Observa(ons of AG Pegasi by the Harvard Observing Projectastrolab/jespinel_AAS_Jan2017.pdf · AG...

Jose Espinel, John A. Lewis, Rimute Terra Budreviciute, Allyson Bieryla, Lehman Garrison, Jane Huang, Andrew Vanderburg, Kate Alexander, Peter Blanchard, Theron Carmichael, SebasGan Gomez, Andrew Mayo, Melissa McIntosh, Evander Price, Sihan Yuan, Munazza K. Alam, Ian Weaver, Rodrigo Cordova References: Kenyon, ScoO J., Daniel Proga, and Charles D. Keyes. "The ConGnuing Slow Decline of AG Pegasi." The Astronomical Journal 122.1 (2001): 349-59. Web. 15 Dec. 2016. "Clay Telescope." Harvard University Astronomy Lab and Clay Telescope. Harvard University, n.d. Web. 15 Dec. 2016. "Harvard Observing Program." Harvard University Astronomy Lab and Clay Telescope. Harvard University, n.d. Web. 15 Dec. 2016. hOps://lh3.googleusercontent.com/-p2pv0aUoqpE/V3YvR00f7_I/AAAAAAAACP4/E18BYybF2uM/800px--ArGst%252527s_impression_of_vampire_star_OGG_thumb %25255B3%25255D.jpg?imgmax=800 hOp://spaceflight.nasa.gov/gallery/images/staGon/crew-24/hires/iss024e013421.jpg Waagen, E.O., 2015, AAVSO Alert NoGce, 521 Harvard University Scan Poster Contact InformaGon Presenter: Jose Espinel Email: [email protected] ß AG Pegasi Observa(ons of AG Pegasi by the Harvard Observing Project Harvard Observing Project (HOP) The Harvard Observing Project (see talk 314.03 by A. Bieryla and poster 240.32 by C. Schumer) engages both graduate and undergraduate students alike in learning about our universe. The program uses Harvard’s Clay Telescope, a 0.4m DFM design, and an Apogee Alta U47 imaging CCD. ObservaGon - HOP observed AG Peg from September 3 rd , 2015, to December 10 th , 2016 using Harvard's 16-inch Clay Telescope - Observed during 2015 and 2016 Fall semesters - Over 800 images obtained - Exposures ranged from 1-150sec - ObservaGons in Bessel BVR filters AG Pegasi is a symbioGc binary star, composed of a red supergiant and a white dwarf. The white dwarf’s luminosity is variable, periodically fluctuaGng between 400 – 3700 L ☉ . Between 1860 and 1870, AG Peg brightened from magnitude 9 to 6, before gradually dimming for over a century. In 2001, Kenyon et al. proposed accreGon from the larger star as a possible explanaGon for the increases in luminosity. Consistent with reports of AG Peg's 2015 outburst (Alert NoGce 521), HOP observed that AG Peg had begun to brighten once more. ReducGon & Analysis - MaximDL sorware was used for image reducGon and photometry - Absolute photometry was performed on the B and V filters using SDSS magnitudes for reference stars - RelaGve photometry was performed on all filters - The light curves produced for the B, R, and V bands suggest that the star’s luminosity has decreased since 2015 What is AG Pegasi? AG Pegasi and reference stars ß AG Pegasi RA: 21h 51m 01.97413s DEC: +12° 37ʹ 32.1218″ Conclusions - AG Peg’s luminosity increased by approximately one magnitude from September to October 2015 - AG Peg’s luminosity decreased by two magnitudes from October 2015 to December 2016 - ConGnued monitoring is necessary to determine ongoing variability -5.5 -4.5 -3.5 -2.5 -1.5 2457200 2457300 2457400 2457500 2457600 2457700 2457800 RELATIVE MAGNITUDE AG PEG RELATIVE PHOTOMETRY R B V JULIAN DATE 7.5 8.5 9.5 10.5 11.5 12.5 2457200 2457300 2457400 2457500 2457600 2457700 2457800 ABSOLUTE MAGNITUDE AG PEG ABSOLUTE PHOTOMETRY B V JULIAN DATE

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Transcript of Observa(ons of AG Pegasi by the Harvard Observing Projectastrolab/jespinel_AAS_Jan2017.pdf · AG...

Page 1: Observa(ons of AG Pegasi by the Harvard Observing Projectastrolab/jespinel_AAS_Jan2017.pdf · AG Pegasi is a symbioGc binary star, composed of a red supergiant and a white dwarf.

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

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102457260 2457280 2457300 2457320

ABSO

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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

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