Xi1 Sagittarii

For other stars with this Bayer designation, see ξ Sagittarii.
Xi1 Sagittarii
Location of ξ1 Sagittarii (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sagittarius
Right ascension 18h 57m 20.47670s[1]
Declination −20° 39′ 22.8539″[1]
Apparent magnitude (V) +5.06[2]
Characteristics
Spectral type B9/A0 Ib[3]
U−B color index −0.14[2]
B−V color index +0.12[2]
Astrometry
Proper motion (μ) RA: −1.46[1] mas/yr
Dec.: −5.75[1] mas/yr
Parallax (π)1.58 ± 0.26 mas[1]
Distanceapprox. 2,100 ly
(approx. 600 pc)
Absolute magnitude (MV)−3.92[4]
Details
Mass7.8±0.1[5] M☉
Radius15[6] R☉
Luminosity2,753[7] L☉
Surface gravity (log g)2.3[8] cgs
Temperature9,400[8] K
Metallicity [Fe/H]−0.20[8] dex
Rotational velocity (v sin i)10[9] km/s
Age39.8±4.9[5] Myr
Other designations
ξ1 Sgr, 36 Sgr, BD−20° 5339, HD 175687, HIP 93057, HR 7145, SAO 187498[10]
Database references
SIMBADdata

Xi1 Sagittarii (ξ1 Sagittarii) is a solitary,[11] blue-white hued star in the zodiac constellation of Sagittarius. It is visible to the naked eye with an apparent visual magnitude of +5.06.[2] Based upon a small annual parallax shift of 1.58 mas as seen from Earth,[1] this system is located roughly 2,100 light years from the Sun.

This is a massive supergiant star[6] with a stellar classification of B9/A0 Ib.[3] With an estimated 7.8[5] times the mass of the Sun and an age of about 40[5] million years it has depleted the hydrogen at its core, causing it to expand to about 15 times the Sun's radius.[6] It is radiating 2,753[7] times the Sun's luminosity from its photosphere at an effective temperature of about 9,400 K.[8]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference fernie1983 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Venn1995 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Soubiran2010 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Royer2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).