HD 25171
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Reticulum |
| Right ascension | 03h 55m 49.44032s[1] |
| Declination | –65° 11′ 12.0363″[1] |
| Apparent magnitude (V) | 7.79[2] |
| Characteristics | |
| Spectral type | F8 V[2] |
| B−V color index | 0.554[2] |
| Astrometry | |
| Radial velocity (Rv) | +42.8[3] km/s |
| Proper motion (μ) | RA: +143.97[1] mas/yr Dec.: +80.69[1] mas/yr |
| Parallax (π) | 18.19 ± 0.45[1] mas |
| Distance | 179 ± 4 ly (55 ± 1 pc) |
| Absolute magnitude (MV) | 4.09±0.07[2] |
| Details | |
| Mass | 1.09±0.03[2] M☉ |
| Radius | 1.18±0.04[2] R☉ |
| Luminosity | 1.89[2] L☉ |
| Surface gravity (log g) | 4.43±0.1[2] cgs |
| Temperature | 6160±65[2] K |
| Metallicity [Fe/H] | −0.11±0.04[2] dex |
| Rotational velocity (v sin i) | 1.0[2] km/s |
| Age | 4.0±1.6[2] Gyr |
| Other designations | |
HD 25171 is a star in the southern constellation of Reticulum, the reticle. With an apparent visual magnitude of 7.79,[2] this star is too faint to be viewed with the naked eye. However, it is readily visible through a small telescope from the southern hemisphere. Parallax measurements made during the Hipparcos mission place it at a distance of roughly 179 light-years (55 parsecs) from Earth.[1] It has a planetary companion that was announced December 2009.[4]
Based upon its spectrum, this is an ordinary F-type main sequence star with a stellar classification of F8 V. It is slightly larger than the Sun, with 9% more mass and an 18% greater radius. As such, it is radiating 189% of the Sun's luminosity from its outer atmosphere at an effective temperature of 6,160 K. This gives it the yellow-white hued glow of an F-type star. It appears to be roughly the same age as the Sun; around four billion years.[2]
The planetary companion was discovered with the HARPS instrument, which measured the radial velocity displacement caused by the gravitational perturbation of the star by the planet. This data provided an orbital period of 1,845 days and set a lower bound of the planet's mass at 95% of the mass of Jupiter.[2]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b[4] | 0.95 MJ | 3.02±0.16 | 1845±15 | 0.08±0.06 | — | — |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 Moutou, C. et al. (March 2011), "The HARPS search for southern extra-solar planets. XXVII. Seven new planetary systems", Astronomy & Astrophysics 527: A63, arXiv:1012.3830, Bibcode:2011A&A...527A..63M, doi:10.1051/0004-6361/201015371.
- ↑ Holmberg, J.; Nordstrom, B.; Andersen, J. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191.
- ↑ 4.0 4.1 HD 25171 System
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