13 Delphini

13 Delphini
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Delphinus
A
Right ascension 20h 47m 48.3330s
Declination +06° 00 29.551
Apparent magnitude (V) 5.66
B
Right ascension 20h 47m 48.3012s
Declination +06° 00 28.127
Apparent magnitude (V) 8.51
Characteristics
Evolutionary stage main sequence
Spectral type A0 V
U−B color index −0.09
B−V color index −0.01
Astrometry
Radial velocity (Rv)−7±4.3 km/s
Absolute magnitude (MV)−0.01
A
Proper motion (μ) RA: +8.255 mas/yr
Dec.: −13.162 mas/yr
Parallax (π)6.9265±0.0489 mas
Distance471 ± 3 ly
(144 ± 1 pc)
B
Proper motion (μ) RA: +5.663 mas/yr
Dec.: −12.280 mas/yr
Parallax (π)6.6697 ± 0.0989 mas
Distance489 ± 7 ly
(150 ± 2 pc)
Details
Mass2.51+0.31
0.36
 M
Radius3.7±0.4 R
Luminosity119+20
17
 L
Surface gravity (log g)3.69+0.61
0.69
 cgs
Temperature9,840+91
90
 K
Metallicity [Fe/H]0.00 dex
Rotational velocity (v sin i)170 km/s
Age307 Myr
Other designations
13 Del, 18 G. Delphini, AG+05°3035, BD+05°4613, GC 28986, HD 198069, HIP 102633, HR 7953, SAO 126222, WDS J20478+0600A
Database references
SIMBADdata

13 Delphini is a binary star in the equatorial constellation Delphinus, with a combined apparent magnitude of 5.64. The system is located at a distance of 471 light years but is approaching the Solar System with a heliocentric radial velocity of about −7 km/s.

13 Delphini A has an apparent magnitude of 5.66, while its companion has an apparent magnitude of 8.51. As of 2016, the pair have a separation of 1.5 located at a position angle of 200°.

13 Delphini has a blended stellar classification of A0 V, indicating that it is an ordinary A-type main-sequence star. However, when the components are analysed individually, the primary star is given a class of B9V. It has 2.51 times the mass of the Sun and has an effective temperature of 9,840 K. However, the star is large for its class, having a radius almost 4 times that of the Sun and a luminosity 119 times greater. This is due to 13 Delphini having completed 86.1% of its main sequence lifetime and has led one source to classify it as a subgiant instead. It spins rapidly with a projected rotational velocity of 170 km/s and has an age of 307 million years.