Nu Phoenicis is a F-type main-sequence star in the southern constellation of Phoenix. It is visible to the naked eye with an apparent visual magnitude of 4.95.[2] This is a solar analogue, meaning its observed properties appear similar to the Sun, although it is somewhat more massive. At an estimated distance of around 49.5 light years,[4] this star is located relatively near the Sun.
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Phoenix |
Right ascension | 01h 15m 11.12150s[1] |
Declination | –45° 31′ 53.9954″[1] |
Apparent magnitude (V) | 4.95[2] |
Characteristics | |
Spectral type | F9 V Fe+0.4[3] |
U−B color index | +0.09[2] |
B−V color index | +0.57[2] |
Astrometry | |
Radial velocity (Rv) | +11.82 ± 0.15[4] km/s |
Proper motion (μ) | RA: 664.28[4] mas/yr Dec.: 179.06[4] mas/yr |
Parallax (π) | 65.8894 ± 0.1803 mas[4] |
Distance | 49.5 ± 0.1 ly (15.18 ± 0.04 pc) |
Absolute magnitude (MV) | 4.07[5] |
Details[5] | |
Mass | 1.17 M☉ |
Radius | 1.26 ± 0.04 R☉ |
Luminosity | 2.0 ± 0.1 L☉ |
Surface gravity (log g) | 4.31 ± 0.10 cgs |
Temperature | 6,066 ± 70 K |
Metallicity [Fe/H] | +0.16 ± 0.06 dex |
Rotational velocity (v sin i) | 3.7 ± 0.5 km/s |
Age | 4.2[6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Based on observations of excess infrared radiation from this star, it may possess a dust ring that extends outward several AU from an inner edge starting at 10 AU.[8]
This is an F-type main-sequence star with a spectral type of F9V Fe+0.4,[3] indicating it is similar to the Sun but somewhat hotter and more luminous. The notation 'Fe+0.4' indicates strong iron absorption lines; the star is indeed metal-rich, with an iron abundance 45% greater than the Sun's. Nu Phoenicis has an estimated mass of 1.17 times the solar mass and a radius of 1.26 times the solar radius. It is shining with about double the solar luminosity at an effective temperature of 6,070 K.[5]
Nu Phoenicis has a projected rotational velocity of 3.7 km/s,[5] and a low chromospheric activity index (log R′HK = −4.95).[9] These values indicate that the star is not particularly young and has an age of a few billion years; empirical calibrations estimate from the rotational velocity an age of 2.4 billion years, and from the activity index an age of 5.67 billion years.[9] Similarly, stellar evolution models estimate an age between 1 and 6 billion years, with a more probable value of 4.2 billion years.[6]
Nu Phoenicis has no known companions, and is considered to be a single star.[5] As a bright star similar to the Sun, it has been targeted in a number of studies searching for planets with the radial velocity method, but no detection has been made. High-precision observations with the HARPS spectrograph show that the radial velocity of the star has no significant variability, and is constant to 2.67 m/s, a value similar to the estimated jitter level of 2.48 m/s.[10] The star has also been included in the observations of the Anglo-Australian Planet Search, which did not find Jupiter-analogs with periods up to 6,000 days.[11]
Nu Phoenicis emits a significant amount of infrared excess, in comparison to the expected emission from the star's photosphere, indicating it has a circumstellar debris disk that is warmed by the star and emits thermal radiation.[8] The excess has been detected in long wavelengths, between 30[8] and 100 μm,[12] indicating relatively cold dust many astronomical units away from the star. Modeling the emission as a black body, the disk has an estimated temperature of 96 K and a radius of 12 AU, contributing to 0.00024% of the system's luminosity.[12]