J/ApJ/929/29ivo://CDS.VizieR/J/ApJ/929/29doi:10.26093/cds/vizier.19290029CDSGutierrez C.M.Ramos-Chernenko N.2025-07-18T20:13:13Z2024-04-08T09:29:28ZCDS support team

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

cds-question@unistra.frradial-velocityopen-star-clustersvisible-astronomyA key observational prediction of Einstein's Equivalence Principle is that light undergoes redshift when it escapes from a gravitational field. Although astrophysics provides a wide variety of physical conditions in which this redshift should be significant, until very recently the observational evidence for this gravitational effect was limited to the light emitted by the Sun and white dwarfs. Gaia-DR2 astrometric and kinematic data, in combination with other spectroscopic observations, provides a test bench to validate such predictions in statistical terms. The aim of this paper is to analyze several thousand main-sequence and giant stars in open clusters (OCs) in order to measure the gravitational redshift effect. Observationally, a spectral shift will depend on the stellar mass-to-radius ratio as expected from the theoretical estimation of relativity. After the analysis, the obtained correlation coefficient between theoretical predictions and observations for 28 (51) OCs is a=0.977+/-0.218 (0.899+/-0.137). The result has proven to be statistically robust and with little dependence on the details of the methodology or sample selection criteria. This study represents one of the more extensive validations of a fundamental prediction of gravity theories.2022ApJ...929...29Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/929/29CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)I/349 : StarHorse, Gaia DR2 photo-astrometric distances (Anders+, 2019)J/A+A/322/460 : NGC 3680 photometry and radial velocities (Nordstrom+ 1997)J/A+A/381/446 : Astrometric Radial Velocities. III. (Madsen+, 2002)J/A+A/526/A127 : Velocities of M67 MS and giant stars (Pasquini+, 2011)J/A+A/550/A103 : Model 1D (LHD) and 3D (CO5BOLD) sp. (Allende Prieto+, 2013)J/A+A/619/A155 : Open cluster kinematics with Gaia DR2 (Soubiran+, 2018)J/A+A/627/A119 : Extended halo of NGC 2682 (M 67) (Carrera+ 2019)J/MNRAS/483/5026 : Radial velocities of Hyades stars (Leao+, 2019)J/A+A/633/A99 : Gaia DR2 open clusters in the MW. II (Cantat-Gaudin+, 2020)J/A+A/640/A1 : Portrait Galactic disc (Cantat-Gaudin+, 2020)J/A+A/643/A146 : The solar gravitational redshift (Gonzalez Hernandez+, 2020)J/A+A/647/A19 : 3D Kinematics and age of OCs (Tarricq+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/929/29https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/929/29http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/929/29https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/929/29https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/929/29http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/929/29GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/929/29/table1 (Full results for Method B (see Section 3.2) with and without modeling the convective shift (CS) contribution for 47 clusters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/929/29/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/929/29/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/929/29/table1?GETtext/xml+votable180.050000true99.1269.4650.005555555555555556Cone search capability for table J/ApJ/929/29/table2 (The base used in the paper for 86 open clusters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/929/29/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/929/29/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/929/29/table2?GETtext/xml+votable180.050000true58.756584140863612.48554217274550.0055555555555555565/84 113 115 118 121 124 442 784 1171 1174 1177 1180 3688 3927 4122 5514 5721 5723 5881 5883 7120-7121 7177 7180 7432 9307 9398 9838 9928 10328 10330 10603 6/272 309 318 320 322-323 325-326 333-334 340-342 348-349 357 365 367 373 378 381 383 437 449 451 457-459 464 466-467 470 476 478 480 483 492-493 500 1024-1026 1032-1033 1035-1036 1038 1042 1044 1057-1058 1060 1075 1656 1683 1717 1727 1760 1762 1766 1772 1774 1784 1787 1952 1954 2350-2351 2433 2435-2436 2438-2439 2991 3062-3063 3069 3093-3095 3099 3101 3103 3110 3125 3140 3144 3167 3169 3177 3196 3254 3260-3262 3281 3284 3299 3304 3306 3435 3526-3528 3534-3535 3553 3555-3556 3558 3563 3591 3601-3606 3609 3611-3612 3614 3633 3648 3908 4075-4076 4078-4079 4253 4255 4296 4298 4679 4690-4691 4700 4702 4724-4726 4728 4783 6148-6149 10369 10403 10787 13194-13196 13198 14173 14175 14196-14197 14573 14575 14584 14586 15386 15392 15396-15397 15593-15595 15759 16445 16447 16494 16533 16541 16576-16577 16579 16582 16584 20562 20903 20909 21372 21438 21518-21519 21529 21550 21557 21586 21717-21719 22216 22218 22237 22239 22498-22499 22851 22854-22855 22859-22860 22862-22863 22870-22872 22877 22880-22881 22883 22891 22906 22980-22981 23017 23035 23286 23313 23315 23321 23329 23339 23344 23368 23387 23408 23413 23418 23450 23453-23454 23478-23479 23487 23489 23496-23497 23501-23504 23511 23514 23518 23523 23529 23537-23540 23542 23544-23545 23547-23548 23550 23637-23639 23695 23704 23706-23707 23716-23717 23719 23725 23727-23728 23730-23731 23736 23739 23745 24068 24070 24099 24104 24109-24110 24115 24120-24121 24126 24175 24192 24194 24200-24201 24203 24206-24207 24209 24211 24228 24232-24234 24239 24248 24251 24344-24345 24479 24520 24522 28027 28085 28092-28094 28116 28123 28128-28129 28134 28137-28138 28140 28150 28416 28439 28442 28445 28447 28452 28455 28489-28490 28496 28515 28526 28560 28683 28686 28705 28707 28713 28716-28718 28724 28727-28729 28804 28806-28807 28812 28814 28822-28823 29015 29022-29023 29045 29047 29704 29736 29740 30215 30226 30234-30235 30257 30438-30439 30444-30445 30456 30635 31782 31787-31790 31809 31811-31812 31814-31815 32089 37240 37242 37313 37316-37318 37325 37586-37587 37785 37787-37788 37790 37809 37811 37813 37932-37934 37938-37939 37942 37944 38441 39181 39183 39192 39194 39205 39207 39216-39218 39251 39254 39256-39257 39259-39260 39343 39347 39350 39356 39358 39542 39551 39685-39686 39688 39695-39698 39718 39720-39722 39812 39895 39901 40450-40451 40457 41247 41261 41264 41268-41270 41275 41279 41290 41294 41317-41319 41327 41329-41330 41348-41349 41367 41409 41466 41607 41612-41613 41791 41832 41834 42103 42177 42210 42216 42250-42251 42253-42255 42258 42263 42267-42269 42272 42274-42275 42282 42289 42304-42305 42307 42310 42321 42336 42365 42406 42419 42424 42426-42427 42464 42496 42756-42757 42768 43023 43032 43034 47650 47746https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/929/29?format=asciiOpticaldefaultJ/ApJ/929/29/table1Full results for Method B (see Section 3.2) with and without modeling the convective shift (CS) contribution for 47 clustersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClHost cluster identifiermeta.id;meta.maincharprimaryRVel[-61.6/106.3] Radial velocitykm/sphys.veloc;pos.heliocentricfloatnullablee_RVel[0.049/0.4] Uncertainty in RVelkm/sstat.error;spect.dopplerVelocfloatnullablerms[0.7/2.8] Standard deviationkm/sstat.stdevfloatnullableNgr[50/581] Number of stars with the gravitational redshift (GR) estimationmeta.numberintnullableaGR[-13.7/9.8] Slope result of fit with only GR consideredstat.fit.paramfloatnullablee_aGR[0.3/9] Uncertainty in aGRstat.errorfloatnullablebGR[-2.5/2.6] Intercept result of fit with only GR consideredkm/sstat.fit.paramfloatnullablee_bGR[0.15/2.2] Uncertainty in bGR with only GR consideredkm/sstat.errorfloatnullableNcs[1/478] Number of stars with the CS estimationmeta.numberintnullableaCS[-2/5.2]? Slope result of fit with GR & CS consideredstat.fit.paramfloatnullablee_aCS[0.39/6]? Uncertainty in aCSstat.errorfloatnullablebCS[-1.3/1.3]? Intercept result of fit with GR & CS consideredkm/sstat.fit.paramfloatnullablee_bCS[0.18/1.5]? Uncertainty in bCSkm/sstat.errorfloatnullableFlagResult flag (1)meta.code.errorcharNsTotal number of stars considered for this cluster (link to Table 2)meta.numberintnullable_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.mainSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/ApJ/929/29/table2The base used in the paper for 86 open clustersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR2Gaia DR2 identifiermeta.id;meta.mainRAJ2000DR2 Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-72/86] DR2 Declination (J2000)degpos.eq.dec;meta.mainRVel[-922/998] Radial velocity (1)km/sphys.veloc;pos.heliocentricdoubleClHost cluster identifiermeta.id.parentcharSimbadSimbad column added by the CDSmeta.ref.urlchare_RVel[0/1] Uncertainty in RVel (1)km/sstat.error;spect.dopplerVelocfloatCS[-0.33/0.81]? Convective shift (2)km/sphys.veloc;arith.difffloatnullableGR[0.004/1.3] Gravitational shift (2)km/sphys.veloc;arith.difffloat