J/A+A/656/A66ivo://CDS.VizieR/J/A+A/656/A66doi:10.26093/cds/vizier.36560066CDSTrabucchi M.Mowlavi N.Lebzelter T.2022-10-10T15:09:20Z2021-12-03T09:19:57ZCDS support team

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

cds-question@unistra.frvariable-starsmagellanic-cloudsphotometryvisible-astronomySemi-regular variables (SRVs) are similar to Miras in brightness, and they also follow PLRs, though not necessarily the same as Miras. As potential standard candles they are more challenging than Miras due to their smaller variability amplitudes and less regular light curves, but they are substantially more numerous and especially promising to probe old stellar populations. We aim to characterize the variability of SRVs, with focus on their connection with Miras, in order to prepare the ground for investigating their potential as distance indicators. We examine SRVs and Miras in the Magellanic Clouds from OGLE-III observations, with data from Gaia and 2MASS. After cleaning the sample from variability periods unrelated to pulsation, we classify each source by chemical type and combination of pulsation modes. We examine the results in terms of global photometric and pulsation properties. We identify four SRVs groups that fit the general evolutionary scenario predicted by theory. SRVs dominated by fundamental-mode pulsation are very similar to Miras, especially if mono-periodic. They further split into two sub-groups, one of which follows the same sequence as Miras in the period-luminosity and period-amplitude diagram, without discontinuity. The similarities between Miras and SRVs suggest that the latter can be adopted as complementary distance indicators to the former, thereby at least doubling the available number of LPVs suitable for use as distance indicators. The traditional amplitude-based separation between Miras and SRVs is not necessarily appropriate, and a more physically sound criterion should also involve pulsation periods. While this would require comparatively longer time series, they are expected to become accessible in the coming years even for weak sources thanks to current and future large-scale surveys. The table of reclassified LPVs is made public.2021A&A...656A..66Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/656/A66CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)I/345 : Gaia DR2 (Gaia Collaboration, 2018)I/350 : Gaia EDR3 (Gaia Collaboration, 2020)J/AcA/59/239 : VI light curves of LMC long-period variables (Soszynski+, 2009)J/AcA/61/217 : VI light curves of SMC long-period variables (Soszynski+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/656/A66https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/656/A66http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/656/A66https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/656/A66https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/656/A66http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/656/A66GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/656/A66/table3 (Properties and classification of Miras and SRVs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/656/A66/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/656/A66/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/656/A66/table3?GETtext/xml+votable180.050000true67.1214583-70.36166670.0055555555555555564/2068 5/8261 8263 8268-8269 8271 8280 8323-8324 8326 8329 9376 9378 6/33049 33051 33069 33080-33081 33083 33104-33106 33112 33124-33126 33128-33130 33287 33289 33291 33313 33315 33321 33323-33326 33328-33330 33409 33412 37416 37418 37536 37538https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/656/A66?format=asciiOpticaldefaultJ/A+A/656/A66/table3Properties and classification of Miras and SRVsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDOGLE-III source ID, OGLE-LMC-LPV-NNNNN or OGLE-SMC-LPV-NNNNNmeta.id;meta.maincharPa[21.135/1859.0] Primary pulsation perioddtime.perioddoublePb[17.75/608.6]? Secondary pulsation period (1)dtime.perioddoublenullableAa[0.010/4.328] Amplitude of the primary pulsation period in the I band of OGLEmagsrc.var.amplitudefloatAb[0.008/1.285]? Amplitude of the secondary pulsation period in the I band of OGLE (1)magsrc.var.amplitudefloatnullableNa[0/1] Radial order of oscillation corresponding to the primary pulsation period (2)meta.numberintNb[0/1]? Radial order of oscillation corresponding to the secondary pulsation period (1) (2)meta.numberintnullableKa[1/3] Rank of the primary pulsation period as it appears in the OGLE-III catalogs (3)meta.numberintKb[2/3]? Rank of the secondary pulsation period as it appears in the OGLE-III catalogs (1) (3)meta.numberintnullableGroupVariability group according to the classification by variability type and pulsation periods (4)src.classcharChTypeChemical type of the source based on optical and near-infrared photometric data (5)meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainindexed_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainindexed