Theta Piscis Austrini, a white main-sequence star in Piscis Austrinus
Theta Piscis Austrini is a white main-sequence star in the constellation Piscis Austrinus. At 321 light years away, it shines at an apparent visual magnitude of 5.02.
Theta Piscis Austrini (HIP 107608)
Theta Piscis Austrini is a white main-sequence star in the constellation Piscis Austrinus. At 321 light years away, it shines at an apparent visual magnitude of 5.02. It is moving through the Galaxy at a speed of 20.5 km/s relative to the Sun.
Sky position: RA 21h 47.7m, Dec -30° 53.9'
Common designations: Theta Piscis Austrini, 10 Piscis Austrini, HR 8326, HD 207155, Gaia DR3 6592981614920839168, HIP 107608
Theta Piscis Austrini 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 Theta Piscis Austrini in the sky
Theta Piscis Austrini lies in Piscis Austrinus. With a declination of -30° 53.9', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 59° N. Observers poleward of latitude 59° 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 September, which makes the weeks around that month the best time to observe it.
Tabulated data for Theta Piscis Austrini
Astrometry and spectroscopy
| Right Ascension (J2000) | 326.93395804° (21h 47.7m) |
| Declination (J2000) | -30.89830629° (-30° 53.9') |
| Galactic Longitude | 16.23991063° |
| Galactic Latitude | -49.93956557° |
| Proper motion RA | -34.40 mas/yr |
| Proper motion Dec | -0.08 mas/yr |
| Parallax | 10.16 ± 0.40 mas |
| Spectral Type | A1V |
| Radial Velocity | 12.80 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| B | 5.06 | 0.09 |
| V | 5.02 | 0.05 |
| J | 4.93 | -0.04 |
| H | 4.96 | -0.01 |
| K | 4.85 | -0.12 |
Colour index B-V: +0.04
Derivations
- Heliocentric distance: 98.43 pc (321 light years) (3.9% margin of error)
- Absolute visual magnitude: 0.05
- Transverse velocity: 16.1 km/s
- Space velocity relative to the Sun: 20.5 km/s
- Galactic position (X, Y, Z): 60.8 pc, 17.7 pc, -75.3 pc
- Galactic velocity (U, V, W): 20.1 km/s, 3.9 km/s, 0.5 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.