题目内容：
EtaCarinaeAspossiblythegalaxy’s（银河）mostmassivestar,EtaCarinaeisnowengaginginsomeveryunusualbehaviour.Australianastronomers,beingintheSouthernHemisphere（半球）,areabletoobserveitclearly.
Inthe19thcentury,EtaCarinaewasforatimethethirdbrighteststarinthesky.Ithasnowbecomelessbrightsothatbinoculars（双筒望远镜）areneededtoseeit.“Itseemstobebrighteningandbecominglessbrightoveraperiodofmanyyears”,saidDrBobDuncanfromtheAustraliaTelescopeNationalFacility.
Whileitisnotunusualforstarstovaryinbrightness,theperiodisusuallymuchshorter.“Since1992ithasbecomefourtimesbrighter,andthenlastyearitbegantodropdramatically,”hesaid
TheprobleminobservingEtaCarinaeisthatithasbeensurroundedbyacloudofgasanddust,makingithardtoseethestardirectly.However,radiowavesandinfraredlight（红外线）canpassthroughthiscloud,sotelescopesthatreceivethesewavelengthscanobservewhatisoccurring.
EtaCarinaeisofparticularinteresttoastronomersbecauseitseemstobeinitsdeaththroes（剧痛）.Beingsolargeitwillendupasasupernova（超新星）.Therehasnotbeenasupernovainourgalaxysincetheinventionofthetelescope.Whilea1987explosioninanearbygalaxygaveastronomersplentyofvaluabledata,theyarehungryforanevencloserlook.
EtaCarinaehasotheruniquefeatures,andistheonlystarknowntoproduceanultraviolet（紫外线）laserthatisbrighterthanthatproducedbytheSun.Lasershavebeenobservedinotherfrequenciesfromafew&
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