Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Mensa |
Right ascension | 05h 44m 31.9180s [1] |
Declination | −70° 08′ 36.858″ [1] |
Apparent magnitude (V) | 8.07±0.01 [2] |
Characteristics | |
Spectral type | K0 V [3] |
U−B color index | +0.26 [4] [5] |
B−V color index | +0.76 [4] [5] |
Astrometry | |
Radial velocity (Rv) | 13.90±0.10 [6] km/s |
Proper motion (μ) |
RA: −309.273
mas/
yr
[1] Dec.: +1238.862 mas/ yr [1] |
Parallax (π) | 37.8235 ± 0.0206 mas [1] |
Distance | 86.23 ± 0.05
ly (26.44 ± 0.01 pc) |
Absolute magnitude (MV) | +6.02 [7] |
Details | |
Mass | 0.71 [8] M☉ |
Radius | 0.74 [9] R☉ |
Luminosity | 0.389 [10] L☉ |
Surface gravity (log g) | 4.61±0.05 [11] cgs |
Temperature | 5,205±23 [11] K |
Metallicity [Fe/H] | −0.61±0.02 [11] dex |
Rotational velocity (v sin i) | 2 [12] km/s |
Age | 11.7 [8] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
HD 39194 (Gliese 217.2; LHS 210) is a star located in the southern circumpolar constellation Mensa. It has an apparent magnitude of 8.07, [2] making it readily visible in binoculars but not to the naked eye. The object is relatively close at a distance of 86 light years [1] but is receding with a heliocentric radial velocity of 13.9 km/s. [6]
HD 39194 has a general stellar classification of K0 V, [3] indicating that it is a K-type main-sequence star. Houk & Cowley found a slightly warmer class of G8 V, [13] instead making it a G-type main-sequence star. Nevertheless, it has 71% the mass of the Sun [8] and an effective temperature of 5,205 K, [11] giving an orange hue. It radius of 0.74 R☉ [9] yields a luminosity only 38% that of the Sun. [10] HD 39194 is estimated to be 11.7 billion years old [8] and is extremely chromospherically inactive. [3] Despite being a planetary host, it has an iron abundance only 24% that of the Sun. [11] HD 39194's projected rotational velocity is similar to the Sun's, with the value being 2 km/s. [12]
Three planet candidates around this star were first reported in a 2011 preprint. [14] After 10 years of observations, a team of astronomers confirmed 3 super-Earths circling HD 39194 in eccentric orbits; [10] none of the planets are in the habitable zone. HD 39194 b and d have similar masses.
This star was selected as a potential candidate for future exoplanet imaging missions in 2015. [9]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥4.13±0.20 M🜨 | 0.056±0.001 | 5.6368±0.0004 | <0.207 | — | — |
c | ≥6.29±0.51 M🜨 | 0.103±0.002 | 14.030±0.003 | <0.154 | — | — |
d | ≥4.13±0.60 M🜨 | 0.185±0.003 | 33.91±0.03 | <0.333 | — | — |
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Mensa |
Right ascension | 05h 44m 31.9180s [1] |
Declination | −70° 08′ 36.858″ [1] |
Apparent magnitude (V) | 8.07±0.01 [2] |
Characteristics | |
Spectral type | K0 V [3] |
U−B color index | +0.26 [4] [5] |
B−V color index | +0.76 [4] [5] |
Astrometry | |
Radial velocity (Rv) | 13.90±0.10 [6] km/s |
Proper motion (μ) |
RA: −309.273
mas/
yr
[1] Dec.: +1238.862 mas/ yr [1] |
Parallax (π) | 37.8235 ± 0.0206 mas [1] |
Distance | 86.23 ± 0.05
ly (26.44 ± 0.01 pc) |
Absolute magnitude (MV) | +6.02 [7] |
Details | |
Mass | 0.71 [8] M☉ |
Radius | 0.74 [9] R☉ |
Luminosity | 0.389 [10] L☉ |
Surface gravity (log g) | 4.61±0.05 [11] cgs |
Temperature | 5,205±23 [11] K |
Metallicity [Fe/H] | −0.61±0.02 [11] dex |
Rotational velocity (v sin i) | 2 [12] km/s |
Age | 11.7 [8] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
HD 39194 (Gliese 217.2; LHS 210) is a star located in the southern circumpolar constellation Mensa. It has an apparent magnitude of 8.07, [2] making it readily visible in binoculars but not to the naked eye. The object is relatively close at a distance of 86 light years [1] but is receding with a heliocentric radial velocity of 13.9 km/s. [6]
HD 39194 has a general stellar classification of K0 V, [3] indicating that it is a K-type main-sequence star. Houk & Cowley found a slightly warmer class of G8 V, [13] instead making it a G-type main-sequence star. Nevertheless, it has 71% the mass of the Sun [8] and an effective temperature of 5,205 K, [11] giving an orange hue. It radius of 0.74 R☉ [9] yields a luminosity only 38% that of the Sun. [10] HD 39194 is estimated to be 11.7 billion years old [8] and is extremely chromospherically inactive. [3] Despite being a planetary host, it has an iron abundance only 24% that of the Sun. [11] HD 39194's projected rotational velocity is similar to the Sun's, with the value being 2 km/s. [12]
Three planet candidates around this star were first reported in a 2011 preprint. [14] After 10 years of observations, a team of astronomers confirmed 3 super-Earths circling HD 39194 in eccentric orbits; [10] none of the planets are in the habitable zone. HD 39194 b and d have similar masses.
This star was selected as a potential candidate for future exoplanet imaging missions in 2015. [9]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥4.13±0.20 M🜨 | 0.056±0.001 | 5.6368±0.0004 | <0.207 | — | — |
c | ≥6.29±0.51 M🜨 | 0.103±0.002 | 14.030±0.003 | <0.154 | — | — |
d | ≥4.13±0.60 M🜨 | 0.185±0.003 | 33.91±0.03 | <0.333 | — | — |