GJ 3685

GJ 3685
Observation data
Epoch J2000      Equinox J2000
Constellation Leo
Right ascension 11h 47m 40.74723s[1]
Declination +00° 15′ 20.1018″[1]
Apparent magnitude (V) 13.34[2]
Characteristics
Spectral type M4V[3]
V−R color index +1.22[4]
R−I color index +1.55[4]
Variable type Flare star
Astrometry
Radial velocity (Rv)7.02 ± 0.32[5] km/s
Proper motion (μ) RA: −314.284 mas/yr[1]
Dec.: −100.757 mas/yr[1]
Parallax (π)53.1361 ± 0.0304 mas[1]
Distance61.38 ± 0.04 ly
(18.82 ± 0.01 pc)
Details
Surface gravity (log g)4.5[6] cgs
Temperature3100[6] K
Metallicity0.23[3]
Rotational velocity (v sin i)5.60 ± 1.40[5] km/s
Other designations
LP 613-49, LTT 13239, G 10-49, G 11-21[7]
Database references
SIMBADdata
ARICNSdata

GJ 3685 is a star in the constellation of Leo. It is extremely faint; its apparent magnitude is 13.3,[2] and can only be seen with a ten-inch (25 cm) telescope (see Limiting magnitude). Based on a parallax of 53.1361 milliarcseconds,[1] the system is located 61.4 light-years (18.8 parsecs) away from the Earth.

This is a part of a binary star system consisting of two components separated by 24″.[8] The primary component, GJ 3685 (also known as GJ 3685 A), is a very old red dwarf that is also a flare star. A 20-minute flare was observed in 2004 by the GALEX satellite.[9] Its companion, GJ 3686, is another faint red dwarf with a spectral type of M5. It is also known as LP 613-50 and is also located roughly the same distance as its primary.[10]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference UCAC4 was invoked but never defined (see the help page).
  3. ^ a b Newton, Elisabeth R. (2014). "Near-infrared Metallicities, Radial Velocities, and Spectral Types for 447 Nearby M Dwarfs". The Astronomical Journal. 147 (1): 20. arXiv:1310.1087. Bibcode:2014AJ....147...20N. doi:10.1088/0004-6256/147/1/20. S2CID 26818462.
  4. ^ a b "N1 990 A". ARICNS. Centre of Astronomy, Heidelberg University. 5 November 1998. Retrieved 21 March 2017.
  5. ^ a b Cite error: The named reference Deshpande was invoked but never defined (see the help page).
  6. ^ a b Lépine, Sébastien (2013). "A Spectroscopic Catalog of the Brightest (J < 9) M Dwarfs in the Northern Sky". The Astronomical Journal. 145 (4): 102. arXiv:1206.5991. Bibcode:2013AJ....145..102L. doi:10.1088/0004-6256/145/4/102. S2CID 117144290.
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ "N1 990 B". ARICNS. Centre of Astronomy, Heidelberg University. 5 November 1998. Retrieved 21 March 2017.
  9. ^ Robinson, Richard D.; Wheatley, Jonathan M.; Welsh, Barry Y.; Forster, Karl; Morrissey, Patrick; Seibert, Mark; Rich, R. Michael; Salim, Samir; Barlow, Tom A.; Bianchi, Luciana; Byun, Yong-Ik; Donas, Jose; Friedman, Peter G.; Heckman, Timothy M.; Jelinsky, Patrick N.; Lee, Young-Wook; Madore, Barry F.; Malina, Roger F.; Martin, D. Christopher; Milliard, Bruno; Neff, Susan G.; Schiminovich, David; Siegmund, Oswald H. W.; Small, Todd; Szalay, Alex S.; Wyder, Ted K. (2005). "GALEX Observations of an Energetic Ultraviolet Flare on the dM4e Star GJ 3685A". The Astrophysical Journal. 633 (1): 447–51. arXiv:astro-ph/0507396. Bibcode:2005ApJ...633..447R. doi:10.1086/444608. S2CID 14054351.
  10. ^ Phan-Bao, N.; Bessell, M. S. (2006). "Spectroscopic distances of nearby ultracool dwarfs". Astronomy and Astrophysics. 446 (2): 515–523. arXiv:astro-ph/0509321. Bibcode:2006A&A...446..515P. doi:10.1051/0004-6361:20054064. S2CID 18565840.