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arXiv · 2004.12829

WISEA J083011.95+283716.0: A Missing Link Planetary-Mass Object

Daniella C. Bardalez Gagliuffi·Jacqueline K. Faherty·Adam C. Schneider·Aaron Meisner·Dan Caselden·Guilluame Colin·Sam Goodman·J. Davy Kirkpatrick·Marc J. Kuchner·Jonathan Gagné·Sarah E. Logsdon·Adam J. Burgasser·Katelyn Allers·John Debes·John Wisniewski·Austin Rothermich·Nikolaj S. Andersen·Melina Thévenot·Jim Walla
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Abstract

We present the discovery of WISEA J083011.95+283716.0, the first Y dwarf candidate identified through the Backyard Worlds: Planet 9 citizen science project. We identified this object as a red, fast-moving source with a faint $W2$ detection in multi-epoch \textit{AllWISE} and unWISE images. We have characterized this object with Spitzer Space Telescope and \textit{Hubble Space Telescope} follow-up imaging. With mid-infrared detections in \textit{Spitzer}'s \emph{ch1} and \emph{ch2} bands and flux upper limits in Hubble Space Telescope $F105W$ and $F125W$ filters, we find that this object is both very faint and has extremely red colors ($ch1-ch2 = 3.25\pm0.23$ mag, $F125W-ch2 \geq 9.36$ mag), consistent with a T$_{eff}\sim300$ K source, as estimated from the known Y dwarf population. A preliminary parallax provides a distance of $11.1^{+2.0}_{-1.5}$ pc, leading to a slightly warmer temperature of $\sim350$ K. The extreme faintness and red Hubble Space Telescope and Spitzer Space Telescope colors of this object suggest it may be a link between the broader Y dwarf population and the coldest known brown dwarf WISE J0855$-$0714, and highlight our limited knowledge of the true spread of Y dwarf colors. We also present four additional Backyard Worlds: Planet 9 late-T brown dwarf discoveries within 30 pc.

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Daniella C. Bardalez Gagliuffi, Jacqueline K. Faherty, Adam C. Schneider, Aaron Meisner, Dan Caselden, Guilluame Colin, Sam Goodman, J. Davy Kirkpatrick, Marc J. Kuchner, Jonathan Gagné, Sarah E. Logsdon, Adam J. Burgasser, Katelyn Allers, John Debes, John Wisniewski, Austin Rothermich, Nikolaj S. Andersen, Melina Thévenot, Jim Walla. 2020-04-27. WISEA J083011.95+283716.0: A Missing Link Planetary-Mass Object. https://doi.org/10.3847/1538-4357%2Fab8d25

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