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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. 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.

  13. [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

  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. 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.

  3. 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

  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

    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.

  10. 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.

  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 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.

  16. 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.

  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. 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.

  4. Nova Mus 2008 = QY Mus

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2008-10-01

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

  5. 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!

    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.

  14. 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.

  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. 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.

  17. 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.

  18. 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.

  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. 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.

  12. 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.

  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. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  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. 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.

  12. 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.

  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. 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.

  9. 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.

  10. 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.

  11. 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.

  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. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  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. 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.

  9. 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.

  10. 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…

  11. 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…

  12. 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.

  13. 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.

  14. 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)…

  15. 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…

  16. 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.

  17. 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

  18. 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

  19. 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…

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  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. 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.

  12. 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.

  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. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  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. 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.

  18. 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…

  19. 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).

  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

    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.

  7. 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.

  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.

    2016-05-01

    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.

  16. 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.

  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. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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).

  5. 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.

  6. 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.

  7. 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.

  8. 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).

  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.