HD 109271

HD 109271
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Virgo
Right ascension 12h 33m 35.555s[1]
Declination −11° 37′ 18.73″[1]
Apparent magnitude (V) 8.05 ± 0.01[2]
Characteristics
Spectral type G5 V[2] + DA[3]
B−V color index +0.658±0.002[2]
Astrometry
Radial velocity (Rv)−4.971±0.0011[4] km/s
Proper motion (μ) RA: −169.971 mas/yr[1]
Dec.: 81.000 mas/yr[1]
Parallax (π)17.9082 ± 0.0379 mas[1]
Distance182.1 ± 0.4 ly
(55.8 ± 0.1 pc)
Absolute magnitude (MV)4.1±0.1[2]
Position (relative to HD 109271 A)[3]
ComponentHD 109271 B
Epoch of observation2018
Angular distance5.425
Position angle267.354°
Projected separation304 AU
Details[2]
HD 109271 A
Mass1.047±0.024 M
Radius1.295+0.023
−0.020
[5] R
Luminosity1.649±0.008[5] L
Surface gravity (log g)4.28±0.10 cgs
Temperature5,783±62 K
Metallicity [Fe/H]0.10±0.05 dex
Rotational velocity (v sin i)2.7 km/s
Age7.3±1.2 Gyr
HD 109271 B
Mass~0.6[3] M
Other designations
BD−10° 3494, HD 109271, HIP 61300, SAO 157362, LTT 4770[6]
Database references
SIMBADdata
Exoplanet Archivedata

HD 109271 is a wide binary star system in the constellation of Virgo. The brighter member of the binary has a pair of orbiting exoplanets. With an apparent visual magnitude of 8.05,[2] it cannot be seen with the naked eye. Parallax measurements made by Gaia put the star at a distance of 181 light-years (55 parsecs) away from the Sun, but it is drifting closer with a radial velocity of −5 km/s.[4] The system shows a high proper motion, traversing the celestial sphere at an angular rate of 0.232 arcsec yr−1.[7]

The primary component is an ordinary G-type main-sequence star with a stellar classification of G5 V. It is a much older star than the Sun with an age of about 7.3 billion years, and is spinning with a projected rotational velocity of 2.7 km/s.[2] This star has 7% more mass than the Sun and a 30% greater girth.[5] The abundance of iron, a measure of the star's metallicity, is similar but slightly higher than in the Sun.[2] It is radiating 1.65[5] times the luminosity of the Sun from its photosphere at an effective temperature of around 5,783 K.[2]

In 2020, a white dwarf companion of 0.6 M was found orbiting the primary at an angular separation of 5.4 along a position angle of 267°. At the distance of this system, this corresponds to a projected separation of 304 AU. That is, they are physically separated by at least this distance. Additional stellar companions are ruled out down to a separation of 0.15″ from the primary.[3]

  1. ^ a b c d Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h i Cite error: The named reference HARPS was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Ginski_et_al_2021 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Soubiran_et_al_2018 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Johns_et_al_2018 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Luyten1995 was invoked but never defined (see the help page).