HD 75289
From Wikipedia, the free encyclopedia
| Observation data Epoch 2000 |
|
|---|---|
| Constellation (pronunciation) |
Vela |
| Right ascension | 8h 47m 40.39s |
| Declination | -41° 44' 12.45" |
| Apparent magnitude (V) | 6.36 |
| Distance | 94.36 ly (28.94 pc) |
| Spectral type | G0 V |
| Other designations | |
|
CD-41°4507, HIP 43177
|
|
HD 75289 is a 6th magnitude star in the constellation of Vela. Like our Sun, it is a yellow dwarf but slightly more massive, hotter and luminous. The spectral type of the star is G0 V. Under exceptionally good circumstances it might be visible to the unaided eye; however, usually binoculars are needed.
In 1999 a planet was discovered orbiting the star, and in 2004 a possible red dwarf companion was detected.
Contents |
[edit] HD 75289 b
|
Discovery
|
|
|---|---|
| Discovered by | Udry et al. |
| Discovery date | 1999 |
| Detection method | Radial velocity |
| Semi-major axis | 0.0482 ± 0.0028 AU |
| Eccentricity | 0.034 ± 0.029 |
| Orbital period | 3.509267 ± 0.000064 d |
| Angular distance | 2 mas |
| Longitude of periastron | 141° |
| Time of periastron | 2,450,830.34 ± 0.48 JD |
| Semi-amplitude | 54.9 ± 1.8 m/s |
|
Physical characteristics
|
|
| Mass | >0.467 ± 0.041 MJ |
HD 75289 b is an extrasolar planet orbiting the star HD 75289. It has a mass half that of Jupiter, and it orbits in a very short orbit completing one revolution around the star in three and a half days. By studying the starlight scientists have concluded that the planet must have an albedo less than 0.12, rather low for a gas giant. Otherwise its reflected light would have been detected.
[edit] HD 75289 B
| Observation data Epoch 2000 |
|
|---|---|
| Constellation (pronunciation) |
Vela |
| Right ascension | 8h 47m 42.24s |
| Declination | -41° 44' 7.70" |
| Apparent magnitude (V) | ? |
| Distance | 94.36? ly (28.94? pc) |
| Spectral type | M2-M5 V |
| Other designations | |
|
n/a
|
|
HD 75289 B is a possible red dwarf star orbiting HD 75289. The stars share the same proper motion so they are likely related. Apparent distance between the two stars is about 21.5 arcseconds, at a distance of 94 light years that would be 621 astronomical units. However, the radial distance between the stars is unknown, so they are likely further apart. In any case, one revolution around the primary would take thousands of years to complete.
The study that found the red dwarf also rules out any further stellar companions beyond 140 AUs and massive brown dwarf companions from 400 AU up to 2000 AU.
[edit] References
- Udry et al. (2000). "The CORALIE survey for southern extra-solar planets II. The short-period planetary companions to HD 75289 and HD 130322". Astronomy and Astrophysics 356: 590–598.
- Butler et al. (2006). "Catalog of Nearby Exoplanets" (abstract). The Astrophysical Journal 646 (1): 505 – 522. doi:. (web Preprint)
