J/ApJ/923/48ivo://CDS.VizieR/J/ApJ/923/48doi:10.26093/cds/vizier.19230048CDSFaherty J.K.Gagne J.Popinchalk M.Vos J.M.Burgasser A.J.,Schumann J.Schneider A.C.Kirkpatrick J.D.Meisner A.M.Kuchner M.J.,Bardalez Gagliuffi D.C.Marocco F.Caselden D.Gonzales E.C.,Rothermich A.Casewell S.L.Debes J.H.Aganze C.Ayala A.Hsu C.-C.,Cooper W.J.Smart R.L.Gerasimov R.Theissen C.A.,The Backyard Worlds: Planet 9 Collaboration2023-11-03T12:19:07Z2023-07-19T11:42:29ZCDS support team

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

cds-question@unistra.frbrown-dwarfsl-dwarfsmultiple-starsinfrared-astronomyspectroscopyvisible-astronomyk-starsThrough the Backyard Worlds: Planet 9 citizen science project we discovered a late-type L dwarf co-moving with the young K0 star BD+60 1417 at a projected separation of 37" or 1662au. The secondary-CWISER J124332.12+600126.2 (W1243)-is detected in both the CatWISE2020 and 2MASS reject tables. The photometric distance and CatWISE proper motion both match that of the primary within ~1{sigma} and our estimates for a chance alignment yield a zero probability. Follow-up near-infrared spectroscopy reveals W1243 to be a very red 2MASS (J-Ks=2.72), low surface gravity source that we classify as L6-L8{gamma}. Its spectral morphology strongly resembles that of confirmed late-type L dwarfs in 10-150Myr moving groups as well as that of planetary mass companions. The position on near- and mid-infrared color-magnitude diagrams indicates the source is redder and fainter than the field sequence, a telltale sign of an object with thick clouds and a complex atmosphere. For the primary we obtained new optical spectroscopy and analyzed all available literature information for youth indicators. We conclude that the LiI abundance, its loci on color-magnitude and color-color diagrams, and the rotation rate revealed in multiple TESS sectors are all consistent with an age of 50-150Myr. Using our re-evaluated age of the primary and the Gaia parallax, along with the photometry and spectrum for W1243, we find Teff=1303+/-31K, log g=4.3+/-0.17cm/s^2^, and a mass of 15+/-5MJup. We find a physical separation of ~1662au and a mass ratio of ~0.01 for this system. Placing it in the context of the diverse collection of binary stars, brown dwarfs, and planetary companions, the BD+60 1417 system falls in a sparsely sampled area where the formation pathway is difficult to assess.2021ApJ...923...48Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/923/48CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/259 : The Tycho-2 Catalogue (Hog+ 2000)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/365 : The CatWISE2020 catalog (updated version 28-Jan-2021) (Marocco+, 2021)IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)J/ApJ/670/1367 : Gemini Deep Planet Survey (Lafreniere+, 2007)J/ApJ/676/1281 : L and T dwarfs in 2MASS/SDSS (Metchev+, 2008)J/ApJS/181/62 : Survey of young solar analogs (Metchev+, 2009)J/A+A/517/A76 : Near-IR spectrum of 2M1207b (Patience+, 2010)J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)J/ApJ/752/56 : BDKP. III. Plx for 70 ultracool dwarfs (Faherty+, 2012)J/ApJ/777/160 : NIR survey for planets around MG stars (Biller+, 2013)J/ApJ/794/159 : Statistical analysis of exoplanet surveys (Brandt+, 2014)J/ApJ/788/81 : BANYAN III. RVel and rotation of low-mass stars (Malo+, 2014)J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)J/ApJ/810/158 : M,L,T dwarfs fundamental param. and SEDs (Filippazzo+, 2015)J/ApJS/219/33 : BANYAN. VII. Candidate YMG members from BASS (Gagne+, 2015)J/ApJ/798/122 : Abundances from SEGUE Stellar Param. Pipeline (Miller+, 2015)J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)J/ApJ/833/96 : Hawaii IR parallax program. II. Ultracool dwarfs (Liu+, 2016)J/AJ/152/113 : Pleiades members with K2 LCs. I. Periods (Rebull+, 2016)J/ApJ/818/176 : HST/WFC3 NIR photometry of 2M1207b (Zhou+, 2016)J/A+A/587/A57 : HR 8799e and HR 8799d spectra (Zurlo+, 2016)J/ApJ/842/83 : Praesepe members rot. periods from K2 LCs (Douglas+, 2017)J/ApJ/838/73 : BD surface gravities with Keck/NIRSPEC (Martin , 2017)J/AJ/154/245 : Survey of Spitzer-detected debris disks (Meshkat+, 2017)J/AJ/153/101 : Pleiades members stellar properties (Somers+, 2017)J/A+A/603/A3 : VLT/NaCo Large prog. IV. Statistical analysis (Vigan+, 2017)J/AJ/155/34 : Analysis of the NIR sp. of neighboring L dwarfs (Cruz+, 2018)J/ApJ/862/138 : BANYAN. XIII. Nearby young assoc. with GaiaDR2 (Gagne+, 2018)J/ApJ/856/23 : BANYAN. XI. The BANYAN {Sigma} algorithm (Gagne+, 2018)J/AJ/155/226 : Gemini Planet Imager sp. of HR 8799 c/d/e (Greenbaum+, 2018)J/AJ/156/102 : TESS Input Catalog and Candidate Target List (Stassun+, 2018)J/AJ/158/13 : The first 300 stars observed by the GPIES (Nielsen+, 2019)J/MNRAS/485/4423 : The Gaia ultracool dwarf sample (Smart+, 2019)J/AJ/159/257 : Hawaii IR plx program. IV. L0-T8 BDs with UKIRT (Best+, 2020)J/AJ/159/63 : New AO obs. of exoplanets & BD companions (Bowler+, 2020)J/ApJ/889/176 : Very low-mass binaries with Gaia DR2 data (Faherty+, 2020)J/ApJ/903/96 : The {mu}Tau Association (MUTA) (Gagne+, 2020)J/ApJ/899/123 : Spitzer follow up of 95 brown dwarfs (Meisner+, 2020)J/ApJ/893/67 : Smoothed amplitudes from Kepler, K2 & TESS (Morris, 2020)J/ApJ/898/77 : NIR spectra of 2 extreme T-type subdwarfs (Schneider+, 2020)J/AJ/160/38 : Spitzer variability detections of 79 BDs (Vos+, 2020)J/A+A/649/A6 : Gaia Cat. of Nearby Stars - GCNS (Gaia collaboration, 2021)J/ApJS/253/7 : A full-sky census of BDs within 20pc (Kirkpatrick+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/923/48https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/923/48http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/923/48https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/923/48https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/923/48http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/923/48GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/923/48/fig2The SpeX Prism spectrum for CWISER J124332.12+600126.2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelengthumem.wldoubleFluxFlux in erg/s/cm^2^/{AA}cW.m**-2.nm**-1phot.fluxdoublee_FluxUncertainty in FluxcW.m**-2.nm**-1stat.error;phot.fluxdoubleJ/ApJ/923/48/fig6The Kast optical spectrum of BD+60 1417recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelength; Angstroms0.1nmem.wldoubleFluxFlux in erg/s/cm^2^/{AA}cW.m**-2.nm**-1phot.fluxdoublee_FluxUncertainty in FluxcW.m**-2.nm**-1stat.error;phot.fluxdouble