Temperature constraints on the coldest brown dwarf known: WISE 0855-0714

J. C. Beamín, V. D. Ivanov, A. Bayo, K. Mužić, H. M.J. Boffin, F. Allard, D. Homeier, D. Minniti, M. Gromadzki, R. Kurtev, N. Lodieu, E. L. Martin, R. A. Mendez

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


Context. Nearby isolated planetary mass objects are beginning to be discovered, but their individual properties are poorly constrained because their low surface temperatures and strong molecular self-absorption make them extremely faint. Aims. We aimed to detect the near-infrared emission of the coldest brown dwarf (BD) found so far, WISE0855-0714, located ~2.2 pc away, and to improve its temperature estimate (Teff = 225-260 K) from a comparison with state-of-the-art models of BD atmospheres. Methods. We observed the field containing WISE0855-0714 with HAWK-I at the VLT in the Y band. For BDs with Teff< 500 K theoretical models predict strong signal (or rather less molecular absorption) in this band. Results. WISE0855-0714 was not detected in our Y-band images, thus placing an upper limit on its brightness to Y> 24.4 mag at 3σ level, leading to Y-[4.5] > 10.5. Combining this limit with previous detections and upper limits at other wavelengths, WISE0855-0714 is confirmed as the reddest BD detected, further supporting its status as the coldest known brown dwarf.

Original languageEnglish
Article numberL8
JournalAstronomy and Astrophysics
Publication statusPublished - 1 Oct 2014


  • Brown dwarfs
  • Infrared: stars
  • Proper motions
  • Solar neighborhood
  • Stars: individual: WISE 0855-0714
  • Stars: low-mass

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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