Iota Trianguli Australis, a yellow-white subgiant star in Triangulum Australe
Iota Trianguli Australis is a yellow-white subgiant star in the constellation Triangulum Australe. At 130 light years away, it shines at an apparent visual magnitude of 5.29.
Iota Trianguli Australis (HIP 80645)
Iota Trianguli Australis is a yellow-white subgiant star in the constellation Triangulum Australe. At 130 light years away, it shines at an apparent visual magnitude of 5.29. It is moving through the Galaxy at a speed of 12.3 km/s relative to the Sun.
Sky position: RA 16h 28.0m, Dec -64° 3.5'
Common designations: Iota Trianguli Australis, HR 6109, HD 147787, HIP 80645, Gaia DR3 5828317422956035072
Iota Trianguli Australis has the spectral type F0IV. F-type stars are yellow-white stars of about 6,000 to 7,500 K, slightly hotter and more massive than the Sun. Their hydrogen lines are weaker than in A stars and metal lines become prominent. Its luminosity class IV marks it as a subgiant: it has exhausted hydrogen in its core and is beginning to expand toward the giant phase.
How to find Iota Trianguli Australis in the sky
Iota Trianguli Australis lies in Triangulum Australe. With a declination of -64° 3.5', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 26° N. Observers poleward of latitude 26° 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 June, which makes the weeks around that month the best time to observe it.
Tabulated data for Iota Trianguli Australis
Astrometry and spectroscopy
| Right Ascension (J2000) | 246.98893977° (16h 28.0m) |
| Declination (J2000) | -64.05794042° (-64° 3.5') |
| Galactic Longitude | 324.06337888° |
| Galactic Latitude | -10.48067122° |
| Proper motion RA | 53.43 mas/yr |
| Proper motion Dec | 25.64 mas/yr |
| Parallax | 25.09 ± 0.09 mas |
| Spectral Type | F0IV |
| Radial Velocity | -5.10 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| B | 5.61 | 2.61 |
| V | 5.29 | 2.29 |
| J | 4.54 | 1.54 |
| H | 4.57 | 1.57 |
| K | 4.41 | 1.41 |
Colour index B-V: +0.32
Derivations
- Heliocentric distance: 39.86 pc (130 light years) (0.4% margin of error)
- Absolute visual magnitude: 2.29
- Transverse velocity: 11.2 km/s
- Space velocity relative to the Sun: 12.3 km/s
- Galactic position (X, Y, Z): 31.7 pc, -23.0 pc, -7.2 pc
- Galactic velocity (U, V, W): 1.4 km/s, 11.8 km/s, -3.1 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.