Gliese 105

Gliese 105 A/B/C

Observation data Epoch J2000      Equinox J2000
Constellation	Cetus
Right ascension	A: 02^h 36^m 04.89^s[1] B: 02^h 36^m 15.0^s C: 02^h 35^m 58.8^s
Declination	A: +06° 53′ 12.7″[1] B: +06° 52′ 18″ C: +06° 52′ 00″
Apparent magnitude (V)	5.82/11.66/16.9
Characteristics
Spectral type	K3 V/M3.5 Vn/M7 V
U−B color index	0.81/1.12
B−V color index	0.97/1.60
Variable type	None/BY Draconis
Astrometry
Radial velocity (Rv)	25.7 km/s
Proper motion (μ)	RA: 1807.78 ± 0.89[1] mas/yr Dec.: 1444.02 ± 0.40[1] mas/yr
Parallax (π)	139.27 ± 0.45[1] mas
Distance	23.42 ± 0.08 ly (7.18 ± 0.02 pc)
Absolute magnitude (MV)	6.49/12.34/17.58
Details
Mass	0.81/0.21/0.08 M☉
Radius	0.650 ± 0.053[2]/0.28 R☉
Luminosity	0.21/0.0001/0.0000075 L☉
Temperature	4,841[3] K
Metallicity	85.11%[3]/ ? Z☉
Rotation	?
Age	4.8-6.6 (Sun=4.6) ×10^9 years
Other designations
268 G. Ceti, BX Ceti (B only), Gl 105, HR 753, BD +06°398, HD 16160, LHS 15/16, LTT 10858/10859, GCTP 520.00, SAO 110636, FK5 1073, G 73-70/71, G 76-11/12, LFT 217/218, HIP 12114.
Database references
SIMBAD	data

Gliese 105.

Gliese 105 (also known as 268 G. Ceti) is a triple star system in the constellation of Cetus. It is located relatively near the Sun at an estimated distance of less than 24 light years,^[1] but even the brightest component is too faint to see directly with the unaided eye. No planets have yet been detected around any of the stars in this system.

The companion star B has a common proper motion with A, and the two have an estimated separation of 1,200 AUs. It is a BY Draconis variable star that has been given the designation "BX Ceti".

The third companion C lies much closer to A, at a distance of approximately 24 AU. The pair A-C have an estimated orbital period of 61 years. Component C is a relatively minuscule star that lies at the low end of the mass range needed to achieve nuclear fusion.

References

1. van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
2. van Belle, Gerard T.; von Braun, Kaspar (2009). "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars". The Astrophysical Journal 694 (2): 1085–1098. arXiv:0901.1206. Bibcode:2009ApJ...694.1085V. doi:10.1088/0004-637X/694/2/1085.
3. Soubiran, C.; Bienaymé, O.; Mishenina, T. V.; Kovtyukh, V. V. (2008). "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants". Astronomy and Astrophysics 480 (1): 91–101. arXiv:0712.1370. Bibcode:2008A&A...480...91S. doi:10.1051/0004-6361:20078788.

External links

• Gliese 105 / HR 753 ABC SolStation entry.
• Hubble Spies a Really Cool Star
• Gliese 105