{{Short description|Variable star in the constellation Apus}} {{Distinguish|Zeta Apodis}} {{Starbox begin | name = Z Apodis}} {{Starbox image | image = 250px | caption = A visual band light curve for Z Apodis, plotted from ''ASAS-SN'' data<ref name="ASAS-SN">{{cite web |url=https://asas-sn.osu.edu/variables/lookup |website=ASAS-SN Variable Stars Database|title=ASAS-SN Variable Stars Database|publisher=ASAS-SN |access-date=6 January 2022}}</ref> }} {{Starbox observe | epoch = J2000.0 | equinox = J2000.0 (ICRS) | constell = Apus | ra = {{RA|14|06|54.82}}<ref name=dr3/> | dec = {{DEC|−71|22|16.7}}<ref name=dr3/> | appmag_v=10.8 to 12.0<ref name=AAVSOZ/> }} {{Starbox character | class = | b-v = +1.5 - +1.75<ref name=rv/> | u-b = +0.5 - +1.5<ref name=rv/> | variable = RV Tau?<ref name=AAVSOZ/> }} {{Starbox astrometry | prop_mo_ra = −3.841<ref name=dr3/> | prop_mo_dec = −1.604<ref name=dr3/> | parallax = 0.3135 | p_error = 0.0131 | parallax_footnote = <ref name=dr3>{{cite Gaia DR3|5845741379403386624}}</ref> }} {{Starbox detail | mass = 3.2<ref name=starhorse2>{{cite journal |bibcode=2022yCat.1354....0A |title=VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022) |last1=Anders |first1=F. |last2=Khalatyan |first2=A. |last3=Queiroz |first3=A. B. A. |last4=Chiappini |first4=C. |last5=Ardevol |first5=J. |last6=Casamiquela |first6=L. |last7=Figueras |first7=F. |last8=Jimenez-Arranz |first8=O. |last9=Jordi |first9=C. |last10=Monguio |first10=M. |last11=Romero-Gomez |first11=M. |last12=Altamirano |first12=D. |last13=Antoja |first13=T. |last14=Assaad |first14=R. |last15=Cantat-Gaudin |first15=T. |last16=Castro-Ginard |first16=A. |last17=Enke |first17=H. |last18=Girardi |first18=L. |last19=Guiglion |first19=G. |last20=Khan |first20=S. |last21=Luri |first21=X. |last22=Miglio |first22=A. |last23=Minchev |first23=I. |last24=Ramos |first24=P. |last25=Santiago |first25=B. X. |last26=Steinmetz |first26=M. |journal=Vizier Online Data Catalog |year=2022 }}</ref> | temperature = 4,579<ref name=dr3/> | luminosity = 405<ref name=dr3/> | radius = 27.6<ref name=dr3/> | gravity = 2.12<ref name=dr3/> | metal_fe = −0.76<ref name=starhorse2/> | age_gyr = 11<ref name=fouesneau2022>{{cite journal |bibcode=2022A&A...662A.125F |title=Astrophysical parameters from Gaia DR2, 2MASS, and AllWISE |last1=Fouesneau |first1=M. |last2=Andrae |first2=R. |last3=Dharmawardena |first3=T. |last4=Rybizki |first4=J. |last5=Bailer-Jones |first5=C. A. L. |last6=Demleitner |first6=M. |journal=Astronomy and Astrophysics |year=2022 |volume=662 |pages=A125 |doi=10.1051/0004-6361/202141828 |arxiv=2201.03252 |s2cid=245837778 }}</ref> }} {{Starbox catalog | names=Z Aps, TYC 9252-1914-1, 2MASS J14065484-7122167, AAVSO 1358-70A }} {{Starbox reference | Simbad=Z+aps}} {{Starbox end}}
'''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,<ref name=AAVSOZ/> over a period of 39.37 days.<ref name=AAVSOZ>{{cite web|url=http://www.aavso.org/vsx/index.php?view=detail.top&oid=534 |title=Z Apodis |author =Watson, Christopher |date=4 January 2010 |work=The International Variable Star Index|publisher=American Association of Variable Star Observers|access-date=20 Nov 2022}}</ref> Although described in the ''General Catalogue of Variable Stars'' as a cataclysmic variable star, it appears that it is a pulsating variable star,<ref name=rv>{{cite journal|bibcode=1991IBVS.3664....1M|title=Z Apodis is a Pulsating - not a Cataclysmic - Variable Star|journal=Information Bulletin on Variable Stars|volume=3664|pages=1|last1=Marino|first1=B. F.|last2=Walker|first2=W. S. G.|year=1991}}</ref> and has been classed as an RV Tauri variable star, type RVa.<ref name=AAVSOZ/> Other sources classify it is a type II (W Virginis) Cepheid.<ref name=ripepi2019>{{cite journal |bibcode=2019A&A...625A..14R |title=Reclassification of Cepheids in the Gaia Data Release 2. Period-luminosity and period-Wesenheit relations in the Gaia passbands |last1=Ripepi |first1=V. |last2=Molinaro |first2=R. |last3=Musella |first3=I. |last4=Marconi |first4=M. |last5=Leccia |first5=S. |last6=Eyer |first6=L. |journal=Astronomy and Astrophysics |year=2019 |volume=625 |page=625 |doi=10.1051/0004-6361/201834506 |arxiv=1810.10486 |s2cid=119338608 }}</ref>
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.<ref name="Swope">{{cite journal |last1=Swope |first1=Henrietta H. |title=New Variable Stars in Centaurus and Circinus |journal=Harvard College Observatory Bulletin |date=June 1931 |volume=883 |pages=23–30 |bibcode=1931BHarO.883...23S }}</ref>
==References== {{reflist}}
{{Stars of Apus}}
Category:Apus Category:RV Tauri variables Apodis, Z
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