HD 198357

HD 198357
Location of HD 198357 on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Microscopium
Right ascension 20h 51m 00.75817s[1]
Declination −37° 54′ 47.9922″[1]
Apparent magnitude (V) 5.50±0.01[2]
Characteristics
Spectral type K3 III[3] or K3 II[4]
B−V color index +1.38[5]
Astrometry
Radial velocity (Rv)16.5±2.9[6] km/s
Proper motion (μ) RA: −7.436 mas/yr[1]
Dec.: −17.374 mas/yr[1]
Parallax (π)5.7348 ± 0.0797 mas[1]
Distance569 ± 8 ly
(174 ± 2 pc)
Absolute magnitude (MV)−0.75[7]
Details
Mass1.81±0.44[8] M☉
Radius37.8±1.9[9] R☉
Luminosity417+16
−15[1] L☉
Surface gravity (log g)1.06[10] cgs
Temperature4,318±51[11] K
Metallicity [Fe/H]−0.12[10] dex
Rotational velocity (v sin i)<1.0[12] km/s
Other designations
28 G. Microscopii[13], CD−38°14250, CPD−38°8121, GC 29053, HD 198357, HIP 102916, HR 7971, SAO 212488[14]
Database references
SIMBADdata

HD 198357 (HR 7971; 28 G. Microscopii) is a solitary star located in the southern constellation Microscopium. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.50.[2] Gaia DR3 parallax measurements imply a distance of 569 light-years[1] and the object is currently receding with a heliocentric radial velocity of 16.5 km/s.[6] At its current distance, HD 198357's brightness is diminished by 0.18 magnitudes due to interstellar extinction[15] and it has an absolute magnitude of −0.75.[7]

HD 198357 has a stellar classification of K3 III,[3] indicating that it is an evolved K-type giant star. David Stanley Evans gave a classification of K3 II, indicating a more evolved bright giant.[4] It has 1.81 times the mass of the Sun[8] but it has expanded to 37.8 times the radius of the Sun.[9] It radiates 417 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 4,318 K.[11] HD 198357 is slightly metal deficient with an iron abundance three-quarters that of the Sun or [Fe/H] = −0.12[10] and it spins too slowly for its projected rotational velocity to be measured accurately.[12] HD 198357 has a peculiar velocity of 27.7+3.9
−4.1 km/s, indicating that it may be a runaway star (46% chance).[16]

  1. ^ a b c d e f g 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 Houk1982 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Evans1966 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Lake1965 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 Cite error: The named reference Hohle2010 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 c Cite error: The named reference Park2013 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference De Medeiros2014 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).