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V603 Aquilae (or Nova Aquilae 1918) was a bright nova occurring in the constellation Aquila in 1918. It is a binary system, comprising a white dwarf and donor low-mass star in close orbit to the point of being only semidetached. The white dwarf sucks matter off its companion, which has filled its Roche lobe, onto its accretion disk and surface until the excess material is blown off in a thermonuclear event.〔 This material then forms an expanding shell, which eventually thins out and disappears.〔 Discovered on the night of 8 June 1918, Nova Aquilae reached a peak magnitude of −0.5; it was the brightest nova recorded in the era of the telescope. It was brighter than all stars bar Sirius and Canopus. Tycho's and Kepler's supernovae were brighter, but both occurred before the invention of the telescope. Originally a star system with a magnitude of 11.43, it took twelve days to fade three magnitudes and then 18.6 years to fade to quiescence.〔 In 1964 Robert P. Kraft ascertained that it was a binary system, recently determined to be true for several other novae at the time. The star system has settled to an average apparent magnitude of 11.4 since the 1940s, fading by around 1/100 of a magnitude per decade. Spectroscopic analysis conducted by Arenas and colleagues indicated the system consisted of a white dwarf of about 1.2 times as massive as the sun, with an accretion disk, and a companion star with about 20% of the Sun's mass.〔 This second star is most likely a red dwarf.〔 The two stars orbit each other approximately every 3 hours 20 minutes. ==References== * * (Image V603 Aquilae ) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「V603 Aquilae」の詳細全文を読む スポンサード リンク
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