was a luminous, fast nova. Its outburst magnitude is consistent with that for a fast nova using the maximum magnitude-rate of decline relationship for classical novae.

  1. NovaNET User Manual for "Crouter" Instructors.

    ERIC Educational Resources Information Center

    Fortner, Monica B.; Davis, Dennis M.

    Intended to teach instructors how to use the NovaNET computer system or the PLATO system to deliver instruction, this manual provides instructions for using both NovaNET, which supercedes PLATO, and the crouter software package, which is a general purpose tool for managing instruction on the NovaNET computer. This self-instructional manual is…

  2. 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.

  3. 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.

  4. 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. PMID:25082700

  5. A Universal Decline Law of Classical Novae. II. GK Persei 1901 and Novae in 2005

    NASA Astrophysics Data System (ADS)

    Hachisu, Izumi; Kato, Mariko

    2007-06-01

    Optical and infrared light curves of classical novae are approximately homologous among various white dwarf (WD) masses and chemical compositions when free-free emission from optically thin ejecta is spherical and dominates the continuum flux of novae. Such a homologous template light curve is called ``a universal decline law.'' Various nova light curves are approximately reproduced from this universal law by introducing a timescaling factor which stretches or squeezes the template light curve to match the observation. The timescale of the light curve depends strongly on the WD mass but weakly on the chemical composition, so we are able to roughly estimate the WD mass from the light-curve fitting. We have applied the universal decline law to the old nova GK Persei 1901 and recent novae that outbursted in 2005. The estimated WD mass is 1.15 Msolar for GK Per, which is consistent with a central value of the WD mass determined from the orbital velocity variations. The other WD masses of 10 novae in 2005 are also estimated to be 1.05 Msolar (V2361 Cyg), 1.15 Msolar (V382 Nor), 1.2 Msolar (V5115 Sgr), 0.7 Msolar (V378 Ser), 0.9 Msolar (V5116 Sgr), 1.25 Msolar (V1188 Sco), 0.7 Msolar (V1047 Cen), 0.95 Msolar (V476 Sct), 0.95 Msolar (V1663 Aql), and 1.30 Msolar (V477 Sct), within a rough accuracy of +/-0.1 Msolar. Four (V382 Nor, V5115 Sgr, V1188 Sco, and V477 Sct) of 10 novae in the year 2005 are probably neon novae on an O-Ne-Mg WD. Each WD mass depends weakly on the chemical composition (especially the hydrogen content X in mass weight), i.e., the obtained WD masses increase by +0.5(X-0.35) Msolar for the six CO novae and by +0.5(X-0.55) Msolar for the four neon novae above. Various nova parameters are discussed in relation to its WD mass.

  6. A catalogue of low-resolution IUE spectra of dwarf novae and nova-like stars

    NASA Technical Reports Server (NTRS)

    La Dous, Constanze

    1990-01-01

    A catalogue is presented of all the low-resolution IUE spectra of dwarf novae and nova-like stars that were recorded until the end of 1987. All spectra have been reduced, and are displayed, in a homogeneous way. In addition to details about these data, to the extent available, their position in the outburst light curves is given, physical information about each system, and a comprehensive list of references for published observations in all wavelength ranges.

  7. FUSE Observations of Galactic and LMC Novae in Outburst

    NASA Technical Reports Server (NTRS)

    Huschildt, P. H.

    2001-01-01

    This document is a collection of five abstracts from papers written on the 'FUSE Observations of Galactic and LMC Novae in Outburst'. The titles are the following: (1) Analyzing FUSE Observations of Galactic and LMC Novae; (2) Detailed NLTE Model Atmospheres for Novae during Outburst: Modeling Optical and Ultraviolet Observations for Nova LMC 1988; (3) Numerical Solution of the Expanding Stellar Atmosphere Problem; (4) A Non-LTE Line-Blanketed Expanding Atmosphere Model for A-supergiant Alpha Cygni; and (5) Non-LTE Model Atmosphere Analysis of the Early Ultraviolet Spectra of Nova Andromedae 1986. A list of journal publications is also included.

  8. Enriched Students Program: Nova Scotia, Canada.

    ERIC Educational Resources Information Center

    Aylward, Margaret

    1987-01-01

    The Russell C. Gordon Elementary School (Nova Scotia, Canada) offers the Enriched Students Program (ESP) for academically gifted students. ESP goals include: fostering and developing individual interests of students; initiating higher level thinking skills; strengthening task commitment; stimulating creativity; promoting leadership qualities; and…

  9. Nova Sct 2009 (V496 Sct)

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2009-11-01

    As initially announced in CBET 2008 (Daniel W. E. Green, ed.) and AAVSO Special Notice #176 (M. Templeton), and expanded on in IAU Circular No. 9093 (Green, ed.), Nova Scutum 2009 (V496 Sct) was discovered by H. Nishimura (Miyawaki, Kakegawa, Japan) on 2009 November 8.370 UT at unfiltered CCD magnitude of 8.8, using 120-mm camera lens, derived by S. Nakano (Sumoto, Japan) from Nishimura's discovery images. RA: 18:43:45.57 , Dec: -7:36:42.0 (equinox 2000.0) from E. Guido and G. Sostero. Spectroscopy by F. Teyssier (Rouen, France); D. Balam (NRCC) and G. Sarty (U. Sask.); and U. Munari et al. (INA-Padova & the Asiago Novae and Symbiotic Stars Collaboration) confirm the object as a nova, with emission lines showing P Cygni profiles. Munari et al. show the presence of FeII, indicating a nova of the Fe II-type. Observations should be reported to the AAVSO International Database as V496 SCO.

  10. NOvA: Exploring Neutrino Mysteries

    SciTech Connect

    Vahle, Tricia; Messier, Mark

    2012-09-06

    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.

  11. 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.

  12. 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.

  13. The NOvA DAQ Monitor System

    NASA Astrophysics Data System (ADS)

    Baird, Michael; Grover, Deepika; Kasahara, Susan; Messier, Mark

    2015-12-01

    The NOvA (NuMI Off-Axis ve Appearance) experiment is a long-baseline neutrino experiment designed to search for vµ (v̅µ) to ve (v̅e) oscillations using Fermilab's NuMI main injector neutrino beam. The experiment consists of two detectors; both positioned 14 mrad off the beam axis: a 220 ton Near Detector constructed in an underground cavern at Fermilab and a 14 kton Far Detector constructed in Ash River, MN, 810 km from the beam source. The health and performance of the NOvA Data Acquisition (DAQ) system is monitored with a DAQ Monitor system based on the Ganglia distributed monitoring system, an open source third-party product which provides much of the NOvA DAQ monitoring needs “out-of-the-box”. This paper will discuss the use of the Ganglia system for this purpose, including augmentations we have made to the Ganglia base for the specific needs of our system. This paper will also discuss two other systems used to monitor the quality of the data collected by the NOvA detectors: an Online Monitoring system and Event Display, both of which leverage tools from the offline framework to provide close to real time diagnostic tools of detector performance.

  14. 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 a flight. "Lost King of the…

  15. 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…

  16. 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.

  17. Engineering the Petawatt Laser into Nova

    SciTech Connect

    Tietbohl, G.L.; Bell, P.M.; Hamilton, R.M.

    1997-12-23

    The engineering process of integrating the Petawatt (10{sup 15} watts) laser system into the existing 30 kJ (UV) Nova laser at Lawrence Livermore National Laboratory (LLNL) is described in detail. The nanosecond-long, chirped Petawatt laser pulse is initially generated in a separate master oscillator room and then injected into one of Nova`s 10 beamlines. There, the pulse is further amplified and enlarged to {approximately}{phi}60 cm, temporally compressed under vacuum to <500 fs using large diameter diffraction gratings, and then finally focused onto targets using a parabolic mirror. The major Petawatt components are physically large which created many significant engineering challenges in design, installation and implementation. These include the diffraction gratings and mirrors, vacuum compressor chamber, target chamber, and parabolic focusing mirror. Other Petawatt system components were also technically challenging and include: an injection beamline, transport spatial filters, laser diagnostics, alignment components, motor controls, interlocks, timing and synchronization systems, support structures, and vacuum systems. The entire Petawatt laser system was designed, fabricated, installed, and activated while the Nova laser continued its normal two-shift operation. This process required careful engineering and detailed planning to prevent experimental downtime and to complete the project on schedule.

  18. 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 Link"; (6) "Shackleton's Voyage of Endurance"; and (7)…

  19. 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 Trial"; (5) "Life's Greatest…

  20. 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.

  1. 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. PMID:25363778

  2. Creating healthy futures. 2000 NOVA Award winners.

    PubMed

    Larson, L

    2000-05-01

    Winners of this year's NOVA awards, sponsored by the American Hospital Association and H&HN magazine, all share a broad definition of health. These five stars of community benefit also understand that a community and a health care organization share responsibility for what creates health, and that collaborative efforts are the only way to sustain innovative programs. PMID:11785219

  3. 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.

  4. NOvA: Exploring Neutrino Mysteries

    ScienceCinema

    Vahle, Tricia; Messier, Mark

    2014-08-12

    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.

  5. The NOvA simulation chain

    DOE PAGESBeta

    Aurisano, A.; Backhouse, C.; Hatcher, R.; Mayer, N.; Musser, J.; Patterson, R.; Schroeter, R.; Sousa, A.

    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

  6. 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. PMID:25693569

  7. 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.

  8. 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

  9. OGLE Atlas of Classical Novae. I. Galactic Bulge Objects

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

    Eruptions of classical novae are possible sources of lithium formation and gamma-ray emission. Nova remnants can also become Type Ia supernovae (SNe Ia). The contribution of novae to these phenomena depends on nova rates, which are not well established for the Galaxy. Here, we directly measure a Galactic bulge nova rate of 13.8 ± 2.6 {{yr}}-1. This measurement is much more accurate than any previous measurement of this kind thanks to many years’ monitoring of the bulge by the Optical Gravitational Lensing Experiment (OGLE) survey. Our sample consists of 39 novae eruptions, ∼1/3 of which are OGLE-based discoveries. This long-term monitoring allows us to not only measure the nova rate but also to study in detail the light curves of 39 eruptions and more than 80 post-nova candidates. We measured orbital periods for 9 post-novae and 9 novae, and in 14 cases we procured the first estimates. The OGLE survey is very sensitive to the frequently erupting recurrent novae. We did not find any object similar to M31 2008-12a, which erupts once a year. The lack of detection indicates that there is only a small number of them in the Galactic bulge.

  10. 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.

  11. Getting to know classical novae with Swift

    NASA Astrophysics Data System (ADS)

    Osborne, Julian P.

    2015-09-01

    Novae have been reported as transients for more than two thousand years. Their bright optical outbursts are the result of explosive nuclear burning of gas accreted from a binary companion onto a white dwarf. Novae containing a white dwarf close to the Chandrasekhar mass limit and accreting at a high rate are potentially the unknown progenitors of the type Ia supernovae used to measure the acceleration of the Universe. Swift X-ray observations have radically transformed our view of novae by providing dense monitoring throughout the outburst, revealing new phenomena in the super-soft X-rays from the still-burning white dwarf such as early extreme variability and half- to one-minute timescale quasi-periodic oscillations. The distinct evolution of this emission from the harder X-ray emission due to ejecta shocks has been clearly delineated. Soft X-ray observations allow the mass of the white dwarf, the mass burned and the mass ejected to be estimated. In combination with observations at other wavelengths, including the high spectral resolution observations of the large X-ray observatories, high resolution optical and radio imaging, radio monitoring, optical spectroscopy, and the detection of GeV gamma-ray emission from recent novae, models of the explosion have been tested and developed. I review nine novae for which Swift has made a significant impact; these have shown the signature of the components in the interacting binary system in addition to the white dwarf: the re-formed accretion disk, the companion star and its stellar wind.

  12. 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.

  13. 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.

  14. Early X-ray emission from novae: The case of the symbiotic recurrent nova RS Ophiuchi

    NASA Astrophysics Data System (ADS)

    Delgado, L.; Hernanz, M.

    2014-07-01

    Novae can be sources of high-energy photons, reaching GeV energies. Such emission is a consequence of π^{0} decay and/or Inverse Compton, which are related to particle (p and e^{-}) acceleration. The strong shock between matter ejected by the white dwarf and the circumstellar medium is responsible for this process. The 2006 outburst of RS Ophiuchi was the first nova for which particle acceleration was predicted. This prediction showed that the blast wave decelerated faster than expected as a consequence of acceleration of particles in the shock and their escape. RS Oph is a recurrent nova in a symbiotic system composed of a white dwarf and a red giant with a recurrence period of ˜ 21 years. Five novae have been detected by Fermi/LAT so far. Our aim is to understand the acceleration process through the analysis of contemporaneous X-ray emission. We present an analysis of the XMM-Newton's observations of RS Oph early after its 2006 outburst both with RGS and EPIC-MOS, which have a broader energy range than RGS. We will compare with RXTE, Swift/BAT and Chandra observations, to get a global picture of VHE γ-ray emission in novae and its relationship with particle acceleration.

  15. Tracking the NOvA Detectors' Performance

    NASA Astrophysics Data System (ADS)

    Psihas, Fernanda; NOvA Collaboration

    2016-03-01

    The NOvA experiment measures long baseline νμ -->νe oscillations in Fermilab's NuMI beam. We employ two detectors equipped with over 10 thousand sets of data-taking electronics; avalanche photo diodes and front end boards which collect and process the scintillation signal from particle interactions within the detectors. These sets of electronics -as well as the systems which power and cool them- must be monitored and maintained at precise working conditions to ensure maximal data-taking uptime, good data quality and a lasting life for our detectors. This poster describes the automated systems used on NOvA to simultaneously monitor our data quality, diagnose hardware issues, track our performance and coordinate maintenance for the detectors.

  16. Overshoot Convective Mixing in Nova Outbursts

    NASA Astrophysics Data System (ADS)

    Glasner, A. S.; Livne, E.; Truran, J. W.

    2014-12-01

    We present a 2D study of the overshoot convective mechanism in nova outbursts for a wide range of possible compositions of the layer underlying the accreted envelope. Previous surveys studied this mechanism only for solar composition matter accreted on top of carbon oxygen (CO) white dwarfs. Since, during the runaway, mixing with carbon enhances the hydrogen burning rates dramatically, one should question whether significant enrichment of the ejecta is possible also for other underlying compositions (He, O, Ne, Mg) predicted by stellar evolution models. When needed we upgraded our reaction network and simulated several non-carbon cases. Despite large differences in rates, time scales and energetics, our results show that the convective dredge up mechanism predicts significant enrichment in all cases, including that of helium enrichment in recurrent novae.

  17. 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.

  18. Observational selection among classical novae in outburst.

    NASA Astrophysics Data System (ADS)

    Ritter, H.; Politano, M. J.; Livio, M.; Webbink, R. F.

    The authors investigate to what extent observational selection can account for the prevalence of massive white dwarfs among classical novae as was originally proposed by Truran and Livio (1986). For this the authors elaborate on their approach by taking into account a detailed model distribution function for the masses of newly-formed cataclysmic binaries from Politano (1988, 1990), an improved ignition condition for the thermonuclear runaway, as well as effects of the secular evolution of the systems and flux limitation of the observations (including interstellar absorption). The results agree qualitatively with those obtained by Truran and Livio (1986). However, since Politano's model calculations do not take into account the formation of O-Ne-Mg white dwarfs, the authors cannot make any quantitative prediction as to their expected abundance among observed novae.

  19. Possible new optical Nova in M 31

    NASA Astrophysics Data System (ADS)

    Burwitz, V.; Pietsch, W.; Henze, M.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2007-11-01

    We report the discovery of an optical nova candidate in M 31 on 3*60sec and 8*60sec stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2007 Nov 13.27 and 13.38 with respective magnitudes of 17.4 and 17.5. The position for the nova candidate is RA = 00h43m04.14s, Dec = +41d15'54.3" (J2000, accuracy of 0.3"), which is 3' 43" east and 14" south of the core of M 31.

  20. Possible new optical Nova in M 31

    NASA Astrophysics Data System (ADS)

    Henze, M.; Burwitz, V.; Pietsch, W.; Updike, A.; Hartmann, D.; Milne, P.; Williams, G.

    2007-12-01

    We report the discovery of an optical nova candidate in M 31 on two 8*60sec stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) Livermore Optical Transient Imaging System (Super- LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2007 Dec 18.19 and 18.30 with respective magnitudes of 17.2 and 17.4. The position for the nova candidate is RA = 00h41m54.96s, Dec = +41d09'47.3" (J2000, accuracy of 0.3"), which is 9' 17" west and 6' 22" south of the core of M 31.

  1. Optical Nova Candidate in M 31

    NASA Astrophysics Data System (ADS)

    Henze, M.; Burwitz, V.; Pietsch, W.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2008-05-01

    We report the discovery of an optical nova candidate in M 31 on two 8x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2008 May 26.45 and 27.45 UT with respective magnitudes of 17.0 and 17.5. The position for the nova candidate is RA = 00h43m12.08s, Dec = +41d19'15.8" (J2000, accuracy of 0.3"), which is 5'13" east and 3'6" north of the core of M 31.

  2. Possible optical Nova in M 31

    NASA Astrophysics Data System (ADS)

    Pietsch, W.; Burwitz, V.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D.

    2007-11-01

    We report the discovery of an optical nova candidate in M 31 on two 8*60sec stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) Livermore Optical Transient Imaging System (Super- LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA) on 2007 Nov 2.28 and 2.37 with respective magnitudes of 16.9 and 17.0. The position for the nova candidate is RA = 00h42m37.29s, Dec = +41d17'10.3" (J2000, accuracy of 0.2"), which is 1' 19" west and 1' 2" north of the core of M 31.

  3. Optical Nova Candidate in M 31

    NASA Astrophysics Data System (ADS)

    Burwitz, V.; Henze, M.; Pietsch, W.; Updike, A.; Hartmann, D.; Milne, P.; Williams, G.

    2008-01-01

    We report the discovery of an optical nova candidate in M 31 on two 12*60sec stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2008 Jan 20.21 and 21.21 with respective magnitudes of 17.2 and 17.9. The position for the nova candidate is RA = 00h42m58.54s, Dec = 41d14'44.1" (J2000, accuracy of 0.3"), which is 2'41" west and 1'25 south of the core of M 31.

  4. Optical Nova Candidate in M 31

    NASA Astrophysics Data System (ADS)

    Henze, M.; Burwitz, V.; Pietsch, W.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2008-06-01

    We report the discovery of an optical nova candidate in M 31 on two 11x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2008 June 14.46 and 16.46 UT with respective magnitudes of 18.0 and 17.7. The position for the nova candidate is RA = 00h42m37.72s, Dec = +41d12'30.0"(J2000, accuracy of 0.3"), which is 1'14" west and 3'39" south of the core of M 31. All magnitudes given are obtained from a photometric solution using R magnitudes of the Local Group Survey M 31 catalogue (Massey et al.

  5. 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.

  6. On Li-7 production in nova explosions

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

    Calculations of Li-7 production occurring as a concomitant of thermonuclear runaways in hydrogen envelopes of white dwarfs are reported. It is found that sufficient Li-7 can be produced in models displaying fast-nova-like features to suggest that the corresponding objects represent significant contributors to the enrichment of galactic matter. The sensitivities of these results to various assumptions and uncertainties are discussed.

  7. V723 Cas a borderline classical nova

    NASA Astrophysics Data System (ADS)

    Friedjung, M.; Iijima, T.

    2002-11-01

    V723 Cas had a light curve similar to that of HR Del before maximum, with a very slow pre-maximum rise, explained according to [2] by the presence of an optically thin wind before maximum unlike the optically thick wind generally seen for classical novae after maximum. Examination of the Fe II emission lines by the SAC method, is compatible with this also having been the case for V723 Cas.

  8. 1729-19 Nova Ophiuchi 1994

    NASA Astrophysics Data System (ADS)

    Mattei, Janet A.

    1994-06-01

    Akihiko Tago and Minoru Yamamoto discover an apparent nova in Ophiuchus at mag. 7.0. Position RA 17h 32m 47.56" DEC -19° 17' 41.8". TV Crv is in outburst with current magnitude estimates approximating 13.0. An error was made reporting a bright outburst of UV Per in Alert Notice 186 and should be ignored. The star continues to be bright, however, with estimates approximating 12.5.

  9. Nova power systems: status and operating experience

    SciTech Connect

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

    1983-11-28

    This paper describes the pulse power systems that are used in these lasers; the status and the operating experiences. The pulsed power system for the Nova Laser is comprised of several distinct technology areas. The large capacitor banks for driving flashlamps that excite the laser glass is one area, the fast pulsers that drive pockels cell shutters is another area, and the contol system for the pulsed power is a third. This paper discusses the capacitor banks and control systems.

  10. Mechanical construction of the 22 Nova laser

    SciTech Connect

    Hurley, C.A.; Frick, F.A.; Patton, H.G.; Bradley, G.; Martos, A.

    1983-11-22

    The Nova laser system for Inertial Confinement Fusion studies at Lawrence Livermore National Laboratory is under construction and will be completed October 1984 with first operations scheduled for 1985. This system is the largest precision opto-mechanical engineering system ever built. Major engineering and subsystems are mechanical, optical, and electrical power. A series of system technologies include alignment, diagnostics, target, frequency conversion, and controls. This paper will only discuss the mechanical system.

  11. 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.

  12. Dwarf Nova Outbursts with Magnetorotational Turbulence

    NASA Astrophysics Data System (ADS)

    Coleman, M. S. B.; Kotko, I.; Blaes, O.; Lasota, J.-P.; Hirose, S.

    2016-08-01

    The phenomenological Disc Instability Model has been successful in reproducing the observed light curves of dwarf nova outbursts by invoking an enhanced Shakura-Sunyaev α parameter ˜0.1 - 0.2 in outburst compared to a low value ˜0.01 in quiescence. Recent thermodynamically consistent simulations of magnetorotational (MRI) turbulence with appropriate opacities and equation of state for dwarf nova accretion discs have found that thermal convection enhances α in discs in outburst, but only near the hydrogen ionization transition. At higher temperatures, convection no longer exists and α returns to the low value comparable to that in quiescence. In order to check whether this enhancement near the hydrogen ionization transition is sufficient to reproduce observed light curves, we incorporate this MRI-based variation in α into the Disc Instability Model, as well as simulation-based models of turbulent dissipation and convective transport. These MRI-based models can successfully reproduce observed outburst and quiescence durations, as well as outburst amplitudes, albeit with different parameters from the standard Disc Instability Models. The MRI-based model lightcurves exhibit reflares in the decay from outburst, which are not generally observed in dwarf novae. However, we highlight the problematic aspects of the quiescence physics in the Disc Instability Model and MRI simulations that are responsible for this behavior.

  13. Local thermonuclear runaways among classical novae

    NASA Astrophysics Data System (ADS)

    Orio, Marina; Shaviv, Giora

    1993-04-01

    A classical nova may accrete a nonhomogeneous envelope, which can result in the ignition of a local thermonuclear runaway on the surface of the white dwarf. We studied the propagation of thermal flows along the meridian in the hydrogen rich envelope, to find the conditions under which a thermonuclear runaway is not spherically symmetric. We included mass accretion and tested the effect of temperature inhomogeneities in the secular evolution of the envelope, supposing perturbations with different wavelengths, ranging from very small to comparable with the radius of the white dwarf. The calculations were stopped at the onset of a thermonuclear runaway, when the hydrodynamic expansion starts. We found the ranges of accretion rates and masses of white dwarfs for which the runaway ignites locally. The propagation time of the runaway along the meridian may be as long as days and weeks. 'Local' thermonuclear runaways can explain the asymmetries and inhomogeneities of the nova shells and account for the slow rise time to maximum (about one week) of many novae.

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

    SciTech Connect

    Habig, Alec; Zirnstein, Jan

    2015-01-01

    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 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.

  15. 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.

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

    DOE PAGESBeta

    Habig, Alec; Zirnstein, Jan

    2015-01-01

    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 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. Variable Radio Emission from 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.

    2011-08-01

    The EVLA Nova Team reports additional radio flux measurements of the classical nova V5588 Sgr (IAUC #9203, CBET #2707) which indicate significant variability. Observations taken 66 days after the initial discovery of this nova yield non-detections at 5.9 and 33.1 GHz; the derived upper limits are significantly lower than our previously reported detections on day 48 (ATel #3397).

  18. Hohlraum drive and implosion experiments on Nova. Revision 1

    SciTech Connect

    Kilkenny, J.D.; Suter, L.J.; Cable, M.D.

    1994-09-08

    Experiments on Nova have demonstrated hohlraum radiation temperatures up to 300 eV and in lower temperature experiments reproducible time integrated symmetry to 1--2%. Detailed 2-D LASNEX simulations satisfactorily reproduce Nova`s drive and symmetry scaling data bases. Hohlraums has been used for implosion experiments achieving convergence ratios (initial capsule radius/final fuel radius) up to 24 with high density glass surrounding a hot gas fill.

  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. DAO Spectroscopic Study of Nova Cygni 1992

    NASA Astrophysics Data System (ADS)

    Garnavich, Peter M.

    1992-12-01

    The spectral development of Nova Cygni 1992 is being monitored at the Dominion Astrophysical Observatory. The brightest nova in over 15 years provides a rare opportunity to study, in detail, nova evolution from maximum to the late nebular stages. Our spectra during the early phases of the outburst had a resolution of 0.6 Angstroms while in the nebular phase the resolution ranged from 2 Angstroms to 4 Angstroms . The nova was observed at DAO on more than 40 nights in 1992. Our first spectrum was obtained near maximum light on February 22, 1992. It showed weak Hβ and Fe II emission lines with P-Cygni absorption components at -910 and -1670 km/s (IAUC 5457). During the early decline, the P-Cygni absorption complex spread blueward, eventually reaching -2900 km/s by the ides of March. Observations by IUE showed absorption troughs of UV lines extending to -2800 km/s even before maximum (IAUC 5456). This suggests that the apparent increase in the velocity of the diffuse-enhanced absorption is due to opacity effects, not a physical acceleration of the gas or the changing geometry of the expanding shells. The transition to the nebular phase occurred in late April, 1992. The emission lines were broad (FWHM of 2200 km/s) and contained as many as 10 velocity components. The temperature and density evolution of the major velocity components are estimated from diagnostic line ratios during the nebular stage. The similarity between Nova Cygni 1992 and V1500 Cyg suggested that the coronal line, [Fe X] 6374 Angstroms , might be present in the early nebular phase. The unusual shape and strength of the [O I] line at 6363 Angstroms added to this suspicion. In spectra taken 90 days after outburst, the [O I] 6300 Angstroms line was used to deconvolve the emission, but the contamination was found to be due to the Si II doublet 6347/71 Angstroms . Infrared observations indicated the onset of a coronal phase 200 days after maximum (IAUC 5612), and our data from this period are analyzed

  1. 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.

  2. Investigation of the Nebular Remnants of Novae

    NASA Astrophysics Data System (ADS)

    Ribeiro, Valério A. R. M.

    2011-01-01

    Classical and recurrent nova outbursts occur on the surface of a white dwarf in a close binary system. It is widely established that the outburst is due to a thermonuclear runaway. Their study provides a real-time laboratory for the understanding of a wide range of astrophysical phenomena. These include for example, mass transfer in close binary systems, nuclear powered outbursts, dust formation, mass loss from red giants, and many others. Recurrent novae have also been suggested as the progenitors of Type Ia Supernovae. This thesis concentrates on investigating the nebular remnants of novae by studying both resolved imaging (where available) and spectroscopic evolution and combining this with detailed modelling. Such studies have wider implications for example in our understanding of the shaping of proto-Planetary Nebulae. Here, using a morpho-kinematical code, the true 3D geometry, from which information such as the remnant's inclination angle and expansion velocity can be derived, of the recurrent nova RS Ophiuchi and classical novae V2491 Cygni, V2672 Ophiuchi and KT Eridani are established and related to other characteristics of each system. Each of the classical novae have also been suggested as a recurrent nova candidate. Furthermore, several enhancements to the modelling code were implemented prompted by the work described in this thesis. The RS Oph work entailed detailed modelling of Hubble Space Telescope resolved imaging combined with ground-based spectroscopic observations. Here it was shown that the bipolar morphology of RS Oph consisted of two distinct components with an outer dumbbell and an inner hour glass overdensity, which were required to reproduce both the observed images and spectra. This morphology was suggested to arise due to the interaction between the pre-existing anisotropic red-giant wind and the ejecta. The observed asymmetry in the ACS/HRC image was shown to be due to the finite width and offset from the [OIII] line's rest wavelength

  3. The Dusty Nova: An Examination of Dust Production and Processing in the Ejecta of Classical Novae

    NASA Astrophysics Data System (ADS)

    Helton, L. A.; Evans, A.; Woodward, C. E.; Gehrz, R. D.; Vacca, W.

    2014-12-01

    Classical novae (CNe) are known to frequently produce dust in their ejecta. Infrared observations have revealed that the dust produced can be of a variety of different species, including silicates, amorphous carbon, hydrocarbons, and silicon carbide. Due to their relatively rapid evolution, CNe provide unique laboratories for the examination of the processes of dust condensation, grain growth, and destruction. Here we present analysis of the near- to mid-IR spectra of a number of recent dust forming novae, including V2361 Cyg, V2362 Cyg, and V1280 Sco. We discuss the implications for our understanding of dust formation and processing with particular emphasis on the role of hydrocarbon species.

  4. 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

  5. Spectroscopic and Photometric Analysis of Novae: A New Classification Method

    NASA Astrophysics Data System (ADS)

    Esenoglu, H.

    1997-11-01

    This study deals with the relationship between the absolute visual magnitude at maximum and the rate of decline (MMRD or M_v -- t_3) for classical novae. Considering the most reliable data including the nebular expansion parallax method for 24 galactic novae, we find that there are two distinct kinds of galactic novae. Slopes of very fast and fast novae were found from a least-squares fit to their MMRD relation. The values of these two slope angles are similar. A similar result was found for moderately fast and slow novae, whose mean slopes differ by only a small amount. Therefore very fast novae can be grouped with fast novae, and moderately fast novae can be grouped with slow novae, so that we have only two separate novae groups. These two groups of novae are distinguished from each other by the Eddington luminosity. Our conclusions agree well with those of Duerbeck (1981, PASP, 93, 165), based on the light curves of approximately 100 galactic novae. Considering numerical nova model calculations (Livio 1992, ApJ, 393, 516), it seems that there is a good agreement between the observed and the theoretical MMRD relation. Moreover, we applied the same classification method to novae in M31 (Massimo and Livio, 1995, ApJ, 452, 704), and found the same two separate groups. We also determined expansion parallaxes for QZ Aur, V1974 Cyg, FH Ser, XX Tau, RW UMi, and QU Vul, and expansion velocities for Nova Aql 1995, V1974 Cyg and FH Ser. These results were found from H-alpha imaging and spectroscopic observations made by the author and A.Bianchini and T.Iijima (University of Padova), using the 1.82- and 1.22-m telescopes at the Ekar and Asiago Observatories. When we compare our images with those in the literature, we can obtain expansion parallaxes for QU Vul, QZ Aur, V1974 Cyg, and RW UMi. Shell diameters in the light of H-alpha for QU Vul, QZ Aur, V1974 Cyg and RW UMi were found to be 0.82, 0.83, 0.76 and 2.94 arcsec, respectively (epoch 1994-5). The literature gives

  6. 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.

  7. 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.

  8. Near-infrared studies during maximum and early decline of Nova Cephei 2014 and Nova Scorpii 2015

    NASA Astrophysics Data System (ADS)

    Srivastava, Mudit K.; Ashok, N. M.; Banerjee, D. P. K.; Sand, D.

    2015-12-01

    We present multiepoch near-infrared photospectroscopic observations of Nova Cephei 2014 and Nova Scorpii 2015, discovered in outburst on 2014 March 8.79 UT and 2015 February 11.84 UT, respectively. Nova Cep 2014 shows the conventional NIR characteristics of a Fe II class nova characterized by strong C I, H I and O I lines, whereas Nova Sco 2015 is shown to belong to the He/N class with strong He I, H I and O I emission lines. The highlight of the results consists in demonstrating that Nova Sco 2015 is a symbiotic system containing a giant secondary. Leaving aside the T CrB class of recurrent novae, all of which have giant donors, Nova Sco 2015 is shown to be only the third classical nova to be found with a giant secondary. The evidence for the symbiotic nature is threefold; first is the presence of a strong decelerative shock accompanying the passage of the nova's ejecta through the giant's wind, second is the H α excess seen from the system and third is the spectral energy distribution of the secondary in quiescence typical of a cool late-type giant. The evolution of the strength and shape of the emission line profiles shows that the ejecta velocity follows a power-law decay with time (t-1.13±0.17). A Case B recombination analysis of the H I Brackett lines shows that these lines are affected by optical depth effects for both the novae. Using this analysis, we make estimates for both the novae of the emission measure n_e^2L, the electron density ne and the mass of the ejecta.

  9. 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.

  10. 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.

  11. EXPANDED VERY LARGE ARRAY NOVA PROJECT OBSERVATIONS OF THE CLASSICAL NOVA V1723 AQUILAE

    SciTech Connect

    Krauss, Miriam I.; Chomiuk, Laura; Rupen, Michael; Roy, Nirupam; Mioduszewski, Amy J. E-mail: lchomiuk@nrao.edu E-mail: nroy@nrao.edu

    2011-09-20

    We present radio light curves and spectra of the classical nova V1723 Aql obtained with the Expanded Very Large Array (EVLA). This is the first paper to showcase results from the EVLA Nova Project, which comprises a team of observers and theorists utilizing the greatly enhanced sensitivity and frequency coverage of EVLA radio observations, along with observations at other wavelengths, to reach a deeper understanding of the energetics, morphology, and temporal characteristics of nova explosions. Our observations of V1723 Aql span 1-37 GHz in frequency, and we report on data from 14 to 175 days following the time of the nova explosion. The broad frequency coverage and frequent monitoring show that the radio behavior of V1723 Aql does not follow the classic Hubble-flow model of homologous spherically expanding thermal ejecta. The spectra are always at least partially optically thin, and the flux rises on faster timescales than can be reproduced with linear expansion. Therefore, any description of the underlying physical processes must go beyond this simple picture. The unusual spectral properties and light curve evolution might be explained by multiple emitting regions or shocked material. Indeed, X-ray observations from Swift reveal that shocks are likely present.

  12. Expanded Very Large Array Nova Project Observations of the Classical NovaV1723 Aquilae

    NASA Technical Reports Server (NTRS)

    Krauss, Miriam I.; Chomiuk, Laura; Rupen, Michael; Roy, Nirupam; Mioduszewski, Amy J.; Sokoloski, J. L.; Nelson, Thomas; Mukai, Koji; Bode, M. F.; Eyres, S. P. S.; OBrien, T. J.

    2011-01-01

    We present radio light curves and spectra of the classical nova VI723 Aql obtained with the Expanded Very Large Array (EVLA). This is the first paper to showcase results from the EVLA Nova Project, which comprises a team of observers and theorists utilizing the greatly enhanced sensitivity and frequency coverage of EVLA radio observations, along with observations at other wavelengths, to reach a deeper understanding of the energetics, morphology, and temporal characteristics of nova explosions. Our observations of VI723 Aql span 1-37 GHz in frequency, and we report on data from 14 to 175 days following the time of the nova explosion. The broad frequency coverage and frequent monitoring show that the radio behavior of VI723 Aql does not follow the classic Hubble-flow model of homologous spherically expanding thermal ejecta. The spectra are always at least partially optically thin, and the flux rises on faster timescales than can be reproduced with linear expansion. Therefore, any description of the underlying physical processes must go beyond this simple picture. The unusual spectral properties and light curve evolution might be explained by multiple emitting regions or shocked material. Indeed, X-ray observations from Swift reveal that shocks are likely present.

  13. Expanded Very Large Array Nova Project Observations of the Classical Nova V1723 Aquilae

    NASA Astrophysics Data System (ADS)

    Krauss, Miriam I.; Chomiuk, Laura; Rupen, Michael; Roy, Nirupam; Mioduszewski, Amy J.; Sokoloski, J. L.; Nelson, Thomas; Mukai, Koji; Bode, M. F.; Eyres, S. P. S.; O'Brien, T. J.

    2011-09-01

    We present radio light curves and spectra of the classical nova V1723 Aql obtained with the Expanded Very Large Array (EVLA). This is the first paper to showcase results from the EVLA Nova Project, which comprises a team of observers and theorists utilizing the greatly enhanced sensitivity and frequency coverage of EVLA radio observations, along with observations at other wavelengths, to reach a deeper understanding of the energetics, morphology, and temporal characteristics of nova explosions. Our observations of V1723 Aql span 1-37 GHz in frequency, and we report on data from 14 to 175 days following the time of the nova explosion. The broad frequency coverage and frequent monitoring show that the radio behavior of V1723 Aql does not follow the classic Hubble-flow model of homologous spherically expanding thermal ejecta. The spectra are always at least partially optically thin, and the flux rises on faster timescales than can be reproduced with linear expansion. Therefore, any description of the underlying physical processes must go beyond this simple picture. The unusual spectral properties and light curve evolution might be explained by multiple emitting regions or shocked material. Indeed, X-ray observations from Swift reveal that shocks are likely present.

  14. 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.

  15. 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 years 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 SALT 11.5 years after the outburst showed a prominent He II 4686A line and the Bowen blend, which reveal a very hot region, but with peak temperature shifted to the ultraviolet (UV) 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.

  16. V4743 Sgr, a magnetic nova?

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    Two XMM Newton observations of Nova V4743 Sgr (Nova Sgr 2002) were performed shortly after it returned to quiescence, 2 and 3.5 years 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 SALT 11.5 years 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 (UV) 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.

  17. The Accretion Rates and White Dwarf Components of Nova-Like Cataclysmic Variables

    NASA Astrophysics Data System (ADS)

    Mizusawa, Trisha; Merritt, J.; Bonaro, M.; Foran, S.; Plumberg, C.; Stewart, H.; Wiley, T.; Ballouz, R.; Sion, E.

    2009-01-01

    We present the results of a multi-component synthetic spectral analysis of the archival far ultraviolet spectra of several key nova-like variables including members of the SW Sex, RW Tri, UX UMa and VY Scl subclasses: KR Aur, V795 Her, BP Lyn, V825 Her, HL Aqr, RW Tri and V425 Cas. Accretion rates as well as the flux contribution of the accreting white dwarf are included in our analysis. Except for RW Tri which has a reliable trigonometric parallax, we computed the distances to the nova-like systems using the method of Knigge(2006, MNRAS, 373, 484). For KR Aur, we find that the white dwarf has T_eff = 29,000 +/- 2000K, log g = 8.4 and contributes 18% of the FUV flux while an accretion disk with accretion rate Mdot = 3 x 10-10 Msun/yr at an inclination of 41 degrees, contributes the remainder. Our analysis of seven archival IUE spectra of RW Tri at its parallax distance consistently yields a low mass (0.4 Msun) white dwarf and an average accretion rate, Mdot = 6.3 x 10-9 Msun/yr. We find that an accreting white dwarf rather than accretion disk dominates the far UV spectrum of V425 Cas while HL Aqr's and V825 Her's FUV spectra are dominated by an accretion disk with Mdot = 1 x 10-9 Msun/yr and 3 x 10-9 Msun/yr, respectively. For BP Lyn we find Mdot = 1 x 10-8 Msun/yr and we explore the possiblity that V795 Her is an intermediate polar. We discuss the implications of our results for the evolutionary status of nova-like variables. This work is supported by NSF grant AST-0807892 to Villanova University and by the Delaware Space Grant Consortium

  18. New disk nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Henze, M.; Pietsch, W.; Burwitz, V.; Rodriguez, J.; Bochinski, J.; Busuttil, R.; Haswell, C. A.; Holmes, S.; Kolb, U.

    2012-02-01

    We report the discovery of a possible nova in the south-western disk of M 31 on a 5x120s dithered stacked CCD image obtained with the Open University PIRATE Planewave CDK17 0.43m Dall-Kirkham f/6.7 telescope at the Observatorio Astronomico de Mallorca (Costitx, Spain), using an SBIG STX 16803 CCD Camera (with a Kodak 4k x 4k chip with 9 microns sq. pixels) and Baader clear filter, on 2012 Feb 15.803 UT with a R magnitude of 17.5 (accuracy of 0.2 mag).

  19. Photometry of the old nova HZ Pup

    NASA Astrophysics Data System (ADS)

    Cassanelli, Tomas; Abbott, Tim

    2016-01-01

    This study of the old nova HZ Pup involved obtaining image data, removing the instrumental signature, performing photometry on the stellar images present, and generating light curves. Relative photometry between the target star and other stars in the image was used to remove atmospheric effects. A periodogram of this light curve shows the historically known periodicity close to 20 minutes. However, other periodicities are also present and it is not clear from the data which are real and which are artifacts of the sampling. These data will be combined with data from other telescopes collected contemporaneously in order to resolve this ambiguity.

  20. 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.

  1. Nova isolates noise to quieten stations

    SciTech Connect

    Milner, G.J.; Frank, L.D.

    1993-10-01

    This paper reviews a technique developed by Nova Corp., to help isolate and measure the acoustic power of individual components in a pipeline compressor and pumping station. The procedure calculates the sound pressure levels of each piece of equipment independently. Based on these measurements, a prediction can be made of the effect of various types of noise treatment techniques on the overall sound levels currently generated or proposed in a future project. This paper describes the equipment to measure the sound levels, techniques for actually measuring the compressor station or equipment area, and techniques used to generate a remediation plan.

  2. 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).

  3. Optical Nova Candidate in M 31

    NASA Astrophysics Data System (ADS)

    Henze, M.; Pietsch, W.; Burwitz, V.; Updike, A.; Hartmann, D.; Milne, P.; Williams, G.

    2008-02-01

    We report the discovery of an optical nova candidate in M 31 on a 12x60 s stacked R filter CCD image obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2008 Feb 07.17 UT with a magnitude of 18.2 and is clearly visible on several of the individual 60 s images.

  4. New optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Burwitz, V.; Pietsch, W.; Henze, M.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.; Rodriguez, J.; Holmes, S.; Kolb, U.; Lucas, R.

    2010-01-01

    We report the discovery of a possible nova in M 31 on two 10x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k, 13.5 micron sq. pixels) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA) on 2010 January 11.13 and 12.09 UT with respective R magnitudes of 17.6, 16.3.

  5. New optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Podigachoski, P.; Pietsch, W.; Henze, M.; Burwitz, V.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2009-11-01

    We report the discovery of a possible nova in M 31 on two 12x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k, 13.5 microns sq. pixels) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2009 November 6.26 and 8.26 UT with respective magnitudes of 19.3 and 18.5.

  6. New optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Podigachoski, P.; Pietsch, W.; Henze, M.; Burwitz, V.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2009-11-01

    We report the discovery of a possible nova in M 31 on a 12x60s stacked R filter CCD image obtained with the robotic 60cm telescope with an E2V CCD (2kx2k, 13.5 micron sq. pixels) of the Livermore OpticalTransient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was detected on 2009 November 19.19 UT with magnitude of 18.1. The object is clearly visible on the individual images.

  7. New optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Pietsch, W.; Podigachoski, P.; Haberl, F.; Henze, M.; Burwitz, V.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2009-11-01

    We report the discovery of a possible nova in M 31 on two 12x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k, 13.5 micron sq. pixels) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2009 November 20.25 and 21.14 UT with respective magnitudes of 18.7 and 18.5.

  8. Optical Nova Candidates in M 31

    NASA Astrophysics Data System (ADS)

    Henze, M.; Burwitz, V.; Pietsch, W.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2008-06-01

    We report the discovery of an optical nova candidate in M 31 on two 11x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2008 June 06.47 and 07.47 UT with respective magnitudes of 18.0 and 17.9.

  9. 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.

  10. UBVRI Polarimetry of Nova Sgr 2015#2

    NASA Astrophysics Data System (ADS)

    Muneer, S.; Anupama, G. C.; Raveendran, A. V.; Muniyandi, A.; Baskar, R.

    2015-03-01

    We report here the first polarimetric observations of Nova Sgr 2015#2 (PNV J18365700-2855420). The linear polarization observations of the nova in UBVRI spectral bands were obtained during 16-22 March 2015 with a two beam, multichannel polarimeter attached to the 1-m Carl-Zeiss telescope at the Vainu Bappu Observatory, Kavalur, India.

  11. ON THE SPECTROSCOPIC CLASSES OF NOVAE IN M33

    SciTech Connect

    Shafter, A. W.; Darnley, M. J.; Bode, M. F.; Ciardullo, R.

    2012-06-20

    We report the initial results from an ongoing multi-year spectroscopic survey of novae in M33. The survey resulted in the spectroscopic classification of six novae (M33N 2006-09a, 2007-09a, 2009-01a, 2010-10a, 2010-11a, and 2011-12a) and a determination of rates of decline (t{sub 2} times) for four of them (2006-09a, 2007-09a, 2009-01a, and 2010-10a). When these data are combined with existing spectroscopic data for two additional M33 novae (2003-09a and 2008-02a), we find that five of the eight novae with available spectroscopic class appear to be members of either the He/N or Fe IIb (hybrid) classes, with only two clear members of the Fe II spectroscopic class. This initial finding is very different from what would be expected based on the results for M31 and the Galaxy where Fe II novae dominate, and the He/N and Fe IIb classes together make up only {approx}20% of the total. It is plausible that the increased fraction of He/N and Fe IIb novae observed in M33 thus far may be the result of the younger stellar population that dominates this galaxy, which is expected to produce novae that harbor generally more massive white dwarfs than those typically associated with novae in M31 or the Milky Way.

  12. 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

    2016-08-01

    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 two. 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.

  13. Uma Krishnaswami and International Imaginings

    ERIC Educational Resources Information Center

    Aldama, Frederick Luis

    2006-01-01

    This article presents an interview with South Asian children's book and young adult fiction writer, Uma Krishnaswami. The interviewer states that "in all her creative endeavors Uma's keen sense of detail, narrative voice, and characterization complicate and humanize portrayals of multicultural peoples worldwide." In this interview, Krishnaswami…

  14. Performance and operation of the upgraded Nova laser

    SciTech Connect

    Kyrazis, D.T.; Speck, D.R.; Bibeau, C.; Ehrlich, R.B.; Hermes, G.L.; Smith, J.R.; Weiland, T.L.; Wegner, P.J.

    1989-01-25

    Over the past year, the Nova laser at the Lawrence Livermore National Laboratory has been undergoing major refurbishment. Concurrently, an extensive research program has been undertaken to characterize and understand, in detail, the characteristics of Nova and the factors which limit its performance. As a result of these combined efforts, Nova now exceeds its original performance goals. Among the topics discussed are the substitution of platinum free laser glass in the power amplifier section of the Nova beamlines; increased frequency conversion efficiency and large optic damage resulting from transverse stimulated Brillouin scattering. When we have implemented the necessary changes on all 10 Nova beamlines, we will soon be able to routinely deliver 120 kilojoules of energy at 1.053 ..mu..m, and 75 kilojoules at 0.351 ..mu..m. 18 refs., 7 figs.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Optical components for the Nova laser

    SciTech Connect

    Wallerstein, E.P.; Baker, P.C.; Brown, N.J.

    1982-05-17

    In addition to its other characteristics, the Nova Laser Fusion facility may well be the largest precision optical project ever undertaken. Moreover, during the course of construction, concurrent research and development has been successfully conducted, and has resulted in significant advances in various technical areas, including manufacturing efficiency. Although assembly of the first two beams of Nova is just commencing, the optical production, including construction of the special facilities required for many of the components, has been underway for over three years, and many phases of the optical manufacturing program for the first 10 beams will be completed within the next two years. On the other hand, new requirements for second and third harmonic generation have created the need to initiate new research and development. This work has been accomplished through the enormous cooperation DOE/LLNL has received from commercial industry on this project. In many cases, industry, where much of the optical component research and development and virtually all of the manufacturing is being done, has made substantial investment of its own funds in facilities, equipment, and research and development, in addition to those supplied by DOE/LLNL.

  1. New optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Pietsch, W.; Henze, M.; Burwitz, V.; Kaur, A.; Hartmann, D. H.; Milne, P.; Williams, G.

    2010-12-01

    We report the discovery of a possible nova in M 31 on a 12x60s stacked R filter CCD image obtained with the robotic 60cm telescope with an E2V CCD (2kx2k, 13.5 micron sq. pixels) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA) on 2010 December 11.095 UT with magnitude of 16.6. The object is visible on all individual images. The position for the nova candidate is RA = 00h42m31.08s, Dec = +41d27'20.3"(J2000, accuracy of 0.3"), which is 149" west and 672" north of the core of M 31. We do not detect the object on a 4x60s stacked SLOTIS CCD image obtained on2010 December 5.213 UT (limiting R magnitude at the position of 19.0). There is no entry in VizieR/CDS for this object and no minor planet could be found on this position using the MPC/IAU Minor Planet Checker (see http://scully.harvard.edu/~cgi/CheckMP) . All magnitudes given are obtained from a photometric solution using R magnitudes of the Local Group Survey M 31 catalogue (Massey et al.

  2. Polymers replace glass in Nova fuel capsules

    SciTech Connect

    Burnham, A.K.

    1986-01-01

    The glass fuel-capsule designs used in previous laser-fusion research are not adaptable to the implosion-physics requirements of Nova and other more powerful laser facilities that may be available in the future. As one tries to learn more about the physics of high-density compression, it becomes increasingly important to replace the glass with lower-Z material. Accordingly, the authors have shut down the high-temperature drop-tower furnaces they used to make glass capsules, and they are focusing all their efforts on developing new techniques for making polymer capsules. These capsules are ten times larger in diameter than the glass capsules used in the early days of laser-fusion research, but they are still only one-tenth as large as a high-gain capsule must be. The polymer capsules will be used in classified indirect-drive targets. This article describes how the decisions were made on which polymers to use in the NOVA fuel capsules, the techniques explored, and the properties of the prototype capsules.

  3. 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.

  4. 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.

  5. 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

  6. 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...

  7. 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...

  8. 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...

  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, 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...

  11. The UBV Color Evolution of Classical Novae. II. Color–Magnitude Diagram

    NASA Astrophysics Data System (ADS)

    Hachisu, Izumi; Kato, Mariko

    2016-04-01

    We have examined the outburst tracks of 40 novae in the color–magnitude diagram (intrinsic B ‑ V color versus absolute V magnitude). After reaching the optical maximum, each nova generally evolves toward blue from the upper right to the lower left and then turns back toward the right. The 40 tracks are categorized into one of six templates: very fast nova V1500 Cyg fast novae V1668 Cyg, V1974 Cyg, and LV Vul moderately fast nova FH Ser and very slow nova PU Vul. These templates are located from the left (blue) to the right (red) in this order, depending on the envelope mass and nova speed class. A bluer nova has a less massive envelope and faster nova speed class. In novae with multiple peaks, the track of the first decay is more red than that of the second (or third) decay, because a large part of the envelope mass had already been ejected during the first peak. Thus, our newly obtained tracks in the color–magnitude diagram provide useful information to understand the physics of classical novae. We also found that the absolute magnitude at the beginning of the nebular phase is almost similar among various novae. We are able to determine the absolute magnitude (or distance modulus) by fitting the track of a target nova to the same classification of a nova with a known distance. This method for determining nova distance has been applied to some recurrent novae, and their distances have been recalculated.

  12. Light-curve Analysis of Neon Novae

    NASA Astrophysics Data System (ADS)

    Hachisu, Izumi; Kato, Mariko

    2016-01-01

    We analyzed light curves of five neon novae, QU Vul, V351 Pup, V382 Vel, V693 CrA, and V1974 Cyg, and determined their white dwarf (WD) masses and distance moduli on the basis of theoretical light curves composed of free-free and photospheric emission. For QU Vul, we obtained a distance of d ˜ 2.4 kpc, reddening of E(B - V) ˜ 0.55, and WD mass of MWD = 0.82-0.96 {M}⊙ . This suggests that an oxygen-neon WD lost a mass of more than ˜ 0.1 {M}⊙ since its birth. For V351 Pup, we obtained d˜ 5.5 {{kpc}}, E(B-V)˜ 0.45, and {M}{{WD}}=0.98-1.1 {M}⊙ . For V382 Vel, we obtained d˜ 1.6 {{kpc}}, E(B-V)˜ 0.15, and {M}{{WD}}=1.13-1.28 {M}⊙ . For V693 CrA, we obtained d˜ 7.1 {{kpc}}, E(B-V)˜ 0.05, and {M}{{WD}}=1.15-1.25 {M}⊙ . For V1974 Cyg, we obtained d˜ 1.8 {{kpc}}, E(B-V)˜ 0.30, and {M}{{WD}}=0.95-1.1 {M}⊙ . For comparison, we added the carbon-oxygen nova V1668 Cyg to our analysis and obtained d˜ 5.4 {{kpc}}, E(B-V)˜ 0.30, and {M}{{WD}}=0.98-1.1 {M}⊙ . In QU Vul, photospheric emission contributes 0.4-0.8 mag at most to the optical light curve compared with free-free emission only. In V351 Pup and V1974 Cyg, photospheric emission contributes very little (0.2-0.4 mag at most) to the optical light curve. In V382 Vel and V693 CrA, free-free emission dominates the continuum spectra, and photospheric emission does not contribute to the optical magnitudes. We also discuss the maximum magnitude versus rate of decline relation for these novae based on the universal decline law.

  13. Recurrent novae as progenitors of Type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Kato, Mariko; Hachisu, Izumi

    2012-09-01

    Recurrent novae are binaries harboring a very massive white dwarf (WD), as massive as the Chandrasekhar mass, because of their short recurrence periods of nova outbursts of 10--100 years. Thus, recurrent novae are considered as candidates of progenitors of Type Ia supernovae (SNe~Ia). In fact, the SN~Ia PTF~11kx showed evidence that its progenitor is a symbiotic recurrent nova. The binary parameters of recurrent novae have been well determined, especially for the ones with frequent outbursts, U Sco and RS Oph, which provide useful information on the elementary processes in binary evolution toward SNe~Ia. Therefore we use them as testbeds for binary evolution models. For example, the original double degenerate (DD) scenario cannot reproduce RS Oph type recurrent novae, whereas the new single degenerate (SD) scenario proposed by Hachisu et al. (1999) naturally can. We review main differences between the SD and DD scenarios, especially for their basic processes of binary evolution. We also discuss observational support for each physical process. The original DD scenario is based on the physics in 1980s, whereas the SD scenario on more recent physics including the new opacity, mass-growth efficiency of WDs, and optically thick winds developed in nova outbursts.

  14. Near-Infrared Emission Lines of Nova Cassiopeiae 1995

    NASA Astrophysics Data System (ADS)

    Rudy, R. J.; Lynch, D. K.; Mazuk, S. M.; Venturini, C. C.; Puetter, R. C.

    2000-12-01

    The slow nova V 723 Cas (Nova Cas 1995) exhibits comparatively narrow emission features (FWHM 500 km sec-1) that make it ideal for classifying weak lines and lines blended with stronger features. We present spectra from 0.8-2.5 microns that track the gradual incrase in excitation of Nova Cas and discuss the emission lines that were present. During the period encompassed by these observations Nova Cas reached only moderate excitation-the most energetic coronal lines were [S VIII] 9913 and [Al IX] 20444; lines such as [S IX] 12523 that are prominent in some novae were not detected. Additional coronal lines present include [Si VI] 19641, [Ca VIII] 23205, and [Si VII] 24807. New lines identified include features of [Fe V], [Fe VI]. These iron features are not coronal lines, arising from transitions among low-lying terms rather than within the ground term itself. Also detected was [Ti VI] 17151 that was first identified in V1974 Cygni (Nova Cyg 1992), and possibly [Ti VII] 22050. Accurate wavelengths for a number of unidentified lines are also presented. These unidentified features are discussed with regard to their likely level of excitation and their presence in other novae. This work was supported by the IR&D program of the Aerospace Corporation. RCP acknowledges support from NASA.

  15. Nova Delphini 2013 = PNV J20233073+2046041

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-08-01

    Announces the discovery of Nova Delphini 2013 = PNV J20233073+2046041 = V339 Del by Koichi Itagaki (Teppo-cho, Yamagata, Japan) on 2013 Aug. 14.584 UT at unfiltered CCD magnitude mag 6.8. Spectra by numerous professional and amateur astronomers show strong H-alpha and H-beta emission and P Cygni profile emission lines, all pointing to a pre-maximum classical nova. For details on spectra, see CBET 3628 and the IAU Circular to be announced shortly. Postings to the AAVSO Spectroscopy Forum (http://www.aavso.org/forums/variable-star-observing/spectroscopy) also contain information on spectra, as well as observing and reporting instructions for spectroscopists. Charts for Nova Del 2013 may be created using the AAVSO Variable Star Plotter (VSP) at http://www.aavso.org/vsp. We have created a binocular sequence for this nova that can be plotted using the Binocular Chart option on VSP. Over 750 observations have been submitted to the AAVSO International Database since the nova's discovery two days ago; the most recent observations show Nova Del 2013 has brightened to visual magnitude 4.4. Observations should be submitted to the AAVSO International Database. Announced on IAU CBAT CBET 3628 (Daniel W. E. Green, ed.). Nova Del 2013 was designated PNV J20233073+2046041 when it was posted on the CBAT TOCP webpage. See full Alert Notice for more details, observations, and links to images.

  16. 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.

  17. GNIRS + SPITZER ToO Novae in the Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Woodward, Chick; Spitzer Too Team

    2005-02-01

    Novae are important contributors to galactic chemical enrichment on local scales. IR spectroscopy of novae provides information about the elemental abundances of the gas and dust in the ejecta dispersing into the interstellar medium as well as kinematic information related to the outburst. We propose to obtain GNIRS `Quick-Response' spectra of Target of Opportunity (ToO) novae in the Magellanic Clouds (MC) to study the dynamics of the ejecta, to determine the temporal evolution of coronal lines and recombination lines (measuring their strength and velocity profiles), and to determine abundances. Being all equidistant, MC nova permit a more robust intepretation of distant-dependent physical parameters of outburst than is generally possible for Galactic novae. The GNIRS data will provide critical spectral coverage and contemporaneous data to support our Cycle 1 Spitzer nova program (PID 2333). Triggering of the GNIRS program will occur when a MC nova becomes brighter than V=12 mag, (assuming that adequate PWFS guide stars exist) as reported in the IAUC or by observers on our team.

  18. A Cosmic Masquerade: Are Novae Disguised Black Holes?

    NASA Astrophysics Data System (ADS)

    Knez, C.; Ringwald, F. A.

    1999-12-01

    Before the 1960s, the X-rays from soft X-ray transients (SXTs) were never detected, since there were no spacecraft. SXT outbursts are thought to be dwarf nova outbursts in black hole binaries. Since, in the visual, SXT outbursts have amplitudes exceeding 10 magnitudes and durations of many weeks, they may have been mistaken for classical novae. V404 Cygni was: it was originally known as Nova Cygni 1938. We report time-resolved photometry from the 0.92-m SARA telescope to search for ellipsoidal variations in the old novae FS Sct (1952) and V606 Aql (1899). Since we expect black holes to be more massive than white dwarfs, we expect these ellipsoidal variations to tell whether these are black hole systems or old novae. We find a possible variation in FS Sct, although more cycles are needed to confirm it. We also find that for V606 Aql, neither candidate star 1 nor 2 of Duerbeck (1987) flicker, as old novae or SXTs do. Is this nova lost, or perhaps hibernating? This work was funded by the NSF through the SARA Research Experiences for Undergraduates Summer Internship Program (NSF AST--9619939).

  19. 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.

  20. Non-detection of nova shells around asynchronous polars

    NASA Astrophysics Data System (ADS)

    Pagnotta, Ashley; Zurek, David

    2016-05-01

    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 Southern African Large Telescope 10 m class telescope and the MDM 2.4 m 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.

  1. 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.

  2. OGLE Atlas of Classical Novae. II. Magellanic Clouds

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    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-1 (LMC) and 0.9 ± 0.4 yr-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.

  3. Tramp Classical Novae as Tracers of Intergalactic Stars

    NASA Astrophysics Data System (ADS)

    Shara, Michael M.

    2006-06-01

    Simulations predict that collisions between galaxies must liberate stars into intergalactic space. The stripping of a galaxy's stars by the potential of a cluster in which it resides must also occur. This prediction is verified by the detections of classical novae, red giants, and planetary nebulae between the galaxies of the Virgo and Fornax Clusters. These tracers suggest a tramp stellar component of 10%-40% of the cluster baryonic mass. I point out that classical novae can usefully extend these results to the 250,000 Mpc3 of intergalactic space outside of galaxy clusters surrounding the Local Group. This is because individual novae are well-understood standard candles, with light curves and spectra that are distinct from all other astrophysical phenomena. In addition, the frequency of nova outbursts in any given galaxy is measured to be directly proportional to that galaxy's K-band luminosity (and independent of its Hubble type). Thus, intergalactic novae should be excellent tracers of the fraction of stars liberated from galaxies over the past 13 Gyr. Pan-STARRS, the Large Synoptic Survey Telescope (LSST), and other large-area synoptic survey telescopes will begin to regularly discover tramp classical novae out to 20-40 Mpc in the coming decade. I estimate the expected discovery rates with LSST-like surveys to be hundreds of intergalactic tramp novae per year, and suggest survey parameters to optimize detections of these tramps.

  4. 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.

  5. 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.

  6. An extremely carbon enhanced 'nova' model

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    Expanding upon the authors' earlier work, Hoyle and Clayton (1974) have suggested that a thermonuclear runaway in a white dwarf envelope that consists of equal numbers of protons and C-12 nuclei will produce the s or r-process elements. The present work studies such a runaway and finds that these initial conditions cause a 'super' nova outburst that does not result in any s or r-process nucleosynthesis. However, the model is very interesting in that it reaches peak temperatures of 1.6 billion K and peak burning rates exceeding 2 times 10 to the 23rd erg/gm/sec. A shock forms and ejects 10 to the 29th grams moving with speeds up to 60,000 km/sec. The peak bolometric magnitude is -21.2 and this model will also produce a gamma-ray burst.

  7. 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.

  8. NOVAE EJECTA AS DISCRETE ADIABATICALLY EXPANDING GLOBULES

    SciTech Connect

    Williams, Robert

    2013-09-15

    Available data for novae show that the X-ray and visible spectral regions correlate with each other as they evolve. Large differences in ionization exist simultaneously in the two wavelength regimes, and a straightforward model is proposed that explains the characteristics observed in both spectral regimes. Its key features are (1) ejected blobs of very high density gas from the white dwarf (WD) that expand to create within each clump a wide range of emitting density, ionization, and velocity, and (2) a more homogeneous circumbinary envelope of gas that is produced by secondary star mass loss. The relative mass loss rates from the two stars determine whether the He/N or the Fe II visible spectrum predominates during decline, when hard X-rays are detected, and when the WD can be detected as a super soft X-ray source.

  9. New optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Henze, M.; Pietsch, W.; Burwitz, V.; Hatzidimitriou, D.; Reig, P.; Primak, N.; Papamastorakis, G.; Updike, A.; Hartmann, D. H.; Milne, P.; Williams, G.

    2008-07-01

    We report the discovery of a possible nova in M 31 on four consecutive dithered stacked 100s R filter CCD images, obtained on 2008 July 06.04, with the 1.3m Ritchey Chretien f/7.5 telescope at Skinakas Observatory, Crete, Greece, using an Andor DZ436-BV CCD Camera (with a Marconi 2k x 2k chip with 13.5μm sq. pixels). The R magnitude of the object was 18.7. The object is already visible with a magnitude of 18.3 on a 12*60s stacked R filter CCD image obtained with the robotic 60cm telescope with an E2V CCD (2kx2k) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA) on 2008 June 30.45.

  10. 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.

  11. 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.

  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. 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.

  14. 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.

  15. The Nova Outburst: Thermonuclear Runaways on Degenerated Dwarfs

    SciTech Connect

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

    1999-07-08

    Observational and theoretical studies of the outbursts of classical novae have provided critical insights into a broad range of astrophysical phenomena. Thermonuclear runaways (TNRs) in accreted hydrogen-rich envelopes on the white dwarf (WD) components of close binary systems constitute not only the outburst mechanism for a classical nova explosion, but also the recurrent novae and a fraction of the symbiotic novae explosions. Studies of the general characteristics of these explosions, both in our own galaxy and in neighboring galaxies of varying metallicity, can teach us about binary stellar evolution, while studies of the evolution of nova binary systems can constrain models for the (as yet unidentified) progenitors of Type Ia supernovae. Further, the empirical relation between the peak luminosity of a nova and the rate of decline, which presents a challenge to theoretical models, allows novae to be utilized as standard candles for distance determinations out to the Virgo Cluster. E xtensive studies of novae with IUE and the resulting abundance determinations have revealed the existence of oxygen-neon white dwarfs in some systems. The high levels of enrichment of novae ejecta in elements ranging from carbon to sulfur confirm that there is significant dredge-up of matter from the core of the underlying white dwarf and enable novae to contribute to the chemical enrichment of the interstellar medium. Observations of the epoch of dust formation in the expanding shells of novae allow important constraints to be placed on the dust formation process and confirm that graphite, SiC, and SiO{sub 2} grains are formed by the outburst. It is possible that grains from novae were injected into the pre-solar nebula and can be identified with some of the pre-solar grains or ''stardust'' found in meteorites. Finally, g-ray observations during the first several years of their outburst, using the next generation of satellite observatories, could confirm

  16. 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.

  17. Liquid Scintillator Production for the NOvA Experiment

    DOE PAGESBeta

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

    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.

  18. Classical Novae in the Swift Era

    NASA Astrophysics Data System (ADS)

    Starrfield, Sumner; Swift-Nova-CV Group

    2008-03-01

    One of the highlights of Swift is that it is a remarkably responsive spacecraft both because of its design and because Neil Gehrels, the PI, is attuned to the great science that can be done with Targets of Opportunity. As a result, we have made important and significant discoveries about the X-ray evolution of Cataclysmic Variables (CV) in general and both Classical (CN) and Recurrent Novae (RN) in particular. Before Swift, both CN and RN were known to emit in both hard and soft X-rays but observations were few, with only a small number of CNe followed through their X-ray bright phase. We have now extended X-ray observations to many more CNe which has answered some questions and, at least as important, posed new questions about the evolution of the explosion. I emphasize that X-ray observations are the only means of following the evolution of the nuclear-burning white dwarf during the outburst. I will review our observations of CN and concentrate on the SSS phase in which the X-ray emission is coming from hot, nuclear-burning, white dwarf outer layers and atmosphere. I will present a brief summary of our results on the 2006 outburst of RS Oph in which a RN was detected with the BAT and then, later, we observed the turn-on of the SSS phase some 26 days into outburst. Finally, I will discuss V723 Cas (1995) which now holds the record for the longest CN observed in outburst in X-rays. I gratefully acknowledge partial support from NSF and NASA grants to ASU and to the members of the Swift-NOVA-CV working group who obtained, extracted, and analyzed the data that I will be presenting.

  19. Newly Identified Rydberg Emission Lines in Novae

    NASA Astrophysics Data System (ADS)

    Lynch, David K.; Rudy, R. J.; Bernstein, L. S.

    2008-09-01

    Newly Identified Rydberg Emission Lines in Novae David K. Lynch, Richard. J. Rudy (The Aerospace Corporation) & Lawrence S. Bernstein (Spectral Sciences, Inc.) Novae spectra in the near infrared frequently show a set of six emission lines that have not been positively identified (Williams, Longmore, & Geballe 1996, MNRAS, 279, 804; Lynch et al. 2001, AJ, 122, 2013; Rudy et al. 2002 ApJ, 573, 794; Lynch et al. 2004 Astron. J. 127, 1089-1097). These lines are at 0.8926, 1.1114, 1.1901, 1.5545, 2.0996 and 2.425 µm ± 0.005 µm. Krautter et al. (1984 A&A 137, 304) suggested that three of the lines were due to rydberg (hydrogenic) transitions in an unspecified atomic species that was in the 4th or 5th ionization stage (core charge = 4 & 5). We believe that Krautter et al.'s explanation is correct based on 4 additional lines that we have identified in the visible and near infrared spectrum of V723 Cassiopeiae. The observed Rydberg lines appear to originate from high angular momentum states with negligible quantum defects. The species cannot be determined with any certainty because in rydberg states, the outer electron sees a nucleus shielded by the inner electrons and together the inner atom appears to have a charge of +1, like hydrogen. As a result, the atom looks hydrogenic and species such as CV, NV, OV, MgV, SiV, etc. have their rydberg transitions at very similar wavelengths. All the lines represent permitted transitions, most likely formed by recombination. Atoms with core charges 4, 5 & 6 are rarely seen in the astrophysical environment because an extremely hot radiation field is necessary to ionize them. Thermonuclear runaways on the surface of a white dwarf can reach millions of degrees K, and thus there are enough X-ray photons available to achieve the necessary high ionization levels.

  20. 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.

  1. 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...

  2. Analysis of Reduced-Scale Nova Hohlraum Experiments

    NASA Astrophysics Data System (ADS)

    Powers, L. V.; Berger, R. L.; Kirkwood, R. K.; Kruer, W. L.; Langdon, A. B.; MacGowan, B. J.; Orzechowski, T. J.; Rosen, M. D.; Springer, P. T.; Still, C. H.; Suter, L. J.; Williams, E. A.; Blain, M. A.

    1996-11-01

    Establishing the practical limit on achievable radiation temperature in high-Z hohlraums is of interest both for ignition targets( S.M. Haan, et al., Phys. Plasmas 2, 2480 (1995).) for the National Ignition Facility (NIF), and for high energy density physics experiments( S.B. Libby, Energy and Technology Review, UCRL-52000-94-12, 23 (1994)). Two related efforts are underway to define the physics issues of high energy density hohlraum targets: 1) experiments on the Nova laser in reduced scale hohlraums, and 2) evaluation of high-temperature hohlraums designs for the NIF. Reduced scale Nova hohlraums approach conditions relevant to NIF high temperature designs, albeit at smaller scale. Analysis of reduced-scale experiments on Nova therefore provides valuable physics information for evaluating the capabilities of NIF for producing high energy density in hohlraums. Simulations of Nova reduced scale hohlraum experiments will be presented, and the relevance to a range of NIF hohlraum target designs will be discussed.

  3. 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.

  4. 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.

  5. X ray and gamma ray emission from classical nova outbursts

    NASA Technical Reports Server (NTRS)

    Truran, James W.; Starrfield, Sumner; Sparks, Warren M.

    1992-01-01

    The outbursts of classical novae are now recognized to be consequences of thermonuclear runaways proceeding in accreted hydrogen-rich shells on white dwarfs in close binary systems. For the conditions that are known to exist in these environments, it is expected that soft x-rays can be emitted, and indeed x-rays were detected from a number of novae. The circumstances for which we expect novae to produce significant x-ray fluxes and provide estimates of the luminosities and effective temperatures are described. It is also known that at the high temperatures that are known to be achieved in this explosive hydrogen-burning environment, significant production of both Na-22 and Al-26 will occur. In this context, we identify the conditions for which gamma-ray emission may be expected to result from nova outbursts.

  6. 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.

  7. 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.

  8. V4633 Sgr - A Double Periodic Classical Nova

    NASA Astrophysics Data System (ADS)

    Lipkin, Y.; Leibowitz, E. M.; Retter, A.

    2002-01-01

    We discovered two closely-spaced photometric periods in the light curve of V4633 Sgr. Only four known post-novae share similar characteristics; three of which are permanent superhump (SH) systems, and the 4th is a nearly-synchronous magnetic CV (NSP). Our results suggest a possible classification of V4633 Sgr in one of the above two classes. However, this post-nova exhibits some properties that are exceptional for either of the two proposed classes.

  9. Searches for the progenitor of Nova ASASSN-16ig

    NASA Astrophysics Data System (ADS)

    Saito, R. K.; Minniti, D.; Catelan, M.; Angeloni, R.; Gutierrez, L. A.

    2016-08-01

    Stanek et al. (ATel #9343) recently reported the discovery of a likely classical nova about 4.2 degrees away from the Galactic center. Nova ASASSN-16ig is located at coordinates RA,DEC(J2000)= 18:01:07.735,-26:31:42.01, corresponding to l,b=3.813,-1.741, within the area covered by the VVV Survey (vvvsurvey.org; Minniti et al. 2010, New Astronomy, 15, 433).

  10. A Search for Novae in the Bulge of M31

    NASA Astrophysics Data System (ADS)

    Rector, T. A.; Jacoby, G. H.; Corbett, D. L.; Denham, M.; RBSE Nova Search Team

    1999-12-01

    We present the initial results of a program currently underway to search for nova in local group galaxies with the KPNO 0.9-meter telescope. The long-term goal is to accurately determine if the nova rate varies for galaxies of different Hubble type. Ciardullo et al. claim that nova rates are very similar when normalized to the total galaxy K-band luminosity. However, Della Valle et al. claim the rates are different by up to a factor of four, with early-type galaxies being deficient in novae. Here we present novae found from eighteen epochs of observations of the bulge of M31. The observations span from September 1995 to July 1999. The results presented here are part of an NSF-funded research-based science education program (RBSE) operated by NOAO, wherein middle- and high-school science students learn astronomy and inquiry-based learning skills by participating in actual research. The novae presented here were discovered by students participating in the RBSE program.

  11. The Nova Rate in Galaxies of Different Hubble Type

    NASA Astrophysics Data System (ADS)

    Rector, Travis A.; Jacoby, Suzanne H.; Jacoby, George H.

    1999-02-01

    We propose to continue a monthly imaging program at the 0.9m to determine the nova rate in several galaxies of different Hubble type. Ciardullo et al. (1990) claims that the nova rates in galaxies of different Hubble type are very similar when normalized to the total galaxy K-band luminosity. However, Della Valle et al. (1994) claims the rates to be different by up to a factor of four, with early-type galaxies being deficient in novae. Since nova rates depend on several properties of the stellar population they derive from, one might expect some variations. The observations proposed here will provide much better statistics on several Local Group galaxies than presently exists in order to improve the nova rate estimates in a variety of stellar populations. This data will also be used in a research-based science education program (RBSE) operated by NOAO, wherein middle- and high-school science students learn astronomy and inquiry-based learning skills via research. Students are able to find the novae easily and derive light curves using available image processing software. This request continues the approved program from last year.

  12. 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

  13. Atypical dust species in the ejecta of classical novae

    NASA Astrophysics Data System (ADS)

    Helton, L. A.; Evans, A.; Woodward, C. E.; Gehrz, R. D.

    2011-03-01

    A classical nova outburst arises from a thermonuclear runaway in the hydrogen-rich material accreted onto the surface of a white dwarf in a binary system. These explosions can produce copious amounts of heavy element enriched material that are ejected violently into the surrounding interstellar medium. In some novae, conditions in the ejecta are suitable for the formation of dust of various compositions, including silicates, amorphous carbon, silicon carbide, and hydrocarbons. Multiple dust grain types are sometimes produced in the same system. CO formation in novae may not reach saturation, thus invalidating the usual paradigm in which the C:O ratio determines the dust species. A few novae, such as V705 Cas and DZ Cru, have exhibited emission features near 6, 8, and 11 μmthat are similar to "Unidentified Infrared" (UIR) features, but with significant differences in position and band structure. Here, we present Spitzer IRS spectra of two recent dusty novae, V2361 Cyg and V2362 Cyg, that harbor similar peculiar emission structures superimposed on features arising from carbonaceous grains. In other astronomical objects, such as star forming regions and young stellar objects, emission peaks at 6.2, 7.7, and 11.3 μmhave been associated with polycyclic aromatic hydrocarbon (PAH) complexes. We suggest that hydrogenated amorphous carbon (HAC) may be the source of these features in novae based upon the spectral behavior of the emission features and the conditions under which the dust formed.

  14. 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

  15. Concurrent X-ray and optical observations of two dwarf novae during eruption

    NASA Technical Reports Server (NTRS)

    Silber, A.; Vrtilek, S. D.; Raymond, J. C.

    1994-01-01

    The dwarf novae SU UMa and RU Peg were each observed with the ROSAT Observatory during outburst. SU UMa was also observed twice between outbursts. The spectrum of SU UMa during quiescence is well fitted by a 2.1 keV thermal bremsstrahlung model with a Gaussian line at 0.97 keV absorbed by a column density of 1.4 x 10(exp 20)/sq cm. During the outburst the X-ray count rate dropped by a factor of 3. The outburst spectrum is well fitted to a similar spectrum with a significantly larger absorption. In outburst the mass transfer rate, dot-M, approaches the critical value for the optically thin/thick transition predicted by theoretical models of the boundary layer while the X-ray emission remains optically thin. The best-fit model to the outburst spectrum of RU Peg is a 4.9 keV thermal bremsstrahlung plus a line at 0.89 keV absorbed by a column density of 2.8 x 10(exp 20)/sq cm. The column density is consistent with the upper limit determined for interstellar absorption. The boundary layer at outburst is expected to be optically thick based on the value of dot-M determined from the IUE spectra. There are no ROSAT observations of RU Peg between outbursts, but the flux detected by ROSAT is a factor of 10 lower than that seen with the Einstein Observatory, probably during quiescence. For both CVs the X-ray flux from the boundary layer significantly decreases at the same time that the optical-UV flux greatly increases. We suggest that during outburst most of the boundary layer energy is carried away as kinetic energy of the wind.

  16. 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

  17. 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.

  18. 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.

  19. New optical nova candidate in M 31, a possible recurrent nova?

    NASA Astrophysics Data System (ADS)

    Pietsch, W.; Henze, M.; Burwitz, V.; Updike, A.; Milne, P.; Williams, G.; Hartmann, D. H.

    2009-02-01

    We report the discovery of a possible nova in M 31 on two 8x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k, 13.5μm sq. pixels) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The object was first detected on 2009 February 20.13 and 21.13 UT with respective magnitudes of 18.5 and 18.6.

  20. The NOVA-2 postlaunch orbit adjustment process

    NASA Astrophysics Data System (ADS)

    Heyler, Gene A.

    The NOVA-2 satellite was the last of three `drag free' spacecraft to be placed into the Transit Navigation Systems's constellation of satellites. After its launch from Vandenburg Air Force Base into an initial 510 x 170 nmi near poar orbit, an intensive two-week operations schedule was implemented to : raise the orbit approximately 450 nmi to within .015 sec of desired period, trim eccentricity to within .003, trim inclination to within .006 degrees of requirement, freeze the phase of the spacecraft in orbit relative to the other two `drag free' satellites, dump extra fuel by deliberately fual wasting burns, and transition the spacecraft from a slow spin mode to gravity gradient. This paper will briefly discuss the concept of a `drag free' satellite, the selection of the orbit plane in the constellations, and the derivation of the required final orbit parameters. The paper will also discuss peripheral support needed to assist the OATS (Orbit Adjust and Transfer System) ground software, including attitude determination and maneuvers, orbit determination, and orbit prediction through the burns. However, the specific focus of this paper is on the design and execution of the nine OATS burns that accomplished the orbital maneuvers.

  1. X-Ray Nova Light Curves

    NASA Astrophysics Data System (ADS)

    Shrader, Chris; Titarchuk, Lev

    2002-04-01

    We describe recent work in which we revisit the database of historical X-Ray nova (XRN) light curves compiled by Chen, Shrader & Livio (1997, ApJ 491, 312), augmented by subsequent events recorded by RXTE, in an attempt to gain a better understanding of the outburst phenomenon. Previously, we demonstrated that, given the occurrence of an instability in the mass transfer rate from the secondary, a model based on viscous diffusion of matter through the disk (Wood et al, 2001, astro-ph/0108189) we could reproduce a large number of fast-rise exponential decay (FRED) type XRN light curves. We augment this effort by considering deviations from the FRED form, such as plateaus and power-law decay forms are also considered within this framework. More complex structures are, in a number of instances, successfully modeled as a superposition of mass- injection, diffusive propagation events. In addition, for a large number of cases, we perform a joint analysis of optical light curve data. In particular, we will attempt to characterize empirical characteristics such as possible tie lags, and relative decay time scales, and then interpret such effects withing the context of diffusive propagation in the disk.

  2. X-Ray Nova Light Curves

    NASA Astrophysics Data System (ADS)

    Shrader, C. R.; Titarchuk, L.

    2001-12-01

    We describe recent work in which we revisit the database of historical X-Ray nova (XRN) light curves compiled by Chen, Shrader & Livio (1997, ApJ 491, 312), augmented by subsequent events recorded by RXTE, in an attempt to gain a better understanding of the outburst phenomenon. In this presentation, we demonstrate that, given the occurrence of an instability in the mass transfer rate from the secondary, a model based on viscous diffusion of matter through the disk (Wood et al, 2001, astro-ph/0108189) can reproduce a large number of fast-rise exponential decay (FRED) type XRN light curves. Deviations from the FRED form, such as plateaus and power-law decay forms are also considered within this framework. More complex structures are, in a number of instances, successfully modeled as a superposition of mass-injection, diffusive propagation events. Limitations to this approach are considered. For example, recent concerns regarding the ability of viscous diffusion scenarios to reproduce the typical XRN rise and time scales (e.g. Cannizzo, ApJ, astro-ph/0110117) are discussed, as are possible time-dependent viscosity effects.

  3. Aminoglycoside binding to Oxytricha Nova Telomeric DNA

    PubMed Central

    Ranjan, Nihar; Andreasen, Katrine F.; Kumar, Sunil; Hyde-volpe, David; Arya, Dev P.

    2012-01-01

    Telomeric DNA sequences have been at the center stage of drug design for cancer treatment in recent years. The ability of these DNA structures to form four stranded nucleic acid structures, called G-quadruplexes, has been perceived as target for inhibiting telomerase activity vital for the longevity of cancer cells. Being highly diverse in structural forms, these G-quadruplexes are subjects of detailed studies of ligand–DNA interactions of different classes, which will pave the way for logical design of more potent ligands in future. The binding of aminoglycosides were investigated with Oxytricha Nova quadruplex forming DNA sequence (GGGGTTTTGGGG)2. Isothermal Titration calorimetry (ITC) determined ligand to quadruplex binding ratio shows 1:1 neomycin:quadruplex binding with association constants (Ka ) ~ 105M−1 while paromomycin was found to have a two-fold weaker affinity than neomycin. The CD titration experiments with neomycin resulted in minimal changes in the CD signal. FID assays, performed to determine the minimum concentration required to displace half of the fluorescent probe bound, showed neomycin as the best of the all aminoglycosides studied for quadruplex binding. Initial NMR footprint suggests that ligand-DNA interactions occur in the wide groove of the quadruplex. Computational docking studies also indicate that aminoglycosides bind in the wide groove of the quadruplex. PMID:20886815

  4. A nebula around Nova BT Monocerotis

    NASA Technical Reports Server (NTRS)

    Marsh, T. R.; Oke, J. B.; Wade, R. A.

    1983-01-01

    H-alpha observations of Nova BT Mon obtained on December 15, 1981 using an 800x800-pixel CCD detector on the double spectrograph of the 5-m Hale telescope at Palomar Observatory are reported. The reciprocal dispersion at H-alpha was 6.04 A/pixel and the angular scale along the 1.0-arcsec-wide east-west slit was 0.58 arcsec/pixel; resolution of the combined, processed image is about 12 A. A ring-shaped nebular emission with a center displaced slightly from the stellar image and an expansion distance to BT Mon of about 1800 pc was detected. The velocity diameter is found to be about 1500 km/sec along the ridge line and 2100 km/sec along the 10-unit contour. The mass of the visible nebula is estimated as 0.00003 solar mass, similar to the BT Mon ejection mass determined by Schaefer and Patterson (1983).

  5. The Distance to Nova V959 Mon from VLA Imaging

    NASA Astrophysics Data System (ADS)

    Linford, J. D.; Ribeiro, V. A. R. M.; Chomiuk, L.; Nelson, T.; Sokoloski, J. L.; Rupen, M. P.; Mukai, K.; O'Brien, T. J.; Mioduszewski, A. J.; Weston, J.

    2015-06-01

    Determining reliable distances to classical novae is a challenging but crucial step in deriving their ejected masses and explosion energetics. Here we combine radio expansion measurements from the Karl G. Jansky Very Large Array with velocities derived from optical spectra to estimate an expansion parallax for nova V959 Mon, the first nova discovered through its γ-ray emission. We spatially resolve the nova at frequencies of 4.5-36.5 GHz in nine different imaging epochs. The first five epochs cover the expansion of the ejecta from 2012 October to 2013 January, while the final four epochs span 2014 February-May. These observations correspond to days 126 through 199 and days 615 through 703 after the first detection of the nova. The images clearly show a non-spherical ejecta geometry. Utilizing ejecta velocities derived from three-dimensional modeling of optical spectroscopy, the radio expansion implies a distance between 0.9 ± 0.2 and 2.2 ± 0.4 kpc, with a most probable distance of 1.4 ± 0.4 kpc. This distance implies a γ-ray luminosity of 0.6× {{10}35} erg s-1, which is much less than the prototype γ-ray-detected nova, V407 Cyg, possibly due to the lack of a red giant companion in the V959 Mon system. V959 Mon also has a much lower γ-ray luminosity than other classical novae detected in γ-rays to date, indicating a range of at least a factor of 10 in the γ-ray luminosities for these explosions.

  6. The nature and evolution of Nova Cygni 2006

    NASA Astrophysics Data System (ADS)

    Munari, U.; Siviero, A.; Henden, A.; Cardarelli, G.; Cherini, G.; Dallaporta, S.; Dalla Via, G.; Frigo, A.; Jurdana-Sepič, R.; Moretti, S.; Ochner, P.; Tomaselli, S.; Tomasoni, S.; Valisa, P.; Navasardyan, H.; Valentini, M.

    2008-12-01

    Aims: Nova Cyg 2006 has been intensively observed throughout its full outburst. We investigate the energetics and evolution of the central source and of the expanding ejecta, their chemical abundances and ionization structure, and the formation of dust. Methods: We recorded low, medium, and/or high-resolution spectra (calibrated into accurate absolute fluxes) on 39 nights, along with 2353 photometric UBVR_cIc measures on 313 nights, and complemented them with IR data from the literature. Results: The nova displayed initially the normal photometric and spectroscopic evolution of a fast nova of the FeII-type. Pre-maximum, principal, diffuse-enhanced, and Orion absorption systems developed in a normal way. After the initial outburst, the nova progressively slowed its fading pace until the decline reversed and a second maximum was reached (eight months later), accompanied by large spectroscopic changes. Following the rapid decline from second maximum, the nova finally entered the nebular phase and formed optically thin dust. We performed a photo-ionization analysis of the emission-line spectrum during the nebular phase, which showed a strong enrichment of the ejecta in nitrogen and oxygen, and none in neon, in agreement with theoretical predictions for the estimated 1.0 M_⊙ white dwarf in Nova Cyg 2006. The similarities with the poorly investigated V1493 Nova Aql 1999a are discussed. Table are only available in electronic form at http://www.aanda.org Full Table ? is 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/492/145 Based in part on observations obtained with the Asiago telescopes.

  7. The Nova Rate in Galaxies of Different Hubble Type

    NASA Astrophysics Data System (ADS)

    Rector, Travis A.; Cool, Richard

    2006-02-01

    We propose to continue a monthly imaging program at the 0.9m to determine the nova rate in several galaxies of different Hubble type. Ciardullo et al. (1990) claim that the nova rates in galaxies of different Hubble type are very similar when normalized to the total galaxy K-band luminosity. However, Della Valle et al. (1994) claim the rates to be different by up to a factor of four, with early-type galaxies being deficient in novae. Since nova rates depend on several properties of the stellar population they derive from, one might expect some variations. The observations proposed here will provide much better statistics on several Local Group galaxies than presently exists in order to improve the nova rate estimates in a variety of stellar populations, in particular in M33 and the disk of M31. This data will also be used in an NSF-funded research-based science education program (TLRBSE) operated by NOAO, wherein middle- and high- school science students learn astronomy and inquiry-based learning skills by participating in an actual research program. This request represents the continuation of the approved program from prior semesters.

  8. The Nova Rate in Galaxies of Different Hubble Type

    NASA Astrophysics Data System (ADS)

    Rector, Travis; Jacoby, George; Jacoby, Suzanne

    2002-08-01

    We propose to continue a monthly imaging program at the 0.9m to determine the nova rate in several galaxies of different Hubble type. Ciardullo et al. (1990) claim that the nova rates in galaxies of different Hubble type are very similar when normalized to the total galaxy K-band luminosity. However, Della Valle et al. (1994) claim the rates to be different by up to a factor of four, with early-type galaxies being deficient in novae. Since nova rates depend on several properties of the stellar population they derive from, one might expect some variations. The observations proposed here will provide much better statistics on several Local Group galaxies than presently exists in order to improve the nova rate estimates in a variety of stellar populations, in particular in M33 and the disk of M31. This data will also be used in an NSF-funded research-based science education program (TLRBSE) operated by NOAO, wherein middle- and high- school science students learn astronomy and inquiry-based learning skills by participating in an actual research program. This request represents the continuation of the approved program from 2002A and prior years.

  9. 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.

  10. The Spectroscopic Evolution of Nova Cygni 1992

    NASA Astrophysics Data System (ADS)

    Moro-Martin, A.; Garnavich, P. M.; Noriega-Crespo, A.; Alpert, A.

    1996-12-01

    Optical spectroscopic observations of Nova Cygni 1992 spanning 4 years are modeled in this study. The data were obtained primarily with the DAO 1.8m telescope and cover a wavelength range from ~ 3200 - 8000 Angstroms. The observations begin on May 92 (85 days after the outburst) and end on June 1996, i.e. during most of the optically thin evolutionary phase. The spectra were modeled in a relatively straightforward way by using the flux predicted by a photoionization code [1] for most of the emission lines (down to 0.1% of Hβ ) and transforming these numbers into a synthetic spectrum. There are, however, significant differences in the detailed procedure in comparison with similar works [2]. First, the photoionization models were run at a fixed abundance value for the most prominent elements (i.e. H, He, C, O, N, Ne, Fe, etc) over the entire time sequence. Second, the brightest lines, e.g. [Ne V], [Ne III], [O III] and the Balmer lines, were initially used as guide to match the observations. The rest of the spectra, which includes the fainter lines, were then directly predicted by the photoionization code. Considering the complicated structure of the shell [3], the lack of well defined values of its gas density and our limited knowledge of the time evolution of the surface temperature of the photoionization source, the comparison between models and observations agrees remarkably well. It was found that the time evolution of some of the Iron coronal lines, [Fe VII] 6087 Angstroms and [Fe X] 6374 Angstroms, closely follows that of the X-rays [4]. [1] Ferland, G.J 1993, CLOUDY, U. of Kentucky Dept. Phys & Astr. Internal Report. [2] Austin et al. 1992, AJ, 111, 869 [3] Paresce, Livio, Hack & Korista (1995) A&A, 299, 823 [4] Krautter et al. (1996), ApJ, 456, 788

  11. 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.

  12. A Decade of Progress in Understanding the Eruptions of Classical Novae

    NASA Astrophysics Data System (ADS)

    Shara, M. M.

    2014-12-01

    During the 11 years since the 2002 Sitges Nova conference, over 700 refereed papers dealing with classical novae have been published. Rather than spend 2.3 seconds reviewing each one, I've tried to focus on the main themes that have captured the interests of most researchers. I've also used, as examples, the most influential and cited papers in each subfield, though a decade from now some of my choices may seem dated, provincial, or flat-out wrong. The key topics that I address include theory and simulations of nova explosions; the recurrent novae; observations of ejecta; symbiotic novae; connections between novae and type Ia supernovae; connections between classical and dwarf novae; extragalactic novae; the maximum magnitude - rate of decline relationship; and a set of challenges and unanswered questions that I hope we will have made much progress on by the time we reassemble around 2024.

  13. Analyses of the ONeMg Novae in the IUE Archives II: Nova V693 CrA 1981

    NASA Astrophysics Data System (ADS)

    Vanlandingham, K. M.; Starrfield, S.; Wagner, R. M.; Shore, S. N.; Sonneborn, G.

    1996-12-01

    We have begun a study of the subclass of novae known as `neon' or ONeMg novae (Starrfield, Sparks & Truran 1986). Novae of this type are characterized by strong neon emission lines in their spectra and high ejecta velocities. These novae are thought to occur on ONeMg white dwarfs with masses near the Chandrasekhar limit. Our study includes Nova Herculis 1991, Nova Corona Austrinae 1981, and Nova LMC 1990 #1. Analysis of Her 91 (Vanlandingham et al. 1996 MNRAS 282 563) is complete and we are currently working on LMC 90 #1. Here we present our recent results for Corona Austrinae 1981. Nova V693 Corona Austrinae (CrA81) was discovered on April 2.75 UT 1981. Observations with IUE began on 1981 April 10 and continued through 1981 November 14. CrA81 was a fast ONeMg nova, with t_2 =~ 8 days and t_3 =~ 14 days. By matching the SWP and LWR spectra together at 2000 Angstroms and adjusting the value of the reddening until the continuum had a roughly constant slope we find E(B-V) =~ 0.2+/-0.1 for the nova. Using maximum magnitude-decay rate relationships (Della Valle 1995; Livio 1992) we find the distance to CrA81 to be 14.3+/-0.2 kpc. We used the photoionization code CLOUDY 84 and the minimization routine MINUIT to determine elemental abundances for the nova. Our results show all of the elements to be enhanced relative to solar material. While helium, carbon, and magnesium are only marginally enhanced, oxygen and silicon are about 20 times solar, and nitrogen and neon are 140 and 287 times solar, respectively. The high neon abundance supports the fact that CrA81 is an ONeMg nova. These results are based on independent fits to three different observations, spanning over six months. Williams et al (1985) and Andrea et al (1994) also performed abundance analyses on CrA81. Andrea's values are 2 to 5 times larger than those of Williams. Our abundance values are lower than both Williams and Andrea for He, C, O, Mg, and Al, with our values being closer to Williams for N, Ne, and Si

  14. Near-infrared spectroscopic and photometric evolution of nova V476 Scuti - a nova that formed optically thin dust

    NASA Astrophysics Data System (ADS)

    Das, R. K.; Banerjee, D. P. K.; Ashok, N. M.; Mondal, Soumen

    2013-09-01

    We present results of near-infrared (near-IR) JHK (1.07 - 2.5 μm) spectroscopic and photometric observations of Nova V476 Scuti (V476 Sct) which was discovered in outburst in 2005 September. The near-IR observations of the nova presents the evolution of the post-maxima spectra and near-IR light curve. The spectra of V476 Sct, observed on 9 different epochs, show prominent lines due to HI, OI, CI and NI. Based on the IR spectral signatures we independently identify it as a Fe II type of nova, consistent with the same classification obtained from optical spectra. A detailed identification of the observed spectral lines is presented. The near-IR JHK light curve extending for a period of about 59 days after outburst clearly shows the formation of a optically thin dust shell, a phenomenon which is not commonly observed in novae. By fitting black body curves to the spectral energy distributions (SEDs) the temperatures of the dust shell on different epochs have been estimated. Dust formation in V476 Sct is consistent with the presence of lines of elements with low-ionization potential like Na and Mg in the early spectra which had earlier been suggested by us to be potential indicators of dust formation at a later phase in a nova's development.

  15. Sudden grain nucleation and growth in supernova and nova ejecta

    NASA Technical Reports Server (NTRS)

    Clayton, D. D.

    1979-01-01

    The thermal conditions leading to the rapid nucleation and growth of dust in astronomical explosions are examined. The contribution to nucleation physics lies only in the clarification of the ambient conditions where it apparently occurs. In both nova and interior shells of supernovae, dust precipitates in gas densities of the order of 10 to the -14th g/cu cm a few months after the explosion. The ambient conditions differ widely, however. Supernova condensation occurs in a thermal equilibrium, with photons, ions, electrons, and grains having equal temperatures. In novae huge disequilibria exist, with photon and electron temperatures near 50,000 K, photon energy density near 750 K, and forming refractory grains near 1800 K. In neither type of explosion can the condensed matter easily maintain chemical equilibrium with the total system. Interesting isotopic anomalies are trapped in both types of refractory condensate in the interstellar medium. The nova provides the best astronomical laboratory for observing the condensation.

  16. 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.

  17. An X-ray survey of nine historical novae

    NASA Technical Reports Server (NTRS)

    Becker, R. H.; Marshall, F. E.

    1981-01-01

    The Einstein Observatory Imaging Proportional Counter has been used to search for X-ray emission from nine nearby historical novae. Six of the novae have been detected with estimated X-ray intensities between 0.1 and 4 keV of 10 to the -13th to 10 to the -11th erg/sq cm-sec, comparable to the intensities of previously detected cataclysmic variables. The X-ray intensity of one of the novae, V603 Aql, varies over times of several hundred seconds. The data suggest a correlation between the decay rate of the historical outburst and the current X-ray luminosity. Alternatively, the X-ray luminosity may be related to the inclination of the binary system.

  18. Nova Monocerotis 2012 = PNV J06393874+0553520

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2012-08-01

    The discovery is reported of Nova Monocerotis 2012 = PNV J06393874+0553520 by Shigehisa Fujikawa (Kanonji City, Kagawa Prefecture, Japan, reported by Mitsuru Soma, National Astronomical Observatory of Japan) at magnitude C=9.4 on 2012 Aug. 09.8048 UT. Coordinates: 06 39 38.74 +05 53 52.0 (2000.0). Spectroscopy by multiple teams indicate a classical nova evolving toward the nebular phase. Announced on IAU CBAT Central Bureau Electronic Telegram 3202 (Daniel 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, particularly regarding spectra and nearby stars, and observations of Nova Mon 2012 already reported to the AAVSO.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. The spectroscopic evolution of the γ-ray emitting classical nova Nova Mon 2012. I. Implications for the ONe subclass of classical novae

    NASA Astrophysics Data System (ADS)

    Shore, S. N.; De Gennaro Aquino, I.; Schwarz, G. J.; Augusteijn, T.; Cheung, C. C.; Walter, F. M.; Starrfield, S.

    2013-05-01

    Aims: Among the classical novae, the ONe subgroup, distinguished by their large overabundance of neon, are thought to occur on the most massive white dwarfs. Nova Mon 2012 was the first classical nova to be detected as a high energy γ-ray transient, by Fermi-LAT, before its optical discovery. The first optical spectra obtained about 55 days after γ-ray peak, were strikingly similar to the ONe class after the transition to the nebular (optically thin) spectrum. The current paper presents our subsequent optical and ultraviolet observations. Methods: A time sequence of optical echelle spectra (3700-7400 Å) with the Nordic Optical Telescope (NOT) began on 2012 Aug. 16, immediately following the optical announcement, and are continuing. The nova was observed almost simultaneously with the NOT on 2012 Nov. 21, with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope at medium echelle resolution (1150-3050 Å) on Nov. 20, and with the CHIRON CTIO/SMARTS echelle spectrograph at medium resolution (4500-8900 Å) on Nov. 22. We used plasma diagnostics (e.g. [O III] and Hβ line flux) to constrain electron densities and temperatures, and the filling factor, for the ejecta. Using Monte Carlo modeling, we derived the structure from comparisons to the optical and ultraviolet line profiles. We also compared observed fluxes for Nova Mon 2012 with those predicted by photoionization modeling with Cloudy using element abundances derived for other ONe novae, the parameters derived from the line profile modeling and multiwavelength continuum measurements. Results: Nova Mon 2012 is confirmed as an ONe nova first observed spectroscopically in the nebular stage. We derive an extinction of E(B - V) = 0.85 ± 0.05 and hydrogen column density NH ≈ 5 × 1021 cm-2. The corrected continuum luminosity is nearly the same in the entire observed energy range compared to V1974 Cyg, V382 Mon, and Nova LMC 2000 at the same epoch after outburst. The distance, about 3

  4. 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.

  5. 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.

  6. 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.

  7. EVLA Radio Upper Limits for 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.

    2011-05-01

    The EVLA Nova Team has observed the classical nova V5588 Sgr (IAUC #9203, CBET #2707) with the EVLA on 2011 April 21.5, April 30.3, and May 1.3, corresponding to 24.6, 33.4, and 34.4 days after its discovery. These observations are part of an ongoing monitoring effort. The last two observations bracket an episode of re-brightening reported in optical observations (CBET #2707; see also the AAVSO Light Curve Generator). All observations yield non-detections, as enumerated in the table below.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. X-ray Observations of Novae with Swift

    NASA Astrophysics Data System (ADS)

    Page, Kim

    2016-07-01

    The rapid response capabilities of the Swift satellite, together with the daily planning of its observing schedule, make it an ideal mission for following novae in the X-ray and UV bands, particularly during their early phases of rapid evolution. A number of both classical and recurrent novae have been extensively monitored by Swift throughout their super-soft phase and later decline. We report results from these observations, including the high-amplitude flux variation often see at the start of the super-soft emission, the differing relationships between the X-ray and UV variability, and the spectral evolution seen in the X-ray band.

  13. Nova V1281 Sco now a bright SSS

    NASA Astrophysics Data System (ADS)

    Ness, J. U.; Starrfield, S.; Schwarz, G.; Bode, M. F.; Osborne, J. P.; Page, K. L.

    2008-01-01

    On behalf of the Swift nova-cv group, we report the detection of a bright SSS X-ray spectrum for Nova V1281 Sco (discovered on 2007, Feb. 19.85) with the Swift XRT instrument (0.25-10 keV) on Jan. 24.18, 2008. The average count rate was 0.15±0.01 cps over the 5.24 ks observation. The spectrum peaks at 0.5 keV and can be fitted with an absorbed blackbody with parameters T=5x105 K and NH=8x1021 cm-2.

  14. Spectroscopic Observations of the Recent M33 Nova Candidate

    NASA Astrophysics Data System (ADS)

    Shafter, A. W.; Ciardullo, R.; Bode, M. F.; Darnley, M. J.; Misselt, K. A.

    2010-10-01

    We report spectroscopic observations of the recent M33 nova candidate (M33N 2010-10a?), which was discovered by K. Nishiyama and F. Kabashima (Miyaki-Argenteus Observatory, Japan) on 2010 Oct. 26.65 UT. At our request a spectrum (410-950 nm) of the nova candidate was obtained by John Caldwell on 2010 Oct. 28.37 UT (~2 days post discovery) with the Marcario Low-Resolution Spectrograph on the 9.2m Hobby-Eberly Telescope.

  15. Spectral behavior of Nova GQ Mus in the ultraviolet

    NASA Astrophysics Data System (ADS)

    Sanad, M. R.; Abdel-Sabour, M. A.

    2016-05-01

    We present ultraviolet spectroscopic study of nova GQ Mus observed with the International Ultraviolet Explorer (IUE) during the period 1983-1985. Different spectra showing the changes in line fluxes at different times are presented. The outflow velocity of the ionized ejecta was calculated to be 1010-2900 km s^{-1} (FWHM). We estimated a new value of the reddening from the 2200 Å absorption feature, E(B-V) = 0.16 ± 0.02. The models generated by Jose and Hernanz (1998) indicate that GQ Mus is a CO5/CO6 nova with WD mass of {˜} 1.15 M_{⊙}.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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…

  7. Chlamydia trachomatis infection in rural Nova Scotia.

    PubMed Central

    Langille, D B; Shoveller, J

    1993-01-01

    OBJECTIVE: To examine the demographic characteristics of patients who underwent testing for Chlamydia trachomatis and to determine the clinical and behavioural characteristics and the types of treatment for those who had positive test results. DESIGN: Case series. SETTING: Rural county in Nova Scotia. PATIENTS: All residents of the county for whom testing for C. trachomatis was ordered at the regional hospital from Sept. 1, 1990, to Mar. 31, 1991. MAIN OUTCOME MEASURES: Rates of testing and of positive test results by age and sex. Comparison of patient and physician characteristics in relation to testing rates. RESULTS: Of the 1116 patients tested 58 (5.2%) had positive test results. Females accounted for 82.8% of those with positive results whose sex could be determined. Among the females the mean age of those with a positive result was 22.3 years, as compared with 27.5 years for those with a negative result (p < 0.0001). Females 15 to 19 years of age were less likely to have a test performed than women 20 to 29 years and were more likely to have a positive test result than the women in the older groups. Almost 9% of the testing among the females was in those over 39 years of age, although no infection was seen in this age group. The number of tests ordered per general or family practitioner varied from 1 to 154; the physicians' sex, practice location and length of time in practice did not predict the rates of positive test results. Treatment was most often in keeping with that recommended by national guidelines. Four (8.5%) of the 47 patients with positive results who were interviewed were not aware of their diagnosis, either because they had not returned for follow-up or had not being notified by the physician's office. CONCLUSIONS: The frequency of testing for C. trachomatis infection may be less than is desirable among young patients, who, if tested, are more likely than older patients to have positive results. More understanding of the diagnostic approach

  8. Timing in the NOvA detectors with atomic clock based time transfers between Fermilab, the Soudan mine and the NOvA Far detector

    NASA Astrophysics Data System (ADS)

    Norman, A.; Niner, E.; Habig, A.

    2015-12-01

    The NOvA experiment uses a GPS based timing system both to internally synchronize the readout of the DAQ components and to establish an absolute wall clock reference which can be used to link the Fermilab accelerator complex with the neutrino flux that crosses the NOvA detectors. We describe the methods that were used during the commissioning of the NOvA DAQ and Timing systems to establish the synchronization between the Fermilab beam and the NOvA far detector. We present how high precision atomic clocks were trained and transported between the MINOS and NOvA detectors during a Northern Minnesota blizzard to validate the absolute time offsets of the experiments and make the first observation of beam neutrinos in the NOvA far detector.

  9. 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…

  10. A SHORT DESCRIPTION OF THE PLAN OF NOVA HIGH SCHOOL.

    ERIC Educational Resources Information Center

    HIERS, NAN

    THE NOVA HIGH SCHOOL IS AN EDUCATIONAL EXPERIMENT TO MAKE LEARNING AND ACHIEVEMENT INTERESTING, CHALLENGING, AND EXCITING TO THE STUDENT. THE PROGRAM IS BASED ON THE CONCEPT OF INDIVIDUAL PROGRESS WITH EMPHASIS ON QUALITY EDUCATION. FEATURES OF THE SCHOOL ENVIRONMENT INCLUDE AIR-CONDITIONING, CARPETING, MULTIPURPOSE CLASSROOMS, INDIVIDUAL STUDY…

  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. A Maritime Picture: Nova Scotia Scene Looked At.

    ERIC Educational Resources Information Center

    Bone, Janet

    1983-01-01

    Discussion of current funding problems experienced by public, school, university, and special libraries in Nova Scotia indicates that cutbacks are causing staff layoffs and loss of purchasing power. Small public libraries are particularly affected, but new graduate librarians find employment, and free-lance librarians are extending service beyond…

  13. The Nova Project in Secondary Teacher Education 1970-1973.

    ERIC Educational Resources Information Center

    Crum, Clyde; McCoy, Leone

    The Nova Project of the Department of Secondary Education at California State University, San Diego, is described in this report. This one-year preparation program for secondary school teachers combines school and community experience with the focus on a team approach. Faculty and students work with local school personnel in the joint planning,…

  14. 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

  15. Epidemiology of Lyme Disease, Nova Scotia, Canada, 2002-2013.

    PubMed

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

    2015-10-01

    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

  16. 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.

  17. 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).

  18. FUSE observations of galactic and LMC novae in outburst

    NASA Astrophysics Data System (ADS)

    Shore, Steven

    We propose target of opportunity observations of classical novae in the Galaxy and the Large Magellanic Cloud in the early stages of outburst. The FUV represents the final frontier in the study of the early history of the expansion of nova ejecta, when the overlying optically thick metallic line absorption spectrum (called the ``iron curtain'') lifts and it is possible to see through the ejected shell to the deepest layers of the still optically thick ejecta. During the period following the explosion, the central source illuminates the ejecta. To date, only three novae have been observed in the region from 900 - 1200Å, V1974 Cyg 1992 (Voyager UVS, ORFEUS), Cir 1995 (HUT), and Aql 1995 (HUT). The 1995 novae were observed only at relatively low resolution with HUT during the ASTRO-2 mission and within one month of outburst, while V1974 Cyg was observed nearly 4 years after maximum and only with limited S/N. The ability to correctly model the outburst, determine the abundances in the ejecta, and obtain a comprehensive picture of the energetics of the outburst can only be achieved through multiwavelength observations. The FUV plays a vital part in these studies.

  19. Internship and the Nova Scotia Government Experience. Case Study.

    ERIC Educational Resources Information Center

    Dodge, R. Bruce; McKeough, Mary

    2003-01-01

    Internship programs are traditionally seen as a social responsibility or means of screening potential employees. In a Nova Scotia government agency internship program, the agency benefitted in a different way: from the enthusiasm, fresh perspectives, and technology skills interns brought to the workplace. (SK)

  20. 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.

  1. New studies of nuclear decay {gamma}-rays from novae

    SciTech Connect

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

    1997-11-01

    The cause of the nova outburst is a thermonuclear runaway (TNR) in hydrogen rich material transferred by a companion onto a white dwarf. Studies of this phenomenon have shown that the TNR produces large concentrations of the short lived positron unstable isotopes of the CNO nuclei which are transported to the surface by convection so that early in the outburst we expect significant numbers of radioactive decays to occur at the surface. The resulting {gamma}-ray emission may be detectable from nearby novae early in their outbursts. The TNR is also expected to produce substantial amounts of {sup 7}Be and {sup 22}Na. Their decays also yield potentially detectable levels of {gamma}-ray emission for relatively nearby novae. We are also interested in the role played by novae in the production of the {approximately}2M{circle_dot} of {sup 26}Al found in the galaxy. In order to improve our predictions of this phenomenon, we have performed a new set of calculations of TNR`s on ONeMg and CO white dwarfs with an updated nuclear reaction network and opacities.

  2. 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…

  3. Two new Galactic novae discovered in the VVV disk images

    NASA Astrophysics Data System (ADS)

    Pena, C. Contreras; Lucas, P. W.; Saito, R. K.; Minniti, D.; Kurtev, R.

    2016-04-01

    We report two novae in the Galactic plane discovered serendipitously during a search for high amplitude variable young stellar objects (Contreras Pena et al. 2016, arXiv:1602.06267) in the VVV Survey data (vvvsurvey.org; Minniti et al. 2010, New Astronomy, 15, 433).

  4. 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.

  5. 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.

  6. 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.

  7. NOvA: Building a Next Generation Neutrino Experiment

    SciTech Connect

    Perko, John; Williams, Ron; Miller, Bill

    2013-12-05

    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.

  8. 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.

  9. Observational evidence for expansion in the SSS spectra of novae

    NASA Astrophysics Data System (ADS)

    Ness, J.-U.

    2010-02-01

    For several novae, a bright X-ray source with a spectrum resembling the class of Super Soft X-ray Sources (SSS) has been observed a few weeks to months after outburst. Novae are powered by explosive nuclear burning on the surface of a white dwarf, and enough energy is produced to power a radiatively driven wind. Owing to the evolution of the opacity of the ejecta, the observable spectrum gradually shifts from optical to soft X-rays (SSS phase). It has sometimes been assumed that at the beginning of the SSS phase no more mass loss occurs. However, high-resolution X-ray spectra of some novae have shown highly blue-shifted absorption lines, indicating a significant expansion. In this paper, I show that all novae that have been observed with X-ray gratings during their SSS phase show significant blue shifts. I argue that all models that attempt to explain the X-ray bright SSS phase have to accommodate the continued expansion of the ejecta.

  10. Model atmospheres for Novae in the SSS phase

    NASA Astrophysics Data System (ADS)

    van Rossum, D.

    2014-07-01

    One of the fascinating things about novae is the diversity with which they appear in the sky. In X-rays, high-quality datasets obtained with XMM-Newton and Chandra present a wealth of detailed information about the physical conditions deep inside the nova. With all the diversity in the X-ray datasets, the grating spectra have one thing in common: they exhibit blue-shifted absorption lines. Apparently, these observations exhibit the basis of the nova where a mix of accreted, processed, and dredged-up material continues to leave the system. In this talk, I give an overview on different hydro-static and expanding model atmospheres that are used to interpret the X-ray data, and compare their synthetic spectra. I will show how the models are constrained by details in X-ray grating spectra and how they enable us to determine from the observations what the physical conditions are in deep layers of novae in outburst.

  11. A survey of IRAS data on 41 classical novae

    NASA Technical Reports Server (NTRS)

    Harrison, T. E.; Gehrz, R. D.

    1988-01-01

    The IRAS database has been searched for detections of 41 classical novae using coadditions of survey scans; 15 were detected. IRAS temporal observations of novae in outburst are discussed. The observed long-wavelength infrared distributions of DQ Her, and possibly HR Del, can be explained by emission from small (a of about 0.1 microns) dust grains heated by the central object. An alternative explanation for the energy distributions of DQ Her and HR Del is emission from fine-structure lines. FH Ser and LW Ser display energy distributions that have color temperatures much too hot to be due to heating of dust by the central source in any plausible scenario. Line emission is probably the best explanation of their observed energy distributions. The novae NQ Vul and LV Vul have energy distributions that may be contaminated by emission from galactic cirrus. The unusual object PL 1547.3-5612 exhibits an energy distribution that does not resemble those of planetary nebulae or other novae detected in this sample. An IRAS low-resolution spectrum of RR Tel shows the 10-micron silicate emission feature.

  12. 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.

  13. 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.

  14. Independent Discovery of a Probable Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Kucakova, H.

    2016-06-01

    We report the independent discovery of a probable nova in M81 (first reported by M. Henze et al. in ATel #9175) on a co-added 3960-s unfiltered CCD frame taken on 2016 Jun. 20.880 UT with the 0.65-m telescope at Ondrejov.

  15. NOvA: Building a Next Generation Neutrino Experiment

    ScienceCinema

    Perko, John; Williams, Ron; Miller, Bill;

    2014-05-30

    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.

  16. Discovery of an Apparent Nova in M31

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Kucakova, H.

    2016-03-01

    We report the discovery of an apparent nova in M31 on a co-added 720-s R-band CCD frame taken on 2016 Mar. 6.806 UT with the 0.65-m telescope at Ondrejov. The object designated PNV J00421951+4111137 is located at R.A. = 0h42m19s.51, Decl.

  17. Fotometria col filtro LPR alla nova V5668 SGR

    NASA Astrophysics Data System (ADS)

    Sigismondi, Costantino

    2016-09-01

    The nova SGR 2015 no. 2 or V5668 SGR was visually observed with the LPR filter to evaluate the OIII emission. The contributions of B, V, R and Visual components to the LPR magnitude are modeled and compared with the observations in scotopic vision.

  18. Spectral eclipse mapping of the accretion disk in the nova-like variable UX Ursae Majoris

    NASA Technical Reports Server (NTRS)

    Rutten, R. G. M.; Dhillon, V. S.; Horne, K.; Kuulkers, E.

    1994-01-01

    We analyze narrow-band eclipse light curves of the nova-like cataclysmic variable UX UMa, obtained from low-resolution spectra spanning lambda lambda 3600-9800 A . The light curves for narrow bands in the continuum as well as those for individual spectral lines are treated independently, and are used to construct images of the accretion disk's brightness distribution using the maximum-entropy eclipse-mapping technique. Particular attention is paid to the propagation of statistical uncertainties in the data and to how the analysis may introduce systematic errors in the final result. From the many narrrow band images we have reconstructed the spectra from isolated parts of the accretion disk. These spectra reveal that the inner disk radiates a continuum spectrum which peaks in the near UV and has the hydrogen Balmer lines in absorption (with the exception of H-alpha), whereas the outer disk is much fainter, has a much redder spectrum, and has Balmer emission lines. Our analysis reveals the presence of an uneclipsed component of the total light, whose spectrum is very red and has Balmer lines in emission. This unexpected feature of the eclipse mapping technique offers a new tool for an independent assessment of the secondary star's spectrum in eclipsing cataclysmic variables.

  19. Measurement of Reactions on 30P for Nova Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Ma, Z.; Guidry, M. W.; Hix, W. R.; Smith, M. S.

    2003-05-01

    Replace these paragraphs with your abstract. We encourage you to include a sentence acknowledging your funding agency. In a recent study the 30P(p,gamma)31S rate played a crucial role in the synthesis of heavier nuclear species, from Si to Ca, in nova outbursts on ONe White Dwarfs [1]. The adopted rate of this reaction, based on a Hauser-Feshbach calculation [2], has a large uncertainty and could be as much as a factor of 100 too high or too low [3]. In their study, Jose et al.[1] varied the 30P(p,gamma)31S reaction rate within this uncertainty and found that, when rate is reduced by a factor of 100, the synthesis of elements above Si is lowered by a factor 10 with respect to the values found with the nominal rate. This has important consequences for nova nucleosynthesis, as overproduction of isotopes in the Si to Ca mass region has been observed in the ejecta from some nova explosions (e.g.,[4,5]). While generally valid at higher temperatures, Hauser-Feshbach calculations of the rates at nova temperatures can have large uncertainties. At these temperatures, the rate is more likely dominated by a few individual nuclear resonances. At present there are about 10 31S resonances known above the 30P + p threshold that may contribute to the 30P(p,gamma)31S reaction rate at nova temperatures. The excitation energies of these levels are known but spins and parities (for all but two) are not. We plan to measure the 30P(p,p)30P and 30P(p,gamma)31S reactions at HRIBF to better determine this reaction rate. A detailed description of the experiments will be given. We are also conducting a new nova nucleosynthesis simulation over multiple spatial zones of the exploding envelope to investigate the influence of the 30P(p,gamma)31S reaction rate on nova nucleosynthesis. The results of these calculations will be discussed. 1. Jose , J., Coc, A., Hernanz, M., Astrophys. J., 560, 897(2001). 2. Thielemann, F.-K et al., 1987, Advances in Nuclear Astrophysics, ed. E. Vangioni-Flam ( Gif

  20. 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...

  1. 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

  2. PHOTOMETRIC AND SPECTROSCOPIC PROPERTIES OF NOVAE IN THE LARGE MAGELLANIC CLOUD

    SciTech Connect

    Shafter, A. W.

    2013-05-15

    The photometric and spectroscopic properties of the 43 known LMC nova candidates are summarized and reviewed. Of these, photometric data sufficient to establish decline rates are available for 29 novae, while spectroscopic data sufficient to establish the spectroscopic classes are available for 18 systems. Half of the 18 novae belong to the Fe II class, with the remaining nine belonging to either the He/N or the Fe IIb classes. As seen in previous nova studies of M31 and M33, the He/N and Fe IIb novae have on average faster photometric developments than do their Fe II counterparts. Overall, the available photometry confirms earlier studies, and shows conclusively that LMC novae have faster rates of decline than do novae in the Galaxy and M31. It appears that the increased fraction of faster, He/N and Fe IIb novae observed in the LMC compared with M31 is almost certainly the result of differences in the underlying stellar population between the two galaxies. We propose that the younger population seen in the LMC compared with M31's bulge (where most of the novae are found), produces progenitor binaries with higher average white dwarf masses. The higher mean white dwarf mass not only produces a larger fraction of fast, He/N novae compared with M31, but also results in a relatively large recurrent nova population.

  3. 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.

  4. Are presolar dust grains from novae actually from supernovae?

    NASA Astrophysics Data System (ADS)

    Nittler, L. R.; Hoppe, P.

    2005-05-01

    Meteorites contain presolar stardust grains that formed in prior generations of stars and exhibit large isotopic anomalies reflecting the nuclear processes that occurred in their individual parent stars. RGB and AGB stars and supernovae are well established as sources of many of these grains. Novae have been proposed as sources for a few SiC and graphite grains with low 12}C/{13C and 14}N/{15N ratios and unusual Si isotopic ratios (Amari et al., ApJ, 551, 1065). We have found three SiC grains from the Murchison meteorite with C and N isotopic ratios similar to the previously-reported putative nova grains. However, the isotopic signatures of Si, Ca, Al and Ti in one of the grains (334-2) clearly indicate a supernova origin, especially excess 28Si correlated with excess 44Ca. The latter signature is attributable to in situ decay of (half-life=50yr) 44Ti. Another 13C- and 15N-rich grain (151-4) has a large 47Ti enrichment. This signature is not expected for nova nucleosynthesis. Thus, the new isotopic data raise the possibility that the grains previously reported to have formed in novae actually formed in supernovae, and that novae have not left a record in the presolar grain populations that have been so far studied. Moreover, the results in grain 334-2 indicate that supernovae contain regions highly enriched in both 13C and 15N. This is not predicted by current models but may bear on the cosmic origin of 15N. This work was funded in part by NASA.

  5. 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.

  6. Discovery of an Apparent Nova in M81 and H-alpha Confirmation of Three M81 Nova Candidates

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    We report the discovery of an apparent nova 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 ~1.6" seeing on 2014 Jun. ...

  7. 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

  8. Very high-energy γ-ray observations of novae and dwarf novae with the MAGIC telescopes

    NASA Astrophysics Data System (ADS)

    Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Chatterjee, A.; Clavero, R.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; de Oña Wilhelmi, E.; Delgado Mendez, C.; Di Pierro, F.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher Glawion, D.; Elsaesser, D.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giammaria, P.; Godinović, N.; González Muñoz, A.; Guberman, D.; Hanabata, Y.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Hughes, G.; Idec, W.; Kellermann, H.; Kodani, K.; Konno, Y.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Majumdar, P.; Makariev, M.; Mallot, K.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Nakajima, D.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Nishijima, K.; Noda, K.; Orito, R.; Overkemping, A.; Paiano, S.; Palacio, J.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Saito, T.; Saito, K.; Satalecka, K.; Scapin, V.; Schultz, C.; Schweizer, T.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Stamerra, A.; Steinbring, T.; Strzys, M.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Torres, D. F.; Toyama, T.; Treves, A.; Verguilov, V.; Vovk, I.; Will, M.; Zanin, R.; Desiante, R.; Hays, E.

    2015-10-01

    Context. In the last five years the Fermi Large Area Telescope (LAT) instrument detected GeV γ-ray emission from five novae. The GeV emission can be interpreted in terms of an inverse Compton process of electrons accelerated in a shock. In this case it is expected that protons in the same conditions can be accelerated to much higher energies. Consequently they may produce a second component in the γ-ray spectrum at TeV energies. Aims: We aim to explore the very high-energy domain to search for γ-ray emission above 50 GeV and to shed light on the acceleration process of leptons and hadrons in nova explosions. Methods: We have performed observations, with the MAGIC telescopes of the classical nova V339 Del shortly after the 2013 outburst; optical and subsequent GeV γ-ray detections triggered the MAGIC observations. We also briefly report on VHE observations of the symbiotic nova YY Her and the dwarf nova ASASSN-13ax. We complement the TeV MAGIC observations with the analysis of contemporaneous Fermi-LAT data of the sources. The TeV and GeV observations are compared in order to evaluate the acceleration parameters for leptons and hadrons. Results: No significant TeV emission was found from the studied sources. We computed upper limits on the spectrum and night-by-night flux. The combined GeV and TeV observations of V339 Del limit the ratio of proton to electron luminosities to Lp ≲ 0.15 Le. Appendix A is available in electronic form at http://www.aanda.org

  9. A multiwavelength study of the remnant of nova GK Persei

    NASA Astrophysics Data System (ADS)

    Anupama, G. C.; Kantharia, N. G.

    2005-05-01

    We present new observations of the nebular remnant of the old nova GK Persei 1901 in the optical using the Himalayan Chandra Telescope (HCT) and at low radio frequencies using the Giant Metrewave Radio Telescope (GMRT). The dimensions of the shell in the optical emission lines of [NII], [OIII] and [OII] are 108× 94 arcsec2, 104× 94 arcsec2 and 99× 87 arcsec2, respectively. The evolution of the nova remnant indicates shock interaction with the ambient medium, especially in the southwest quadrant. Application of a simple model for the shock and its evolution to determine the time dependence of the radius of the shell in the southwest quadrant indicates that the shell is now expanding into an ambient medium that has a density of 0.12 cm-3, compared to the density of the ambient medium of 0.8 cm-3 ahead of the shock in 1987. There are indications of a recent interaction of the nova remnant with the ambient medium in the northeast quadrant. There is a distinct flattening of the shell, as well as an increase in the number and brightness of the knots in the region. The brightest optical knots in this region are also detected in the radio images. The nova remnant of GK Per is detected at all the observed radio frequencies and is of a similar extent to the optical remnant. Putting together our radio observations with VLA archival data on GK Per from 1997, we obtain three interesting results: 1. the spectrum above 1.4 GHz follows a power law with an index -0.7 (S∝ να) and below 1.4 GHz follows a power law with an index ˜ -0.85. This could be due to the presence of at least two populations of electrons dominating the global emission at different frequencies; 2. we record an annual secular decrease of 2.1% in the flux density of the nova remnant at 1.4 and 4.9 GHz between 1984 and 1997 which has left the spectral index unchanged at -0.7. No such decrease is observed in the flux densities below 1 GHz; 3. we record an increase in the flux density at 0.33 GHz compared to

  10. Photometric evolution, orbital modulation and progenitor of Nova Mon 2012

    NASA Astrophysics Data System (ADS)

    Munari, U.; Dallaporta, S.; Castellani, F.; Valisa, P.; Frigo, A.; Chomiuk, L.; Ribeiro, V. A. R. M.

    2013-10-01

    We present and discuss accurate and densely mapped BVRCIC light curves of the neon Nova Mon 2012, supplemented by the evolution in Stromgren b and y bands and in the integrated flux of relevant emission lines. Our monitoring started with the optical discovery of the nova (50 days past the first detection in gamma-rays by Fermi-LAT) and extend to day +270, well past the end of the super-soft phase in X-rays. The nova was discovered during the nebular decline, well past t3 and the transition to optically thin ejecta. It displayed very smoothly evolving light curves. A bifurcation between y and V light curves took place at the start of the super-soft X-ray source (SSS) phase, and a knee developed towards the end of the SSS phase. The apparent magnitude of the nova at the unobserved optical maximum is constrained to +3 ≤ V ≤ 4.5. The appearance, grow in amplitude and then demise of a 0.29585 (±0.00002) days orbital modulation of the optical brightness was followed along the nova evolution. The observed modulation, identical in phase and period with the analogue seen in the X-ray and satellite ultraviolet, has a near-sinusoidal shape and a weak secondary minimum at phase 0.5. We favour an interpretation in terms of super-imposed ellipsoidal distortion of the Roche lobe filling companion and irradiation of its side facing the WD. Similar light curves are typical of symbiotic stars where a Roche lobe filling giant is irradiated by a very hot WD. Given the high orbital inclination, mutual occultation between the donor star and the accretion disc could contribute to the observed modulation. The optical+infrared spectral energy distribution of Nova Mon 2012 during the quiescence preceding outburst is nicely fitted by an early K-type main-sequence star (˜K3V) at 1.5 kpc distance, reddened by E(B - V) = 0.38, with a WD companion and an accretion disc contributing to the observed blue excess and moderate Hα emission. A typical early K-type main-sequence star with a mass

  11. 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.

  12. 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.

  13. High-Velocity Jets in Recurrent Nova Outbursts

    NASA Astrophysics Data System (ADS)

    Kato, Mariko; Hachisu, Izumi

    2003-04-01

    Very fast bipolar mass outflows are suggested from emission-line profiles during the early stage of outbursts in the recurrent nova U Sco. The ejection velocity reaches 5000 or 6000 km s-1 at the optical peak and gradually decreases in time. Such properties have not been reproduced so far in nova theories. We propose a jet-shaped mass outflow as a mechanism of acceleration up to several thousand kilometers per second. The mass flow is accelerated where the jet is shaped, which is deep inside the region where the spherically symmetric winds would be accelerated. The terminal jet velocity depends sensitively on the white dwarf mass but weakly on other parameters.

  14. A new optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Burwitz, V.; Pietsch, W.; Cikota, M.; Henze, S.; Violat-Bordonau, F.

    2008-06-01

    We report the discovery of an optical nova candidate in M 31 on 10*120s stacked unfiltered CCD images obtained with a 0.45m f/2.8 reflector and a SBIG STL-11000M CCD Camera (3008 pixels x 2674 pixels each 9 x 9 micron square), of the Observatorio de La Sagra, Spain, on 2008 Jun 26.11 with a magnitude of 16.1. The object is visible on all individual images. The position for the nova candidate is RA = 00h42m27.81s, Dec = +41d14'48.2" (J2000, accuracy of 0.4"), which is 186" west and 80" south of the core of M 31.

  15. From RoboNova to HUBO: Platforms for Robot Dance

    NASA Astrophysics Data System (ADS)

    Grunberg, David; Ellenberg, Robert; Kim, Youngmoo E.; Oh, Paul Y.

    A robot with the ability to dance in response to music could lead to novel and interesting interactions with humans. For example, such a robot could be used to augment live performances alongside human dancers. This paper describes a system enabling humanoid robots to move in synchrony with music. A small robot, the Hitec RoboNova, was initially used to develop smooth sequences of complex gestures used in human dance. The system uses a real-time beat prediction algorithm so that the robot’s movements are synchronized with the audio. Finally, we implemented the overall system on a much larger robot, HUBO, to establish the validity of the smaller RoboNova as a useful prototyping platform.

  16. 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.

  17. Nocardia nova mycetoma over forehead in a lepromatous leprosy patient.

    PubMed

    Dhingra, M; Kaistha, N; Bansal, N; Solanki, L S; Chander, J; Thami, G P; van de Sande, W W

    2012-07-01

    We present a case of a 31-year-old male, a known patient with lepromatous leprosy with a type 2 lepra reaction, who presented with a slowly growing asymptomatic swelling with multiple discharging sinuses over the forehead that developed over 6 months. Smears of the serosanguinous discharge on Gram staining showed Gram-positive branching filamentous bacilli, which on culture on blood agar showed chalky-white colonies. Histology of the lesion showed suppurative granulomas with polymorphs surrounding characteristic grains. The isolate was identified as Nocardia nova by gene sequencing and the patient was started on combined antibiotic therapy that resulted in complete resolution of the infection in six months. To the best of our knowledge, this is the first report of mycetoma related to Nocardia nova in association with leprosy. PMID:22863625

  18. 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.

  19. A search for novae in M 31 globular clusters

    NASA Technical Reports Server (NTRS)

    Ciardullo, Robin; Tamblyn, Peter; Phillips, A. C.

    1990-01-01

    By combining a local sky-fitting algorithm with a Fourier point-spread-function matching technique, nova outbursts have been searched for inside 54 of the globular clusters contained on the Ciardullo et al. (1987 and 1990) H-alpha survey frames of M 31. Over a mean effective survey time of about 2.0 years, no cluster exhibited a magnitude increase indicative of a nova explosion. If the cataclysmic variables (CVs) contained within globular clusters are similar to those found in the field, then these data imply that the overdensity of CVs within globulars is at least several times less than that of the high-luminosity X-ray sources. If tidal capture is responsible for the high density of hard binaries within globulars, then the probability of capturing condensed objects inside globular clusters may depend strongly on the mass of the remnant.

  20. 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.

  1. 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.

  2. Classical Rayleigh-Taylor instability experiments at Nova

    SciTech Connect

    Budil, K.S.; Remington, B.A.; Weber, S.V.; Perry, T.S.; Peyser, T.A.

    1997-11-10

    The evolution of the Rayleigh-Taylor (RT) instability at an embedded, or classical, interface is examined in a series of experiments at the Nova laserfacility .[reference for Nova] These experiments focused on the transition from the linear to nonlinear regimes for both single- and multimode initialperturbations. The development of a single mode at the embedded interface is compared to its evolution at an ablation front and the effect of ablativestabilization is experimentally demonstrated. The multimode experiments have shown evidence of the process of bubble competition, whereinneighboring structures either continue to rise or are washed downstream in the flow depending upon their relative size. The experiments with simulations performed with either the LASNEX are comparedcode [G. B.Zimmerman and W. L. Kruer, Comments Plasma Phys. Controlled Fusion 2,51 (1975).], a two-dimensional Lagrangian radiation-hydrodynamics code, or CALE [R. Tipton, reference for CALE], a two-dimensional arbitrary Lagrange-Eulerian radiation-hydrodynamics code.

  3. Explosive hydrogen burning of 17O in classical novae.

    PubMed

    Fox, C; Iliadis, C; Champagne, A E; Coc, A; José, J; Longland, R; Newton, J; Pollanen, J; Runkle, R

    2004-08-20

    We report on the observation of a new resonance at E(lab)(R)=190 keV in the 17O(p,gamma)18F reaction. The measured resonance strength amounts to omegagamma(pgamma)=(1.2+/-0.2)x10(-6) eV. With this new value, the uncertainties in the 17O(p,gamma)18F and 17O(p,alpha)14N thermonuclear reaction rates are reduced by orders of magnitude at nova temperatures. Our significantly improved reaction rates have major implications for the galactic synthesis of 17O, the stellar production of the radioisotope 18F, and the predicted oxygen isotopic ratios in nova ejecta. PMID:15447168

  4. Discovery of a Nova in the Virgo Galaxy M100

    NASA Astrophysics Data System (ADS)

    Ferrarese, Laura; Livio, Mario; Freedman, Wendy; Saha, Abhijit; Stetson, Peter B.; Ford, Holland C.; Hill, Robert J.; Madore, Barry F.

    1996-09-01

    We present the V and I light curves of a nova discovered in the disk of the spiral galaxy M100, located in the Virgo Cluster. In spite of the fact that the light curve is not well sampled around maximum light and the reddening to the nova is not accurately known, by adopting the maximum magnitude versus rate of decline relation by Della Valle & Livio we derive a distance modulus to M100 of mu 0 ~31.0 +/- 0.3 mag, fully consistent with the Cepheid distance modulus of 31.04 +/- 0.17 mag found by Ferrarese et al. from the same set of HST/WFPC2 data.

  5. CNO abundances and hydrodynamic models of the nova outburst.

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Truran, J. W.; Sparks, W. M.; Kutter, G. S.

    1972-01-01

    We have used a fully implicit, Lagrangian, hydrodynamic computer code incorporating a nuclear reaction network to follow thermonuclear runaways in the hydrogen-rich envelopes of white dwarfs in order to produce a nova outburst. Because of the short time-scales and the high nuclear burning rates produced in our models, the nuclear reactions are far out of equilibrium and the beta-plus unstable nuclei become the most abundant nuclei in the envelope except for hydrogen and helium. Our models have ejected 1.00017 solar mass with kinetic energies of 8 times 10 to the 44-th power ergs, a value that agrees quite closely with the observed values for novae.

  6. A search for novae in M 31 globular clusters

    NASA Astrophysics Data System (ADS)

    Ciardullo, Robin; Tamblyn, Peter; Phillips, A. C.

    1990-10-01

    By combining a local sky-fitting algorithm with a Fourier point-spread-function matching technique, nova outbursts have been searched for inside 54 of the globular clusters contained on the Ciardullo et al. (1987 and 1990) H-alpha survey frames of M 31. Over a mean effective survey time of about 2.0 years, no cluster exhibited a magnitude increase indicative of a nova explosion. If the cataclysmic variables (CVs) contained within globular clusters are similar to those found in the field, then these data imply that the overdensity of CVs within globulars is at least several times less than that of the high-luminosity X-ray sources. If tidal capture is responsible for the high density of hard binaries within globulars, then the probability of capturing condensed objects inside globular clusters may depend strongly on the mass of the remnant.

  7. Nova Sco 2013 = PNV J17335943-3606216

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-06-01

    Announcement of discovery of Nova Sco 2013 = PNV J17335943-3606216 by Koichi Nishiyama (Kurume, Japan) and Fujio Kabashima (Miyaki, Japan) at unfiltered CCD magnitude 11.1 on 2013 June 03.6146 UT. Coordinates: R.A. = 17 33 59.44, Decl.= -36 06 20.7 (2000.0). Confirmed as nova (likely highly reddened) via spectra by C. Buil (Toulouse, France) taken on 2013 June 3.960 UT and by T. Bohlsen (Armidale, NSW, Australia) on 2013 June 4. Announced on IAU CBET 3542 (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.

  8. Nova in Eridanus (KT Eri = N Eri 2009)

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2009-12-01

    The discovery is reported of Nova Eri 2009 = KT Eri by K. Itagaki, Yamagata, Japan, on Nov. 25.536 UT at unfiltered CCD magnitude 8.1. Spectra from several sources indicates KT Eri is a He/N nova. Pre-discovery images indicate KT Eri actually reached 5th magnitude, and the apparent progenitor is relatively bright at 15th magnitude. Initially announced in CBET 2050 (Daniel W. E. Green, ed.) and AAVSO Special Notice #181 (Elizabeth O. Waagen), with additional information in Special Notices #182 (Arne A. Henden) and #183 (Henden) and CBETs 2053 and 2055 (Daniel 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.

  9. Nova in Sagittarius (V5585 Sgr = N Sgr 2010)

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2010-01-01

    The discovery is reported of Nova Sgr 2010 = V5585 Sgr by John Seach (Chatsworth Island, NSW, Australia) on 2010 Jan. 20.72 UT at approximately 8.5, using a DSLR with 50-mm f/1.4 lens and orange filter. Spectra by H. Maehara (Kwasan Observatory, Kyoto University) indicates that this object is a Fe II class nova. Previously announced in IAU CBET 2140 (Daniel W. E. Green, Editor) and AAVSO Special Notice #190 (Matthew Templeton); additional information from CBET 2142 (Green) and IAU Circular 9112 (Green). 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.

  10. The Thermonuclear Runaway and the Classical Nova Outburst

    NASA Astrophysics Data System (ADS)

    Starrfield, S.; Iliadis, C.; Hix, W. R.

    2016-05-01

    Nova explosions occur on the white dwarf component of a cataclysmic variable binary stellar system that is accreting matter lost by its companion. When sufficient material has been accreted by the white dwarf, a thermonuclear runaway occurs and ejects material in what is observed as a classical nova explosion. We describe both the recent advances in our understanding of the progress of the outburst and outline some of the puzzles that are still outstanding. We report on the effects of improving both the nuclear reaction rate library and including a modern nuclear reaction network in our one-dimensional, fully implicit, hydrodynamic computer code. In addition, there has been progress in observational studies of supernovae Ia with implications about the progenitors, and we discuss that in this review.

  11. 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.

  12. X-ray Observations of Shocked Nova Ejecta

    NASA Astrophysics Data System (ADS)

    Mukai, K.; Nelson, T.; Chomiuk, L.; Mioduszewski, A.; Rupen, M. P.; Sokoloski, J. L.; Weston, J. H. S.; Bode, M. F.; Eyres, S. P. S.; O'Brien, T. J.

    2014-12-01

    We present X-ray observations of novae, obtained in conjunction with radio observations. The 1-10 keV X-rays are optically thin thermal emission from the ejecta shock-heated to >10 million degrees, while the radio emission is often dominated by Bremsstrahlung emission from ˜10,000 K gas, perhaps with additional contributions from shocks. The very presence of hard X-ray emission requires faster ejecta to catch up with a slower material ejected earlier. The X-ray temperatures allow us to estimate the velocity differential between the two systems. Non-ionization-equilibrium signatures, when present, allow us to constrain the density of the shocked plasma. The absorbing columns, usually observed to decrease as the ejecta expand, constrain the amount of the slower, earlier ejecta that still remain unshocked. Specifically, we will present our analysis of the Swift and Suzaku observations of T Pyx and Nova Mon 2012 and discuss implications.

  13. Portrait of a Novel Nova: V1500 Cygni

    NASA Astrophysics Data System (ADS)

    Lance, Catherine M.; McCall, Marshall L.; Uomoto, Alan K.

    1988-02-01

    A comprehensive study of Nova V1500 Cygni 1975 is presented. All previous work is carefully reviewed to arrive at a self-consistent set of fundamental physical properties for the system. These data are then combined with old and new observations to derive models for the ejecta and the remnant and to arrive at a possible explanation for the extreme nature of the outburst.

  14. 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).

  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. Shocks in nova outflows. II. Synchrotron radio emission

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    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 timescale of months with a brightness temperature which is too high to result from freely expanding photo-ionized 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 v_sh ≲ 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 favoring 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.

  17. Liverpool Telescope Spectrum of Classical Nova ASASSN-16ig

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    We obtained an optical spectrum of classical nova ASASSN-16ig in Sagittarius (see ATels #9343, #9352, #9359, CBET 4295, 4299) with the FRODOSpec spectrograph (Barnsley et al. 2012) on the 2.0m Liverpool Telescope (Steele et al. 2004) on 2016 August 11.88 UT. The spectrum was taken using the higher resolution mode, which gives a wavelength coverage of 3900 to 5100 A and 5900 to 8000 A, with a resolution of R ~ 5400.

  18. Liverpool Telescope Spectrum of OGLE-2016-NOVA-02

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    We obtained a spectrum of OGLE-2016-NOVA-02 (ATel #9246) with the FRODOSpec spectrograph (Barnsley et al. 2012) on the 2.0m Liverpool Telescope (Steele et al. 2004) on 2016 July 15.97 UT. The spectrum was taken using the higher resolution mode, which gives a wavelength coverage of 5900 to 8000 & Aring and resolution of R = 5300 in the red arm (no significant features were detected in the blue arm, which covers 3900 to 5100 & Aring).

  19. Discovery of an Apparent Nova in M31

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Carey, G.; Kucakova, H.

    2015-11-01

    We report the discovery of an apparent nova in M31 on a co-added 900-s R-band CCD frame taken on 2015 Nov. 22.718 UT with the 0.65-m telescope at Ondrejov and independently on two 600-s luminance filter CCD frames taken on Nov. 22.756 UT with the 0.20-m telescope at Bromsgrove.

  20. Three new optical nova candidates in M 31

    NASA Astrophysics Data System (ADS)

    Pietsch, W.; Henze, M.; Burwitz, V.; Kaur, A.; Hartmann, D. H.; Williams, G.; Milne, P.

    2011-06-01

    We report the discovery of three nova candidates in M 31 on 7x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k, 13.5 micron sq. pixels) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA) on 2011 June 7.418 UT. The objects are visible on all individual images.

  1. 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.

  2. {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.

  3. Laboratory Analysis of Presolar Silicate Stardust from a Nova

    NASA Astrophysics Data System (ADS)

    Leitner, J.; Kodolányi, 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 17O/16O ratio (6.3 ± 0.2 × 10-3) relative to solar values, whereas its 18O/16O ratio is solar within measurement uncertainty. It also shows enrichments in 25,26Mg and a significant excess in 30Si relative to solar system compositions, with δ25Mg = 79 ± 21‰, δ26Mg = 70 ± 20‰, and δ30Si = 379 ± 92‰. This isotopic composition is consistent with an origin in the ejecta of a ~1.3-1.4 M ⊙ 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.

  4. The early spectral evolution of Nova Cassiopeiae 1993

    NASA Technical Reports Server (NTRS)

    Hauschildt, Peter H.; Starrfield, Sumner; Shore, Steven N.; Gonzalez-Riestra, Rosario; Sonneborn, George; Allard, France

    1994-01-01

    In this paper we describe the evolution of Nova Cas 1993 over the first two months of its outburst. We present an ultraviolet light curve that covers the period from announcement to just after dust began forming in the ejecta (1994 Feb. 15) and International Ultraviolet Explorer (IUE) spacecraft constraints forced us to halt our observations. We have used spherical, expanding, Non-local Thermodynamic Equilibrium (NLTE) stellar atmospheres to compute synthetic spectra and have compared the results to combined ultraviolet (low-resolution 1200-3400 A and high-resolution 2400-3300 A) spectra. Our fits show that the effective temperature of the ejecta increased from approx. 8000 to about approx. 16 000 K between 1993 Dec. 12 and 1993 Dec. 26. The temperature then increased more slowly to approx. 24 000 on 1994 Jan. 28. A preliminary abundance analysis shows evidence for hydrogen depletion, as we also found for Nova V1974 Cygni; however we find a larger enhancement of carbon, nitrogen, and oxygen. We also show that the principal mechanism for mass ejection in this nova is a radiation pressure driven wind and that mechanical driving is not necessary.

  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. 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.

  7. Nucleosynthesis - An introduction. The case of classical nova explosions

    NASA Astrophysics Data System (ADS)

    José, Jordi

    2012-11-01

    The text presents a brief, historical introduction to the genesis of nuclear astrophysics, establishing links between the distribution of isotopic abundances in the Solar System and the nuclear processes that operate in stars. A number of suggestions and warnings to be taken into account for accurate numerical modeling in nuclear astrophysics are also outlined. The second part of the paper is devoted to classical nova outbursts, stellar explosions powered by thermonuclear runaways that take place in the H-rich accreted envelopes of white dwarfs in close binary systems. Extensive numerical simulations of nova outbursts have shown that the accreted envelopes attain peak temperatures ranging between 108 and 4×108 K, for about several hundred seconds, and therefore, their ejecta is expected to show signatures of a significant nuclear activity. Indeed, it has been claimed that novae can play a certain role in the enrichment of the interstellar medium through a number of intermediate-mass elements. This includes 17O, 15N, and 13C, systematically overproduced in huge amounts with respect to solar abundances, with a lower contribution in a number of other species with A < 40, such as 7Li, 19F, or 26Al.

  8. 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).

  9. IUE Archival Observations of the Old Nova V841

    NASA Astrophysics Data System (ADS)

    Engle, S.; Sion, E. M.

    2002-12-01

    We have carried out a synthetic spectral analysis of archival IUE of the old nova V841 Oph Lacertae (Nova Oph 1848). The spectrum, obtained with the E140M disperser, reveals a rising continuum shortward of 1560 A, a C IV P-Cygni profile indicative of wind outflow associated with disk accretion, a deep Ly alpha profile, and strong N V (1238 A, 1242 A) and O V (1371 A) wind/coronal absorption lines. Numerous sharp interstellar resonance lines are also present. A grid of accretion disk models, spanning a wide range of inclinations, accretion rates and white dwarf masses, is compared to sets of de-reddened data. High gravity model atmospheres and white dwarf atmsopheres combined with disks are also fit to the data. From the best composite disk plus photosphere model fits, we present the most likely parameters characterizing the far-UV spectrum of V841 Oph. Our results are compared to a very similar old nova, DI Lac (Moyer et al. 2002, AJ in press).

  10. Statistical analysis of properties of dwarf novae outbursts

    NASA Astrophysics Data System (ADS)

    Otulakowska-Hypka, Magdalena; Olech, Arkadiusz; Patterson, Joseph

    2016-08-01

    We present a statistical study of all measurable photometric features of a large sample of dwarf novae during their outbursts and superoutbursts. We used all accessible photometric data for all our objects to make the study as complete and up to date as possible. Our aim was to check correlations between these photometric features in order to constrain theoretical models which try to explain the nature of dwarf novae outbursts. We managed to confirm a few of the known correlations, that is the Stolz and Schoembs relation, the Bailey relation for long outbursts above the period gap, the relations between the cycle and supercycle lengths, amplitudes of normal and superoutbursts, amplitude and duration of superoutbursts, outburst duration and orbital period, outburst duration and mass ratio for short and normal outbursts, as well as the relation between the rise and decline rates of superoutbursts. However, we question the existence of the Kukarkin-Parenago relation but we found an analogous relation for superoutbursts. We also failed to find one presumed relation between outburst duration and mass ratio for superoutbursts. This study should help to direct theoretical work dedicated to dwarf novae.

  11. 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.

  12. Nova Scorpii 2011 = PNV J16551100-3838120

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2011-06-01

    Announces the discovery of Nova Scorpii 2011 = PNV J16551100-3838120 by John Seach (Chatsworth Island, NSW, Australia) on 2011 June 1.40 UT at magnitude 9.5 (DSLR + orange filter). Spectra by Bernard Heathcote (South Yarra, Vic, Australia) on Jun 2.4896 UT, A. Arai, T. Kajikawa, and M. Nagashima (Kyoto Sangyo University, Japan) on 2011 June 2.68 UT, and Masayuki Yamanaka and Ryosuke Itoh (Hiroshima University, Japan) on Jun 2 UT indicate a highly-reddened classical nova. Initially reported to the AAVSO by Seach and announced in AAVSO Special Notice #240 (Arne Henden) and IAU CBET 2735 (Daniel W. E. Green, ed.). The object was designated PNV J18102135-2305306 when posted on the Central Bureau's Transient Objects Confirmation Page (TOCP) webpage. 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, observations, and links to images. [Nova Sco 2011 subsequently assigned the name V1312 Sco

  13. Statistical analysis of properties of dwarf novae outbursts

    NASA Astrophysics Data System (ADS)

    Otulakowska-Hypka, Magdalena; Olech, Arkadiusz; Patterson, Joseph

    2016-08-01

    We present a statistical study of all measurable photometric features of a large sample of dwarf novae during their outbursts and superoutbursts. We used all accessible photometric data for all our objects to make the study as complete and up-to-date as possible. Our aim was to check correlations between these photometric features in order to constrain theoretical models which try to explain the nature of dwarf novae outbursts. We managed to confirm a few of the known correlations, that is the Stolz and Schoembs Relation, the Bailey Relation for long outbursts above the period gap, the relations between the cycle and supercycle lengths, amplitudes of normal and superoutbursts, amplitude and duration of superoutbursts, outburst duration and orbital period, outburst duration and mass ratio for short and normal outbursts, as well as the relation between the rise and decline rates of superoutbursts. However, we question the existence of the Kukarkin-Parenago Relation but we found an analogous relation for superoutbursts. We also failed to find one presumed relation between outburst duration and mass ratio for superoutbursts. This study should help to direct theoretical work dedicated to dwarf novae.

  14. X-ray Evolution of Classical Novae: Timescales for the SSS Phase

    NASA Astrophysics Data System (ADS)

    Stringfellow, Guy

    2005-10-01

    The outbursts of novae are driven by a thermonuclear runaway at the base of an accreted shell. Soft X-ray emission resulting from high surface temperatures on the WD after outburst are expected, but seldom observed (SSS phase). Some novae enter the SSS phase within the first year after outburst, and quickly turn off thereafter (the very fast ONeMg novae). Others (e.g., slow novae) are delayed years after outburst before entering the SSS stage, which then lasts many years. ROSAT detected only 3 novae in their SSS state; XMM has observed 5, 3 which have SSS spectrums. Insight into the diversity and evolution of novae can be gained by determining when (or if) the SSS stage begins, when turnoff occurs, and how this relates to composition and the mass of the WD.

  15. 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.

  16. Is the Nova V2672 Oph a Luminous X-ray Source in Quiescence?

    NASA Astrophysics Data System (ADS)

    Mukai, Koji

    2014-09-01

    The very fast nova V2672 Oph had one of the shortest decay times (t2=2.3 d) and the broadest emission lines (FWZI up to 12,000 km/s) ever observed in novae. It may well be a recurrent nova with a near Chandrasekhar mass white dwarf. There is also a ROSAT all-sky survey Faint Source Catalog source consistent with its position: if confirmed, V2672 Oph would be only the third nova to have been detected in X-rays before the nova eruption. We therefore propose an ACIS-S imaging observation to provide the precise location, and rough timing and spectral characteristics of the ROSAT source. V2672 Oph may join V2487 Oph and V2491 Cyg as novae with quiescent X-ray luminosities not seen in normal cataclysmic variables.

  17. Gamma-ray constraints on Na-22 yields in nova explosions

    NASA Technical Reports Server (NTRS)

    Higdon, J. C.; Fowler, William A.

    1987-01-01

    The longitudinal distribution of diffuse 1.275 MeV emission produced by the decay of interstellar Na-22 generated by a limited class of energetic novae-accreting ONeMg white dwarfs is modeled. The probability distributions for the locations of disk novae are derived as functions of Galactocentric cylindrical coordinates. The occurrence rate for novae of all classes in the Galactic disk is about 30/yr. An occurrence rate of about 16/yr is found for spheroid novae of all classes. By comparing these simulation results with HEAO 3 upper limits on diffuse 1.275 MeV emission, upper limits of (3-5.6) x 10 to the -7th solar mass are determined for the mean Na-22 yield for energetic novae generated by accreting ONeMg white dwarfs. These Na-22 limits constrain future models of explosive nucleosynthesis in energetic nova explosions.

  18. Confirmation of a recent optical nova candidate in M 31 and H- alpha identification of seven M 31 novae

    NASA Astrophysics Data System (ADS)

    Henze, M.; Pietsch, W.; Burwitz, V.; Updike, A.; Hartmann, D. H.; Milne, P.; Williams, G.

    2008-07-01

    We report the confirmation of a nova candidate in M 31 recently reported to us by K. Hornoch. We detected this object with an R magnitude of 18.7 in a 12x60s stacked R filter CCD image obtained on 2008 June 30.43 with the robotic 60cm telescope with an E2V CCD (2kx2k) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA). The position of the nova candidate is RA = 00h43m08.30s, Dec = +41d18'38.0" (J2000, accuracy of 0.3"), which is 4'30" east and 2'29" north of the core of M 31.

  19. Evolution of Nova TrA 2008 into a High Mass-Accretion Rate Post-Nova

    NASA Astrophysics Data System (ADS)

    Walter, Frederick M.

    2015-06-01

    NR TrA (Nova TrA 2008) was a normal slow Fe II novae for its first year of evolution. During its third year eclipses appeared, and optical spectra revealed the presence of hot permitted lines of C IV, N V, and O VI in addition to the usual nebular lines. The light curve and spectra resemble those of the V Sge stars. The orbital period is 5.25 hours. The time-resolved spectra show a prominent S-wave in the hot lines with an amplitude of about 100 km/s. We conclude that the system is a CV with a high mass accretion rate that has persisted for some 6 years after the explosion.

  20. ON THE PROGENITORS OF LOCAL GROUP NOVAE. I. THE M31 CATALOG

    SciTech Connect

    Williams, S. C.; Darnley, M. J.; Bode, M. F.; Keen, A.; Shafter, A. W.

    2014-07-01

    We report the results of a survey of M31 novae in quiescence. This is the first catalog of extragalactic systems in quiescence to be published, and contains data for 38 spectroscopically confirmed novae from 2006 to 2012. We used Liverpool Telescope images of each nova during eruption to define an accurate position for each system. These positions were then matched to archival Hubble Space Telescope (HST) images and we performed photometry on any resolved objects that were coincident with the eruption positions. The survey aimed to detect quiescent systems with red giant secondaries, as only these, along with a few systems with bright sub-giant secondaries, will be resolvable in the HST images. There are only a few confirmed examples of such red giant novae in our Galaxy, the majority of which are recurrent novae. However, we find that a relatively high percentage of the nova eruptions in M31 may occur in systems containing red giant secondaries. Of the 38 systems in this catalog, 11 have a progenitor candidate whose probability of being a coincidental alignment is less than 5%. We show that at the 3σ limit, up to only 2 of these 11 systems may be due to chance alignments, leading to an estimate of the M31 nova population with evolved secondaries of up to 24%, compared to the ∼3% seen Galactically. Such an elevated proportion of nova systems with evolved secondaries may imply the presence of a much larger population of recurrent novae than previously thought. This would have considerable impact, particularly with regards to their potential as Type Ia supernova progenitors. Additionally, for several novae, serendipitous HST images had been taken when the nova was still fading; this allowed us to produce light curves that go fainter than is usually achievable for most extragalactic systems. Finally, as this survey is astrometric in nature, we also update the position of each nova in the catalog.

  1. 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.

  2. HUBBLE SEES CHANGES IN GAS SHELL AROUND NOVA CYGNI 1992

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The European Space Agency's ESA Faint Object Camera utilizing the corrective optics provided by NASA's COSTAR (Corrective Optics Space Telescope Axial Replacement), has given astronomers their best look yet at a rapidly ballooning bubble of gas blasted off a star. The shell surrounds Nova Cygni 1992, which erupted on February 19, 1992. A nova is a thermonuclear explosion that occurs on the surface of a white dwarf star in a double star system. The new HST image [right] reveals an elliptical and slightly lumpy ring-like structure. The ring is the edge of a bubble of hot gas blasted into space by the nova. The shell is so thin that the FOC does not resolve its true thickness, even with HST's restored vision. An HST image taken on May 31 1993, [left] 467 days after the explosion, provided the first glimpse of the ring and a mysterious bar-like structure. But the image interpretation was severely hampered by HST's optical aberration, that scattered light from the central star which contaminated the ring's image. A comparison of the pre and post COSTAR/FOC images reveals that the ring has evolved in the seven months that have elapsed between the two observations. The ring has expanded from a diameter of approximately 74 to 96 billion miles. The bar-like structure seen in the earlier HST image has disappear. These changes might confirm theories that the bar was produced by a dense layer of gas thrown off in the orbital plane of the double star system. The gas has subsequently grown more tenuous and so the bar has faded. The ring has also grown noticeably more oblong since the earlier image. This suggests the hot gas is escaping more rapidly above and below the system's orbital plane. As the gas continues escaping the ring should grow increasingly egg-shaped in the coming years. HST's newly improved sensitivity and high resolution provides a unique opportunity to understand the novae by resolving the effects of the explosion long before they can be resolved in ground

  3. 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. PMID:25296250

  4. 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.

  5. EFFECTS OF A COMPANION STAR ON SLOW NOVA OUTBURSTS-TRANSITION FROM STATIC TO WIND EVOLUTIONS

    SciTech Connect

    Kato, Mariko; Hachisu, Izumi E-mail: hachisu@ea.c.u-tokyo.ac.jp

    2011-12-20

    Two types of nova evolutions can occur in low-mass white dwarfs of {approx}0.5-0.7 M{sub Sun }, i.e., an evolution with optically thick winds like in usual classical novae, or an another type of evolution without them like in the symbiotic nova PU Vul. The latter type is characterized by spectra with no indication of strong winds as well as a long-lasting flat optical peak in its light curve. We propose a transition from evolution with no optically thick wind to usual evolution with optically thick winds as a new outburst model for slow novae that show a relatively long-lasting multipeak phase followed by a wind phase like in the slow novae V723 Cas, HR Del, and V5558 Sgr. We calculated nova envelopes with one-dimensional approximation of the companion's effects and found that when the companion star is deeply embedded in the extended nova envelope, the structure of the static envelope approaches that of the optically thick wind solution. Thus, the transition from static to wind solution is triggered by the effect of the companion. The transition occurs in a close binary nova like V723 Cas, but is not triggered in a long-period binary like PU Vul. We reconfirm our previous results that the frictional energy deposition is negligibly small in almost all hydrogen/helium novae because of the low envelope density at the orbit.

  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. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

    2014-10-01

    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 10-4 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. The MMRD relation of the Galactic Novae: insights from a new distance estimation method

    NASA Astrophysics Data System (ADS)

    Ak, Tansel; Guver, Tolga; Ozdonmez, Aykut

    2016-07-01

    In order to re-establish the Maximum Magnitude Rate of Decline (MMRD) relation of galactic novae, we used the distances of them obtained from the reddening-distance relations and expansion parallaxes. We investigated the relation using about 70 Galactic novae, which have the distance measurement, the magnitude at maximum of the nova outburst and the decline rate, and compared the relation with that found for M31. It is possible to use the MMRD relation as a standard tool for distance measurement. In addition, the relations for our Galaxy and the ones obtained from other galaxies can be compared to understand the differences of nova distributions in different galaxies.

  10. DISCOVERY OF A NEW PHOTOMETRIC SUB-CLASS OF FAINT AND FAST CLASSICAL NOVAE

    SciTech Connect

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

    2011-07-10

    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.

  11. Novae in External Galaxies: M51, M87, and M101

    NASA Astrophysics Data System (ADS)

    Shafter, A. W.; Ciardullo, R.; Pritchet, C. J.

    2000-02-01

    As part of a program to determine the stellar population of novae, we have conducted a multiepoch Hα survey of the galaxies M51, M87, and M101. A total of nine and 12 novae were detected in the spiral galaxies M51 and M101, respectively, during four epochs of observation, and two epochs of observation yielded a total of nine novae in the giant elliptical galaxy M87. After correcting for the effective survey time and for the fraction of luminosity sampled, we find global nova rates of 18+/-7, 91+/-34, and 12+/-4 novae per year for M51, M87, and M101, respectively. After normalizing to the total K-band luminosity of each galaxy, we estimate luminosity-specific nova rates for M51, M87, and M101 of 1.09+/-0.47, 2.30+/-0.99, and 0.97+/-0.38 novae per year per 1010 solar luminosities in K. When we compare these data with measured values for the luminosity-specific nova rates of other galaxies, we find no compelling evidence for a significant variation with Hubble type. Possible ramifications of this result are discussed within the context of current theoretical models for nova production in galaxies.

  12. 0.8 - 2.5 μ m Spectroscopy of Five Recent Novae or Novae-Like Objects: V4642 (Nova Sgr 2000), CI Aql, V1493 Aql (Nova Aql 1999 #1), V1494 Aql (Nova Aql 1999 #2) and V4444 Sgr (Nova Sgr 1999).

    NASA Astrophysics Data System (ADS)

    Lynch, D. K.; Rudy, R. J.; Venturini, C. C.; Mazuk, S.; Puetter, R. C.

    2000-12-01

    We report spectroscopy of a number of recent novae or recurrent novae. Near infrared spectroscopy provides a wealth of diagnostic detail about novae and the evolution of their shells because of the number and variety of special-utility lines that are available. Low excitation hydrogen Paschen and Brackett lines provide a background against which to assess abundances, electron densities and temperatures. They also reveal information about the shell geometry, kinematics and optical depths. The intrinsic flux ratio of the OI lines at 0.8446 μ m and 1.1287 μ m is well known and therefore any departure from it is usually a good indicator of interstellar reddening. Neutral and low ionization permitted lines of nitrogen, oxygen, carbon, phosphorus, silicon, calcium, magnesium and iron often provide crucial abundance information which in turn can be related to the initial composition, evolutionary state and surface mixing of the white dwarf (WD) before the outburst . As the ejecta cools and thins to reveal the hot WD, higher ionization forbidden ``coronal" lines begin to appear such as [S VIII] 0.9913 μ m, [Fe XIII] 1.0747, [S IX] 1.2523 μ m, [Al IX] 2.0469 μ m, [Ca VIII] 2.3214 μ m, and [Si VII] 2.4827 μ m . By noting their relative strengths, time of emergence and critical densities, much can be learned about the conditions in the shell. Our spectra show a variety of line widths, shapes and levels of excitation. Of particular interest are the lines that have remained unidentified in these and other novae spectra. This work supported by The Aerospace Corporation's Independent Research and Development Program. Also see posters by Rudy et al. and Venturini et al. .

  13. Chandra Discovers Eruption and Pulsation in Nova Outburst

    NASA Astrophysics Data System (ADS)

    2001-09-01

    NASA's Chandra X-ray Observatory has discovered a giant outburst of X-rays and unusual cyclical pulsing from a white dwarf star that is closely orbiting another star -- the first time either of these phenomena has been seen in X-rays. The observations are helping scientists better understand the thermonuclear explosions that occur in certain binary star systems. The observations of Nova Aquilae were reported today at the "Two Years of Science with Chandra" symposium by an international team led by Sumner Starrfield of Arizona State University. "We found two important results in our Chandra observations. The first was an underlying pulsation every 40 minutes in the X-ray brightness, which we believe comes from the cyclical expansion and contraction of the outer layers of the white dwarf," said Starrfield. "The other result was an enormous flare of X-rays that lasted for 15 minutes. Nothing like this has been seen before from a nova, and we don't know how to explain it." Novas occur on a white dwarf (a star which used up all its nuclear fuel and shrank to roughly the size of the Earth) that is orbiting a normal size star. Strong gravity tides drag hydrogen gas off the normal star and onto the white dwarf, where it can take more than 100,000 years for enough hydrogen to accumulate to ignite nuclear fusion reactions. Gradually, these reactions intensify until a cosmic-sized hydrogen bomb blast results. The outer layers of the white dwarf are then blown away, producing a nova outburst that can be observed for a period of months to years as the material expands into space. "Chandra has allowed us to see deep into the gases ejected by this giant explosion and extract unparalleled information on the evolution of the white dwarf whose surface is exploding," said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics. The brightening of Nova Aquilae was first detected by optical astronomers in December 1999. "Although this star is at a distance of more than 6

  14. DISCOVERY OF A NOVA-LIKE CATACLYSMIC VARIABLE IN THE KEPLER MISSION FIELD

    SciTech Connect

    Williams, Kurtis A.; De Martino, Domitilla; Silvotti, Roberto; Bruni, Ivan; Dufour, Patrick; Riecken, Thomas S.; Kronberg, Martin; Mukadam, Anjum; Handler, G.

    2010-06-15

    We announce the identification of a new cataclysmic variable (CV) star in the field of the Kepler Mission, KIC J192410.81+445934.9. This system was identified during a search for compact pulsators in the Kepler field. High-speed photometry reveals coherent large-amplitude variability with a period of 2.94 hr. Rapid, large-amplitude quasi-periodic variations are also detected on time scales of {approx}1200 s and {approx}650 s. Time-resolved spectroscopy covering one half photometric period shows shallow, broad Balmer and He I absorption lines with bright emission cores as well as strong He II and Bowen blend emission. Radial velocity variations are also observed in the Balmer and He I emission lines that are consistent with the photometric period. We therefore conclude that KIC J192410.81+445934.9 is a nova-like (NL) variable of the UX UMa class in or near the period gap, and it may belong to the rapidly growing subclass of SW Sex systems. Based on Two Micron All Sky Survey photometry and companion star models, we place a lower limit on the distance to the system of {approx}500 pc. Due to limitations of our discovery data, additional observations including spectroscopy and polarimetry are needed to confirm the nature of this object. Such data will enable further understanding of the behavior of NL variables in the critical period range of 3-4 hr, where standard CV evolutionary theory finds major problems. The presence of this system in the Kepler Mission field of view also presents a unique opportunity to obtain a continuous photometric data stream of unparalleled length and precision on a CV system.

  15. Naval Observatory Vector Astrometry Software (NOVAS) Version 3.1:Fortran, C, and Python Editions

    NASA Astrophysics Data System (ADS)

    Kaplan, G. H.; Bangert, J. A.; Barron, E. G.; Bartlett, J. L.; Puatua, W.; Harris, W.; Barrett, P.

    2012-08-01

    The Naval Observatory Vector Astrometry Software (NOVAS) is a source - code library that provides common astrometric quantities and transformations to high precision. The library can supply, in one or two subroutine or function calls, the instantaneous celestial position of any star or planet in a variety of coordinate systems. NOVAS also provides access to all of the building blocks that go into such computations. NOVAS is used for a wide variety of applications, including the U.S. portions of The Astronomical Almanac and a number of telescope control systems. NOVAS uses IAU recommended models for Earth orientation, including the IAU 2006 precession theory, the IAU 2000A and 2000B nutation series, and diurnal rotation based on the celestial and terrestrial intermediate origins. Equinox - based quantities, such as sidereal time, are also supported. NOVAS Earth orientation calculations match those from SOFA at the sub - microarcsecond level for comparable transformations. NOVAS algorithms for aberration an d gravitational light deflection are equivalent, at the microarcsecond level, to those inherent in the current consensus VLBI delay algorithm. NOVAS can be easily connected to the JPL planetary/lunar ephemerides (e.g., DE405), and connections to IMCCE and IAA planetary ephemerides are planned. NOVAS Version 3.1 introduces a Python edition alongside the Fortran and C editions. The Python edition uses the computational code from the C edition and currently mimics the function calls of the C edition. Future versions will expand the functionality of the Python edition to exploit the object - oriented features of Python. In the Version 3.1 C edition, the ephemeris - access functions have been revised for use on 64 - bit systems and for improved performance in general. NOVAS source code, auxiliary files, and documentation are available from the USNO website (http://aa.usno.navy.mil/software/novas/novas_info.php).

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Answering Fundamental Questions about Cataclysmic Variables and Classical Novae

    NASA Astrophysics Data System (ADS)

    Harrison, T. E.

    2014-09-01

    Cataclysmic variables (CVs) are interacting binaries consisting of a white dwarf primary, and a non-degenerate secondary star. There are numerous subclasses of CVs (any of which could become a Classical Nova), but broadly, these classifications are believed to arise from either differing values of the mass accretion rate, or whether the white dwarf primary is magnetic. There continue to be numerous questions about the origin, and evolution of these systems. We will review some of the outstanding issues, and address how advances in interferometry might be used to resolve them.

  1. 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.

  2. First mix experiments at Nova, the LoRo series

    SciTech Connect

    Rupert, V.C.

    1991-09-12

    The first series of experiments using the Nova laser to investigate mix at an interface between different materials has been completed. Mix was induced by a shock crossing the interface and initiating a Richtmyer-Meshkov instability. Both low and high Atwood number targets were used and the results compare favorably with simulations using a k{var epsilon} mix model. These experiments pave the way for new designs which should provide data needed to develop mix models with predictive capabilities. 9 refs., 8 figs.

  3. NOvA experiment in light of large θ13

    NASA Astrophysics Data System (ADS)

    Perevalov, Denis

    2014-04-01

    NOvA is an off-axis long baseline neutrino experiment searching for νμ → νe oscillations using an upgraded NuMI neutrino beam from Fermilab, Batavia, IL. The main physics goal is a measurement of the CP violation and establishing the neutrino masses hierarchy. A large 14 kton Far detector, comprised of liquid scintillator contained in extruded PVC cells, will also provide an opportunity for other non-accelerator physics searches. While civil construction at the far detector is underway, a smaller prototype near detector has been assembled at Fermilab and is being studied.

  4. MAXI Nova Alert System and the Latest Scientific Results

    SciTech Connect

    Negoro, H.; Miyoshi, S.; Ozawa, H.; Ishiwata, R.; Nakajima, N.; Matsuoka, M.; Kawasaki, K.; Ueno, S.; Tomida, H.; Suzuki, M.; Ishikawa, M.; Mihara, T.; Kohama, M.; Sugizaki, M.; Nakagawa, Y.; Tsunemi, H.; Kawai, N.; Morii, M.; Yoshida, A.; Yamaoka, K.

    2010-07-15

    MAXI, Monitor of All-sky X-ray Image, is the first astronomical telescope onboard the ISS. One of the main goals of our mission is to discover new transient objects by scanning more than 95% of the sky every {approx}92 min with two types of X-ray cameras, Gas Slit Camera (GSC) and Solid-state Slit Camera (SSC). We have developed a completely new data analysis system, a nova alert system, to find transient objects and send alerts to the world as soon as possible. Here we describe the current status of the system, and transient objects discovered with the system.

  5. 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.

  6. Nova control system: goals, architecture, and system design

    SciTech Connect

    Suski, G.J.; Duffy, J.M.; Gritton, D.G.; Holloway, F.W.; Krammen, J.R.; Ozarski, R.G.; Severyn, J.R.; Van Arsdall, P.J.

    1982-05-19

    The control system for the Nova laser must operate reliably in a harsh pulse power environment and satisfy requirements of technical functionality, flexibility, maintainability and operability. It is composed of four fundamental subsystems: Power Conditioning, Alignment, Laser Diagnostics, and Target Diagnostics, together with a fifth, unifying subsystem called Central Controls. The system architecture utilizes a collection of distributed microcomputers, minicomputers, and components interconnected through high speed fiber optic communications systems. The design objectives, development strategy and architecture of the overall control system and each of its four fundamental subsystems are discussed. Specific hardware and software developments in several areas are also covered.

  7. Discovery of a Possible Nova in M31

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    We report the discovery of a new transient in M31, probably the eruption of a previously unknown nova system, in data obtained with the IO:O CCD camera on the Liverpool Telescope (Steele et al. 2004) on 2015 October 26.91 UT. We calculate the position of the transient to be RA = 00:43:15.343, Dec. = +41:20:16.61 (J2000) and measure it to have a V-band magnitude of 19.56 & plusmn; 0.06 and r' = 19.52 & plusmn; 0.04 on 2015 October 26.91.

  8. X-ray detection of the old nova DK Lacertae

    NASA Astrophysics Data System (ADS)

    Boardman, S. F.; Takei, D.; Drake, J. J.; Sakamoto, T.; Fruscione, A.

    2016-01-01

    We report the detection of the old nova DK Lacertae with Chandra X-Ray Observatory's ACIS-S CCD imaging spectrometer on 3 February 2015. DK Lacertae, located at (J2000) 22:49:46.970 +53:17:19.66, was discovered in 1950 at a brightness of 6 mag (Bertaud, C., 1950, IAUC, 1254, 1). Chandra detected 92.5 +/- 9.6 net counts from the source at a count rate of 0.0306 +/- 0.0032 c/s over an exposure time of 3025.6 s. No significant variability was observed during the length of the observation.

  9. Exploration for coalbed methane starts up in northwestern Nova Scotia

    SciTech Connect

    Sakashita, B.J. )

    1993-03-29

    A consortium of three Canadian companies and a U.S. firm, Resources Enterprises Inc. (REI), Salt Lake City, has been awarded the rights for coalbed methane gas exploration on 250,000 acres in the Cumberland basin of Nova Scotia, Canada. The license agreement requires that geological and engineering studies be performed during 1993 to select exploratory well locations. Three slimhole wells must be drilled by yearend 1994, and three production test wells must be completed by yearend 1995. The paper describes the Cumberland basin exploration license; market outlets for the methane; and geothermal potential of the Cumberland basin in combination with dewatering the coal seam.

  10. 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.

  11. Deriving an X-ray luminosity function of dwarf novae

    SciTech Connect

    Byckling, Kristiina; Osborne, Julian; Mukai, Koji

    2010-07-15

    Current measurements of X-ray luminosity functions of dwarf novae contain biases due to high X-ray flux sources. We have obtained Suzaku, XMM-Newton and ASCA observations of nearby DNe which have parallax-based distance measurements, and carried out X-ray spectral analysis for these sources. Our primary goal is to derive a reliable X-ray luminosity function for this sample, and to compare it with existing X-ray luminosity functions. We briefly introduce the source sample and preliminary results.

  12. Linear Polarization Measurements of Nova Sco 2015 (PNV J17032620-3504140)

    NASA Astrophysics Data System (ADS)

    Muneer, S.; Anupama, G. C.; Raveendran, A. V.

    2015-03-01

    We report here the first polarimetric observations of Nova Sco 2015 (PNV J17032620-3504140). The nova was observed during 19-25 Febuary 2015 with a two-beam, broadband, multi-channel polarimeter attached to the 1-m Carl-Zeiss telescope at the Vainu Bappu Observatory, Kavalur, India.

  13. Innovation and Skills Development in the Rural Voluntary Sector in Nova Scotia

    ERIC Educational Resources Information Center

    Canadian Rural Partnership, 2002

    2002-01-01

    This report is a summary of discussions that took place at the Rural Voluntary Sector Leaders' Dialogue, entitled "Innovation and Skills Development in the Rural Voluntary Sector in Nova Scotia", held in Truro, Nova Scotia on September 20, 2002. Many of the discussions took place in brainstorming sessions at which no limits were placed on the…

  14. 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…

  15. 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…

  16. Ten-year literature review of global endometrial ablation with the NovaSure® device

    PubMed Central

    Gimpelson, Richard J

    2014-01-01

    This review examines the peer-reviewed literature describing prospective studies that report amenorrhea rates, patient satisfaction, and surgical reintervention rates following the NovaSure® endometrial ablation procedure. A search of the English-language literature published from 2000 to 2011 was conducted using PubMed. Ten prospective studies, six single-arm NovaSure trials, and four randomized controlled trials comparing the NovaSure procedure with other global endometrial ablation modalities met the inclusion criteria and were reviewed. The follow-up periods ranged from 6 to 60 months. Amenorrhea rates for the NovaSure procedure ranged from 30.0% to 75.0%. Patients who reported being satisfied with the NovaSure procedure ranged from 85.0% to 94.0%. In randomized controlled trials with other global endometrial ablation modalities, amenorrhea rates at 12 months with the NovaSure procedure ranged from 43.0% to 56.0%, while other modalities ranged from 8% to 24%. In addition, this manuscript reviews the following: the NovaSure technology; use of the NovaSure procedure in the office setting; intraoperative and postoperative pain; effects on premenstrual syndrome (PMS); dysmenorrhea; special circumstances, including presence of uterine disease, history of cesarean delivery, coagulopathy, or use of anticoagulant medication; post-procedure uterine cavity assessment and cancer risk; contraception and pregnancy; and safety. PMID:24648771

  17. 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,…

  18. 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 network…

  19. Demonstration of efficient full aperture Type I/Type II third harmonic conversion on Nova

    SciTech Connect

    Wegner, P.J.; Henesian, M.A.; Marchi, F.T.; Speck, D.R.

    1987-11-19

    Type I/Type II third harmonic conversion has been implemented at the 74 cm aperture of the Nova laser system. We discuss the performance capabilities and alignment issues of this scheme for Nova relative to conventional Type II/Type II conversion. 3 refs., 2 figs.

  20. Near-Infrared spectroscopy of Nova Sco 2016 (PNV J17381927-3725077)

    NASA Astrophysics Data System (ADS)

    Srivastava, Mudit; Banerjee, D. P. K.; Ashok, N. M.; Joshi, Vishal

    2016-06-01

    Near-infrared observations are reported of Nova Sco 2016 detected in outburst on 10.629 June 2016 (CBET 4285). A classification of the nova as a Fe II or He/N type was not suggested from its optical spectrum (CBET 4285).