The Collapse of the Wien Tail in the Coldest Brown Dwarf? Hubble Space Telescope Near-infrared Photometry of WISE J085510.83-071442.5
Abstract
We present Hubble Space Telescope (HST) near-infrared photometry of the coldest known brown dwarf, WISE J085510.83-071442.5 (WISE 0855-0714). WISE 0855-0714 was observed with the Wide Field Camera 3 (WFC3) on board HST using the F105W, F125W, and F160W filters, which approximate the Y, J, and H near-infrared bands. WISE 0855-0714 is undetected at F105W with a corresponding 2σ magnitude limit of ∼26.9. We marginally detect WISE 0855-0714 in the F125W images (S/N ∼ 4), with a measured magnitude of 26.41 ± 0.27, more than a magnitude fainter than the J-band magnitude reported by Faherty et al. WISE J0855-0714 is clearly detected in the F160W band, with a magnitude of 23.86 ± 0.03, the first secure detection of WISE 0855-0714 in the near-infrared. Based on these data, we find that WISE 0855-0714 has extremely red {{F}}105{{W}}-{{F}}125{{W}} and {{F}}125{{W}}-{{F}}160{{W}} colors relative to other known Y dwarfs. We find that when compared to the models of Saumon et al. and Morley et al., the {{F}}105{{W}}-{{F}}125{{W}} and {{F}}125{{W}}-{{F}}160{{W}} colors of WISE 0855-0714 cannot be accounted for simultaneously. These colors likely indicate that we are seeing the collapse of flux on the Wien tail for this extremely cold object.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2016
- DOI:
- 10.3847/2041-8205/823/2/L35
- arXiv:
- arXiv:1605.05618
- Bibcode:
- 2016ApJ...823L..35S
- Keywords:
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- brown dwarfs;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted for publication in ApJ Letters