| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cetus[1] |
| Right ascension | 02h 34m 11.04689s[2] |
| Declination | −12° 23′ 3.4570″[2] |
| Apparent magnitude (V) | 9.85 |
| Characteristics | |
| Spectral type | F2V-IV[3][4][note 1] |
| Apparent magnitude (B) | 10.18[2] |
| Apparent magnitude (V) | 9.85[2] |
| Apparent magnitude (J) | 8.790[2] |
| Apparent magnitude (H) | 8.516[2] |
| Apparent magnitude (K) | 8.457[2] |
| Astrometry | |
| Radial velocity (Rv) | 23.62[2] km/s |
| Proper motion (μ) | RA: 57.27[2]mas/yr Dec.: -187.74[2]mas/yr |
| Parallax (π) | 8.93[2] mas |
| Distance | 376.1 ly (115.3[3] pc) |
| Details | |
| Mass | 0.83 ± 0.05[4] M☉ |
| Radius | 1.6 ± 0.1[3] R☉ |
| Temperature | 6040 ± 210[4] K |
| Metallicity[Fe/H] | –1.95 ± 0.09[3][note 2] dex |
| Age | 12.8 ± 2.6[4] Gyr |
| Other designations | |
| LP 710-89,BD-13° 482,HD 16031,HIP 11952,NLTT 8361,PPM 211702,SAO 148474,TYC 5288-192-1[2] | |
| Database references | |
| SIMBAD | data |
HIP 11952 is astar in theMilky Way galaxy, located 375 light-years away from theSun. While the spectral lines strongly indicate that the star is of spectral type F2V-IV, previous analyses have stated that the star is a G8III giant star and an F0V main-sequence star.[3] Located in the constellation Cetus, the star has ametallicity only 1% that of theSun. It is nearing the end of its lifetime on themain sequence, and will soon begin the transition into ared giant.[5]
In 2012 it was announced that HIP 11952 had two giant planets, this would have made it the oldest and most metal-poor planet host star known.[5] This would have posed a challenge to planetary formation, as the chances of a planet forming so early in the Universe's history, with such a small amount of heavy elements with which to form planets, are believed to be remote.[6]
Further measurements of HIP 11952 were made on 35 nights over about 150 days, from August 7, 2012, to January 6, 2013, using the newly installed high resolution spectrographHARPS-N at the 3.58mTelescopio Nazionale Galileo telescope on La Palma Island (Canary Islands) andHARPS at the European Southern Observatory's 3.6m telescope onLa Silla (Chile). Following their analysis, they were able to confidently exclude, through non-detection, the presence of the two giant planets with periods of 6.95 ± 0.01 days and 290.0 ± 16. 2 days.[7] They also reasoned that the previously mistaken detections were probably due to instrument measurement errors.[7] Re-analysis of the FEROS data revealed a problem with the barycentric correction used to derive the radial velocities; this error had led to the erroneous detection claim.[8]
