J/A+A/708/L8ivo://CDS.VizieR/J/A+A/708/L8CDSCruz Reyes M.Anderson R.I.Lengen B.2026-07-07T07:20:24Z2026-07-07T08:19:58ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsglobular-star-clustersvisible-astronomyWe have calibrated the tip of the red giant branch (TRGB) using our recent catalogue of homogeneous globular cluster (GC) distances. The GC distances were determined via a global joint fit to optical period-Wesenheit relations of their member RR Lyrae stars and type-II Cepheids, anchored by trigonometric parallaxes; all data were taken from the ESA Gaia mission's (early) third data release (GDR3). Using I-band measurements of 48 GCs from P. Stetson's database, we determined M_I,0_=-3.948^+0.037^_-0.034_mag (1.6% in distance). Calibrating the TRGB using Gaia's homogeneous, space-based RP photometry of 53 GCs, we found M_RP,0_=-3.807^+0.041^_-0.035_mag (1.8%). The stated uncertainties include statistical and systematic effects, including the correlated nature of the GC distances. The robustness of our calibrations was evaluated via tests against small-number statistics and analysis choices. Within the (small) uncertainties, no significant metallicity effect is detected in our sample of old, low-metallicity GCs. We measured approximately 2% distances to the Large and Small Magellanic Clouds, 18.447^+0.036^_-0.042_mag (48.9+/-0.9kpc) and 18.898^+0.049^_-0.054_mag (60.2+/-1.4kpc), respectively, using a single photometric system: RP (spectro-)photometry from GDR3. Our new TRGB distances, whose absolute scale derives from Gaia parallaxes, are fully independent of the well-known detached eclipsing binary (DEB) distances and agree with them to within the uncertainties. Combining our new TRGB and existing DEB distances, we illustrate how additional constraints can be incorporated into the Local Distance Network and obtain H0=73.52+/-0.80km/s/Mpc. Expected improvement thanks to the upcoming fourth Gaia data release are discussed.2026A&A...708L...8Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/708/L8CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/708/L8https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/708/L8http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/708/L8https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/708/L8https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/708/L8http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/708/L8GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/708/L8/tablec2 (Clusters used for the TRGB calibration in each band)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/708/L8/tablec2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/708/L8/tablec2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/708/L8/tablec2?GETtext/xml+votable180.050000true245.89675-26.525750.0055555555555555566/6389 9436 9666 10008 10321 10336 12405 12425 12531 19091 21017 24843 25873 27981 27986 28067 28973 29195 29202 29222 29318 29377 29870 31019 31043 31095 31398 31417 33330 33635 34242 37294 38465 41011 41257 41304 41522 41847 42955 42990 43125 43193 43227 44086 44427 47620 47825 47903 47935 47971 48434 48698 48952https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/708/L8?format=asciiOpticaldefaultJ/A+A/708/L8/tablec2Clusters used for the TRGB calibration in each bandrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIGDR3[0/1] Boolean flag indicating whether the cluster was used in the I-band TRGB calibration (based on photometric transformations)meta.codeintRP[0/1] Boolean flag indicating whether the cluster was used in the RP-band TRGB calibrationmeta.codeintSimbadNameSimbad column added by the CDSmeta.idcharnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainClusterCluster namemeta.id;meta.maincharIStetson[0/1] Boolean flag indicating whether the cluster was used in the TRGB calibration in the I bandmeta.codeint