Theta Normae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Norma |
| Right ascension | 16h 15m 15.31794s |
| Declination | −47° 22′ 19.2710″ |
| Apparent magnitude (V) | 5.13 |
| Characteristics | |
| Spectral type | B8 V |
| B−V color index | −0.12 |
| Astrometry | |
| Radial velocity (Rv) | +1.4±4.2 km/s |
| Proper motion (μ) | RA: −34.771 mas/yr Dec.: −45.813 mas/yr |
| Parallax (π) | 9.2718±0.1692 mas |
| Distance | 352 ± 6 ly (108 ± 2 pc) |
| Absolute magnitude (MV) | −0.23 |
| Details | |
| Mass | 3.6 M☉ |
| Radius | 3.05 R☉ |
| Luminosity | 184 L☉ |
| Surface gravity (log g) | 4.5 cgs |
| Temperature | 12,341 K |
| Rotational velocity (v sin i) | 251 km/s |
| Age | 17 Myr |
| Other designations | |
| θ Nor, CPD−47°10611, HD 145842, HIP 79653, HR 6045, SAO 226600 | |
| Database references | |
| SIMBAD | data |
θ Normae, Latinised as Theta Normae, is a binary star system in the constellation Norma. It has an apparent visual magnitude of 5.13 and is visible to the naked eye as a faint, blue-white-hued point of light. Based upon an annual parallax shift of 9.27 mas as seen from Earth, this system is located about 352 light-years from the Sun. At that distance, the visual magnitude of these stars is diminished by an extinction of 0.45 due to interstellar dust.
Chini et al. (2012) identified this as a single-lined spectroscopic binary system. The visible component is a B-type main-sequence star with a stellar classification of B8 V. It is about 17 million tears old and is spinning rapidly with a projected rotational velocity of 251 km/s. The star has 3.6 times the mass of the Sun and 3.05 times the Sun's radius. It is radiating about 184 times the Sun's luminosity from its photosphere at an effective temperature of 12,341 K. This system displays an infrared excess, suggesting a debris disk is orbiting at a mean radius of 21.8 AU with a temperature of 220 K.