HD 102195

HD 102195 / Flegetonte
Observation data
Epoch J2000      Equinox J2000
Constellation Virgo
Right ascension 11h 45m 42.29278s[1]
Declination +02° 49′ 17.3262″[1]
Apparent magnitude (V) 8.07[2]
Characteristics
Spectral type K0 V[3]
B−V color index 0.835[2]
Astrometry
Radial velocity (Rv)1.85±0.15[1] km/s
Proper motion (μ) RA: −188.735[1] mas/yr
Dec.: −113.403[1] mas/yr
Parallax (π)34.0560 ± 0.0555 mas[1]
Distance95.8 ± 0.2 ly
(29.36 ± 0.05 pc)
Absolute magnitude (MV)5.76[2]
Details[4]
Mass0.88±0.03 M☉
Radius0.84±0.02 R☉
Luminosity0.49±0.01 L☉
Surface gravity (log g)4.53±0.03 cgs
Temperature5,283±29 K
Metallicity [Fe/H]+0.09[5] dex
Rotation12.3 d[6]
Rotational velocity (v sin i)2.6[2] km/s
Age5.9±3.5 Gyr
Other designations
BD+03°2549, HD 102195, HIP 57370, HR 4293, SAO 119033, LTT 13232, NLTT 28458[7]
Database references
SIMBADdata

HD 102195 is an orange-hued star in the zodiac constellation of Virgo with a confirmed exoplanet companion.[2] With an apparent visual magnitude of 8.07,[2] the star is too faint to be seen with the naked eye. The distance to HD 102195 can be estimated from its annual parallax shift of 34.06 mas,[1] yielding 95.8 light years. It is moving further away from the Earth with a heliocentric radial velocity of 1.85 km/s.[1] This is a high proper motion star and a possible member of the η Cha stellar kinematic group.[8]

The star HD 102195 is named Flegetonte. The name was selected in the NameExoWorlds campaign by Italy, during the 100th anniversary of the IAU. Flegetonte is the underworld river of fire from Greek Mythology in the Italian narrative poem on the afterlife Divina Commedia.[9][10]

This K-type main-sequence star has a stellar classification of K0 V.[3] It is a quasi-periodic variable star with a cycle of 11.5 days, a variation range of 3.65%, and a phased amplitude of 94%.[11] HD 102195 is around six billion years old with a rotation period of 12.3 days.[6] It has 88% of the Sun's mass and 84% of the Sun's radius. It is radiating 49% of the Sun's luminosity from its photosphere at an effective temperature of 5,283 K.[4]

In 2005, an orbiting companion was detected using the Exoplanet Tracker instrument.[12] This near Jupiter-mass exoplanet has an orbital period of 4.1 days with a circular orbit. By comparing the rotation period and radius of the star with the projected rotational velocity, Melo et al. (2007) derived an orbital inclination of 47°. This would suggest a planetary mass of 0.62 MJ.[2]

The HD 102195 planetary system[2]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b / Lete ≥0.45 MJ 0.0491[12] 4.113775±0.000557 0.0 (assumed) — —
  1. ^ a b c d e f g h Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h Cite error: The named reference Melo2007 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1999 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Bonfanti2016 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Brewer2016 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Vidotto2014 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Nakajima2012 was invoked but never defined (see the help page).
  9. ^ "Approved names". NameExoworlds. Retrieved 2020-01-02.
  10. ^ "International Astronomical Union | IAU". www.iau.org. Retrieved 2020-01-02.
  11. ^ Cite error: The named reference Armstrong2015 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference Ge2006 was invoked but never defined (see the help page).