Astronomers Detect Methane in the Atmosphere of the Nearest T Dwarf Star to Earth

The scientists have found methane in the atmosphere of WISEA J181006.18 −101000.5, the T dwarf closest to Earth. The study was published in the online preprint journal arXiv on March 28, and the final, revised version was published on November 17. The WISE1810 is a metal-poor T dwarf planet, which is situated at a distance of 29 light years from the Earth. The effective temperature of the dwarf is reported to be within the range of 800–1,300 K.

Methane Signature Surprises Astronomers

According to a Phys.org report, the finding is made greatly possible by the present 10.4-m Gran Telescopio Canarias (GTC). The detection of methane in the atmosphere of the dwarf planet has further made its classification as T-type instead of L-type, which was earlier suggested in previous studies, the publication notes. The study further reveal that there are no traces of carbon monoxide and potassium in the atmosphere of the WISE1810. 

The study further highlights that the carbon abundance in the planet is estimated to be -1.5 dex, while the effective temperature could be around 1,000 K. The author of the paper further revealed that the low metallicity of the T dwarf planet could be due to the non-detection of atomic potassium. However, a lower temperature could also boost this effect, the report further highlights. The study also found that WISE1810 has a heliocentric velocity of -83 km/s. 

The 10.4-m Gran Telescopio Canarias (GTC) supplies a significant contribution to finishing WISEA J181006.18−101000 observations. Interestingly, the previous observations of the dwarf platent suggested that the atmosphere of the dwarf planet was dominated by hydrogen and water vapour. Moreover, the study further reveals that findings indicates WISE1810 could more likely to be associated with the Milky Way's thick disk, despite its very low metallicity.