학술논문
Redder than Red: Discovery of an Exceptionally Red L/T Transition Dwarf
Document Type
Working Paper
Author
Schneider, Adam C.; Burgasser, Adam J.; Bruursema, Justice; Munn, Jeffrey A.; Vrba, Frederick J.; Caselden, Dan; Kabatnik, Martin; Rothermich, Austin; Sainio, Arttu; Bickle, Thomas P.; Dahm, Scott E.; Meisner, Aaron M.; Kirkpatrick, J. Davy; Suarez, Genaro; Gagne, Jonathan; Faherty, Jacqueline K.; Vos, Johanna M.; Kuchner, Marc J.; Williams, Stephen J.; Gagliuffi, Daniella Bardalez; Aganze, Christian; Hsu, Chih-Chun; Theissen, Christopher; Cushing, Michael C.; Marocco, Federico; Casewell, Sarah; Worlds, the Backyard; Collaboration, Planet 9
Source
Subject
Language
Abstract
We present the discovery of CWISE J050626.96$+$073842.4 (CWISE J0506$+$0738), an L/T transition dwarf with extremely red near-infrared colors discovered through the Backyard Worlds: Planet 9 citizen science project. Photometry from UKIRT and CatWISE give a $(J-K)_{\rm MKO}$ color of 2.97$\pm$0.03 mag and a $J_{\rm MKO}-$W2 color of 4.93$\pm$0.02 mag, making CWISE J0506$+$0738 the reddest known free-floating L/T dwarf in both colors. We confirm the extremely red nature of CWISE J0506$+$0738 using Keck/NIRES near-infrared spectroscopy and establish that it is a low-gravity late-type L/T transition dwarf. The spectrum of CWISE J0506$+$0738 shows possible signatures of CH$_4$ absorption in its atmosphere, suggesting a colder effective temperature than other known, young, red L dwarfs. We assign a preliminary spectral type for this source of L8$\gamma$-T0$\gamma$. We tentatively find that CWISE J0506$+$0738 is variable at 3-5 $\mu$m based on multi-epoch WISE photometry. Proper motions derived from follow-up UKIRT observations combined with a radial velocity from our Keck/NIRES spectrum and a photometric distance estimate indicate a strong membership probability in the $\beta$ Pic moving group. A future parallax measurement will help to establish a more definitive moving group membership for this unusual object.
Comment: Accepted to ApJ Letters
Comment: Accepted to ApJ Letters