θ Normae, Latinised as Theta Normae, is a binary star system in the constellation Norma. It has an apparent visual magnitude of 5.13[2] 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,[5] 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.[12]
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Norma |
Right ascension | 16h 15m 15.31794s[1] |
Declination | −47° 22′ 19.2710″[1] |
Apparent magnitude (V) | 5.13[2] |
Characteristics | |
Spectral type | B8 V[3] |
B−V color index | −0.12[2] |
Astrometry | |
Radial velocity (Rv) | +1.4±4.2[4] km/s |
Proper motion (μ) | RA: −34.771 mas/yr Dec.: −45.813 mas/yr |
Parallax (π) | 9.2718 ± 0.1692 mas[5] |
Distance | 352 ± 6 ly (108 ± 2 pc) |
Absolute magnitude (MV) | −0.23[6] |
Details | |
Mass | 3.6[7] M☉ |
Radius | 3.05[8] R☉ |
Luminosity | 184[9] L☉ |
Surface gravity (log g) | 4.5[7] cgs |
Temperature | 12,341[9] K |
Rotational velocity (v sin i) | 251[10] km/s |
Age | 17[7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Chini et al. (2012) identified this as a single-lined spectroscopic binary system.[13] The visible component is a B-type main-sequence star with a stellar classification of B8 V.[3] It is about 17[7] million tears old and is spinning rapidly with a projected rotational velocity of 251 km/s.[10] The star has 3.6[7] times the mass of the Sun and 3.05[8] 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.[9] 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.[8]
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