HD 13189

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HD 13189
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Triangulum
Right ascension 02h 09m 40.17260s[1]
Declination +32° 18′ 59.1649″[1]
Apparent magnitude (V) +7.57[2]
Spectral type K1II-III[3]
Radial velocity (Rv)25.39[4] km/s
Proper motion (μ) RA: 2.62[1] mas/yr
Dec.: 5.32[1] mas/yr
Parallax (π)1.78 ± 0.73[1] mas
Distanceapprox. 1,800 ly
(approx. 600 pc)
Absolute magnitude (MV)–3.8[5]
Mass2–7[2] M
Radius45.5[6] to 50.4[7] R
Luminosity3,980[5] L
Surface gravity (log g)1.74[7] cgs
Temperature4,365[6] K
Metallicity [Fe/H]-0.58 ± 0.04[8] dex
Other designations
BD+31° 370, HIP 10085, SAO 55309.[9]
Database references

Coordinates: Sky map 02h 09m 40.1717s, +32° 18′ 59.1690″

HD 13189 is an 8th magnitude star in Triangulum constellation.

In 2005, a planetary companion or brown dwarf was announced in orbit around this star. At the time, the parallax estimate was 0.54 ± 0.93 mas, which would suggest a distance of 6,040 ly (1,850 pc) with a high margin of error.[2] In 2007, van Leeuwen published a revised parallax measurement of 1.78 ± 0.73, which corresponds to a distance of 1,830 ly (560 pc) with a smaller but still significant margin of error.[1]

It has a spectral classification of K1II-III, making it a giant star that has evolved away from the main sequence. The mass is 2–7 times the Sun,[2] while measurements of the star's radius give estimates of 45.5[6] or 50.4[7] solar radii. This mass range is typical of a B-type main sequence star,[10] suggesting the star belong to stellar class B when it was on the main sequence. The atmosphere of the star displays short period radial velocity variations with a primary period of 4.89 days. This behavior is typical for giant K-type stars such as this and it is not the result of a close-orbit planetary companion.[5]

The star is possibly the most massive of all planet-harboring stars[11] although the star NGC 4349-127 is potentially more massive.[12]

HD 13189 b[edit]

HD 13189 b
Exoplanet List of exoplanets
Orbital elements
Semi-major axis(a) 1.85 ± 0.35 AU
Eccentricity (e) 0.28 ± 0.06
Orbital period(P) 471.6 ± 6 d
Argument of
(ω) 160.7 ± 12°
Time of periastron (T0) 2452327.9 ± 20.2 JD
Semi-amplitude (K) 6.8 ± 1.5 m/s
Physical characteristics
Mass(m)>14 ± 6 MJ
Discovery information
Discovery date 2005
Discoverer(s) Hatzes et al.
Discovery method Radial Velocity
Discovery site Tautenburg, Germany
Discovery status Published

HD 13189 b is an exoplanet or brown dwarf with mass ranges from 8 to 20 Jupiter mass. This object is located at a mean distance of 277 Gm (1.85 AU) from the star, taking 472 days to make one elliptical orbit.

This object was discovered in Tautenburg, Germany in 2005.[13]


  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 Hatzes, A. P.; et al. (2005). "A giant planet around the massive giant star HD 13189". Astronomy and Astrophysics. 437 (2): 743–751. Bibcode:2005A&A...437..743H. doi:10.1051/0004-6361:20052850. 
  3. ^ Lee, B.-C.; et al. (May 2011). "A likely exoplanet orbiting the oscillating K-giant α Arietis". Astronomy & Astrophysics. 529. arXiv:1104.4431Freely accessible. Bibcode:2011A&A...529A.134L. doi:10.1051/0004-6361/201016293. 
  4. ^ Famaey, B.; et al. (January 2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430 (1): 165–186. arXiv:astro-ph/0409579Freely accessible. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. 
  5. ^ a b c Hatzes, Artie P.; Zechmeister, Mathias (October 2008). "Stellar oscillations in planet-hosting giant stars". Journal of Physics: Conference Series. 118 (1): 012016. Bibcode:2008JPhCS.118a2016H. doi:10.1088/1742-6596/118/1/012016. 
  6. ^ a b c van Belle, Gerard T.; von Braun, Kaspar (April 2009). "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars". The Astrophysical Journal. 694 (2): 1085–1098. arXiv:0901.1206Freely accessible. Bibcode:2009ApJ...694.1085V. doi:10.1088/0004-637X/694/2/1085.  See Table 3 of the online data.
  7. ^ a b c Baines, Ellyn K.; et al. (June 2008). "CHARA Array Measurements of the Angular Diameters of Exoplanet Host Stars". The Astrophysical Journal. 680 (1): 728–733. arXiv:0803.1411Freely accessible. Bibcode:2008ApJ...680..728B. doi:10.1086/588009. 
  8. ^ Kim, J. H.; et al. (December 2005). "High-Resolution Spectroscopy of the Planetary Host HD 13189: Highly-Evolved and Metal-Poor". Bulletin of the American Astronomical Society. 37: 1269. Bibcode:2006PhuZ...37....4.. doi:10.1002/piuz.200690006. Archived from the original on 2007-03-29. 
  9. ^ "HD 13189 -- Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2011-12-13. 
  10. ^ Habets, G. M. H. J.; Heinze, J. R. W. (November 1981). "Empirical bolometric corrections for the main-sequence". Astronomy and Astrophysics Supplement Series. 46: 193–237. Bibcode:1981A&AS...46..193H.  See Tables VII, VIII.
  11. ^ "Notes for planet HD 13189 b". The Extrasolar Planets Encyclopaedia. Retrieved 2015-09-15. 
  12. ^ "Notes for planet NGC 4349-127b". The Extrasolar Planets Encyclopaedia. Retrieved 2017-08-28. 
  13. ^ A Giant Planet Around The Massive Giant Star HD 13189 Archived 2015-07-20 at the Wayback Machine.

External links[edit]