J/A+A/682/A59ivo://CDS.VizieR/J/A+A/682/A59doi:10.26093/cds/vizier.36820059CDSJian M.Matsunaga N.Jiang B.Yuan H.Zhang R.2024-11-28T20:06:36Z2024-02-02T09:45:30ZCDS support team

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

cds-question@unistra.fremission-line-starsbe-starsAs early-type stars with a rotation speed close to their critical velocity, Be stars experience a kind of event called Be phenomenon. The material in their equator, during the Be phenomenon, is ejected to the outside space and forms a circumstellar disk. The mechanism triggering these events remains poorly understood, and observations of these events are limited since the duration of such events ranges from months to years. Long-term epoch photometry in the infrared bands is expected to be ideal for detecting Be phenomena since the brightness variation is larger than that in the optical, and the effect of interstellar extinction is also smaller. In this work, we conducted a systematic search for Be phenomena among Milky Way OBA stars in the mid-infrared. We examined the brightness and colour variations of known classical Be stars using the WISE W1 and W2 photometry bands to quantify their characteristics. Subsequently, we established a set of criteria to identify similar photometric variations in a large sample of OBA stars. 916 OBA stars have been found to show Be phenomena in the past 13 years, with 736 newly discovered. The peak-to-peak variations in magnitude and colour were found to be correlated, indicating the common presence of a decretion disk. The increase in colour was observed to be strongly correlated with the emission of the H{alpha} line, providing further evidence of the association with circumstellar disks. The brightness variation of a star with Be phenomena can be up to 1.5mag, and colour variations up to 0.4mag. The median durations for the disk build-up and decay phases are 474 and 524 days, respectively (while those less than 180 days are not sampled). The search for Be phenomena in the WISE bands greatly enlarge the number of stars showing disk variation, and makes multi-band photometry analysis of these events possible, with the help of current and future optical photometry surveys.2024A&A...682A..59Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/682/A59CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/328 : AllWISE Data Release (Cutri+ 2013)J/AJ/155/50 : WISE photometry of Be stars in young open clustershttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/682/A59https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/682/A59http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/682/A59https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/682/A59https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/682/A59http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/682/A59GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/682/A59/table2 (Catalogue of BeT stars found in this study)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/682/A59/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/682/A59/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/682/A59/table2?GETtext/xml+votable180.050000true0.147262.55490.0055555555555555565/811 814 905 3661 5530 6/267 989 1077 1127 1145 1148 1220 1227 1235 1243 1284 1288 1293 1297 1301-1305 1307-1309 1318-1319 1321 1328 1330 1333 1335 1338 1341 1346 1348 1351-1352 1356 1358-1360 1362 1386 1390 1411 1415 1420-1421 1423-1424 1427 1435-1436 1439 1444-1445 1447 1452 1455-1458 1462 1468 1474 1481 1492 1514 1593 1627 1638 1654 1663 1689 1717 1751 1753 1755-1756 1758 1765-1766 1771-1772 1778 1782 1786-1788 1793-1794 1801 1803 1806 1818 1822 1824 1830 1832 1835 1837-1838 1843 1848-1849 1896 1920 1923 1930 1939-1940 1945 1953 1955 1958 1961 1963 1965-1966 1976 1989 2526 2550 2909 2929-2930 2940 2942 2955 3002 3005 3018 3024 3026 3039 3043 3045-3046 3052 3054 3060 3064-3065 3068 3086-3087 3125 3127 3132-3133 3135 3140 3142 3146-3147 3154 3157 3162 3165 3167 3172-3174 3177 3179 3184-3185 3192 3195 3198 3223 3227 3251 3253-3255 3260 3262-3263 3265 3269 3273-3277 3281 3283-3285 3290 3296-3297 3303-3305 3307-3308 3311-3313 3316 3326 3328-3330 3332 3362 3461 3587 3589 3591 3600 3602-3605 3609 3611 3613-3618 3625 3629 3631-3632 3634-3636 3638 3650 3652 3654 3658-3660 3666 3681-3682 3713 3715 3721 3723 3725-3726 3745 3748 3751 3763 6822 6846 7120 8804 9221 12955 12961 12964 12988 13039 13042 13277 13288-13289 13295 13934 13999 14047 14061 14071 14073 14076 14172-14173 14190-14191 14207 14219-14220 14227 14230 14235 14251 14254 14261-14263 14266 14268 14273 14279-14280 14290-14291 14293 14295 14297 14299 14301 14303-14306 14310 14320 14325-14326 14331 14360 14388 14391 14406 14411 14431 14451 14453 14461 14592 14594-14595 14602 14622 14624 14627 14630 14640 14653-14654 14666 14671-14672 14677 14682 14686 14688 14691-14693 14695 14700-14701 14705-14706 14713 14956 15378 15383-15384 15388 15407 15433 15442 15448 15452 15455 15484 15513 15571 15575 15616 15618 15620-15621 15627 15632-15633 15635 15639 15646 15650 15668 15681 15703 15800 15829 20801 20816 20818 20846 20861 20863 20980 21338 21371 21458 21534 21544 21558 21645 21656 21677 21689 21698 21748 21938 21943 21951 22029 22040 22042 22044 22047 22053 22059 22064 22071 22075 22080 22088-22090 22110 22131 22139 22147 22162 22167 22171 22173-22174 22196 22199 22209 22212 22214 22218 22220-22222 22230 22234 22236 22239-22240 22242-22244 22246 22248-22249 22252-22253 22255 22257 22259-22260 22333 22411 22434 22437 22458 22860 22871 22896 23571 23617 23619 23624 23629 23631 23634 23638-23639 23654 23665 23669 23672 23675 23729 23755 23764-23765 23768 23772 23774 23778 23802 23806 23816 23818 23820 23832-23833 23851-23852 23854 23937 23943 23947 23949 23952 23954-23955 23958 23964 23967 23970 23972 23976-23977 23982 23992-23993 23995-23996 24010 24148 24180 24182 24261 24290-24291 24323 24330 24332-24333 24335 24337-24339 24346-24347 24353 24359 24367 24369 24371 24375 24379-24380 24384 24389 24392 24424 24446 24448 24454 24457 24462 24464-24465 24467-24469 24472-24474 24482-24483 24485 24489 24491 24493 24500 24503 24506 24510 24512 24520 24550 24555 28673 28745 28775 28794 28851 28866 28886 29046 29082 29100 29117 29158 29164 29172 29183 29211 29456 29518 29530 29688 29882 29929 30219 30264 30294 30310 30332 30387 30406 30455 30474 30538 30615 30632 30697 30711 32092 32431 32550 33102 33115 33563 33826 34777 34878 36282 36977 37179 37190 37229 37237 37247 37301 37316 37321 37329 37331 37333-37335 37338 37340 37349-37351 37360 37364-37365 37375 37438 37660 37699-37700 37714 37724 37742 37752-37753 37795 37819 37863 37868 37882 37895 37897 37901 37905-37906 37909 37912 37922-37923 37926 37930-37932 37934-37935 37958 38016 38018-38019 38022 38024 38031-38032 38051 38236 38538 38563 38628 39133 39214 39254 39257 39261 39288 39316 39368 39373 39417 39517 39733 39764-39765 39774 39780 39783 39788 39853 39860 39876 40488 40616 40865 41020 41379 41588 41592 41599 41662 41664 41670 41684-41685 41697 41699 41707 41754 41796 41857 41863-41864 42143 42151 42159-42160 42223 42225 42314 42400 42436 42489 42580 43009 43023-43024 43027 43033 43041 43044 43048 43059 43104 43448 47704https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/682/A59?format=asciidefaultJ/A+A/682/A59/table2Catalogue of BeT stars found in this studyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainNameName of the BeT star (HHMMSSss+DDMMSSs)meta.id;meta.maincharprimary(W1-W2)-ptpPeak-to-peak range of (W1-W2)magsrc.var.amplitudefloatW1-ptpPeak-to-peak range of W1magsrc.var.amplitudefloatr-valuePearson correlation coefficientstat.correlationfloatTimeSpanO? Mean timespan of the outburst phasedtime.phase;stat.meanintnullableTimeSpanD? Mean timespan of the decay phasedtime.phase;stat.meanintnullableSampleSample source: golden / extended samplesrc.samplecharClusterThe open cluster if belongs tometa.id.parentcharTypeLVariable type in Labadie-Bartz et al. (2017AJ....153..252L, Cat. J/AH/153/252)src.classcharTypeSVariable type in Simbadsrc.classcharHaindicates H{alpha} line emission in table3meta.ref.urlcharJ/A+A/682/A59/table3The BeT LAMOST spectra and measurement of H{alpha} line emissionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the BeT star (HHMMSSss+DDMMSSs)meta.id;meta.maincharLMJDObservation date, Local Modified Julian Daytime.epochintPlanIdPlan idobs.fieldcharspId[1-16] Spectrograph idmeta.id;instrintFiberIdFiber idmeta.idintW1-W2? Closest-match of (W1-W2)magphot.color;em.IR.3-4um;em.IR.4-8umdoublenullableEWHa? Closest-match of EW(H{alpha})0.1nmspect.line.eqWidth;em.line.Halphadoublenullable