HD 2638
|
Stern HD 2638 |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| AladinLite | |||||||||||
|
Observation dates equinox : J2000.0 , epoch : J2000.0 |
|||||||||||
| Constellation | whale | ||||||||||
| Right ascension | 00 h 29 m 59.87 s | ||||||||||
| declination | -05 ° 45 ′ 50.4 ″ | ||||||||||
| Apparent brightness | 9.44 mag | ||||||||||
| Typing | |||||||||||
| Known exoplanets | 1 | ||||||||||
| Spectral class | G5 | ||||||||||
| Astrometry | |||||||||||
| Radial velocity | (+9.5 ± 0.4) km / s | ||||||||||
| parallax | (20.03 ± 1.49) mas | ||||||||||
| distance | (160 ± 10) ly (50 ± 4) pc |
||||||||||
| Visual absolute brightness M vis | about 6 mag | ||||||||||
| Proper movement | |||||||||||
| Rec. Share: | (−105.63 ± 1.74) mas / a | ||||||||||
| Dec. portion: | (−223.46 ± 1.04) mas / a | ||||||||||
| Physical Properties | |||||||||||
| Metallicity [Fe / H] | 0.16 ± 0.05 | ||||||||||
|
Other names and catalog entries |
|||||||||||
|
|||||||||||
HD 2638 is a star in the constellation Whale, about 175 light years from Earth, with an apparent magnitude of 9.4 mag. In 2005 a companion, HD 2638 b , was discovered around the star .
Data of the star
The star is from the Sun 175.18 light-years away (about 53.71 parsecs ). It belongs to the spectral class G5 and is therefore very similar to the sun. HD 2638 has about 93 percent of the solar mass and 67 percent of the solar radius . Its surface has a temperature of about 5190 Kelvin , its metallicity is [Fe / H] = 0.16 ± 0.05 (1.44 times that of the sun). The star's expected lifespan is over 12 billion years.
Data of the exoplanet
HD 2638 b was discovered in 2005 by the Geneva extrasolar planet research team (Geneva Extrasolar Planet Search) using the radial velocity method and is a typical “ Hot Jupiter ” orbiting its sun in a tight orbit . Its distance to the star is about one twentieth the distance between the sun and the earth (0.044 astronomical units ). It takes about 3.5 days to orbit, and its mass is at least 0.48 masses of Jupiter.
literature
- Moutou et al .: The HARPS search for southern extra-solar planets IV. Three close-in planets around HD 2638, HD 27894 and HD 63454 . In: Astronomy and Astrophysics . 439, 2005, pp. 367-373 ..
Individual evidence
- ↑ a b c Hipparcos catalog (ESA 1997)
- ↑ Pulkovo radial velocities for 35493 HIP stars
- ↑ a b c Hipparcos, the New Reduction (van Leeuwen, 2007)
- ↑ estimated based on the apparent brightness and distance