Astronomy:HD 70642
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Puppis |
| Right ascension | 08h 21m 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[1] mas/yr Dec.: 225.102[1] mas/yr |
| Parallax (π) | 34.1478 ± 0.0154[1] mas |
| 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 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| ARICNS | data |
| Extrasolar Planets Encyclopaedia | 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,[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 inactive a magnetic 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]
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.[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 −2.4 or 150.1+2.4 −2.6° |
— |
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 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. doi:10.1086/504637. Bibcode: 2006AJ....132..161G.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Bonfanti, A. et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics 575: A18. doi:10.1051/0004-6361/201424951. Bibcode: 2015A&A...575A..18B.
- ↑ 5.0 5.1 5.2 5.3 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. doi:10.1051/0004-6361/201220997. A85. Bibcode: 2013A&A...551A..85F.
- ↑ 6.0 6.1 6.2 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. doi:10.1051/0004-6361/201936523. A136. Bibcode: 2020A&A...634A.136C.
- ↑ "HD 70642". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+70642.
- ↑ 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. doi:10.1086/378185. Bibcode: 2003ApJ...593L..43C.
- ↑ 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. doi:10.1051/0004-6361:200809822. Bibcode: 2008A&A...488.1133H.
- ↑ 10.0 10.1 Xiao, Guang-Yao et al. (May 2023). "The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements". Research in Astronomy and Astrophysics 23 (5): 055022. doi:10.1088/1674-4527/accb7e. Bibcode: 2023RAA....23e5022X.
External links
Coordinates: 
08h 21m 28.1361s, −39° 42′ 19.474″
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