Discovery of a new Y dwarf: WISE J030449.03-270508.3
astro-ph.SR
/ Authors
D. J. Pinfield, M. Gromadzki, S. K. Leggett, J. Gomes, N. Lodieu, R. Kurtev, A. C. Day-Jones, M. T. Ruiz, N. J. Cook, C. V. Morley
and 14 more authors
M. S. Marley, F. Marocco, R. L. Smart, H. R. A. Jones, P. W. Lucas, Y. Beletsky, V. D. Ivanov, B. Burningham, J. S. Jenkins, C. Cardoso, J. Frith, J. R. A. Clarke, M. C. Galvez-Ortiz, Z. Zhang
/ Abstract
We present a new Y dwarf, WISE J030449.03-270508.3, confirmed from a candidate sample designed to pick out low temperature objects from the WISE database. The new object is typed Y0pec following a visual comparison with spectral standards, and lies at a likely distance of 10-17 pc. Its tangential velocity suggests thin disk membership, but it shows some spectral characteristics that suggest it may be metal-poor and/or older than previously identified Y0 dwarfs. Based on trends seen for warmer late type T dwarfs, the Y-band flux peak morphology is indicative of sub-solar metallicity, and the enhanced red wing of the J-band flux peak offers evidence for high gravity and/or low metallicity (with associated model trends suggesting an age closer to ~10 Gyr and mass in the range 0.02-0.03 Mo). This object may thus be extending the population parameter-space of the known Y0 dwarfs.