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] |
Distance | 182.1 ± 0.4
ly (55.8 ± 0.1 pc) |
Absolute magnitude (MV) | 4.1±0.1 [2] |
Position (relative to HD 109271 A) [3] | |
Component | HD 109271 B |
Epoch of observation | 2018 |
Angular distance | 5.425 ″ |
Position angle | 267.354° |
Projected separation | 304 AU |
Details [2] | |
HD 109271 A | |
Mass | 1.047±0.024 M☉ |
Radius | 1.295+0.023 −0.020 [5] R☉ |
Luminosity | 1.649±0.008 [5] L☉ |
Surface gravity (log g) | 4.28±0.10 cgs |
Temperature | 5,783±62 K |
Metallicity [Fe/H] | 0.10±0.05 dex |
Rotational velocity (v sin i) | 2.7 km/s |
Age | 7.3±1.2 Gyr |
HD 109271 B | |
Mass | ~0.6 [3] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
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]
From 2003 to 2012, the star was under observance from the High Accuracy Radial Velocity Planet Searcher (HARPS). [2] In 2012, two eccentric hot Neptune-mass planets were deduced by radial velocity. They were published in January 2013. These are close to a 1:4 resonance, so the system is similar to HD 69830. A third Neptune in the Venus zone was hypothesised from the data. These planets managed to survive the post main-sequence epoch of the companion star, when it shed much of its original mass. [3]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | >0.054 ± 0.004 MJ | 0.079 ± 0.001 | 7.8543 ± 0.0009 | 0.25 ± 0.08 | — | — |
c | >0.076 ± 0.007 MJ | 0.196 ± 0.003 | 30.93 ± 0.02 | 0.15 ± 0.09 | — | — |
d (unconfirmed) | >1.3 neptune MJ | 1 | 430 | 0.36 | — | — |
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] |
Distance | 182.1 ± 0.4
ly (55.8 ± 0.1 pc) |
Absolute magnitude (MV) | 4.1±0.1 [2] |
Position (relative to HD 109271 A) [3] | |
Component | HD 109271 B |
Epoch of observation | 2018 |
Angular distance | 5.425 ″ |
Position angle | 267.354° |
Projected separation | 304 AU |
Details [2] | |
HD 109271 A | |
Mass | 1.047±0.024 M☉ |
Radius | 1.295+0.023 −0.020 [5] R☉ |
Luminosity | 1.649±0.008 [5] L☉ |
Surface gravity (log g) | 4.28±0.10 cgs |
Temperature | 5,783±62 K |
Metallicity [Fe/H] | 0.10±0.05 dex |
Rotational velocity (v sin i) | 2.7 km/s |
Age | 7.3±1.2 Gyr |
HD 109271 B | |
Mass | ~0.6 [3] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
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]
From 2003 to 2012, the star was under observance from the High Accuracy Radial Velocity Planet Searcher (HARPS). [2] In 2012, two eccentric hot Neptune-mass planets were deduced by radial velocity. They were published in January 2013. These are close to a 1:4 resonance, so the system is similar to HD 69830. A third Neptune in the Venus zone was hypothesised from the data. These planets managed to survive the post main-sequence epoch of the companion star, when it shed much of its original mass. [3]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | >0.054 ± 0.004 MJ | 0.079 ± 0.001 | 7.8543 ± 0.0009 | 0.25 ± 0.08 | — | — |
c | >0.076 ± 0.007 MJ | 0.196 ± 0.003 | 30.93 ± 0.02 | 0.15 ± 0.09 | — | — |
d (unconfirmed) | >1.3 neptune MJ | 1 | 430 | 0.36 | — | — |