HD 181720

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HD 181720
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Sagittarius
Right ascension 19h 22m 52.99s[1]
Declination –32° 55′ 08.6″[1]
Apparent magnitude (V) 7.84[2]
Spectral type G1V[2]
Apparent magnitude (B) 8.44
Apparent magnitude (J) 6.652
Apparent magnitude (H) 6.346
Apparent magnitude (K) 6.294
V−R color index 0.599[2]
Radial velocity (Rv)–57.2 km/s
Proper motion (μ) RA: 88.03 ± 1.44[1] mas/yr
Dec.: –414.99 ± 0.90[1] mas/yr
Parallax (π)17.22 ± 1.16[1] mas
Distance190 ± 10 ly
(58 ± 4 pc)
Absolute magnitude (MV)4.10[2]
Mass0.92[2] M
Radius1.39[2] R
Luminosity1.94[2] L
Surface gravity (log g)4.24 ± 0.15[2] cgs
Temperature5781 ± 18[2] K
Metallicity-0.53 ± 0.02[2]
Rotation47 days
Rotational velocity (v sin i)1.5[2] km/s
Other designations
CD–33°14164, GCRV 69331, HIP 95262, LTT 7666, NLTT 47718, PPM 298918, SAO 211218
Database references
Exoplanet Archivedata
Extrasolar Planets

HD 181720 is an 8th magnitude G-type main sequence star located approximately 190 light years away in the constellation Sagittarius. This star is larger, hotter, brighter, and less massive than our Sun. Also its metal content is three-tenths as much as the Sun. In 2009, a gas giant planet was found in orbit around the star.

The HD 181720 planetary system[2]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b ≥0.37 MJ 1.78 956 ± 14 0.26 ± 0.06

See also[edit]


  1. ^ a b c d e van Leeuwen, F. (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. Vizier catalog entry
  2. ^ a b c d e f g h i j k l Santos, N. C.; et al. (2010). "The HARPS search for southern extrasolar planets XXI. Three new giant planets orbiting the metal-poor stars HD5388, HD181720, and HD190984". Astronomy and Astrophysics. 512. A47. arXiv:0912.3216. Bibcode:2010A&A...512A..47S. doi:10.1051/0004-6361/200913489.

Coordinates: Sky map 19h 22m 52.9859s, −32° 55′ 08.595″