J/AJ/162/189ivo://CDS.VizieR/J/AJ/162/189doi:10.26093/cds/vizier.51620189CDSDavenport J.R.A.Windemuth D.Warmbein K.Howard E.L.Klein C.Birky J.2022-03-16T11:44:07Z2022-01-07T11:55:21ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frmultiple-starseclipsing-binary-starsccd-photometryHS Hydrae is a short period eclipsing binary (Porb=1.57day) that belongs to a rare group of systems observed to have rapidly changing inclinations. This evolution is due to a third star on an intermediate orbit, and results in significant differences in eclipse depths and timings year to year. Zasche & Paschke revealed that HS Hydrae's eclipses were rapidly fading from view, predicting they would cease around 2022. Using 25 days of photometric data from Sector 009 of the Transiting Exoplanet Survey Satellite (TESS), we find that the primary eclipses for HS Hydrae were only 0.00173{+/-}0.00007mag in depth in March 2019. This data from TESS likely represents the last eclipses detected from HS Hydrae. We also searched the Digitization of the Harvard Astronomical Plate Collection archive for historic data from the system. With a total baseline of over 125yr, this unique combination of data sets-from photographic plates to precision space-based photometry-allows us to trace the emergence and decay of eclipses from HS Hydrae, and further constrain its evolution. Recent TESS observations from Sector 035 confirm that eclipses have ceased for HS Hya, and we estimate they will begin again in 2195.2021AJ....162..189Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/162/189CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/MNRAS/455/4136 : Kepler triples (Borkovits+, 2016)J/A+A/609/A46 : Light curves 0f 6 MC eclipsing binaries (Jurysek+, 2018)http://projects.iq.harvard.edu/dasch : DASCH project pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/162/189https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/162/189http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/162/189https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/162/189https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/162/189http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/162/189GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/AJ/162/189/fig2Phase-folded historical light curves from DASCHrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJD[2412585/2447708] Julian Datedtime.epochdoubleObs.Y[1893/1990] Year of the observationyrtime.epochdoubleDmag[7.2/9.67] Apparent DASCH photgraphic plate magnitudemagphot.mag;arith.diff;instr.platefloate_Dmag[0.07/0.3] Uncertainty in Dmagmagstat.error;phot.mag;arith.difffloatJ/AJ/162/189/fig4Eclipse depths and derived inclination as a function of time for HS HydraerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJD[2416831/2458556]? Julian Datedtime.epochdoublenullableObs.Y[1904/2020] Year of the observationyrtime.epochdoubleDepth[0.001/0.65] Eclipse depthmagphys.absorption.opticalDepthdoublee_Depth[0.00007/0.2] Uncertainty in Depthmagstat.error;phys.absorption.opticalDepthdoublei[71.8/88.9] Inclinationdegsrc.orbital.inclinationfloate_i[0.02/8]? Uncertainty in idegstat.errorfloatnullable