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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Morehouse Fellow Christian Aganze Wins Poster Award at SACNAS

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Christian Aganze, a Morehouse-UCSD Bridge Fellow working in the Cool Star Lab, won a poster award at the 2014 National Conference of the Society for the Advancement of Chicano and Native American Scientists (SACNAS).  Christian won the award for his presentation of work done this summer to investigate the mysterious nature of GJ 660.1B, a cool companion to the nearby M0 dwarf GJ 660.1.  Using data in the SpeX Prism Library and published spectral index relations, Christian has found that this source is either very young or metal poor, but careful inspection supports the latter hypothesis.  This makes GJ 660.1B a new benchmark for metal-poor very low mass dwarfs, and is a cautionary tale for index-based gravity measures.

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Congratulations Christian!

Cool Star Lab Presents at Cool Stars Conference

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Adam Burgasser and Daniella Bardalez Gagliuffi were among hundreds of attendees at the 18th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, held in Flagstaff, AZ, June 8-13.  This biennial conference highlights the latest research in low-temperature, low-mass stars and brown dwarfs, and this year had its fair share of exciting results in both observation and theory.

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Talk on the Future of the SpeX Prism Library

Prof. Adam Burgasser gave a talk on March 21, 2014 at the University of Hawaii’s Institute for Astronomy, describing the impact and future of the SpeX Prism Library (SPL).  The talk can be viewed in its entirety through YouTube:

Initiated over 5 years ago, the SPL is a compilation of nearly 1000 low-resolution near-infrared spectra of M, L and T dwarfs measured with the SpeX spectrograph on the 3-meter IRTF telescope on Mauna Kea, Hawaii.  The data were acquired by several groups over the past decade.  Used in over 100 publications to date, the SPL has been an invaluable resource for studies on cool stars, brown dwarfs, exoplanets and even high redshift quasars!  In addition, SPL data has been used for art (through Project Planetaria) and public outreach/education.

In his talk, Adam described his vision of the future of the SPL , which is aimed at making it a fully curated dataset and more user-friendly for non-expert use; e.g., for research projects for students from middle school to college levels. Some of the main tasks he foresees in realizing this vision are (1) providing a more uniformly calibrated set of spectra through re-reduction of older data; (2) expansion of the dataset, including data published in the literature or languishing in the SpeX computers; (3) development of Python software tools to visualize, measure and manipulate the spectra; and (4) development of visual programming tools so non-experts can explore the data in new ways.  Adam has requested funding from the NSF and NASA to pursue this work.

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Some of the work is already underway, as the Cool Star Lab has started development of the SpeX Prism Library Analysis Toolkit, or SPLAT.  In weekly coding sessions, the group has produced the first iteration of the toolkit, allowing for spectral data reading, plotting and index measurement.  More to come soon!