Dramatic Spectral and Photometric Changes of Pleione (28 Tau) between 2005 November and 2007 April

[摘要] RecentphotometricandspectroscopicobservationsofPleionearereported.Pleioneshowedbrightnessdeclinesinboththe$$B$$and$$V$$bandsby$$sim$$0$$lap{.}{^{mm}}$$25between2006Januaryand2007March.Significantdecreasesinthestrengthsandwidthsofthelong-livedemissioncomponentsinH$$alpha$$andH$$eta$$wereobservedduringthisperiod,whileadditionalouterdouble-emissioncomponentsappearedintheselines.Manymetallicshelllinesstrengthenedduringtheobservationperiod,beingaccompaniedbycentralquasi-emissioncomponents.Weinterpretthesespectralchangesintermsofadoubledisk:theprogressivedeclineofamisalignedolddiskinduecourseofprecessionandtheformationandgrowthofanewdiskinthestar’sequatorialplane.

[学科分类] 天文学(综合)

[关键词] "Stars: atmospheres";"Stars: Be";"Stars: emission line";"Stars: individual: 28 Tau";"Stars: photometry";"Stars: spectroscopy"