NOTABLE STARS EXTRASOLAR PLANETS A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site HD 187123 A star almost identical to the Sun, in the constellation Cygnus, around which has been discovered a planet with at least half the mass of Jupiter. At one ninth the average separation distance of Mercury from the Sun, HD 187123 b orbits more closely to its host star than any other planet discovered up to that time.1 See also extrasolar planets. Host star Distance 156.3 light-years (47.92 pc) Spectral type G5V Apparent magnitude 7.89 Temperature 5,560°C Luminosity (Sun=1) 1.35 Mass (Sun=1) 1.0 Position R.A. 19h 46m 58.11s; Dec. +34° 25' 10.29" Other catalog designations BD+34°3708, HIP 97336, SAO 68845 Planet Mass (Jupiter=1) >0.52 Semi-major axis 0.042 AU (6.3 million km, 3.9 million miles) Orbital period 3.097 days Eccentricity 0.03 ± 0.003 Discovery 1998, Butler et al., SFSU Planet Search, Keck Method radial velocity References Butler, P., Marcy, G., Vogt, S., and Apps, K. "A Planet with a 3.1-day Period Around a Solar Twin," Publications of the Astronomical Society of the Pacific, 110, 1389 (1998). Related categories    • NOTABLE STARS    • EXTRASOLAR PLANETS AND SUBSTELLAR OBJECTS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP