1 Scorpii

This article is about b Scorpii. Not to be confused with β Scorpii.
1 Scorpii
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Scorpius
Right ascension 15h 50m 58.74452s[1]
Declination −25° 45′ 04.6649″[1]
Apparent magnitude (V) 4.63[2]
Characteristics
Spectral type B1.5 Vn[3]
B−V color index −0.072±0.003[2]
Astrometry
Radial velocity (Rv)−3.0±4.7[4] km/s
Proper motion (μ) RA: −14.20[1] mas/yr
Dec.: −25.12[1] mas/yr
Parallax (π)6.59 ± 0.27 mas[1]
Distance490 ± 20 ly
(152 ± 6 pc)
Absolute magnitude (MV)−1.27[2]
Details
Mass8.3±0.2[5] M☉
Radius3.7[6] R☉
Luminosity3,890[6] L☉
Temperature24,000[6] K
Rotational velocity (v sin i)310[7] km/s
Age10.3±5.3[5] Myr
Other designations
b Sco, 1 Sco, CD−25° 11131, HD 141637, HIP 77635, HR 5885, SAO 183854[8]
Database references
SIMBADdata

1 Scorpii, or b Scorpii, is a single[9] star in the southern zodiac constellation of Scorpius. It has an apparent magnitude of 4.63,[2] which is bright enough to be faintly visible to the naked eye on a dark night. The star shows an annual parallax shift of 6.59 mas from Earth's orbit, which equates to a distance of roughly 490 light years. It is a probable (89% chance) member of the Sco OB2 moving group.[10][9]

This is a B-type main-sequence star with a stellar classification of B1.5 Vn,[3] where the 'n' suffix indicates "nebulous" absorption lines being induced by rapid rotation. It has a projected rotational velocity of 310 km/s, which is giving the star an oblate shape with an equatorial bulge that is 13% wider than the polar radius.[7] There is some weak evidence that this is a Be star with a gaseous disk that is being viewed edge-on.[11]

1 Scorpii is a young star at around 10[5] million years old, with 8.3[5] times the mass of the Sun and 3.7 times the Sun's radius.[6] The star is radiating 3,890 times the Sun's luminosity from its photosphere at an effective temperature of about 24,000 K.[6]

  1. ^ a b c d e 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 Anderson2012 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 deBruijne2012 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 d e Cite error: The named reference hernandez2005 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference belle2012 was invoked but never defined (see the help page).
  8. ^ "b Sco". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-21.
  9. ^ a b Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Rizzuto2011 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Rivinius2006 was invoked but never defined (see the help page).