J/AJ/169/41ivo://CDS.VizieR/J/AJ/169/41doi:10.26093/cds/vizier/be-59-19CDSCouperus A.A.Henry T.J.Osten R.A.Jao W.-C.Vrijmoet E.H.Kar A.,Horch E.2026-07-02T11:52:18Z2025-11-13T10:13:27ZCDS support team

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

cds-question@unistra.frdwarf-starsm-starsmultiple-starsvisible-astronomyphotometryspectroscopyradial-velocityline-intensitiesx-ray-sourcesWe present an investigation into the rotation and stellar activity of four fully convective M dwarf "twin" wide binaries. Components in each pair have (1) astrometry confirming they are common-proper-motion binaries, (2) Gaia BP, RP, and 2MASS J, H, and Ks magnitudes matching within 0.10mag, and (3) presumably the same age and composition. We report long-term photometry, rotation periods, multiepoch H{alpha} equivalent widths, X-ray luminosities, time series radial velocities, and speckle observations for all components. Although it might be expected for the twin components to have matching magnetic attributes, this is not the case. Decade-long photometry of GJ 1183 AB indicates consistently higher spot activity on A than B, a trend matched by A appearing 58%+/-9% stronger in L_X_ and 26%+/-9% stronger in H{alpha} on average-this is despite similar rotation periods of A=0.86d and B=0.68d, thereby informing the range in activity for otherwise identical and similarly rotating M dwarfs. The young {beta} Pic Moving Group member 2MA 0201+0117 AB displays a consistently more active B component that is 3.6+/-0.5 times stronger in L_X_ and 52%+/-19% stronger in H{alpha} on average, with distinct rotation at A=6.01d and B=3.30d. Finally, NLTT 44989 AB displays remarkable differences with implications for spindown evolution-B has sustained H{alpha} emission while A shows absorption, and B is >=39+/-4 times stronger in L_X_, presumably stemming from the surprisingly different rotation periods of A=38d and B=6.55d. The last system, KX Com, has an unresolved radial velocity companion, and is therefore not a twin system.2025AJ....169...41Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/169/41CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/simbad : Simbad objects catalogue (M.Wenger 2000)B/sb9 : SB9: 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix+ 2004-2014)B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2020)III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/287 : Northern Sky Variability Survey (NSVS) (Wozniak+, 2004)II/335 : Revised catalog of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)I/350 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)II/386 : VPHAS+ DR3 survey (Drew+, 2025)V/122 : SB9: 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix+ 2005)VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)J/A+A/327/1039 : Structure and evolution of low-mass stars (Chabrier+ 1997)J/ApJ/696/L84 : Primordial circumstellar disks in binary systems (Cieza+, 2009)J/MNRAS/407/465 : Fast-rotating M dwarfs in NGC2516 (Jackson+, 2010)J/AJ/139/743 : Speckle interferometry in 2008-09 (Tokovinin+, 2010)J/ApJ/743/48 : Stars with rotation periods & X-ray luminosities (Wright+, 2011)J/ApJ/751/115 : Millimeter emission from Taurus binary systems (Harris+, 2012)J/ApJ/754/44 : The AstraLux Large M-dwarf Survey (Janson+ 2012)J/AcA/62/67 : ASAS photometry of ROSAT sources (Kiraga, 2012)J/ApJ/764/3 : H{alpha} indices in M low-mass stars (Robertson+, 2013)J/ApJ/795/161 : Activity & rotation in Praesepe & the Hyades (Douglas+, 2014)J/MNRAS/440/2036 : VPHAS+ survey synthetic colours (Drew+, 2014)J/A+A/583/A85 : Binaries in beta Pic moving group (Alonso-Floriano+, 2015)J/ApJ/798/41 : GALEX NUV observations of bright M-type stars (Ansdell+, 2015)J/AJ/150/151 : DSSI obs. of binaries. VI. Measures in 2014 (Horch+, 2015)J/AJ/150/6 : Solar neighborh. XXXVI. VRI variab. of M dwarfs (Hosey+, 2015)J/AJ/152/141 : Solar neighborhood. XXXVII. RVs for M dwarfs (Benedict+, 2016)J/ApJ/821/93 : Rotation & Galactic kinematics of mid M dwarfs (Newton+, 2016)J/AJ/153/240 : ALMA surv. of protoplanetary disks in sigma Ori (Ansdell+, 2017)J/AJ/154/124 : M dwarfs-long-term photometric variability (Clements+, 2017)J/A+A/597/A47 : CARMENES input cat. of M dwarfs II (Cortes-Contreras+ 2017)J/A+A/600/A83 : Photometry of beta Pic members (Messina+, 2017)J/ApJ/834/85 : H{alpha} emission in nearby M dwarfs (Newton+, 2017)J/ApJ/856/23 : BANYAN. XI. The BANYAN {Sigma} algorithm (Gagne+, 2018)J/AJ/155/265 : The solar neighborhood. XLIV. RECONS discoveries (Henry+, 2018)J/AJ/156/140 : 4 new eclipsing mid M-dwarf systems from MEarth (Irwin+, 2018)J/AJ/156/217 : Stellar properties for M dwarfs in MEarth-South (Newton+, 2018)J/ApJ/871/63 : How to constrain M dwarf. II. Nearby binaries (Mann+, 2019)J/A+A/627/A97 : Early disc dispersal in close binaries (Messina, 2019)J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)J/ApJS/247/66 : SUPERWIDE: wide binaries in Gaia & SUPERBLINK (Hartman+, 2020)J/MNRAS/492/1164 : Abundances of Gaia DR2 wide binaries (Hawkins+, 2020)J/ApJ/895/140 : EvryFlare. II. Param. of 122 cool flare stars (Howard+, 2020)J/AJ/160/215 : Solar neighborhood.XLVI. New M dwarf binaries (Vrijmoet+, 2020)J/AJ/161/277 : Sample of 45 H{alpha}EW outliers (Kiman+, 2021)J/AJ/162/176 : The solar neighborhood. XLVIII. (Paredes+, 2021)J/ApJ/916/77 : K2 rotation periods for SDSS & Gaia M dwarfs (Popinchalk+, 2021)J/A+A/649/A3 : Gaia Early Data Release 3 photometric passbands (Riello+, 2021)J/A+A/661/A29 : First eROSITA study of nearby M dwarfs (Magaudda+, 2022)J/ApJ/935/104 : Catalog of Stellar Flares in 219 M-dwarfs (Medina+, 2022)J/AJ/163/278 : Stellar populations in IC 2602 and IC 2391 (Nisak+, 2022)J/AJ/163/178 : Solar Neighborhood. XLIV. M dwarfs with SOAR (Vrijmoet+, 2022)J/AJ/165/192 : Mdwarfs Ha luminosity & phot. amplitudes (Garcia Soto+, 2023)J/AJ/166/63 : Mind the Gap. I. Ha activity for M-Dwarfs (Jao+, 2023)J/AJ/165/265 : Properties of 363 M-dwarfs from TESS (Ment+, 2023)J/AJ/166/16 : Radial velocities of 123 active stars (Pass+, 2023)J/AJ/166/11 : Stellar properties & RV variability for M-dwarfs (Pass+, 2023)J/AJ/165/180 : SOAR Speckle Surv, nearby hierarchical systems (Tokovinin, 2023)J/AJ/167/196 : The solar neighborhood LI. RECONS & TESS obs. (Kar+, 2024)J/other/NatAs/8.223 : Stellar spin-down law (Lu+, 2024)http://cda.cfa.harvard.edu/chaser/searchOcat.action : Chandra X-Ray Centerhttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/169/41https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/169/41http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/169/41https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/169/41https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/169/41http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/169/41GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/169/41/table1_2 (Astrometry, photometry, and mass estimates of the four twin systems (Tables 1 & 2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/169/41/table1_2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/169/41/table1_2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/169/41/table1_2?GETtext/xml+votable180.050000true216.9820417-0.37513890.0055555555555555566/17822 25955 28115 288368.650015785639275e-20 4.621782916333392e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/169/41?format=asciiX-rayOpticaldefaultJ/AJ/169/41/table1_2Astrometry, photometry, and mass estimates of the four twin systems (Tables 1 & 2)Perdtime.periodcharSimbadNameSimbad column added by the CDSmeta.idcharnullableNameTarget namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. 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