48 Librae, a blue-white giant star in Libra
48 Librae is a blue-white giant star in the constellation Libra. At 456 light years away, it shines at an apparent visual magnitude of 4.87.
48 Librae (HIP 78207)
48 Librae is a blue-white giant star in the constellation Libra. At 456 light years away, it shines at an apparent visual magnitude of 4.87. It is moving through the Galaxy at a speed of 28.7 km/s relative to the Sun.
Sky position: RA 15h 58.2m, Dec -14° 16.8'
Common designations: 48 Librae, FX Librae, HR 5941, HD 142983, HIP 78207, Gaia DR3 6263223955904774656
48 Librae has the spectral type B5IIIp_sh. 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 48 Librae in the sky
48 Librae lies in Libra. With a declination of -14° 16.8', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 76° N. It is bright enough to see with the naked eye under dark skies. It is highest in the sky at local midnight around June, which makes the weeks around that month the best time to observe it.
Tabulated data for 48 Librae
Astrometry and spectroscopy
| Right Ascension (J2000) | 239.54736771° (15h 58.2m) |
| Declination (J2000) | -14.27935586° (-14° 16.8') |
| Galactic Longitude | 356.38668614° |
| Galactic Latitude | 28.63165645° |
| Proper motion RA | -13.84 mas/yr |
| Proper motion Dec | -16.27 mas/yr |
| Parallax | 7.15 ± 0.12 mas |
| Spectral Type | B5IIIp_sh |
| Radial Velocity | -25.01 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| U | 4.61 | -1.12 |
| B | 4.77 | -0.96 |
| V | 4.87 | -0.86 |
| R | 4.91 | -0.82 |
| I | 4.96 | -0.77 |
| J | 4.89 | -0.84 |
| H | 4.83 | -0.90 |
| K | 4.59 | -1.14 |
Colour index B-V: -0.10
Derivations
- Heliocentric distance: 139.78 pc (456 light years) (1.7% margin of error)
- Absolute visual magnitude: -0.86
- Transverse velocity: 14.2 km/s
- Space velocity relative to the Sun: 28.7 km/s
- Galactic position (X, Y, Z): 122.4 pc, -7.7 pc, 67.0 pc
- Galactic velocity (U, V, W): -22.6 km/s, -12.8 km/s, -12.4 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.