GJ 1245

GJ 1245 (Gliese 1245) is a double star with components G 208-44 and G 208-45, 14 light-years away, relatively close to the Solar System. G 208-44 is itself a closer double star made up of two red dwarfs, while G 208-45 is also a red dwarf. GJ 1245 is the 37th closest stellar system to the Solar System, located in the constellation Cygnus.[3] GJ 1245 A and B are active flare stars,[4] and the pair are collectively designated V1581 Cygni.[5]

V1581 Cygni

Observation data Epoch J2000      Equinox J2000
Constellation	Cygnus
Right ascension	19^h 53^m 54.492^s
Declination	+44° 24′ 53.41″
Apparent magnitude (V)	13.41 / 14.01 / 16.75
Characteristics
Spectral type	M5.5 / M6 / M5.5
Variable type	UV Cet[1]
Astrometry
Proper motion (μ)	RA: 397 mas/yr Dec.: −482 mas/yr
Parallax (π)	220.2 ± 1.0[2] mas
Distance	14.81 ± 0.07 ly (4.54 ± 0.02 pc)
Absolute magnitude (MV)	15.31 / 15.72 / 18.46
Details
Luminosity	0.000084 / 0.000048 L☉
Age	~300 Myr
Other designations
GJ 1245, WDS J19539+4425, V1581 Cygni
G 208-44: NLTT 48414, LHS 3494, 2MASS J19535443+4424541
G 208-45: NLTT 48415, LHS 3495, 2MASS J19535508+4424550
Database references
SIMBAD	The system
	A
	C
	B

The largest of the three stars, G208-44 A (GJ 1245 A) is only 11% the Sun's mass. Of the other two stars, G 208-44 B (GJ 1245 C), is closest to star A at 8 AU away; it is 7% of the Sun's Mass. The third star, GJ 1245 B, is 33 AU away from star A, and is 10% of the Sun's Mass; it would appear as bright as Venus does from Earth when viewed from star A.

See also

• List of nearest stars

References

1. Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
2. Van Altena W. F.; Lee J. T.; Hoffleit E. D. (1995). "GCTP 2835.01". The General Catalogue of Trigonometric Stellar Parallaxes (Fourth ed.).
3. "The One Hundred Nearest Star Systems". RECONS. Retrieved 2016-08-21.
4. Lurie, John C.; Davenport, James R. A.; Hawley, Suzanne L.; Wilkinson, Tessa D.; Wisniewski, John P.; Kowalski, Adam F.; Hebb, Leslie (2015). "Kepler Flares III: Stellar Activity on GJ 1245A and B". The Astrophysical Journal. 800 (2): 95. arXiv:1412.6109. Bibcode:2015ApJ...800...95L. doi:10.1088/0004-637X/800/2/95. S2CID 51773906.
5. Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (1978). "63rd Name-List of Variable Stars". Information Bulletin on Variable Stars. 1414: 1. Bibcode:1978IBVS.1414....1K.

Further reading

• Harrington, R. S.; Dahn, C. C.; Kallarakal, V. V.; Guetter, H. H.; Riepe, B. Y.; Walker, R. L.; Pier, J. R.; Vrba, F. J.; Luginbuhl, C. B.; Harris, H. C.; Ables, H. D. (1993). "U.S. Naval Observatory photographic parallaxes - List IX". Astronomical Journal. 105 (4): 1571–1580. Bibcode:1993AJ....105.1571H. doi:10.1086/116537.
• Henry, Todd J.; Subasavage, John P.; Brown, Misty A.; Beaulieu, Thomas D.; Jao, Wei-Chun; Hambly, Nigel C. (2004). "The Solar Neighborhood. X. New Nearby Stars in the Southern Sky and Accurate Photometric Distance Estimates for Red Dwarfs". The Astronomical Journal. 128 (5): 2460–2473. arXiv:astro-ph/0408240. Bibcode:2004AJ....128.2460H. doi:10.1086/425052. S2CID 15759789.
• Smart, R. L.; Ioannidis, G.; Jones, H. R. A.; Bucciarelli, B.; Lattanzi, M. G. (2010). "Cool dwarfs stars from the Torino Observatory Parallax Program". Astronomy and Astrophysics. 514: A84. arXiv:1003.1465. Bibcode:2010A&A...514A..84S. doi:10.1051/0004-6361/200913424. S2CID 17961025.
• Dittmann, Jason A.; Irwin, Jonathan M.; Charbonneau, David; Berta-Thompson, Zachory K. (2014). "Trigonometric Parallaxes for 1507 Nearby Mid-to-late M Dwarfs". The Astrophysical Journal. 784 (2): 156. arXiv:1312.3241. Bibcode:2014ApJ...784..156D. doi:10.1088/0004-637X/784/2/156. S2CID 18789867. Table with parallaxes.

External links

• http://jumk.de/astronomie/near-stars/v1581-cygni.shtml
• http://www.answers.com/topic/list-of-nearest-stars?cat=travel
• http://www.richweb.f9.co.uk/astro/nearby_stars.htm