HD 99109

HD 99109 / Shama
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Leo
Right ascension 11h 24m 17.359s[1]
Declination –01° 31′ 44.67″[1]
Apparent magnitude (V) +9.10[2]
Characteristics
Spectral type G8/K0IV[3]
B−V color index 0.874±0.002[2]
Astrometry
Radial velocity (Rv)+33.060±0.0025[4] km/s
Proper motion (μ) RA: −178.689 mas/yr[1]
Dec.: −159.528 mas/yr[1]
Parallax (π)18.178 ± 0.017 mas[1]
Distance179.4 ± 0.2 ly
(55.01 ± 0.05 pc)
Absolute magnitude (MV)5.62[2]
Details
Mass0.93±0.02[5] M☉
Radius0.90±0.03[5] R☉
Luminosity0.56±0.02[5] L☉
Surface gravity (log g)4.49±0.03[5] cgs
Temperature5,270±24[5] K
Metallicity [Fe/H]0.315±0.030[6] dex
Rotational velocity (v sin i)1.86±0.50[6] km/s
Age6±3 Gyr[5]
≥ 12.2[7] Gyr
Other designations
Shama, BD−00°2437, HD 99109, HIP 55664, SAO 138182[8]
Database references
SIMBADdata

HD 99109 is an orange-hued star with an exoplanetary companion in the constellation of Leo. It has an absolute visual magnitude of +9.10,[2] which is too faint to be visible to the naked eye. The distance to this system is 179 light-years based on parallax, and it is drifting further away with a radial velocity of +33 km/s.[1] The star is one and half degrees away from the celestial equator to the south.

The stellar classification of this star is G8/K0IV,[3] matching a late G or early K-type subgiant star. It appears to be past the end of its main sequence lifetime, having exhausted the supply of hydrogen at its core.[7] The star is 93% as massive as the Sun and has 90% of the Sun's radius.[5] It is spinning with a projected rotational velocity of ~2 km/s[6] and has over twice the abundance of iron relative to hydrogen than the Sun. The star is radiating 56% of the Sun's luminosity from its photosphere at an effective temperature of 5,270 K.[5] As of 2006, one extrasolar planet has been confirmed to be orbiting the star.[6]

The star HD 99109 is named Shama. The name was selected in the NameExoWorlds campaign by Pakistan, during the 100th anniversary of the IAU. Shama is an Urdu literary term meaning a small lamp or flame. The exoplanet companion is called Perwana, meaning 'moth' in Urdu, alluding to the eternal love of an object circling a source of light.[9][10]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk_Swift_1999 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Soubiran_et_al_2018 was invoked but never defined (see the help page).
  5. ^ a b c d e f g h Cite error: The named reference Bonfanti_et_al_2016 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Butler2006 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Schwarz_et_al_2007 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference nameexoworlds was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference IAU1912 was invoked but never defined (see the help page).