EPIC 201702477b: a transiting brown dwarf from K2 in A 41 day orbit

D. Bayliss, S. Hojjatpanah, A. Santerne, D. Dragomir, G. Zhou, A. Shporer, K. D. Colón, J. Almenara, D. J. Armstrong, D. Barrado, S. C. C. Barros, J. Bento, I. Boisse, F. Bouchy, D. J. A. Brown, T. Brown, A. Cameron, W. D. Cochran, O. Demangeon, M. DeleuilR. F. Díaz, B. Fulton, K. Horne, G. Hébrard, J. Lillo-Box, C. Lovis, D. Mawet, H. Ngo, H. Osborn, E. Palle, E. Petigura, D. Pollacco, N. Santos, R. Sefako, R. Siverd, S. G. Sousa, M. Tsantaki

Research output: Contribution to journalArticlepeer-review

26 Citations (Scopus)

Abstract

We report the discovery of EPIC 201702477b, a transiting brown dwarf in a long period (40.73691 ± 0.00037 day) and eccentric (e = 0.2281 ± 0.0026) orbit. This system was initially reported as a planetary candidate based on two transit events seen in K2 Campaign 1 photometry and later validated as an exoplanet candidate. We confirm the transit and refine the ephemeris with two subsequent ground-based detections of the transit using the Las Cumbres Observatory Global Telescope 1 m telescope network. We rule out any transit timing variations above the level of ∼30 s. Using high precision radial velocity measurements from HARPS and SOPHIE we identify the transiting companion as a brown dwarf with a mass, radius, and bulk density of 66.9 ± 1.7 MJ, 0.757 ± 0.065 RJ, and 191 ± 51 g cm-3 respectively. EPIC 201702477b is the smallest radius brown dwarf yet discovered, with a mass just below the H-burning limit. It has the highest density of any planet, substellar mass object, or main-sequence star discovered so far. We find evidence in the set of known transiting brown dwarfs for two populations of objects—high mass brown dwarfs and low mass brown dwarfs. The higher-mass population have radii in very close agreement to theoretical models, and show a lower-mass limit around 60 MJ. This may be the signature of mass-dependent ejection of systems during the formation process.

Original languageEnglish
Article number15
Number of pages10
JournalAstronomical Journal
Volume153
Issue number1
DOIs
Publication statusPublished - Jan 2017
Externally publishedYes

Keywords

  • planetary systems
  • techniques: photometric
  • techniques: spectroscopic

Fingerprint Dive into the research topics of 'EPIC 201702477b: a transiting brown dwarf from K2 in A 41 day orbit'. Together they form a unique fingerprint.

Cite this