HD 128311

HD 128311 or HN Boötis is an orange main sequence star located approximately 54 light-years away in the constellation of Boötes. Two extrasolar planet candidates have been detected in orbit around this star.

Planetary system

In 2002, the discovery of the planet HD 128311 b was announced by Paul Butler. In 2005, the discovery of a second planet HD 128311 c was announced by Steve Vogt.

PlanetboxOrbit
exoplanet = b
mass = >2.19 ± 0.20
period = 458.6 ± 6.8
semimajor = 1.100 ± 0.065
eccentricity = 0.25 ± 0.10PlanetboxOrbit
exoplanet = c
mass = >3.22 ± 0.49
period = 928 ± 18
semimajor = 1.76 ± 0.11
eccentricity = 0.170 ± 0.090

See also

* List of stars with confirmed extrasolar planets

Reference

* [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?GJ%203860 GJ 3860]

External links

*
*
* [http://www.lpl.arizona.edu/~rory/research/xsp/dynamics/ Extrasolar Planet Interactions] by Rory Barnes & Richard Greenberg, Lunar and Planetary Lab, University of Arizona
* [http://aladin.u-strasbg.fr/AladinPreview?-c=14+36+00.5607%2B09+44+47.466&ident=V*+HN+Boo&submit=Aladin+previewer Image HD 128311]