HD 180450

HD 180450 is a single^[7] star in the northern constellation of Lyra, positioned about half a degree to the NNW of the globular cluster M56.^[8] At an apparent visual magnitude of 5.88,^[1] it is dimly visible to the naked eye under good viewing conditions. This star is located at a distance of approximately 1,400 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −64.4 km/s.^[2]

HD 180450

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Lyra[1]
Right ascension	19h 15m 24.85937s[2]
Declination	+30° 31′ 34.9760″[2]
Apparent magnitude (V)	5.88[1]
Characteristics
Evolutionary stage	AGB[3]
Spectral type	M1IIIab[1]
U−B color index	+2.03
B−V color index	+1.665±0.007[1]
Astrometry
Radial velocity (Rv)	−64.43±0.23[2] km/s
Proper motion (μ)	RA: 34.425[2] mas/yr Dec.: −26.081[2] mas/yr
Parallax (π)	2.37±0.61 mas[2]
Distance	approx. 1,400 ly (approx. 400 pc)
Absolute magnitude (MV)	−2.03[1]
Details
Mass	1.4[4] M☉
Radius	84[5] R☉
Luminosity	1,218[5] L☉
Surface gravity (log g)	1.58[4] cgs
Temperature	3,733[5] K
Metallicity [Fe/H]	−0.23[4] dex
Other designations
BD+30°3491, GC 26550, HD 180450, HIP 94630, HR 7302, SAO 68040, GSC 02653-01682[6]
Database references
SIMBAD	data

This is an aging red giant star with a stellar classification of M1IIIab,^[1] It is currently on the asymptotic giant branch,^[9] having exhausted the supply of hydrogen in its core and evolved of the main sequence. It has expanded to ~68 times the radius of the Sun and is radiating a thousand times the Sun' luminosity from its enlarged photosphere at en effective temperature of 3,947 K.^[2]