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GJ 1245

Coordinates: Sky map 19h 53m 54.492s, +44° 24′ 53.41″
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(Redirected from G 208-44/208-45)
V1581 Cygni
GJ 1245 is located in the constellation Cygnus.
GJ 1245 is located in the constellation Cygnus.
GJ 1245
Location of GJ 1245 in the constellation Cygnus

Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
GJ 1245 AC
Right ascension 19h 53m 55.142s[1]
Declination +44° 24′ 44.39″[1]
Apparent magnitude (V) 13.46 / 16.75[2]
GJ 1245 B
Right ascension 19h 53m 55.141s[3]
Declination +44° 24′ 54.15″[3]
Apparent magnitude (V) 14.01[2]
Characteristics
Spectral type M6V / M8V[4] / M6V[5]
Variable type UV Cet[6]
Astrometry
Radial velocity (Rv)3.93±0.38[3] km/s
Proper motion (μ) RA: 349.363(56) mas/yr[3]
Dec.: −480.322(54) mas/yr[3]
Parallax (π)214.5745±0.0476 mas[3]
Distance15.200 ± 0.003 ly
(4.660 ± 0.001 pc)
Absolute magnitude (MV)15.12 / 18.41[4] / 15.72[2]
Orbit[7]
PrimaryGJ 1245 A
CompanionGJ 1245 C
Period (P)6147±17 d
Semi-major axis (a)0.8267±0.0008″
Eccentricity (e)0.334±0.002
Inclination (i)135.7±0.1°
Longitude of the node (Ω)261.2±0.2°
Periastron epoch (T)51506.8±2.1
Argument of periastron (ω)
(secondary)		36.1±0.2°
Details
GJ 1245 A
Mass0.120±0.001[4] M☉
Radius0.146±0.007[4] R☉
Luminosity0.0014[4] L☉
Temperature2,927[4] K
Metallicity [Fe/H]−0.07[4] dex
Age~300[citation needed] Myr
GJ 1245 C
Mass0.081±0.001[4] M☉
Radius0.087±0.004[4] R☉
Luminosity0.0003[4] L☉
Temperature2,611[4] K
Metallicity [Fe/H]−0.08[4] dex
GJ 1245 B
Mass0.115[8] M☉
Radius0.142[8] R☉
Luminosity0.00123[8] L☉
Surface gravity (log g)5.20[8] cgs
Temperature2.865[8] K
Metallicity [Fe/H]−0.05[9] dex
Rotation0.71[10] days
Rotational velocity (v sin i)7[10] km/s
Age3.1[9] Gyr
Other designations
V1581 Cyg, GJ 1245, WDS J19539+4425
GJ 1245 AC: G 208-44, LHS 3494, NLTT 48414, KIC 8451868, 2MASS J19535443+4424541[11]
GJ 1245 B: G 208-45, LHS 3495, NLTT 48415, KIC 8451881, 2MASS J19535508+4424550[5]
Database references
AC
B
Blue band light curve for a flare of V1581 Cygni. The left-most point shows a 1 sigma error bar. Adapted from Cristaldi and Rodonò (1976)[12]

GJ 1245 (Gliese 1245) is a double star with components G 208-44 and G 208-45, located 15.2 light-years (4.7 parsecs) away in the constellation Cygnus. 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 43rd closest stellar system to the Solar System.[13] GJ 1245 A and B are both active flare stars,[14] and the pair are collectively designated V1581 Cygni.[15]

The largest of the three stars, GJ 1245 A (G 208-44 A) is only 12% the Sun's mass.[4] Of the other two stars, GJ 1245 C (G 208-44 B), is closest to star A at 2 AU away;[16] it is 8% of the Sun's mass.[4] The third star, GJ 1245 B (G 208-45), is 27 AU away from star A,[16] and is estimated to complete an orbit every 279 years.[17] It is slightly smaller and less luminous than GJ 1245 A.[8]

See also

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References

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  1. ^ a b Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c "The One Hundred Nearest Star Systems". RECONS. Retrieved 2016-08-21.
  3. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  4. ^ a b c d e f g h i j k l m n Dieterich, Serge B.; Simler, Andrew; Henry, Todd J.; Jao, Wei-Chun (April 2021). "The Solar Neighborhood. XLVII. Comparing M-dwarf Models with Hubble Space Telescope Dynamical Masses and Spectroscopy". The Astronomical Journal. 161 (4): 172. arXiv:2012.00915. Bibcode:2021AJ....161..172D. doi:10.3847/1538-3881/abd2c2.
  5. ^ a b "G 208-45". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 11 June 2024.
  6. ^ 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.
  7. ^ Benedict, G. F.; Henry, T. J.; et al. (November 2016). "The Solar Neighborhood. XXXVII: The Mass-Luminosity Relation for Main-sequence M Dwarfs". The Astronomical Journal. 152 (5): 141. arXiv:1608.04775. Bibcode:2016AJ....152..141B. doi:10.3847/0004-6256/152/5/141.
  8. ^ a b c d e f Stassun, Keivan G.; et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467.
  9. ^ a b Mann, Andrew W.; Feiden, Gregory A.; Gaidos, Eric; Boyajian, Tabetha; von Braun, Kaspar (2015). "How to Constrain Your M Dwarf: Measuring Effective Temperature, Bolometric Luminosity, Mass, and Radius". The Astrophysical Journal. 804 (1): 64. arXiv:1501.01635. Bibcode:2015ApJ...804...64M. doi:10.1088/0004-637X/804/1/64.
  10. ^ a b Morin, J.; Donati, J. -F.; Petit, P.; Delfosse, X.; Forveille, T.; Jardine, M. M. (2010). "Large-scale magnetic topologies of late M dwarfs". Monthly Notices of the Royal Astronomical Society. 407 (4): 2269. arXiv:1005.5552. Bibcode:2010MNRAS.407.2269M. doi:10.1111/j.1365-2966.2010.17101.x.
  11. ^ "G 208-44". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 11 June 2024.
  12. ^ Cristaldi, S.; Rodonò, M. (April 1976). "Discovery of Flare Activity in the Visual Binary G 208-44/45". Astronomy and Astrophysics. 48: 165. Bibcode:1976A&A....48..165C.
  13. ^ Reylé, Céline; Jardine, Kevin; Fouqué, Pascal; Caballero, Jose A.; Smart, Richard L.; Sozzetti, Alessandro (30 April 2021). "The 10 parsec sample in the Gaia era". Astronomy & Astrophysics. 650: A201. arXiv:2104.14972. Bibcode:2021A&A...650A.201R. doi:10.1051/0004-6361/202140985. S2CID 233476431. Data available at https://gruze.org/10pc/ Archived 12 March 2023 at the Wayback Machine
  14. ^ 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.
  15. ^ 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.
  16. ^ a b Salama, Maïssa; Ou, James; et al. (September 2021). "Large Adaptive Optics Survey for Substellar Objects around Young, Nearby, Low-mass Stars with Robo-AO". The Astronomical Journal. 162 (3): 102. arXiv:2105.13364. Bibcode:2021AJ....162..102S. doi:10.3847/1538-3881/ac0445.
  17. ^ Tokovinin, Andrei (2018). "The Updated Multiple Star Catalog". The Astrophysical Journal Supplement Series. 235 (1): 6. arXiv:1712.04750. Bibcode:2018ApJS..235....6T. doi:10.3847/1538-4365/aaa1a5.

Further reading

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