AZ Phoenicis (HR 239) is a variable star in the constellation of Phoenix. It has an average visual apparent magnitude of 6.47,[3] so it is at the limit of naked eye visibility. From parallax measurements by the Gaia spacecraft, it is located at a distance of 322 light-years (99 parsecs) from Earth.[2] Its absolute magnitude is calculated at 1.65.[6]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Phoenix |
Right ascension | 00h 50m 03.77s[2] |
Declination | −43° 23′ 41.92″[2] |
Apparent magnitude (V) | 6.47[3] |
Characteristics | |
Spectral type | A9/F0III[4] |
Variable type | δ Scuti[3] |
Astrometry | |
Radial velocity (Rv) | 11.9[5] km/s |
Proper motion (μ) | RA: 6.65[2] mas/yr Dec.: 25.03[2] mas/yr |
Parallax (π) | 10.1141 ± 0.0578 mas[2] |
Distance | 322 ± 2 ly (98.9 ± 0.6 pc) |
Absolute magnitude (MV) | 1.65 ± 0.30[6] |
Details | |
Radius | 2.70[2] R☉ |
Luminosity | 18.6+5.9 −4.5[6] L☉ |
Surface gravity (log g) | 3.78 ± 0.08[6] cgs |
Temperature | 7,278 ± 34[6] K |
Metallicity | [Z] = +0.52 ± 0.15[6] |
Other designations | |
Database references | |
SIMBAD | data |
AZ Phoenicis is a Delta Scuti variable that pulsates with a single period of 79.3 minutes,[1] causing its visual brightness to vary with an amplitude of 0.015 magnitudes.[3] Its variability was discovered by Werner Weiss in 1977, from observations with the 50-cm telescope at La Silla Observatory.[8] AZ Phoenicis has also been classified as a possible Ap star, which remains uncertain, even though the star has a large concentration of metals;[1] the overall metallicity of the star has been measured to about 3 times the solar metallicity.[6]
This star is classified with a spectral type of A9/F0III,[4] corresponding to a giant of type A or F. With an estimated radius of 2.7 times the solar radius,[2] it is shining with 19 times the solar luminosity at an effective temperature of 7,280 K.[6] The astrometric observations by the Hipparcos spacecraft detected a significant acceleration in the proper motion of AZ Phoenicis, indicating it is an astrometric binary.[9]