HD 197630

HD 197630
HD 197630 is the star circled in red
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Microscopium
Right ascension 20h 46m 20.06779s[1]
Declination −39° 11′ 57.3590″[1]
Apparent magnitude (V) 5.47±0.01[2]
Characteristics
Evolutionary stage main sequence star[3]
Spectral type B8/9 V[4]
B−V color index −0.10[5]
Variable type suspected SPB[6]
Astrometry
Radial velocity (Rv)−30±7.4[7] km/s
Proper motion (μ) RA: +50.451 mas/yr[1]
Dec.: −27.196 mas/yr[1]
Parallax (π)9.9354 ± 0.1022 mas[1]
Distance328 ± 3 ly
(101 ± 1 pc)
Absolute magnitude (MV)+0.49[8]
Details
Mass2.83±0.04[3] M☉
Radius2.56±0.13[9] R☉
Luminosity73.5[10] L☉
Surface gravity (log g)4.11±0.14[11] cgs
Temperature10,965+255
−250[12] K
Metallicity59% solar
Metallicity [Fe/H]−0.23[13] dex
Rotational velocity (v sin i)290[14] km/s
Age113[11] Myr
Other designations
23 G. Microscopii[15], CD−39°13960, CPD−39°8771, FK5 3658, GC 28927, HD 197630, HIP 102497, HR 7933, SAO 212416[16]
Database references
SIMBADdata

HD 197630, also known as HR 7933 or rarely 23 G. Microscopii, is a probable astrometric binary located in the southern constellation Microscopium. The visible component is a bluish-white hued star that is faintly visible to the naked eye with an apparent magnitude of 5.47.[2] Based on parallax measurements from the Gaia satellite, the system is estimated to be 328 light years away.[1] However, it is drifting closer with a heliocentric radial velocity of −30 km/s. At its current distance, HD 197630's brightness is diminished by 0.11 magnitudes due to interstellar dust.[17] A 2012 multiplicity survey failed to confirm the velocity variations.[18]

HD 197630 has a stellar classification of B8/9 V,[4] indicating that it is a B-type star with the characteristics of a B8 and B9 main sequence star. It has 2.83 times the mass of the Sun[3] and 2.56 times the Sun's radius. It radiates 73.5 times the luminosity of the Sun[10] from its photosphere at an effective temperature of 10,965 K.[12] The star is estimated to be 113 million years old,[11] having completed roughly half of its main sequence lifetime.[3] HD 19730 is spinning rapidly with a projected rotational velocity of 290 km/s.[14]

A light curve for HD 197630, plotted from TESS data[19]

The object was in a 2002 Hipparcos variability survey and as a result,[20] the AAVSO cataloged HD 197630 as a suspected variable star that fluctuates by 0.005 magnitudes within 7.71 hours.[21] However, subsequent observations have not confirmed this. Further data from the Transiting Exoplanet Survey Satellite suggests that HD 197630 may be a slowly pulsating B-type star plus a variable star with rotation modulations.[6]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Zorec2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1982 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Corben1971 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Pedersen2019 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Kharchenko2007 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 Kervella2004 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  11. ^ a b c Cite error: The named reference David2015 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference AP1999 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Anders2019 was invoked but never defined (see the help page).
  14. ^ a b Cite error: The named reference Levato2004 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).
  18. ^ Cite error: The named reference Chini2012 was invoked but never defined (see the help page).
  19. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  20. ^ Cite error: The named reference Koen2002 was invoked but never defined (see the help page).
  21. ^ Cite error: The named reference AASVO was invoked but never defined (see the help page).