5 Eridani (HIP 13951)

5 Eridani is a blue-white main-sequence star in the constellation Eridanus. At 379 light years away, it shines at an apparent visual magnitude of 5.55. It is moving through the Galaxy at a speed of 29.1 km/s relative to the Sun.

Sky position: RA 2h 59.7m, Dec -2° 27.9'

Common designations: 5 Eridani, HR 899, HD 18633, HIP 13951, Gaia DR3 5186457169251897344

5 Eridani has the spectral type B9V. 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 V means it is a main-sequence (dwarf) star, still fusing hydrogen into helium in its core like the Sun.

How to find 5 Eridani in the sky

5 Eridani lies in Eridanus. With a declination of -2° 27.9', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 88° N. It is bright enough to see with the naked eye under dark skies. It is highest in the sky at local midnight around November, which makes the weeks around that month the best time to observe it.

Tabulated data for 5 Eridani

Astrometry and spectroscopy

Right Ascension (J2000)	44.92150100° (2h 59.7m)
Declination (J2000)	-2.46495615° (-2° 27.9')
Galactic Longitude	179.67512541°
Galactic Latitude	-50.63804978°
Proper motion RA	-3.90 mas/yr
Proper motion Dec	-22.76 mas/yr
Parallax	8.61 ± 0.11 mas
Spectral Type	B9V
Radial Velocity	26.18 km/s

Photometry

Band	Magnitude	Abs. Mag.
B	5.48	0.15
V	5.55	0.22
J	5.69	0.36
H	5.69	0.36
K	5.67	0.34

Colour index B-V: -0.07

Derivations

Heliocentric distance: 116.16 pc (379 light years) (1.2% margin of error)
Absolute visual magnitude: 0.22
Transverse velocity: 12.7 km/s
Space velocity relative to the Sun: 29.1 km/s
Galactic position (X, Y, Z): -73.7 pc, 0.4 pc, -89.8 pc
Galactic velocity (U, V, W): -8.9 km/s, -7.9 km/s, -26.6 km/s

Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.