J/ApJ/926/78ivo://CDS.VizieR/J/ApJ/926/78doi:10.26093/cds/vizier/ba-wy-2eCDSVivas A.K.Martinez-Vazquez C.E.Walker A.R.Belokurov V.Li T.S.,Erkal D.2026-07-02T11:58:29Z2023-11-06T08:18:47ZCDS support team

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

cds-question@unistra.frvariable-starsinfrared-photometryvisible-astronomyphotometrystellar-distanceWe report 350 pulsating variable stars found in four DECam fields (~12deg^2^) covering the Antlia 2 satellite galaxy. The sample of variables includes 318 RR Lyrae stars and eight anomalous Cepheids in the galaxy. Reclassification of several objects designated previously to be RR Lyrae as anomalous Cepheids get rid of the satellite's stars intervening along the line of sight. This in turn removes the need for prolific tidal disruption of the dwarf, in agreement with the recently updated proper motion and pericenter measurements based on Gaia EDR3. There are also several bright foreground RR Lyrae stars in the field, and two distant background variables located ~45kpc behind Antlia 2. We found RR Lyrae stars over the full search area, suggesting that the galaxy is very large and likely extends beyond our observed area. The mean period of the RRab in Antlia 2 is 0.599 days, while the RRc have a mean period of 0.368 days, indicating the galaxy is an Oosterhoff-intermediate system. The distance to Antlia 2 based on the RR Lyrae stars is 124.1kpc ({mu}_0_=20.47) with a dispersion of 5.4kpc. We measured a clear distance gradient along the semimajor axis of the galaxy, with the southeast side of Antlia 2 being ~13kpc farther away from the northwest side. This elongation along the line of sight is likely due to the ongoing tidal disruption of Ant 2.2022ApJ...926...78Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/926/78CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/110/2166 : Variables in Sextans dSph galaxy (Mateo+ 1995)J/AJ/136/1921 : Variable stars of Draco dSph (Kinemuchi+, 2008)J/AJ/139/2014 : BV light curves of 11 RR Lyrae (Kinman+, 2010)J/ApJ/708/717 : Light curve templates of RR Lyrae stars (Sesar+, 2010)J/ApJ/756/108 : HST VI phot. of variable stars in Leo T (Clementini+, 2012)J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)J/AJ/146/141 : BV photometry of dwarf Cepheids in Carina (Vivas+, 2013)J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)J/ApJ/814/71 : Carina project IX: UBVI data of Carina var. (Coppola+, 2015)J/ApJ/833/167 : PAndAS view of Andromeda satellites. II. (Martin+, 2016)J/MNRAS/462/4349 : Variable stars in Sculptor dSph (Martinez-Vazquez+, 2016)J/ApJ/850/137 : ISLAndS project. III. Var. stars (Martinez-Vazquez+, 2017)J/AJ/154/199 : SMASH: the MAgellanic Stellar History (Nidever+, 2017)J/ApJ/855/43 : Distant RR Lyrae stars discovered with HiTS (Medina+, 2018)J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)J/MNRAS/488/2743 : Giant Gal. dwarf satellite in Gaia DR2 (Torrealba+, 2019)J/AJ/157/35 : Pulsating variable stars in Sextans (Vivas+, 2019)J/ApJ/893/47 : MW satellite census. I. DES & PS1 (Drlica-Wagner+, 2020)J/MNRAS/492/1061 : A DECam view of Crater II - Variable stars (Vivas+, 2020)J/ApJ/921/32 : Kinematics of Ant2 & Cra2 with S5 & Gaia (Ji+, 2021)J/ApJ/911/149 : Spectroscopic obs. in ATLAS & Aliqa Uma streams (Li+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/926/78https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/926/78http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/926/78https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/926/78https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/926/78http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/926/78GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/926/78/table3 (Periodic variable stars in the field of Ant 2)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/926/78/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/926/78/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/926/78/table3?GETtext/xml+votable180.050000true143.87486-36.914610.0055555555555555565/9650 9656-9657 6/38583 38589 38604 38606-38607 38632-38633 38635-38636 386382.3230668610021367e-19 3.508503837478091e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/926/78?format=asciiOpticalInfrareddefaultJ/ApJ/926/78/table3Periodic variable stars in the field of Ant 2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification number (VNNN)meta.id;meta.maincharprimaryRAJ2000[141.7/145.7] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-39.2/-34.3] Declination (J2000)degpos.eq.dec;meta.mainPer[0.2/2.8] Perioddtime.perioddoubleo_rmag[12/68] Number of rmag observationsmeta.numberintramp[0.19/1.3] The r-band amplitudemagsrc.var.amplitudefloatrmag[17/22.1] Mean CTIO/DECam magnitude in r bandmagphot.mag;em.opt.R;stat.meanfloato_imag[12/67] Number of imag observationsmeta.numberintiamp[0.14/0.92] The i-band amplitudemagsrc.var.amplitudefloatimag[16.9/22] Mean CTIO/DECam magnitude in i bandmagphot.mag;em.opt.I;stat.meanfloatAi[0.2/0.7] Extinction in the i bandmagphys.absorptionfloatDist[16.4/173]? Distancekpcpos.distancefloatnullablee_Dist[0.3/4]? Error in Distkpcstat.errorfloatnullableTypeVariable type (1)meta.code;src.varcharLCInteractive LC plotmeta.ref.urlcharJ/ApJ/926/78/table6Time series photometry of variable stars in the field of view of Ant 2IDIdentification numbermeta.id;meta.maincharFilt[ir] Filtermeta.id;instr.filtercharMJDModified Julian datedtime.epochdoubleindexedmag[16.76/22.55] Apparent magnitude in Filtermagphot.magfloate_mag[0.002/0.3] Error in magmagstat.error;phot.magfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint