HD 25171

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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]
Spectral type F8 V[2]
B−V color index 0.554[2]
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]
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
Rotation 35.6±8.9 d[4]
Rotational velocity (v sin i) 1.0[2] km/s
Age 4.0±1.6[2] Gyr
Other designations
CD–65 199, GSC 08874-00376, HD 25171, HIP 9141, SAO 248911, TYC 8874-376-1.

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.[5]

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]

The HD 25171 planetary system[5]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b 0.95 MJ 3.02±0.16 1845±15 0.08±0.06


  1. ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d e f g h i j k l m n o Moutou, C.; et al. (March 2011), "The HARPS search for southern extra-solar planets. XXVII. Seven new planetary systems", Astronomy & Astrophysics, 527: A63, arXiv:1012.3830Freely accessible, 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:0811.3982Freely accessible, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191. 
  4. ^ Suárez Mascareño, A.; et al. (September 2015), "Rotation periods of late-type dwarf stars from time series high-resolution spectroscopy of chromospheric indicators", Monthly Notices of the Royal Astronomical Society, 452 (3): 2745–2756, arXiv:1506.08039Freely accessible, Bibcode:2015MNRAS.452.2745S, doi:10.1093/mnras/stv1441. 
  5. ^ a b HD 25171 System