Planet-like object may have spent its youth as hot as a star
Astronomers have discovered an extremely cool object that could have a particularly diverse history - although it is now as cool as a planet, it may have spent much of its youth as hot as a star. The team publish their results in the journal Monthly Notices of the Royal Astronomical Society. The current temperature of the object is 100-150 degrees Celsius, intermediate between that of the Earth and Venus. But the object shows evidence of a possible ancient origin, implying that a large change in temperature has taken place. In the past this object would have been as hot as a star for many millions of years. Read more
Title: Discovery of a new Y dwarf: WISE J030449.03-270508.3 Author: 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, 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
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.