11h28m 30.2137s[1]
+43° 57′ 59.6854″[1]
7.65[2]
Characteristics
K0[3]
B−V color index
1.0[4]
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)
Absolute magnitude (MV)
2.12[5]
Details[2]
1.46 M☉
5.52 R☉
Surface gravity (log g)
3.09 cgs
4,862 K
Metallicity [Fe/H]
Rotational velocity (v sin i)
1.8±0.6[7] km/s
Database references
HD 99706 is an orange-hued star in the northern circumpolar constellationofUrsa Major. With an apparent 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 the Sun, and the Doppler shift shows it is drifting closer with a radial velocity of −30 km/s.[1] It has an absolute 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 aging subgiant[2] star belonging to spectral class K0,[3] having exhausted the supply of hydrogen at its core and begun to evolve into a giant. Its age is younger than the Sun's at 2.8±0.2 billion years and it is spinning slowly with a projected rotational velocity of 2 km/s.[7] The star has 1.5 times the mass of the Sun and has expanded to 5.5 times the Sun's radius. It is slightly enriched in heavy elements, having 110% of solar abundance.[7] HD 99706 is radiating 13[6] times the luminosity of the Sun from its photosphere at an effective temperature of 4,862 K.[2]
An imaging survey at Calar Alto Observatory in 2016 failed to detect any stellar companions to HD 99706.[10]
In 2011 one superjovian exoplanet, HD 99706 b, on a mildly eccentric orbit around star HD 99706 was discovered utilizing the radial velocity method.[4] Another superjovian exoplanet on an outer orbit was detected in 2016.[11]
Companion
(in order from star)
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
—
—
Other
Other