Hellenica World

HD 221287

HD 221287 is a yellow-white main-sequence star approximately 173 light years away in the constellation of Tucana. It has an apparent magnitude of 7.82 and absolute magnitude of 4.20. This star is also named HIP 116084.

Planetary system

On March 5, 2007, the astronomer Dominique Naef used the HARPS spectrograph to uncover HD 221287 b (among others). [1] Using the amplitude from observations with HARPS, he calculated a minimum mass of 3.12 times that of Jupiter, making this a superjovian. This planet orbits 25% further from the star than Earth to the Sun with a low eccentricity.

Stability analysis reveals that the orbits of Earth sized planets in HD 221287 b's Trojan points, located 60 degrees ahead and behind the planet in its orbit, would be stable for long periods of time.[2]

The HD 221287 system[1]
(in order from star)
Mass Semimajor axis
Orbital period
b >3.09 ± 0.79 MJ 1.25 ± 0.04 456.1 ± 6.5 0.08 ± 0.11

See also

* HD 100777
* HD 190647


1. ^ a b Naef et al.; Mayor, M.; Benz, W.; Bouchy, F.; Lo Curto, G.; Lovis, C.; Moutou, C.; Pepe, F. et al. (2007). "The HARPS search for southern extra-solar planets IX. Exoplanets orbiting HD 100777 , HD 190647 , and HD 221287" (abstract). Astronomy and Astrophysics 470 (2): 721–726. doi:10.1051/0004-6361:20077361. http://www.aanda.org/articles/aa/abs/2007/29/aa7361-07/aa7361-07.html. (web preprint)
2. ^ R. Schwarz, R. Dvorak, Á. Süli, and B. Érdi (November 2007). "Survey of the stability region of hypothetical habitable Trojan planets" (PDF). Astronomy and Astrophysics 474: 1023–1029. doi:10.1051/0004-6361:20077994. http://www.univie.ac.at/adg/Research/exotro/aa7994-07.pdf.

Retrieved from "http://en.wikipedia.org/"
All text is available under the terms of the GNU Free Documentation License