An Orbital Period Investigation of the W UMa-Type Binary Y Sextantis

[摘要] Fourcharge-coupleddevice(CCD)photometrictimesoflightminimumoftheovercontactbinaryYSexobtainedfrom2004to2007arepresented.IthasbeendiscoveredthatthelightcurveofYSexisvariational.Combiningthepresenttimesoflightminimumwithvaluescollectedfromtheliterature,weinvestigatedtheorbitalperiodchangesofthesystem.Ithasbeenfoundthattheremayexisttwocyclicperiodoscillationsinthe$$O-C$$diagramofYSex.Oneoscillatesataperiodof51.22 yrwithanamplitudeof0.0218 d,andtheotherchangesataperiodof32.10 yrwithanamplitudeof0.0100 d.Theperiodoscillationscanbeexplainedeitherbythelight-timeeffectviathepresenceofanunseenthirdbodyandanunseenfourthbodyorbymagnetic-activitycyclesofthecomponents.

[学科分类] 天文学(综合)

[关键词] "stars: binaries: eclipsing";"stars: individual (Y Sextantis)"