15 Sagittarii

15 Sagittarii
Observation data
Epoch J2000      Equinox J2000
Constellation Sagittarius
Right ascension 18h 15m 12.90641s[1]
Declination −20° 43′ 41.7738″[1]
Apparent magnitude (V) 5.37[2]
Characteristics
Spectral type O9.7 Iab[3] or B0 Iab[4]
B−V color index 0.007±0.004[5]
Astrometry
Radial velocity (Rv)−6.3±2.8[6] km/s
Proper motion (μ) RA: +1.60[1] mas/yr
Dec.: −1.51[1] mas/yr
Parallax (π)0.10 ± 0.45 mas[1]
Distance4,200±650[7] ly
(1,300±200 pc)
Details[8]
15 Sgr Aa
Mass~30[4] M☉
Radius28.6±12.5 R☉
Luminosity4.47+3.85
−2.07×105 L☉
Surface gravity (log g)3.10 cgs
Temperature28,000±1,000 K
Rotational velocity (v sin i)83±7[4] km/s
Other designations
15 Sgr, BD−20° 5054, HD 167264, HIP 89439, HR 6822, SAO 186543, WDS J18152-2044[9]
Database references
SIMBADdata

15 Sagittarii is a blue-hued binary star[10] system in the southern zodiac constellation of Sagittarius. The estimated distance based upon photometry is around 4,200 ly (1,300 pc).[7] It is faintly visible to the naked eye with an apparent visual magnitude of 5.37.[2] The system is moving closer to the Sun with a heliocentric radial velocity of around −6 km/s.[6]

Chini et al. (2012) identify this as a double-lined spectroscopic binary star system.[10] It shows a stellar classification of O9.7 Iab,[3] matching a massive O-type supergiant star. Along with the O-type star 16 Sgr (HD 167263), it is ionizing an H II region along the western edge of the molecular cloud L291.[11]

The Washington Double Star Catalog lists four companions within a 2 arcsecond angular radius.[12]

  1. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference ducati was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference gosss was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Fraser2010 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Kemp1996 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Martins2015 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Chini2012 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Marti1993 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Sana2014 was invoked but never defined (see the help page).