08h21m28.1361s, −39° 42′ 19.474″| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Puppis |
| Right ascension | 08h21m 28.13685s[1] |
| Declination | −39° 42′ 19.4843″[1] |
| Apparent magnitude (V) | +7.17[2] |
| Characteristics | |
| Spectral type | G6V CN+0.5[3] |
| B−V color index | 0.692±0.022[2] |
| Astrometry | |
| Radial velocity (Rv) | +49.31±0.12[1] km/s |
| Proper motion (μ) | RA: −201.729 mas/yr[1] Dec.: 225.102 mas/yr[1] |
| Parallax (π) | 34.1478 ± 0.0154 mas[1] |
| Distance | 95.51 ± 0.04 ly (29.28 ± 0.01 pc) |
| Absolute magnitude (MV) | +4.93[2] |
| Details | |
| Mass | 1.04±0.02[4] M☉ |
| Radius | 0.97±0.01[4] R☉ |
| Luminosity | 0.917±0.004[4] L☉ |
| Surface gravity (log g) | 4.47±0.02[4] cgs |
| Temperature | 5732±23[4] K |
| Metallicity [Fe/H] | +0.17±0.04[5] dex |
| Rotational velocity (v sin i) | 1.57[6] km/s |
| Age | 1.9±1.1 Gyr[4] 3.8±2.6[6] Gyr |
| Other designations | |
CD−39°4247, GJ 304, HD 70642, HIP 40952, SAO 199126, LTT 3116[7] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| ARICNS | data |
HD 70642 is a star with an exoplanetary companion in the southern constellationofPuppis. It has an apparent visual magnitude of +7.17,[2] which is too dim to be readily visible to the naked eye. The system is located at a distance of 95.5 light-years (29.3 parsecs) from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +49.3 km/s.[1] It came to within 55.3 ly of the Solar System some 329,000 years ago.[2]
This may be considered to be a solar analog star, being similar in physical properties to the Sun.[5] It is a G-type main-sequence star with a stellar classification of G6V CN+0.5.[3] It is comparable to the age of the Sun, estimated to be in the range of 2–6 billion years old. Although chromospherically inactiveamagnetic field has been detected.[5] This star has about the same mass and radius as the Sun, is slightly cooler and less luminous,[4] and is richer in abundance of iron relative to hydrogen.[5] It is spinning at a leisurely rate, showing a projected rotational velocity of 1.6 km/s.[6]
A long period planetary companion to HD 70642 was announced in 2003. This planet orbits in a circular orbit (e=0.034) at 3.232 AU.[8] The star is so like Sol that its habitable zone is in the same place (~ 1 AU). The jovian ensures the stability of an Earth-mass planet at 1 AU. This system is one of the most similar in conditions to the Solar System among currently known planetary systems.[9] In 2023, the inclination and true mass of HD 70642 b were determined via astrometry.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 3.9+0.29 −0.27 MJ |
3.295±0.021 | 5.751+0.038 −0.035 |
0.04+0.034 −0.027 |
29.9+2.6 −2.4or150.1+2.4 −2.6° |
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