HD 25171

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.[6]

HD 25171

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Reticulum
Right ascension	03^h 55^m 49.44032^s[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	1.069±0.041[4] R☉
Luminosity	1.89[2] L☉
Surface gravity (log g)	4.17±0.1[4] cgs
Temperature	6063±50[4] K
Metallicity [Fe/H]	−0.11±0.04[2] dex
Rotation	14.4±0.6 d[5]
Rotational velocity (v sin i)	1.0[2] km/s
Age	4.0±1.6[2] Gyr
Other designations
CD–65 199, HD 25171, HIP 9141, SAO 248911, TYC 8874-376-1.
Database references
SIMBAD	data

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 7% greater radius. As such, it is radiating 189% of the Sun's luminosity from its outer atmosphere at an effective temperature of 6,063 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.[4][2]

The survey in 2015 have ruled out the existence of any stellar companions at projected distances above 26 astronomical units.[7]

Planetary system

The planetary companion was discovered in 2010 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] The planetary system of HD 25171 is analogous to Solar System in the sense that a gas giant orbiting outside the frost line, far enough to do not destabilize orbits within a circumstellar habitable zone.[8]

The HD 25171 planetary system[6]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	>0.956±0.234 MJ	3.02±0.16	1845±15	0.08±0.06	—	—

References

1. 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. 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.
3. 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. A bot will complete this citation soon. Click here to jump the queue arXiv:1802.06794.
5. Characterisation of the radial velocity signal induced by rotation in late-type dwarfs, arXiv:1703.08884
6. HD 25171 System
7. Mugrauer, M.; Ginski, C. (12 May 2015). "High-contrast imaging search for stellar and substellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 450 (3). doi:10.1093/mnras/stv771. Retrieved 19 June 2020.
8. A bot will complete this citation soon. Click here to jump the queue arXiv:1804.06547.