Beta Sagittae

β Sagittae
Location of β Sagittae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sagitta
Right ascension 19h 41m 02.93907s[1]
Declination +17° 28′ 33.7528″[1]
Apparent magnitude (V) 4.38[2]
Characteristics
Spectral type G8 IIIa CN 0.5[3]
U−B color index +0.89[4]
B−V color index +1.05[4]
R−I color index +0.50[4]
Astrometry
Radial velocity (Rv)−22.0±0.3[5] km/s
Proper motion (μ) RA: 7.682 ± 0.258[6] mas/yr
Dec.: −32.987 ± 0.279[6] mas/yr
Parallax (π)7.7237 ± 0.1941 mas[6]
Distance420 ± 10 ly
(129 ± 3 pc)
Absolute magnitude (MV)−1.39+0.22
−0.20[7]
Details
Mass4.33[8] M☉
Radius27±3[9] R☉
Luminosity392[10] L☉
Surface gravity (log g)2.79[7] cgs
Temperature4,850[7] K
Metallicity [Fe/H]–0.03[7] dex
Rotational velocity (v sin i)9.1±0.7[7] km/s
Age129[11] Myr
Other designations
β Sge, 6 Sagittae, BD+17°4048, FK5 1513, GC 27236, HD 185958, HIP 96837, HR 7488, SAO 105133, PPM 136766[12]
Database references
SIMBADdata

Beta Sagittae, Latinized from β Sagittae, is a single[13] star in the northern constellation of Sagitta. It is a faint star but visible to the naked eye with an apparent visual magnitude of 4.38.[2] Based upon an annual parallax shift of 7.7237 mas as seen from the Gaia satellite, it is located 420 light years from the Sun. The star is moving closer to the Sun with a radial velocity of −22 km/s.[5]

This is an evolved red giant[11] with a stellar classification of G8 IIIa CN 0.5.[3] The suffix notation indicates a mild overabundance of the cyanogen molecule in the spectrum. Beta Sagittae is an estimated 129 million years old with 4.33 times the mass of the Sun,[8] and has expanded to roughly 27 times the Sun's radius.[9] The star is radiating 392[10] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,850 K.[7]

  1. ^ a b Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Fernie1983 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Keenan1989 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference bsc1 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  7. ^ a b c d e f Cite error: The named reference aj135_3_892 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Liu2014 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference vanBelle2009 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference takeda14 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference SIMBAD 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).