Pi² Ursae Majoris
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| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Ursa Major |
| Right ascension | 08h 40m 12.8s |
| Declination | +64° 19′ 40″ |
| Apparent magnitude (V) | +4.59 |
| Characteristics | |
| Spectral type | K1IIIb |
| Variable type | None |
| Astrometry | |
| Distance | 252 ± 14 ly (77 ± 4 pc) |
| Details | |
| Mass | 1.234 ± 0.15 M☉ |
| Radius | 18.11 ± 1.47 R☉ |
| Luminosity | 111.7 L☉ |
| Temperature | 4415 ± 70 K |
| Metallicity | -0.25 ± 0.04 |
| Age | 4.604 ± 2 billion years |
| Other designations | |
| Database references | |
| SIMBAD | data |
Pi² Ursae Majoris (π² UMa / π² Ursae Majoris), also known as 4 Ursae Majoris (sometimes abbreviated 4 Uma) or traditionally named Muscida, is an orange giant star approximately 252 light-years away in the constellation of Ursa Major. As of 2011[update], one extrasolar planet has been confirmed to be orbiting the star.
Contents |
[edit] Planetary system
The planet (named 4 Ursae Majoris b) is seven times more massive than Jupiter. Its orbit is eccentric, orbiting 4 Ursae Majoris at 87% the distance from Sun to Earth.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity |
|---|---|---|---|---|
| b | >7.1 ± 1.6 MJ | 0.87 ± 0.04 | 269.3 ± 1.96 | 0.432 ± 0.024 |
[edit] See also
[edit] References
- ^ Döllinger et al. (2007). "Discovery of a planet around the K giant star 4 Ursae Majoris" (abstract). Astronomy and Astrophysics 472 (2): 649–652. arXiv:astro-ph/0703672. Bibcode 2007A&A...472..649D. doi:10.1051/0004-6361:20066987. http://www.aanda.org/articles/aa/abs/2007/35/aa6987-06/aa6987-06.html. (web preprint)
[edit] External links
- Jean Schneider (2011). "Notes for star 4 Uma". Extrasolar Planets Encyclopaedia. http://exoplanet.eu/star.php?st=4+Uma. Retrieved 3 October 2011.
Coordinates: 
08h 40m 12.8s, +64° 19′ 40″
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