Astronomy:Z Apodis
| Observation data 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[2] mas |
| 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 | |
| Database references | |
| SIMBAD | data |
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]
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]
References
- ↑ "ASAS-SN Variable Stars Database". ASAS-SN. https://asas-sn.osu.edu/variables/lookup.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 3.4 Watson, Christopher (4 January 2010). "Z Apodis". The International Variable Star Index. American Association of Variable Star Observers. http://www.aavso.org/vsx/index.php?view=detail.top&oid=534.
- ↑ 4.0 4.1 4.2 Marino, B. F.; Walker, W. S. G. (1991). "Z Apodis is a Pulsating - not a Cataclysmic - Variable Star". Information Bulletin on Variable Stars 3664: 1. Bibcode: 1991IBVS.3664....1M.
- ↑ 5.0 5.1 Anders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardevol, J.; Casamiquela, L.; Figueras, F.; Jimenez-Arranz, O. et al. (2022). "VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022)". Vizier Online Data Catalog. Bibcode: 2022yCat.1354....0A.
- ↑ Fouesneau, M.; Andrae, R.; Dharmawardena, T.; Rybizki, J.; Bailer-Jones, C. A. L.; Demleitner, M. (2022). "Astrophysical parameters from Gaia DR2, 2MASS, and AllWISE". Astronomy and Astrophysics 662: A125. doi:10.1051/0004-6361/202141828. Bibcode: 2022A&A...662A.125F.
- ↑ Ripepi, V.; Molinaro, R.; Musella, I.; Marconi, M.; Leccia, S.; Eyer, L. (2019). "Reclassification of Cepheids in the Gaia Data Release 2. Period-luminosity and period-Wesenheit relations in the Gaia passbands". Astronomy and Astrophysics 625: 625. doi:10.1051/0004-6361/201834506. Bibcode: 2019A&A...625A..14R.
- ↑ Swope, Henrietta H. (June 1931). "New Variable Stars in Centaurus and Circinus". Harvard College Observatory Bulletin 883: 23-30. Bibcode: 1931BHarO.883...23S. https://articles.adsabs.harvard.edu/pdf/1931BHarO.883...23S. Retrieved 15 November 2024.
 |  |
