7/28/2019 WASP48b Poster

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Imagecredit:OlagIllustra1on

Introduc1on AnalysisandResults SearchingforAsymmetryTheexoplanetWASP-48bwasobservedintheBessel-UphotometricbandontheStewardObservatory6-inchKuiperTelescopetodetect

apossiblemagne1cfield.

VidoMoetal.(20)postulatedthatitmaybepossibletodetectthemagne1cfieldofatransi1ngexoplanetbyobservinganasymmetryin

itsnear-UVlightcurve.

Themaingoalofthe projectisto determinewhetherornot thismethodof detec1nga magne1cfieldofan exoplanetcanreveala

magne1cfieldoftheexoplanetWASP-48b.

WhyStudyWASP-48b?

WASP-48bwasdiscoveredaerthepaperbyVidoMoet.al.waspublishedsoitisnotonthelistofobjectsofinterest.

However,thecalculateddensityofpar1clesatthepoten1albowshockdistancewouldputitat37thonthelist.

Also,otherparameterscanbedeterminedbasedonobserva1onstoconfirmandamendtheplanetsmass,radius,density,surfacegravity,

distance,andorbitalinclina1on.

Observa1onandDataReduc1onTheBessel-Ufilterwasusedtotestnear-UVwavelengthsforpossiblediscoveryofabowshock.

ThedatawasobtainedonOctober9th,20forWASP-48b.Datareduc1onconsistedofIRAFprac1cessuchasbiasing,flat-fielding,aperturephotometryandplo_ngalightcurve.Seefigure.

TheIDLTransitAnalysisPackage(TAP)wasusedintheanalysisofthelightcurve,2,5.

Usingtheanaly1cmodelofandelandAgol(2002),TAPsowareappliesarkovChainonteCarlo(CC)techniquestofitlight

curves.

JKTEBOP6wasalsousedintheanalysis.JKTEBOPisusedtomodellightcurvesofeclipsingbinaries,butcanalsousetheparametersgiveninthecircumstanceofanorbi1ng

exoplanet.Itisusefulasitdoesnotassumesymmetryinthelight

curve.

TheTAPmodelandresidualsaredisplayedinfigure.Theobserva1onsofWASP-48bareconsistentwithpreviousop1calobserva1ons3.SeeTable.

Figure:TransitmodelandresidualsofWASP-48b.

Table:TransitparametersderivedbyTAP.

Asymmetryinthelightcurveisanindica1onoftheexistenceofa

bowshock.

Astrongmagne1cfieldcancompressplasmaenoughtobe

observable.

Thiseffectwillchangetheingress1meoftheplanet.See

figure2.

WASP-2bistheonlyplanettohavedemonstratedsuch

behavior4,7.

Figure2:Sketchoflightcurve

obtainedbyobserva1onsinthenear-UV.ImageCredit:VidoMo

et.al.(20).

TAPassumessymmetry,whileJKTEBOPdoesnot.

ObservingintheNear-UV

Figure4:BestfitmodelbyTAPoverlaidbythatfromJKTEBOP.

ConclusionandFurtherStudyThe1medifferencebetweenthetwoisonly2.3minutes.TheSTDEVoftheoverlayoftheTAPandJKTEBOPmodeledlightcurvesis.043mmagwhichisbelowtheprecisionofthelightcurve,

.96mmag,soitcanbeconcludedthelightcurveissymmetricabout

midtransit.

Therefore,WASP-48bdoesnothaveanobservablebowshock.Thereareconsistencieswithpublishedop1calobserva1ons.Thisresultisconsistentwiththenon-detec1onofabow-shockaroundTrES-3b8,anexoplanetinthetoptenobjectsofinterestcompliedbyVidoMoetal.

Futurestudyisplannedtodiscoverwhetheramagne1cfieldispresentinotherexoplanets8,usingthemethodsofVidoMoet.al.

ReferencesandAcknowledgements. CarterandJ.N.Winn,ApJ704,5(2009).2. J.Eastman,E.Agol,andG.S.,inprep(20).3. Enochet.al.AJ,42,86(20).4. Fossa1etal.,ApJ,74,L222(200).5. K.andelandE.Agol,ApJ580,L7(2002)6. Southworth,NRAS,408,689(200)7. Turneretal,NRAS,428,678(203).8. VidoMoetal.,NRAS,4,L46(20).WewouldliketothanktheUniversityofArizonaAstronomyClub,Steward

Observatory,andtheAssociatedStudentsoftheUniversityofArizonafor

suppor1ngthisresearch.

Tofindasymmetries,thelightcurveissubtractedbythemirror

imageofitselfaboutthemid

transit.Seefigure3.

ThemodellightcurvesfromTAPandJKTEBOPareoverlaid

forcomparison.Seefigure4.

Figure3:Thesubtractedmirrorimageoftheresiduals.