Delta Horologii
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Horologium |
| Right ascension | 04h 10m 50.58927s |
| Declination | −41° 59′ 36.8537″ |
| Apparent magnitude (V) | 4.93 (5.15 + 7.29) |
| Characteristics | |
| Spectral type | A9 V |
| U−B color index | +0.084 |
| B−V color index | +0.338 |
| Astrometry | |
| Radial velocity (Rv) | +38.3±2.6 km/s |
| Proper motion (μ) | RA: +199.08 mas/yr Dec.: +70.18 mas/yr |
| Parallax (π) | 18.24±0.41 mas |
| Distance | 179 ± 4 ly (55 ± 1 pc) |
| Absolute magnitude (MV) | 1.50 |
| Details | |
| δ Hor A | |
| Mass | 1.41 M☉ |
| Surface gravity (log g) | 3.71±0.14 cgs |
| Temperature | 7,033±239 K |
| Metallicity [Fe/H] | −0.32 dex |
| Rotational velocity (v sin i) | 220.1±11.0 km/s |
| Age | 768 Myr |
| δ Hor B | |
| Rotational velocity (v sin i) | 51.7±2.6 km/s |
| Other designations | |
| δ Hor, CD−42°1400, HD 26612, HIP 19515, HR 1302, SAO 216682, WDS J04108-4200AB | |
| Database references | |
| SIMBAD | data |
Delta Horologii (δ Horologii) is a binary star system in the constellation Horologium. It is visible to the naked eye with a combined apparent visual magnitude of 4.93. As of 2014, the pair had an angular separation of 0.20 arc seconds along a position angle of 24°. Based upon an annual parallax shift of 18.24 mas as seen from Earth, it is located 179 ± 4 light years from the Sun.
The primary, component A, is a magnitude 5.15 A-type main sequence star with a stellar classification of A9 V. At the estimated age of 768 million years, it is spinning rapidly with a projected rotational velocity of 220 km/s, giving the star an oblate shape with an equatorial bulge that is 15% larger than the polar radius. The star has 1.4 times the mass of the Sun.
The secondary has an apparent magnitude of 7.29.