Cool Star Lab Contributes to the Discovery of 3 Potentially Habitable Earth-Sized Worlds

 

Adam Burgasser and Daniella Bardalez Gagliuffi were part of an international team headed by Michael Gillon at the University of Liege that discovered three Earth-sized planets orbiting around the habitable zone of a nearby ultracool dwarf, TRAPPIST-1. The results were reported in the May 2, 2016 issue of Nature.

This artist’s impression shows an imagined view of the three planets orbiting an ultracool dwarf star just 40 light-years from Earth that were discovered using the TRAPPIST telescope at ESO’s La Silla Observatory. These worlds have sizes and temperatures similar to those of Venus and Earth and may be the best targets found so far for the search for life outside the Solar System. They are the first planets ever discovered around such a tiny and dim star. In this view one of the inner planets is seen in transit across the disc of its tiny and dim parent star.

This artist’s impression shows an imagined view of the three planets orbiting an ultracool dwarf star just 40 light-years from Earth that were discovered using the TRAPPIST telescope at ESO’s La Silla Observatory. These worlds have sizes and temperatures similar to those of Venus and Earth and may be the best targets found so far for the search for life outside the Solar System. They are the first planets ever discovered around such a tiny and dim star. In this view one of the inner planets is seen in transit across the disc of its tiny and dim parent star (ESO/M. Kornmesser, CC BY)

Below is a reproduction of a The Conversation article I wrote for this discovery, with images from the official ESO press release.

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Discovery of a Nearby Star-Brown Dwarf Binary

The nearest star systems to the Sun are some of the most heavily studied, as their proximity makes them brighter and easier to observe. Moreover, nearby systems can be studied at finer resolution than distant ones, making it easier to detect astrometric motion (parallax, proper motion, orbital motion), close companions, and even circumstellar structures such as disks and jets.  As astronomers probe ever cooler stars and brown dwarfs, we are constantly finding new neighbors, such as the recently discovered L dwarf + T dwarf binary Luhman 16AB (3rd closest to the Sun) and the frigid Y dwarf WISE J0855-0714, both around 2 pc (6 lightyears) away.

One of the recent nearby star discoveries is WISE J0720-0846 (Figure 1), uncovered by Ralf-Dieter Scholz in a cross-match of the WISE and 2MASS surveys.  At ~7 pc, this apparently cool late M or L dwarf is an exciting new addition to the Solar Neighborhood. So of course we had to get a peek at it.

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Cloud properties of Nearest Brown Dwarfs Revealed through Spectral Monitoring Study

starweatherWe’ve just reported the first results from our April 2013  campaign to monitor the nearby brown dwarf binary Luhman 16AB, in a paper published in the Astrophysical Journal.  Our results confirm the earlier “flux reversal” seen in FIRE spectroscopy, and allow us to make the first constraints on the cloud coverage fraction and the temperatures of the “clouds” and “holes” in the atmosphere of Luhman 16B.  We also confirm an apparent correlation between rotation period and variability amplitude, which may emerge if cloud features are related to the Rhine’s scale of brown dwarf atmospheres.

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