Z Apodis

Not to be confused with Zeta Apodis.

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]

Z Apodis

A visual band light curve for Z Apodis, plotted from ASAS-SN data[1]
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]