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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Gretel Mercado presents at 2016 CAMP Symposium at UCI

Undergraduate research Gretel Mercado presented her research investigating a possible brown dwarf companion to a nearby star at the 2016 CAMP Statewide Symposium at UC Irvine.

Gretel is a member of the UCSD chapter of the California Louis Stokes Alliance for Minority Participation in Science, Engineering and Mathematics (CAMP – LSAMP). This NSF-funded program provides support and advancement opportunities to students defined as underrepresented by the NSF who are seeking bachelor’s degrees in chemistry, physics, cognitive science, biology, other sciences, mathematics, engineering and technology. It is one of many initiatives started by the recently deceased senator from Ohio Louis Stokes to advance underrepresented minorities in science and education.

Gretel was one of 45 students from across the UC system to present physical science research posters at the day-long event, which were judged by nearly two dozen faculty members from all campuses.  She reported her analysis of a previously unrecognized L dwarf that appears to be a very wide companion to a nearby, young sun-like star. She is currently writing up her research for publication. This was the same research that won Gretel a poster award at the APS Far West meeting in October 2015

 

First SPLAT Publication: An In-depth Analysis of GJ 660.1AB

Screen Shot 2016-01-20 at 10.14.17 PMMorehouse College undergraduate Christian Aganze has led the first result to be published from the SpeX Prism Library Analysis Toolkit (SPLAT) project: an in-depth analysis of the M-dwarf binary system GJ 660.1AB.

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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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Spectral binaries of brown dwarfs

Screen shot 2013-08-22 at 2.02.36 AMHow do brown dwarfs form? Some theories point to a star-like birth, accreting material from a molecular cloud, while some others point to a planet-like formation from a pre-stellar disk. Either way, the essential mechanisms for brown dwarf formation remain under debate by theorists. Given the astronomical timelines of star formation (1-10 million years), we cannot witness the formation process in action, but we can study its consequences on the statistical properties of the systems created.

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