Carnegie Institution for Science | Western University | 2016 Apr 06
[img3="2MASS J1119–1137 belongs in the youngest group of stars in the solar neighborhood, known collectively as the TW Hydrae association, which contains about two dozen 10 million-year-old stars, all moving together through space. This image is a still shot from a video about these results. (Credit: David Rodriguez, with contributions from Jacqueline Faherty, Jonathan Gagné, and Stanimir Metchev)"]https://carnegiescience.edu/sites/carne ... ogPic1.jpg[/img3][hr][/hr]A team of astronomers from Carnegie and Western University in Ontario, Canada, has discovered one of the youngest and brightest free-floating, planet-like objects within relatively close proximity to the Sun. The paper reporting these results will be published by The Astrophysical Journal Letters.
At an age of only 10 million years, which means it’s practically a baby on a galactic time scale, the object identified as 2MASS J1119–1137 is between four and eight times the mass of Jupiter, and hence falls in the mass range between a large planet and a small brown dwarf star. Using data from NASA's Wide-field Infrared Survey Explorer (WISE) and other ground-based telescopes, 2MASS J1119–1137 was identified by its unique light signature using a combination of optical and infrared images from large-area surveys of the sky.
"We identified 2MASS J1119–1137 by its highly unusual light signature," explains lead author Kendra Kellogg, a graduate student at Western's Department of Physics and Astronomy. "It emits much more light in the infrared part of the spectrum than it would be expected to if it had already aged and cooled.”
According to Carnegie’s Jacqueline Faherty, the challenge with identifying such rare objects is distinguishing them from a multitude of potential interlopers.
"Much more commonly, distant old and red stars residing in the far corners of our galaxy can display the same characteristics as nearby planet-like objects," says Faherty. "When the light from the distant stars passes through the large expanses of dust in our galaxy on its way to our telescopes, the light gets reddened so these stars can pose as potentially exciting nearby young planet-like objects in our data, when they actually are not that at all." ...
The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog - Kendra Kellogg et al
- arXiv.org > astro-ph > arXiv:1603.08529 > 28 Mar 2016 (v1), 31 Mar 2016 (v2)