HD 13189 is a star with an orbiting companion in the northern constellation of Triangulum constellation. With an apparent visual magnitude of +7.57,[2] it is too faint to be visible to the normal human eye. The distance to this system is approximately 1,590 light years based on parallax measurements, and it is drifting further away with a radial velocity of 25.39 km/s.[5] In 2005, a planetary companion or brown dwarf was announced in orbit around this star.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 02h 09m 40.1723s[1] |
| Declination | +32° 18′ 59.161″[1] |
| Apparent magnitude (V) | +7.57[2] |
| Characteristics | |
| Spectral type | K1II-III[3] |
| B−V color index | 1.465±0.016[4] |
| Astrometry | |
| Radial velocity (Rv) | 25.39[5] km/s |
| Proper motion (μ) | RA: 2.306±0.024 mas/yr[1] Dec.: 4.935±0.022 mas/yr[1] |
| Parallax (π) | 2.0450 ± 0.0240 mas[1] |
| Distance | 1,590 ± 20 ly (489 ± 6 pc) |
| Absolute magnitude (MV) | −0.3[6] |
| Details | |
| Mass | 1.2[7] M☉ |
| Radius | 38[8] R☉ |
| Luminosity | 503[1] L☉ |
| Surface gravity (log g) | 1.21[7] cgs |
| Temperature | 4,035[7] K |
| Metallicity [Fe/H] | −0.18[7] dex |
| Age | 4.4[9] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
It has a spectral classification of K1II-III, making it a giant star that has evolved away from the main sequence after exhausting the hydrogen at its core. The mass is 1.2 times the Sun's, while measurements of the star's radius give estimates of 38 R☉. The atmosphere of the star displays short period radial velocity variations with a primary period of 4.89 days. This behavior is typical for giant K-type stars such as this and it is not the result of a close-orbit planetary companion.[11]
HD 13189 b
 HD 13189 b as rendered in Celestia | |
| Discovery | |
|---|---|
| Discovered by | Hatzes et al. |
| Discovery site | Tautenburg, Germany |
| Discovery date | 2005 |
| Radial Velocity | |
| Orbital characteristics | |
| 1.85 ± 0.35 AU (277,000,000 ± 52,000,000 km) | |
| Eccentricity | 0.28 ± 0.06 |
| 471.6 ± 6 d | |
| 2452327.9 ± 20.2 | |
| 160.7 ± 12 | |
| Semi-amplitude | 6.8 ± 1.5 |
| Physical characteristics | |
| Mass | >14 ± 6 MJ |
HD 13189 b is an exoplanet or brown dwarf with mass ranges from 8 to 20 Jupiter mass. This object is located at a mean distance of 277 Gm (1.85 AU) from the star, taking 472 days to make one elliptical orbit.
This object was discovered in Tautenburg, Germany in 2005.[12]
References
External links
- "HD 13189 -- Star". SIMBAD. Retrieved December 21, 2007.
- "HD 13189 b -- Extra-solar Planet Candidate". SIMBAD. Retrieved December 21, 2007.