HR 3131 (HIP 39095)

HR 3131 is a white main-sequence star in the constellation Puppis. At 223 light years away, it shines at an apparent visual magnitude of 4.61. It is moving through the Galaxy at a speed of 17.4 km/s relative to the Sun.

Sky position: RA 7h 59.9m, Dec -18° 24.0'

Common designations: HR 3131, HD 65810, HIP 39095, Gaia DR3 5714859436545926016

HR 3131 has the spectral type A1V. A-type stars are white stars with surface temperatures of roughly 7,500 to 10,000 K. Their spectra are dominated by strong hydrogen lines, and many of them rotate rapidly. Its luminosity class V means it is a main-sequence (dwarf) star, still fusing hydrogen into helium in its core like the Sun.

How to find HR 3131 in the sky

HR 3131 lies in Puppis. With a declination of -18° 24.0', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 72° N. It is bright enough to see with the naked eye under dark skies. It is highest in the sky at local midnight around February, which makes the weeks around that month the best time to observe it.

Tabulated data for HR 3131

Astrometry and spectroscopy

Right Ascension (J2000)	119.96686484° (7h 59.9m)
Declination (J2000)	-18.39921691° (-18° 24.0')
Galactic Longitude	237.16416412°
Galactic Latitude	5.99800738°
Proper motion RA	6.46 mas/yr
Proper motion Dec	-43.72 mas/yr
Parallax	14.60 ± 0.21 mas
Spectral Type	A1V
Radial Velocity	-9.80 km/s

Photometry

Band	Magnitude	Abs. Mag.
U	4.77	0.59
B	4.69	0.51
V	4.61	0.43
R	4.46	0.28
I	4.40	0.22
J	4.40	0.22
H	4.33	0.15
K	4.31	0.13

Colour index B-V: +0.08

Derivations

Heliocentric distance: 68.50 pc (223 light years) (1.4% margin of error)
Absolute visual magnitude: 0.43
Transverse velocity: 14.4 km/s
Space velocity relative to the Sun: 17.4 km/s
Galactic position (X, Y, Z): -36.9 pc, -57.2 pc, 7.2 pc
Galactic velocity (U, V, W): 16.1 km/s, 0.5 km/s, -6.6 km/s

Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.