HD 190228

HD 190228 is an approximately 200 light years (about 62 parsecs ) from the sun like distant star with an apparent visual magnitude of 7.3 in the constellation Vulpecula. The star is a supergiant of spectral type G and has an age of about 10 billion years. He is surrounded by a sub-stellar companion, called HD 190228 b (or HD 190228 B), such that it would act around a brown dwarf (possibly also a low-mass star or ).

Companion

The discovery of the companion of HD 190228 was achieved with the help of the radial velocity method, and was published in 2000. Its doing certain, low minimum mass of 5 Jupiter masses made ​​him an exoplanet candidates. With the determination of the orbital inclination to about 4 °, however, showed that the mass of the companion is significantly higher, at approximately (49 ± 15) Jupiter masses. The orbital period of the companion is about 1100 days, its orbit has an eccentricity of 0.5.

Swell

  • Chen et al.: The companion of HD 190228: Planet or brown dwarf? . In: Astron. Astrophys. 374, 2001, pp. L1 - L4. Accessed on 16 December 2007.
  • Sivan et al.: A planetary companion to HD 190228. In: Planetary Systems in the Universe. 2004, pp. 124 Accessed on 16 December 2007.
Declination Astrometry Light-year Intrinsic brightness Proper motion Solar mass Durchmusterung Smithsonian Astrophysical Observatory Star Catalog Guide Star Catalog
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