BG Crucis

BG Crucis

A light curve for BG Crucis, plotted from Hipparcos data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Crux
Right ascension 12h 31m 40.33011s[2]
Declination −59° 25′ 26.1224″[2]
Apparent magnitude (V) 5.49[3] (5.34 - 5.58)[4]
Characteristics
Spectral type F7Ib/II[5] (F5Ib - G0p)[4]
B−V color index 0.622±0.012[3]
Astrometry
Radial velocity (Rv)−19.3±2.2[6] km/s
Proper motion (μ) RA: −12.689[2] mas/yr
Dec.: −4.110[2] mas/yr
Parallax (π)1.7777 ± 0.0873 mas[2]
Distance1,830 ± 90 ly
(560 ± 30 pc)
Absolute magnitude (MV)−2.63[3]
Details
Mass4.3[7] or 6.3±0.5[8] M☉
Radius39.30+2.82
−3.23[2] R☉
Luminosity1,033.93[3] L☉
Surface gravity (log g)2.15[7] cgs
Temperature6,253±30[7] K
Rotational velocity (v sin i)22.0±1.8[9] km/s
Age63.7±15.8[8] Myr
Other designations
BG Cru, CD−58° 4603, HD 108968, HIP 61136, HR 4768, SAO 180937, G 35 Cru[10]
Database references
SIMBADdata

BG Crucis is a suspected binary star[11] system in the southern constellation of Crux. It is visible to the naked eye as a faint yellow-white hued point of light with an apparent visual magnitude that fluctuates around 5.49.[3] The system is located at a distance of approximately 1,830 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −19 km/s.[6]

The visible component is a supergiant star that pulsates between spectral types F5Ib and G0p.[4] It is a small amplitude[12] classical Cepheid variable with an apparent magnitude ranges from 5.34 down to 5.58 over a period of 3.3428 days.[4] On the Hertzsprung–Russell diagram of temperature versus luminosity, it is located near the blue (hotter) edge of the Cepheid instability strip. Models indicate the cepheid region is relatively small in this star, so there are no shock waves produced as a result of the instability.[7]

BG Crucis is 64[8] million years old with four[7] to six[8] times the mass of the Sun. Having exhausted the supply of hydrogen at its core, it has expanded to 39[2] times the Sun's radius. It is radiating over a thousand[3] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 6,253 K.[7]

  1. ^ Cite error: The named reference HipDataAccess was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference gcvs was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference houk1979 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  7. ^ a b c d e f Cite error: The named reference usenko2014 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference AmmlerVonEiff2012 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).
  12. ^ Cite error: The named reference Stobie1970 was invoked but never defined (see the help page).