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K 1-2
K1-2 is a planetary nebula in the constellation Pyxis. It was discovered by Czech astronomer Luboš Kohoutek in 1961. The central star of the nebula—VW Pyxidis—is a Post common envelope binary, post-common-envelope binary composed of a hot degenerate star and a cooler companion in a close orbit. A best-fit calculation from its orbit and spectra yields a white dwarf-like star with around 50% of the Sun's mass and a main sequence lie star around 70% as massive as the Sun. Jets of matter are emanating from the system. One study yielded a surface temperature of 85,000 K for the hotter star. References Planetary nebulae Pyxis {{nebula-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyxis
Pyxis is a small and faint constellation in the southern sky. Abbreviated from Pyxis Nautica, its name is Latin for a mariner's compass (contrasting with Circinus, which represents a draftsman's compasses). Pyxis was introduced by Nicolas-Louis de Lacaille in the 18th century, and is counted among the 88 modern constellations. The plane of the Milky Way passes through Pyxis. A faint constellation, its three brightest stars—Alpha, Beta and Gamma Pyxidis—are in a rough line. At magnitude 3.68, Alpha is the constellation's brightest star. It is a blue-white star approximately distant and around 22,000 times as luminous as the Sun. Pyxis is located close to the stars that formed the old constellation Argo Navis, the ship of Jason and the Argonauts. Parts of Argo Navis were the Carina (the keel or hull), the Puppis (the poop deck or stern), and the Vela (the sails). These eventually became their own constellations. In the 19th century, John Herschel suggested renaming Pyx ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Nebula
A planetary nebula (PN, plural PNe) is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelated to planets. The term originates from the planet-like round shape of these nebulae observed by astronomers through early telescopes. The first usage may have occurred during the 1780s with the English astronomer William Herschel who described these nebulae as resembling planets; however, as early as January 1779, the French astronomer Antoine Darquier de Pellepoix described in his observations of the Ring Nebula, "very dim but perfectly outlined; it is as large as Jupiter and resembles a fading planet". Though the modern interpretation is different, the old term is still used. All planetary nebulae form at the end of the life of a star of intermediate mass, about 1-8 solar masses. It is expected that the Sun will form a planetary ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luboš Kohoutek
Luboš Kohoutek (, born 29 January 1935) is a Czech astronomer and a discoverer of minor planets and comets, including Comet Kohoutek which was visible to the naked eye in 1973. He also discovered a large number of planetary nebulae. Biography Kohoutek was born in 1935 to Hynek and Jarmila Kohoutek. His brother was the Czech composer Ctirad Kohoutek. Kohoutek has been interested in astronomy since high school. He studied physics and astronomy at universities in Brno and Prague (finished 1958). Then he started to work in the Astronomical Institute of Czechoslovak Academy of Sciences, where he published a well-cited catalogue (''Catalogue of Galactic Planetary Nebulae'', 1967). Kohoutek obtained a long term position at the Bergedorf Observatory in Hamburg. After the Soviet occupation of Czechoslovakia (1968) he decided to stay in West Germany (1970). His discoveries in the 1970s made him well-known in the media. In later years Kohoutek worked in observatories in Spain and Chile, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post Common Envelope Binary
A post-common envelope binary (PCEB) or pre-cataclysmic variable is a binary system consisting of a white dwarf or hot subdwarf and a main-sequence star or a brown dwarf. The star or brown dwarf shared a common envelope with the white dwarf progenitor in the red giant phase. In this scenario the star or brown dwarf loses angular momentum as it orbits within the envelope, eventually leaving a main-sequence star and white dwarf in a short-period orbit. A PCEB will continue to lose angular momentum via magnetic braking and gravitational waves and will eventually begin mass-transfer, resulting in a cataclysmic variable. While there are thousands of PCEBs known, there are only a few eclipsing PCEBs, also called ePCEBs. Even more rare are PCEBs with a brown dwarf as the secondary. A brown dwarf with a mass lower than 20 might evaporate during the common envelope phase and therefore the secondary is supposed to have a mass higher than 20 . The material ejected from the common enve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Nebulae
A planetary nebula (PN, plural PNe) is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelated to planets. The term originates from the planet-like round shape of these nebulae observed by astronomers through early telescopes. The first usage may have occurred during the 1780s with the English astronomer William Herschel who described these nebulae as resembling planets; however, as early as January 1779, the French astronomer Antoine Darquier de Pellepoix described in his observations of the Ring Nebula, "very dim but perfectly outlined; it is as large as Jupiter and resembles a fading planet". Though the modern interpretation is different, the old term is still used. All planetary nebulae form at the end of the life of a star of intermediate mass, about 1-8 solar masses. It is expected that the Sun will form a planetary nebula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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