Gamma Sagittae

γ Sagittae
Location of γ Sagittae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sagitta
Right ascension 19h 58m 45.42823s[1]
Declination +19° 29′ 31.7261″[1]
Apparent magnitude (V) +3.47[2]
Characteristics
Evolutionary stage Red giant
Spectral type M0 III[3][4][5]
U−B color index +1.93[2]
B−V color index +1.57[2]
Astrometry
Radial velocity (Rv)−34.0±0.2[6] km/s
Proper motion (μ) RA: +65.005 mas/yr[1]
Dec.: +22.72 mas/yr[1]
Parallax (π)11.3375 ± 0.1652 mas[1]
Distance288 ± 4 ly
(88 ± 1 pc)
Absolute magnitude (MV)−1.11[7]
Details
Mass0.88+0.05
−0.02 M☉[8]
0.9±0.2 M☉[9]
1.3±0.4 M☉[10]
1.77[4] M☉
Radius57.71+0.86
−0.88[11] R☉
Luminosity (bolometric)697±30[12] L☉
Surface gravity (log g)1.06±0.04[12] cgs
Temperature3,904±30[12] K
Metallicity [Fe/H]−0.26±0.06[12] dex
Age2.35[4] Gyr
Other designations
γ Sge, 12 Sagittae, BD+19° 4229, FK5 752, GC 27672, HD 189319, HIP 98337, HR 7635, SAO 105500, PPM 137344
Database references
SIMBADdata

Gamma Sagittae, Latinized from γ Sagittae, is the brightest star in northern constellation of Sagitta. A single star,[13] it is visible to the naked eye with an apparent visual magnitude of +3.47.[2] Based upon an annual parallax shift of 12.62 mas as seen from Earth, it is located about 288 light-years from the Sun.[1] It is moving closer to the Sun with a radial velocity of −34 km/s.[6]

This is a red giant star with a stellar classification of M0 III.[10][14] It is most likely (94% chance) on the red-giant branch of its evolutionary lifespan, fusing hydrogen along a shell to generate energy.[8][15] The star is around 2.35[4] billion years old with roughly 58[11] times the Sun's radius. Mass estimates range from 0.9[8][9] to 1.8[4] times the mass of the Sun. It is radiating nearly 700 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,904 K.[12]

  1. ^ 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.
  2. ^ a b c d Cite error: The named reference ducati was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference perkins was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference Luck2015 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference mk was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference famaey was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Setaiwan2004 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference stock was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Neilson2008 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Wittkowski2006 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference baines2021 was invoked but never defined (see the help page).
  12. ^ a b c d e Cite error: The named reference soubiran was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference strassmeier was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference reffert was invoked but never defined (see the help page).