Discovery of a new Y dwarf: WISE J030449.03-270508.3

Pinfield, D.J.; Gromadzki, M.; Leggett, S.K.; Gomes, J.; Lodieu, N.; Kurtev, R.; Day-Jones, A. C.; Ruiz, M. T.; Cook, N. J.; Morley, C.V.; Marley, M. S.; Marocco, F.; Smart, R.L.; Jones, H.R.A.; Lucas, P.W.; Beletsky, Y.; Ivanov, V. D.; Burningham, B.; Jenkins, J. S.; Cardoso, C.; Frith, J.; Clarke, J. R. A.; Gálvez-Ortiz, M. C.; Zhang, Z.

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Author

Pinfield, D.J.

Gromadzki, M.

Leggett, S.K.

Gomes, J.

Lodieu, N.

Kurtev, R.

Day-Jones, A. C.

Ruiz, M. T.

Cook, N. J.

Morley, C.V.

Marley, M. S.

Marocco, F.

Smart, R.L.

Jones, H.R.A.

Lucas, P.W.

Beletsky, Y.

Ivanov, V. D.

Burningham, B.

Jenkins, J. S.

Cardoso, C.

Frith, J.

Clarke, J. R. A.

Gálvez-Ortiz, M. C.

Zhang, Z.

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 Wide-field Infrared Survey Explorer (WISE) data base. 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 disc membership, but it shows some spectral characteristics that suggest that 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 Mȯ). This object may thus be extending the population parameter space of the known Y0 dwarfs.