Discovery of an L dwarf co-moving BD+60 1417

DOI

Through 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.

Identifier
DOI http://doi.org/10.26093/cds/vizier.19230048
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/923/48
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/923/48
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/923/48
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/923/48
Provenance
Creator Faherty 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 Collaboration
Publisher CDS
Publication Year 2023
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy