| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Puppis |
| Right ascension | 08 21 28.13685 |
| Declination | −39° 42′ 19.4843″ |
| Apparent magnitude (V) | +7.17 |
| Characteristics | |
| Spectral type | G6V CN+0.5 |
| B−V color index | 0.692±0.022 |
| Astrometry | |
| Radial velocity (Rv) | +49.31±0.12 km/s |
| Proper motion (μ) | RA: −201.729 mas/yr Dec.: 225.102 mas/yr |
| Parallax (π) | 34.1478 ± 0.0154 mas |
| Distance | 95.51 ± 0.04 ly (29.28 ± 0.01 pc) |
| Absolute magnitude (MV) | +4.93 |
| Details | |
| Mass | 1.04±0.02 M☉ |
| Radius | 0.97±0.01 R☉ |
| Luminosity | 0.917±0.004 L☉ |
| Surface gravity (log g) | 4.47±0.02 cgs |
| Temperature | 5732±23 K |
| Metallicity | +0.17±0.04 dex |
| Rotational velocity (v sin i) | 1.57 km/s |
| Age | 1.9±1.1 Gyr 3.8±2.6 Gyr |
| Other designations | |
| CD−39°4247, GJ 304, HD 70642, HIP 40952, SAO 199126, LTT 3116 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| ARICNS | data |
HD 70642 is a star with an exoplanetary companion in the southern constellation of Puppis. It has an apparent visual magnitude of +7.17, 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. It came to within 55.3 ly of the Solar System some 329,000 years ago.
This may be considered to be a solar analog star, being similar in physical properties to the Sun. It is a G-type main-sequence star with a stellar classification of G6V CN+0.5. It is comparable to the age of the Sun, estimated to be in the range of 2–6 billion years old. Although chromospherically inactive a magnetic field has been detected. This star has about the same mass and radius as the Sun, is slightly cooler and less luminous, and is richer in abundance of iron relative to hydrogen. It is spinning at a leisurely rate, showing a projected rotational velocity of 1.6 km/s.
Planetary system
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. 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. In 2023, the inclination and true mass of HD 70642 b were determined via astrometry.
| 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 −2.4 or 150.1+2.4 −2.6° |
— |
See also
References
- ^ Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
- ^ Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
- ^ Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951.
- ^ Fossati, L.; et al. (March 2013). "Detection of a magnetic field in three old and inactive solar-like planet-hosting stars". Astronomy & Astrophysics. 551: 4. arXiv:1302.0879. Bibcode:2013A&A...551A..85F. doi:10.1051/0004-6361/201220997. S2CID 53377473. A85.
- ^ Costa Silva, A. R.; et al. (February 2020). "Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur". Astronomy & Astrophysics. 634: 10. arXiv:1912.08659. Bibcode:2020A&A...634A.136C. doi:10.1051/0004-6361/201936523. S2CID 209405391. A136.
- "HD 70642". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-09-04.
- Carter, Brad D.; et al. (2003). "A Planet in a Circular Orbit with a 6 Year Period". The Astrophysical Journal Letters. 593 (1): L43–L46. arXiv:astro-ph/0307066. Bibcode:2003ApJ...593L..43C. doi:10.1086/378185.
- Hinse, T. C.; et al. (2008). "Dynamics and stability of telluric planets within the habitable zone of extrasolar planetary systems - Numerical simulations of test particles within the HD 4208 and HD 70642 systems". Astronomy & Astrophysics. 488 (3): 1133–1147. Bibcode:2008A&A...488.1133H. doi:10.1051/0004-6361:200809822.
- ^ Xiao, Guang-Yao; Liu, Yu-Juan; et al. (May 2023). "The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements". Research in Astronomy and Astrophysics. 23 (5): 055022. arXiv:2303.12409. Bibcode:2023RAA....23e5022X. doi:10.1088/1674-4527/accb7e.
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