J/A+A/695/A277ivo://CDS.VizieR/J/A+A/695/A277doi:10.26093/cds/vizier/bc-nq/lchhCDSTonucci E.Van Kempen T.A.Beaulieu J.-P.Bernard L.2026-07-03T06:36:43Z2025-08-28T08:58:23ZCDS support team

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

cds-question@unistra.frstandard-starsastrometryvisible-astronomyThe ESA space mission Ariel requires bright sources that are stable at the level of 100 ppm over 6 hours in order to accurately measure exoplanet atmospheres through transmission spectroscopy. To ensure this, in-flight instrument calibration can be performed by observing stellar calibrators. In this study, a stellar calibrator candidate list distributed over the sky is created and a flux variability analysis is performed to identify the best stellar calibrators for transit spectroscopy of exoplanet atmospheres with Ariel. A starting candidate sample of 1937 solar-type stars is created using the all-sky surveys Two Micron All Sky Survey and Gaia. Using stellar light curves from the Transit Exoplanet Survey Satellite (TESS), the flux variability of each star is characterised by computing its Lomb-Scargle periodogram and reduced chi-squared. This enables the elimination of stars with detectable variability from the sample. Approximately 22.2% of stars from the starting sample pass the selection as potential calibrators. These do not all necessarily meet Ariel's stability requirement, although some will. No correlation between flux stability and stellar properties is found, as long as the correct value ranges for the parameters are chosen, like a surface temperature between 5000 and 6300K. The only exception is stellar magnitude: Noise in TESS data increases as stars get dimmer, so, a high percentage of faint stars passes the selection since their variability is more likely hidden within the inherent TESS noise. Contrarily, stars brighter than 5mag cannot be used as calibrators. A list of 430 promising bright calibration targets distributed over the sky has been selected. These can potentially be used as stellar calibrators for the Ariel mission. Targets from this list will have to be further studied to determine which ones possess a flux stability better than 100 ppm over 6 hours.2025A&A...695A.277Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/695/A277CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/695/A277https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/695/A277http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/695/A277https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/695/A277https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/695/A277http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/695/A277GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/695/A277/tableb1 (Selected stellar calibrator list)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/695/A277/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/695/A277/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/695/A277/tableb1?GETtext/xml+votable180.050000true281.955-77.8680.0055555555555555566/49 172 185 256 396 464 719 814 944 998 1028 1030 1531 1645 1997 2032 2491 2697 2888 3268 3360 3435 3525 3645 3662 3691 3831 3919 3981 4088 4129 4133 4156 4278 4308 4377 4665 4762 4781 4835 4912 4993 5191 5258 5402 5419 5527 5726 5791 5930 5932 6087 6114 6171 6277 6699 6790 6925 6953 6971 7027 7040 7052 7091 7132 7299 7326 7354 7424 7854 7868 7895 7978 8166 8179 8249 8286 8408 8451 8475 8537 8993 9026 9112 9202 9357 9443 9664 9679 10140 10151 10209 10400 10473 10595 10676 10845 10886 11228 11239 11345 11412 11442 11535 11587 11686 11746 11794 11834 11840 11887 11910 12164 12200 12231 12318 12397 12512 12704 12798 13131 13480 13614 13671 13698 13733 13800 13843 14204 14207 14358 14838 14901 14948 15848 15881 16089 16144 16185 16322 16327 16455 16577 16649 16676 16986 17218 17249 17412 17435 17529 17540 17600 17812 17946 18005 18184 18259 18548 18711 19003 19072 19199 19217 19384 19424 19491 19609 19874 20006 20127 20237 20414 20419 20479 20653 20739 20808 20902 20914 20973 21063 21066 21080 21117 21400 21412 21477 21484 21553 21574 21748 21755 21779 21784 21809 21858 22111 22175 22355 22361 22363 22393 22608 22746 22793 22808 22931 22967 22998 23096 23141 23187 23787 23872-23873 23893 23943 24218 24227-24228 24297 24299 24536 24729 24769 25054 25078 25267 25276 25567 25854 26072 26086 26148 26158 26400 26581 26647 26768 26788 26828 26956 27053 27255 27334 27412 27639 27678 27690 27757 27836 28031 28318 28432 29900 30127 30658 31277 31480 31739 32035 32045 32067 32073 32083 32368 32485 32517 32650 32711 32787 32860 32921 32998 33025 33063 33082 33201 33219 33224 33230 33357 33366 33649 33717 33788 33854 33945 34257 34442 34499 34530 34739 34788 34836 34864 34904 34983 34990 35080 35201 35228 35230 35347 35468 35564 35576 35691 35707 35784 35969 35977 36011 36365 36590 36727 36965 37021 37074 37186 37419 37450 37485 37547 37583 37679 37975 37984 38154 38279 38330 38339 38524-38525 38614 38625 38698 38834 38966 39034 39118 39141 39576 39614 39877 39885 39893 40250 40317 40414 40682 40802 40988 41029 41094 41524 41562 41773 41935 41991 42009 42063 42102 42460 42890 42918 43068 43258 43315 43430 43782 43794 43977 44150 44728 44910 44920 45158 45182 45189 45228 45265 45271 45299 45337 45343 45345 45386 45457 45502 45527 45641 45717 45948 46076 46080 46193 46287 46306 46320 46333 46355 46501 46593 46626 46726 46768 46805 46820 46874 47022 47234 47364 47502 47629 47647 47903 47975 48019 48179 48258-48259 48283 48291 48883https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/695/A277?format=asciiOpticaldefaultJ/A+A/695/A277/tableb1Selected stellar calibrator listrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTICTESS Input Catalog identifiermeta.id;meta.mainlongRA_ICRSRight ascension (ICRS) at Ep=2000.0degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2000.0degpos.eq.dec;meta.mainsigmaMdnDispersion around the median of the light curve time series observation in a normalised unit(10-6)stat.stdevfloatSimbadSimbad column added by the CDSmeta.ref.urlchar