Luyten 726-8

Starbox begin
name=Luyten 726-8 A/B Starbox observe
epoch=J2000
constell=Cetus
ra=01h 39m 01.3s
dec=-17° 57' 01"
appmag_v=12.54/12.99 Starbox character
class=M5.5 V/M6 V
b-v=1.87/?
u-b=1.10/?
variable=Flare stars Starbox astrometry
radial_v=+29.0
prop_mo_ra=3321
prop_mo_dec=562
parallax=373.70
p_error=2.70
absmag_v=14.92/15.37 Starbox visbin
name=Luyten 726-8 B
period=26.5
axis=1.95
eccentricity=0.62
inclination=127.3
node=150.5
periastron=1971.91 Starbox detail
mass=0.10/0.10
radius=0.14/0.14
luminosity=0.00006/0.00004 | temperature=2,670
metal=
rotation=
age="?"/"?" Starbox catalog
names=BL Ceti/UV Ceti, GCTP 343.10 A/B, LHS 9/10, GJ 65 A/B

Luyten 726-8 is a binary star system that is one of Earth's nearest neighbors, the closest star in the constellation Cetus. One of its components is the well-known flare star UV Ceti (Luyten 726-8 B).

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 two stars are of nearly equal brightness, with visual magnitudes of 15.3 and 15.8 as seen from Earth. They orbit one another every 26.5 years. The distance between the two stars varies from 2.1 to 8.8 Astronomical units. Luyten 726-8 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.

ee also

* List of nearest stars

External links

* [http://adsabs.harvard.edu//full/seri/AJ.../0055//0000015.000.html AJ 55 (1949) 15] (Luyten discovers the high proper motion of Luyten 726-8)
* [http://adsabs.harvard.edu//full/seri/ApJ../0109//0000532.000.html AJ 109 (1949) 532–537] (in depth article)
* http://www.aavso.org/vstar/vsots/fall03.shtml
* http://www.solstation.com/stars/luy726-8.htm