Beta Sextantis

β Sextantis

A light curve for Beta Sextantis, plotted from TESS data,[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sextans
Right ascension 10h 30m 17.48s[2]
Declination −00° 38′ 13.30″[2]
Apparent magnitude (V) 5.07[3]
Characteristics
Spectral type B6 V[4] or B5 IV/V[5]
U−B color index −0.51[3]
B−V color index −0.14[3]
Variable type α2 CVn[6]
Astrometry
Radial velocity (Rv)11.6±2.8[7] km/s
Proper motion (μ) RA: −38.805[2] mas/yr
Dec.: −24.290[2] mas/yr
Parallax (π)8.9613 ± 0.2448 mas[2]
Distance364 ± 10 ly
(112 ± 3 pc)
Absolute magnitude (MV)−0.38[8]
Details
Radius3.2[9] R☉
Luminosity184[10] L☉
Surface gravity (log g)4.21[11] cgs
Temperature14,570[11] K
Metallicity [Fe/H]0.19[11] dex
Rotational velocity (v sin i)85±4[11] km/s
Other designations
β Sex, 30 Sextantis, BD+00° 2663, FK5 2841, HD 90994, HIP 51437, HR 4119, SAO 137608.[12]
Database references
SIMBADdata

Beta Sextantis, Latinized from β Sextantis, is a variable star in the equatorial constellation of Sextans. With an apparent visual magnitude of 5.07,[3] it is faintly visible to the naked eye on a dark night. According to the Bortle scale, it can be viewed from brighter lit suburban skies. The distance to this star, based upon an annual parallax shift of 8.96 mas,[2] is around 364 light years.

This star served as a primary standard in the MK spectral classification system with a stellar classification of B6 V,[4] indicating that it is a B-type main sequence star. However, Houk and Swift (1999) list a classification of B5 IV/V, suggesting it may be transitioning into a subgiant star.[5] It has served as a uvby photometric standard, but is also categorized as an Alpha2 Canum Venaticorum variable[6] with a suspected period of 15.4 days. This lengthy a period conflicts with a relatively high projected rotational velocity of 85 km/s, leaving the explanation for the variance unresolved.[11][4]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Crawford1971 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Mathys1986 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference houk1999 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Kholopov1989 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  11. ^ a b c d e Cite error: The named reference Hempel2003 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).