HR 7507, a blue-white giant star in Sagittarius
HR 7507 is a blue-white giant star in the constellation Sagittarius. At 936 light years away, it shines at an apparent visual magnitude of 5.51.
HR 7507 (HIP 97260)
HR 7507 is a blue-white giant star in the constellation Sagittarius. At 936 light years away, it shines at an apparent visual magnitude of 5.51. It is moving through the Galaxy at a speed of 31.8 km/s relative to the Sun.
Sky position: RA 19h 46.0m, Dec -31° 54.5'
Common designations: HR 7507, HD 186500, HIP 97260, Gaia DR3 6748040070433427456
HR 7507 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 7507 in the sky
HR 7507 lies in Sagittarius. With a declination of -31° 54.5', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 58° N. Observers poleward of latitude 58° S see it as circumpolar: it never sets. It is bright enough to see with the naked eye under dark skies. It is highest in the sky at local midnight around August, which makes the weeks around that month the best time to observe it.
Tabulated data for HR 7507
Astrometry and spectroscopy
| Right Ascension (J2000) | 296.50510466° (19h 46.0m) |
| Declination (J2000) | -31.90856839° (-31° 54.5') |
| Galactic Longitude | 8.25072641° |
| Galactic Latitude | -24.78742338° |
| Proper motion RA | -1.65 mas/yr |
| Proper motion Dec | -20.09 mas/yr |
| Parallax | 3.48 ± 0.19 mas |
| Spectral Type | B8III |
| Radial Velocity | -16.02 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| B | 5.52 | -1.77 |
| V | 5.51 | -1.78 |
| J | 5.42 | -1.87 |
| H | 5.34 | -1.95 |
| K | 5.36 | -1.93 |
Colour index B-V: +0.01
Derivations
- Heliocentric distance: 287.02 pc (936 light years) (5.4% margin of error)
- Absolute visual magnitude: -1.78
- Transverse velocity: 27.4 km/s
- Space velocity relative to the Sun: 31.8 km/s
- Galactic position (X, Y, Z): 257.9 pc, 37.4 pc, -120.3 pc
- Galactic velocity (U, V, W): -13.1 km/s, -28.9 km/s, 1.1 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.