| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 11h 28m 30.2137s[1] |
| Declination | +43° 57′ 59.6854″[1] |
| Apparent magnitude (V) | 7.65[2] |
| Characteristics | |
| Evolutionary stage | Subgiant[2] |
| Spectral type | K0[3] |
| B−Vcolor index | 1.0[4] |
| Astrometry | |
| Radial velocity (Rv) | −30.07[1] km/s |
| Proper motion (μ) | RA: 45.406[1]mas/yr Dec.: −87.500[1]mas/yr |
| Parallax (π) | 6.7929±0.0518 mas[1] |
| Distance | 480 ± 4 ly (147 ± 1 pc) |
| Absolute magnitude (MV) | 2.12[5] |
| Details[2] | |
| Mass | 1.46 M☉ |
| Radius | 5.52 R☉ |
| Luminosity | 13.1±0.1[6] L☉ |
| Surface gravity (log g) | 3.09 cgs |
| Temperature | 4,862 K |
| Metallicity [Fe/H] | 0.05[7] dex |
| Rotational velocity (v sin i) | 1.8±0.6[7] km/s |
| Age | 2.8±0.2[6] Gyr |
| Other designations | |
| BD+44°2096,HD 99706,HIP 55994,TYC 3015-1137-1,2MASS J11283020+4357597[8] | |
| Database references | |
| SIMBAD | data |
HD 99706 is an orange-huedstar in the northerncircumpolar constellation ofUrsa Major. With anapparent visual magnitude of 7.65,[2] it is too dim to be visible to the naked eye but can be viewed with a pair of binoculars.[9]Parallax measurements provide a distance estimate of approximately 480 light years from theSun, and theDoppler shift shows it is drifting closer with aradial velocity of −30 km/s.[1] It has anabsolute magnitude of 2.12,[5] indicating it would be visible to the naked eye as a 2nd magnitude star if it were located 10 parsecs away.
This is an agingsubgiant[2] star belonging tospectral class K0,[3] having exhausted the supply of hydrogen at itscore and begun to evolve into agiant. Its age is younger than the Sun's at2.8±0.2 billion years and it is spinning slowly with aprojected rotational velocity of 2 km/s.[7] The star has 1.5 times themass of the Sun and has expanded to 5.5 times theSun's radius. It is slightly enriched in heavy elements, having 110% of solar abundance.[7] HD 99706 is radiating 13[6] times theluminosity of the Sun from itsphotosphere at aneffective temperature of 4,862 K.[2]
An imaging survey atCalar Alto Observatory in 2016 failed to detect any stellar companions to HD 99706.[10]
In 2011 onesuperjovian exoplanet, HD 99706 b, on a mildly eccentric orbit around star HD 99706 was discovered utilizing theradial velocity method.[4] Anothersuperjovian exoplanet on an outer orbit was detected in 2016.[11]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| HD 99706 b | >1.23 MJ | 1.98 | 841 | 0.25 | — | 1.244 RJ |
| HD 99706 c | >5.69+1.43 −0.96 MJ | — | 1278+151 −198 | 0.411+0.231 −0.178 | — | — |
