HR 6928 (HIP 90497)

HR 6928 is a blue-white giant star in the constellation Serpens. At 859 light years away, it shines at an apparent visual magnitude of 5.70. It is moving through the Galaxy at a speed of 32.1 km/s relative to the Sun.

Sky position: RA 18h 28.0m, Dec +6° 11.6'

Common designations: HR 6928, HD 170200, HIP 90497, Gaia DR3 4477148783533394816

HR 6928 has the spectral type B8III. B-type stars are hot (about 10,000 to 30,000 K), luminous and blue-white. They are massive, short-lived stars, typically only tens of millions of years old, and are common in young clusters and OB associations. Its luminosity class III marks it as a giant: an evolved star that has left the main sequence and swollen to many times its original size.

How to find HR 6928 in the sky

HR 6928 lies in Serpens. With a declination of +6° 11.6', it is visible from the entire Northern Hemisphere and from the Southern Hemisphere down to about latitude 84° S. It is bright enough to see with the naked eye under dark skies. It is highest in the sky at local midnight around July, which makes the weeks around that month the best time to observe it.

Tabulated data for HR 6928

Astrometry and spectroscopy

Right Ascension (J2000)	276.99489010° (18h 28.0m)
Declination (J2000)	6.19410347° (+6° 11.6')
Galactic Longitude	35.80934132°
Galactic Latitude	8.02501216°
Proper motion RA	-0.61 mas/yr
Proper motion Dec	-23.94 mas/yr
Parallax	3.80 ± 0.15 mas
Spectral Type	B8III
Radial Velocity	-11.80 km/s

Photometry

Band	Magnitude	Abs. Mag.
U	5.33	-1.77
B	5.67	-1.44
V	5.70	-1.40
J	5.73	-1.38
H	5.75	-1.35
K	5.74	-1.36

Colour index B-V: -0.03

Derivations

Heliocentric distance: 263.29 pc (859 light years) (4.1% margin of error)
Absolute visual magnitude: -1.40
Transverse velocity: 29.9 km/s
Space velocity relative to the Sun: 32.1 km/s
Galactic position (X, Y, Z): 211.4 pc, 152.5 pc, 36.8 pc
Galactic velocity (U, V, W): 7.8 km/s, -27.7 km/s, -14.2 km/s

Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.