JoseEspinel,JohnA.Lewis,RimuteTerraBudreviciute,AllysonBieryla,LehmanGarrison,JaneHuang,AndrewVanderburg,KateAlexander,PeterBlanchard,
TheronCarmichael,SebasGanGomez,AndrewMayo,MelissaMcIntosh,EvanderPrice,SihanYuan,MunazzaK.Alam,IanWeaver,RodrigoCordova
References:Kenyon,ScoOJ.,DanielProga,andCharlesD.Keyes."TheConGnuingSlowDeclineofAGPegasi."TheAstronomicalJournal122.1(2001):349-59.Web.15Dec.2016."ClayTelescope."HarvardUniversityAstronomyLabandClayTelescope.HarvardUniversity,n.d.Web.15Dec.2016."HarvardObservingProgram."HarvardUniversityAstronomyLabandClayTelescope.HarvardUniversity,n.d.Web.15Dec.2016.hOps://lh3.googleusercontent.com/-p2pv0aUoqpE/V3YvR00f7_I/AAAAAAAACP4/E18BYybF2uM/800px--ArGst%252527s_impression_of_vampire_star_OGG_thumb%25255B3%25255D.jpg?imgmax=800hOp://spaceflight.nasa.gov/gallery/images/staGon/crew-24/hires/iss024e013421.jpgWaagen,E.O.,2015,AAVSOAlertNoGce,521
HarvardUniversity
ScanPosterContactInformaGonPresenter:JoseEspinelEmail:[email protected]
ßAGPegasi7.5
8
8.5
9
9.5
102457260 2457280 2457300 2457320
ABSO
LUTEM
AGNITUDE
AGPEGABSOLUTEPHOTOMETRY(2015)
B V
JULIANDATE
Observa(ons of AG Pegasi by the Harvard Observing Project
HarvardObservingProject(HOP)The Harvard Observing Project (seetalk 314.03 by A. Bieryla and poster240.32 by C. Schumer) engages bothg radua te and underg radua testudents alike in learning about ouruniverse.TheprogramusesHarvard’sClay Telescope, a 0.4m DFM design,andanApogeeAltaU47imagingCCD.
ObservaGon- HOPobservedAGPegfromSeptember3rd, 2015, to December 10th, 2016usingHarvard's16-inchClayTelescope
- Observed during 2015 and 2016 Fallsemesters
- Over800imagesobtained- Exposuresrangedfrom1-150sec- ObservaGonsinBesselBVRfilters
AG Pegasi is a symbioGc binary star, composed of a redsupergiantandawhitedwarf.Thewhitedwarf’s luminosity isvariable, periodically fluctuaGng between 400 – 3700 L☉.Between1860and1870,AGPegbrightenedfrommagnitude9to 6, before gradually dimming for over a century. In 2001,Kenyon et al. proposed accreGon from the larger star as apossibleexplanaGonfortheincreasesinluminosity.ConsistentwithreportsofAGPeg's2015outburst(AlertNoGce521),HOPobservedthatAGPeghadbeguntobrightenoncemore.
ReducGon&Analysis- MaximDLsorwarewasusedforimagereducGonandphotometry- AbsolutephotometrywasperformedontheBandVfiltersusingSDSSmagnitudesforreferencestars
- RelaGvephotometrywasperformedonallfilters- ThelightcurvesproducedfortheB,R,andVbandssuggestthatthestar’sluminosityhasdecreasedsince2015
WhatisAGPegasi?
AGPegasiandreferencestars
ß AGPegasiRA:21h51m01.97413sDEC:+12°37ʹ32.1218″
Conclusions- AG Peg’s luminosity increased byapproximately one magnitudefromSeptembertoOctober2015
- AGPeg’s luminositydecreasedbytwo magnitudes from October2015toDecember2016
- ConGnuedmonitoringisnecessarytodetermineongoingvariability
-5.5
-4.5
-3.5
-2.5
-1.5
2457200 2457300 2457400 2457500 2457600 2457700 2457800
RELATIVE
MAG
NITUDE
AGPEGRELATIVEPHOTOMETRYR B V
JULIANDATE
7.5
8.5
9.5
10.5
11.5
12.52457200 2457300 2457400 2457500 2457600 2457700 2457800
ABSO
LUTEM
AGNITUDE
AGPEGABSOLUTEPHOTOMETRYB V
JULIANDATE
