Z Apodis
Variable star in the constellation Apus
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Z Apodis (Z Aps) is a variable star in the constellation of Apus. It has an apparent visual magnitude which varies between 10.8 and 12.8,[3] over a period of 39.37 days.[3] Although described in the General Catalogue of Variable Stars as a cataclysmic variable star, it appears that it is a pulsating variable star,[4] and has been classed as an RV Tauri variable star, type RVa.[3] Other sources classify it is a type II (W Virginis) Cepheid.[7]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Apus |
| Right ascension | 14h 06m 54.82s[2] |
| Declination | −71° 22′ 16.7″[2] |
| Apparent magnitude (V) | 10.8 to 12.0[3] |
| Characteristics | |
| U−B color index | +0.5 - +1.5[4] |
| B−V color index | +1.5 - +1.75[4] |
| Variable type | RV Tau?[3] |
| Astrometry | |
| Proper motion (μ) | RA: −3.841[2] mas/yr Dec.: −1.604[2] mas/yr |
| Parallax (π) | 0.3135±0.0131 mas[2] |
| Distance | 10,400 ± 400 ly (3,200 ± 100 pc) |
| Details | |
| Mass | 3.2[5] M☉ |
| Radius | 27.6[2] R☉ |
| Luminosity | 405[2] L☉ |
| Surface gravity (log g) | 2.12[2] cgs |
| Temperature | 4,579[2] K |
| Metallicity [Fe/H] | −0.76[5] dex |
| Age | 11[6] Gyr |
| Other designations | |
| Z Aps, TYC 9252-1914-1, 2MASS J14065484-7122167, AAVSO 1358-70A | |
| Database references | |
| SIMBAD | data |
Edna B. Florence discovered the variability of Z Apodis by examining photographic plates. The discovery was announced by Henrietta Hill Swope in 1931. Examination of 20 plates taken in 1925 allowed the derivation of a period of 19.5 days, almost exactly half of the currently accepted period. However, observations outside of that time window seemed "...too scattered to give any other indication of a period.", so the star was initially classified as an irregular variable.[8]
