. . . . . . . . . "V838 Herculis"@en . . . . . . "V838 Herculis, also known as Nova Herculis 1991, was a nova which occurred in the constellation Hercules in 1991. It was discovered by George Alcock of Yaxley, Cambridgeshire, England at 4:35 UT on the morning of 25 March 1991. He found it with 10\u00D750 binoculars, and on that morning its apparent visual magnitude was 5 (making it visible to the naked eye). Palomar Sky Survey plates showed that before the outburst, the star was at photographic magnitude 20.6 (blue light) and 18.25 (red light). V838 Herculis declined from its peak brightness very quickly, fading by 2 magnitudes in less than three days, making it one of the fasted classical novae ever recorded. All novae are binary stars, with a \"donor\" star orbiting a white dwarf. The two stars are so close to each other that material is transferred from the donor to the white dwarf. Because the distance between the two stars is comparable to the radius of the donor star, novae are often eclipsing binaries, and V838 Herculis does show such eclipses. The eclipses were first detected a few weeks after the nova outburst, and they show the system's orbital period to be 7 hours, 8 minutes and 36 seconds as of 1991. The shape of the eclipse light curve suggests that the white dwarf itself is not being eclipsed by the donor, but rather that the accretion disk surrounding the white dwarf is being partially eclipsed. The depth of the eclipses was initially only 0.1 magnitudes, but grew over the year following the nova event to 0.7 magnitudes, indicating that the accretion disk re-established itself after the nova outburst during that time. The white dwarf in the V838 Herculis system is an oxygen-neon-magnesium white dwarf, with a mass of about 1.35, M\u2609 which is near the Chandrasekhar limit for white dwarf masses. The donor star is believed to be a main sequence star."@en . . . . "\uD5E4\uB974\uCFE8\uB808\uC2A4\uC790\uB9AC V838\uC740 \uD5E4\uB974\uCFE8\uB808\uC2A4\uC790\uB9AC\uC5D0 \uC788\uB294 \uC2E0\uC131\uC774\uB2E4."@ko . . . . . . . . . . . . "V838 Herculis (ou Nova Herculis 1991) \u00E9tait une nova qui survint en 1991 dans la constellation d'Hercule. Elle atteignit une magnitude minimale (correspondant \u00E0 une luminosit\u00E9 maximale) de 5,0."@fr . "V838 Herculis"@it . . . "\uD5E4\uB974\uCFE8\uB808\uC2A4\uC790\uB9AC V838\uC740 \uD5E4\uB974\uCFE8\uB808\uC2A4\uC790\uB9AC\uC5D0 \uC788\uB294 \uC2E0\uC131\uC774\uB2E4."@ko . "V838 Herculis \u00E8 una nova scoperta il 24 marzo 1991 dagli astrofili Matsuo Sugano, giapponese, e George Eric Deacon Alcock, inglese. La nova appartiene al tipo nova veloce (NB). V838 Herculis \u00E8 ritenuta una probabile nova ricorrente, ma l'appartenenza a questo tipo di nova si potr\u00E0 accertare solo dopo una nuova eventuale esplosione; le caratteristiche fisiche del sistema indicano che nel caso si trattasse davvero di una nova ricorrente essa sarebbe quasi certamente di tipo U Sco."@it . "\u6B66\u4ED9\u5EA7V838"@zh . . . "V838 Herculis eller Nova Herculis 1991 var en nova i stj\u00E4rnbilden Herkules. Novan uppt\u00E4cktes den 24 mars 1991 oberoende av varandra av M. Sugano (fotografisk uppt\u00E4ckt) och George Alcock (visuell uppt\u00E4ckt). V 838 Herculis n\u00E5dde magnitud 5,3 i maximum och avklingade sedan snabbt."@sv . . . . . . "0.4642"^^ . . "V838 Herculis"@es . . "V838 Herculis \u00E8 una nova scoperta il 24 marzo 1991 dagli astrofili Matsuo Sugano, giapponese, e George Eric Deacon Alcock, inglese. La nova appartiene al tipo nova veloce (NB). V838 Herculis \u00E8 ritenuta una probabile nova ricorrente, ma l'appartenenza a questo tipo di nova si potr\u00E0 accertare solo dopo una nuova eventuale esplosione; le caratteristiche fisiche del sistema indicano che nel caso si trattasse davvero di una nova ricorrente essa sarebbe quasi certamente di tipo U Sco."@it . "V838 Herculis"@fr . "2380033"^^ . . . . . . "V838 Herculis"@de . . . . . . . "1098712101"^^ . . "\uD5C8\uD058\uB9AC\uC2A4\uC790\uB9AC V838"@ko . "V838 Herculis es el nombre que los astr\u00F3nomos le dieron a la nova aparecida en la constelaci\u00F3n de H\u00E9cules, en 1991 y que alcanz\u00F3 un brillo de magnitud 5.0. Coordenadas: \n* Ascensi\u00F3n Recta : 18h 46m 31s.55 \n* Declinaci\u00F3n : +12\u00B0 14' 05\".0"@es . . "5.3"^^ . . "V838 Herculis"@en . . . "19.1"^^ . . . . . . . "7835"^^ . . . . "\u6B66\u4ED9\u5EA7V838\uFF08V838 Herculis\uFF09\u662F\u4E00\u9897\u4F4D\u4E8E\u6B66\u4ED9\u5EA7\u7684\u65B0\u661F\uFF0C1991\u5E74\u7206\u53D1\u3002\u7206\u53D1\u65F6\u6700\u4EAE\u89C6\u661F\u7B49\u4E3A5.0\u3002"@zh . . . . . . . . "V838 Herculis eller Nova Herculis 1991 var en nova i stj\u00E4rnbilden Herkules. Novan uppt\u00E4cktes den 24 mars 1991 oberoende av varandra av M. Sugano (fotografisk uppt\u00E4ckt) och George Alcock (visuell uppt\u00E4ckt). V 838 Herculis n\u00E5dde magnitud 5,3 i maximum och avklingade sedan snabbt."@sv . "V838 Herculis (ou Nova Herculis 1991) \u00E9tait une nova qui survint en 1991 dans la constellation d'Hercule. Elle atteignit une magnitude minimale (correspondant \u00E0 une luminosit\u00E9 maximale) de 5,0."@fr . "V838 Herculis"@sv . "V838 Herculis (auch Nova Herculis 1991) war eine Nova, die 1991 im Sternbild Herkules aufleuchtete und eine Helligkeit von 5,0 mag erreichte."@de . . . "V838 Herculis es el nombre que los astr\u00F3nomos le dieron a la nova aparecida en la constelaci\u00F3n de H\u00E9cules, en 1991 y que alcanz\u00F3 un brillo de magnitud 5.0. Coordenadas: \n* Ascensi\u00F3n Recta : 18h 46m 31s.55 \n* Declinaci\u00F3n : +12\u00B0 14' 05\".0"@es . . . . . . "0.7106"^^ . . "J2000.0"@en . "V838 Herculis (auch Nova Herculis 1991) war eine Nova, die 1991 im Sternbild Herkules aufleuchtete und eine Helligkeit von 5,0 mag erreichte."@de . . . . "\u6B66\u4ED9\u5EA7V838\uFF08V838 Herculis\uFF09\u662F\u4E00\u9897\u4F4D\u4E8E\u6B66\u4ED9\u5EA7\u7684\u65B0\u661F\uFF0C1991\u5E74\u7206\u53D1\u3002\u7206\u53D1\u65F6\u6700\u4EAE\u89C6\u661F\u7B49\u4E3A5.0\u3002"@zh . . . "V838 Herculis, also known as Nova Herculis 1991, was a nova which occurred in the constellation Hercules in 1991. It was discovered by George Alcock of Yaxley, Cambridgeshire, England at 4:35 UT on the morning of 25 March 1991. He found it with 10\u00D750 binoculars, and on that morning its apparent visual magnitude was 5 (making it visible to the naked eye). Palomar Sky Survey plates showed that before the outburst, the star was at photographic magnitude 20.6 (blue light) and 18.25 (red light)."@en .