Location of HD 101782 (circled) | |
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Chamaeleon |
Right ascension | 11h41m 01.30826s[1] |
Declination | −83° 05′ 59.7773″[1] |
Apparent magnitude (V) | 6.33±0.01[2] |
Characteristics | |
Evolutionary stage | horizontal branch[3] |
Spectral type | K0 III[4] |
U−B color index | +0.88[5] |
B−V color index | +1.08[5] |
Astrometry | |
Radial velocity (Rv) | 11.5±0.4[6] km/s |
Proper motion (μ) | RA: −59.825 mas/yr[1] Dec.: +9.477 mas/yr[1] |
Parallax (π) | 9.1605 ± 0.0172 mas[1] |
Distance | 356.0 ± 0.7 ly (109.2 ± 0.2 pc) |
Absolute magnitude (MV) | +1.11[7] |
Details | |
Mass | 2±0.5[8] M☉ |
Radius | 10.1[9] R☉ |
Luminosity | 55.25±0.21[1] L☉ |
Surface gravity (log g) | 2.73[1] cgs |
Temperature | 4,663±127[10] K |
Metallicity [Fe/H] | +0.04[11] dex |
Rotational velocity (v sin i) | <1.1[12] km/s |
Age | 455[1] Myr |
Other designations | |
33 G. Chamaeleontis[13], CD−82°224, CPD−82°469, GC 16057, HD 101782, HIP 56996, HR 4507, SAO 258621, WDS J11410-8306A[14] | |
Database references | |
SIMBAD | data |
HD 101782, also known as HR 4507, is a yellowish-orange hued star located in the southern circumpolar constellationofChamaeleon. It has an apparent magnitude of 6.33,[2] placing it near the limit for naked eye visibility. Based on parallax measurements from Gaia DR3, the object is estimated to be 356 light years away from the Solar System.[1] It appears to be receding with a heliocentric radial velocityof11.5 km/s.[6] De Mederios found the radial velocity to be variable, suggesting that it may be a spectroscopic binary.[12] Eggen (1989) lists it as a member of the young disk population.[11]
HD 101782 has a stellar classification of K0 III,[4] indicating that it is an evolved red giant. It is currently on the horizontal branch (HB), fusing helium at its core.[3] The star is located on the cool end of the red clump, a region on the HR diagram with metal-rich HB stars. It has double the mass of the Sun[8] but has expanded to 10.1 times its girth.[9] It radiates 55 times the luminosity of the Sun[1] from its photosphere at an effective temperatureof4,663 K.[10] It has an iron abundance 110% that of the Sun's, placing it at solar metallicity.[11] Like most giants it spins slowly, having a projected rotational velocity lower than 1.1 km/s.[12]
TYC 9507-3649-1 is a 10th magnitude optical companion located 25.9″ away along a position angle of 139°.[15] This companion was first noticed by Sir John Herschel in 1837.[16]