13 Delphini
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 .

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  located at a position angle of .

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  and has an age of 307 million years.

References

Delphinus
A-type main-sequence stars
Delphini, 13
Delphini, 18
BD+05 4613
198069
102633
7953
Binary stars