10 Delphini

10 Delphini (10 Del) is a solitary star in the equatorial constellation Delphinus. It has an apparent magnitude of 6.00, allowing it to be faintly seen with the naked eye. Parallax measurements put the object at a distance of 493 light years but is drifting closer with a heliocentric radial velocity of −32 km/s.

10 Delphini

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Delphinus
Right ascension	20h 41m 16.2079s[1]
Declination	+14° 34′ 58.3606″[1]
Apparent magnitude (V)	6.00±0.01[2]
Characteristics
Spectral type	K4 III[3]
U−B color index	+1.44[4]
B−V color index	+1.24[5]
Astrometry
Radial velocity (Rv)	−32±2[6] km/s
Proper motion (μ)	RA: −9.462 mas/yr[1] Dec.: −0.344 mas/yr[1]
Parallax (π)	6.6178±0.0397 mas[1]
Distance	493 ± 3 ly (151.1 ± 0.9 pc)
Absolute magnitude (MV)	+0.06[7]
Details
Mass	2.42±0.71[8] M☉
Radius	18.47+1.02 −1.03[9] R☉
Luminosity	125±2[9] L☉
Surface gravity (log g)	2.27[10] cgs
Temperature	4,378[10] K
Metallicity [Fe/H]	0.00[10] dex
Age	794±33[8] Myr
Other designations
10 Del, AG+14°2269, BD+14°4393, GC 28826, HD 197121, HIP 102080, HR 7918, SAO 106384
Database references
SIMBAD	data

10 Delphini has a stellar classification of K4 III^[3] or K2 III,^[11] both indicating that it is a red giant. However, there is some uncertainty behind the first classification. It has twice the mass of the Sun^[8] but at an age of 794 million years^[8] — expanded to 18 times the radius of the Sun.^[9] It shines at 125 L_☉^[9] from its enlarged photosphere at an effective temperature of 4,378 K,^[10] giving it an orange glow. 10 Del has a solar metallicity.^[10]

10 Del has been suspected to be a variable star, although it hasn't been catalogued as such in the GCVS.^[12]