Luyten 726-8
Encyclopedia : L : LU : LUY : Luyten 726-8
|- style="vertical-align: top;" | B-V color index | |- style="vertical-align: top;" | U-B color index | |- style="vertical-align: top;" | Variable type |
|- ! style="background-color: #FFFFC0;" colspan="2" | Visual binary orbit |- style="vertical-align: top;" | Companion | Luyten 726-8 B |- style="vertical-align: top;" | Period (P) | 26.5 years |- style="vertical-align: top;" | Semimajor axis (a) | 1.95" |- style="vertical-align: top;" | Eccentricity (e) | 0.62 |- style="vertical-align: top;" | Inclination (i) | 127.3° |- style="vertical-align: top;" | Node (Ω) | 150.5° |- style="vertical-align: top;" | Periastron epoch (T) | 1971.91
|- ! style="background-color: #FFFFC0;" colspan="2" | Details |- |style="vertical-align: baseline;" | Mass | M☉ |- |style="vertical-align: baseline;" | Radius | R☉ |- |style="vertical-align: baseline;" | Luminosity | L☉ |- |style="vertical-align: baseline;" | Temperature | K |- |style="vertical-align: baseline;" | Metallicity | |- |style="vertical-align: baseline;" | Rotation | |- |style="vertical-align: baseline;" | Age | })<()or(}})=()and(}})<())}}} years
|- ! style="background-color: #FFFFC0;" colspan="2" | Other designations |- | colspan="2" |
Although UV Ceti was not the first flare star discovered, it is the most prominent example of such a star, and in fact flare stars are sometimes called "UV Ceti variables". It goes through fairly extreme changes of brightness: for instance, in 1952, its brightness increased by 75 times in only 20 seconds. UV Ceti is a red dwarf of spectral type M6.0e.
The other component is BL Ceti (Luyten 726-8 A), a red dwarf of spectral type M5.5e. It is also a flare star, but not nearly as remarkable or extreme in its behavior as UV Ceti.
The Luyten 726-8 star system is approximately 2.63 pc or 8.57 light-years from Earth's Solar System, in the constellation Cetus, and is thus the sixth closest star system to Earth. Its own nearest neighbour is Tau Ceti, 0.88 pc or 2.87 ly away from it.
BL Ceti (Luyten 726-8 A) is also catalogued as G 272-061.
Discovery
The star system was discovered in 1948 by Willem Jacob Luyten in the course of compiling a catalogue of stars of high proper motion; he noted its exceptionally high proper motion of 3.37 arcsec annually and catalogued it as Luyten 726-8. Soon after it was discovered that the fainter B component of this system was a flare star, and it was accordingly given the variable star designation UV Ceti.See also
External links
- [AJ 55 (1949) 15] (Luyten discovers the high proper motion of Luyten 726-8)
- [AJ 109 (1949) 532–537] (in depth article)
- http://www.aavso.org/vstar/vsots/fall03.shtml
- http://www.solstation.com/stars/luy726-8.htm
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