HD 196737

HD 196737
Location of HD 196737 (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Microscopium
Right ascension 20h 40m 19.82792s[1]
Declination −33° 25′ 54.6462″[1]
Apparent magnitude (V) 5.47±0.01[2]
Characteristics
Evolutionary stage red giant branch[3]
Spectral type K1 III[4]
U−B color index +1.08[5]
B−V color index +1.12[5]
Astrometry
Radial velocity (Rv)14.2±2.8[6] km/s
Proper motion (μ) RA: +21.953 mas/yr[1]
Dec.: +34.487 mas/yr[1]
Parallax (π)13.5581 ± 0.0691 mas[1]
Distance241 ± 1 ly
(73.8 ± 0.4 pc)
Absolute magnitude (MV)+1.17[7]
Details
Mass1.4±0.1[8] M☉
Radius11.5[9] R☉
Luminosity43.7+3.1
−2.9[10] L☉
Surface gravity (log g)2.46±0.34[11] cgs
Temperature4,681±122[12] K
Metallicity [Fe/H]−0.02[13] dex
Rotational velocity (v sin i)<1[14] km/s
Age3.4±0.6[8] Gyr
Other designations
13 G. Microscopii[15], CD−33°15119, CPD−33°5922, FK5 1540, GC 28776, HD 196737, HIP 102014, HR 7893, SAO 212333[16]
Database references
SIMBADdata

HD 196737, also designated as HR 7893, is a solitary orange hued star[17] located in the southern constellation Microscopium. It has an apparent magnitude of 5.47,[2] allowing it to be faintly visible to the naked eye. The object is located relatively close at a distance of 241 light years based on Gaia DR3 parallax measurements,[1] but is receding with a heliocentric radial velocity of 14.2 km/s.[6] At its current distance, HD 196737's brightness is diminished by 0.14 magnitudes due to interstellar dust.[18] It has an absolute magnitude of 1.17.[7]

This is an evolved giant star with a stellar classification of K1 III.[4] HD 196737 is estimated to be 3.4 billion years old based on asteroseismologic measurements,[8]enough for it to cool and expand onto the red giant branch; it is now fusing a hydrogen shell around an inert helium core.[3] It has 1.4 time the mass of the Sun[8] and an enlarged radius of 11.5 R☉.[9] It radiates 43.7 times the luminosity of the Sun[10] from its photosphere at an effective temperature of 4,681 K.[12] HD 196737 has a solar metallicity — what astronomers dub chemical elements heavier than helium. The star has a projected rotational velocity too low to be measured accurately.[14]

  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 Cite error: The named reference Jones2011 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. ^ a b Cite error: The named reference Oja1970 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Aguirre2020 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Kervella2004 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Charbonnel2020 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference AP1999 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference McWilliam1990 was invoked but never defined (see the help page).
  14. ^ a b Cite error: The named reference De Medeiros2014 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 Eggleton2008 was invoked but never defined (see the help page).
  18. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).