NASA | JPL-Caltech | Spitzer | Swift | 2016 Nov 10
[img3="This illustration depicts a newly discovered brown dwarf, an object that weighs in somewhere between our solar system's most massive planet (Jupiter) and the least-massive known star. Credit: NASA/JPL-Caltech"]http://www.spitzer.caltech.edu/uploaded ... 20_Med.jpg[/img3][hr][/hr]In a first-of-its-kind collaboration, NASA's Spitzer and Swift space telescopes joined forces to observe a microlensing event, when a distant star brightens due to the gravitational field of at least one foreground cosmic object. This technique is useful for finding low-mass bodies orbiting stars, such as planets. In this case, the observations revealed a brown dwarf.
Brown dwarfs are thought to be the missing link between planets and stars, with masses up to 80 times that of Jupiter. But their centers are not hot or dense enough to generate energy through nuclear fusion the way stars do. Curiously, scientists have found that, for stars roughly the mass of our sun, less than 1 percent have a brown dwarf orbiting within 3 AU (1 AU is the distance between Earth and the sun). This phenomenon is called the "brown dwarf desert."
The newly discovered brown dwarf, which orbits a host star, may inhabit this desert. Spitzer and Swift observed the microlensing event after being tipped off by ground-based microlensing surveys, including the Optical Gravitational Lensing Experiment (OGLE). The discovery of this brown dwarf, with the unwieldy name OGLE-2015-BLG-1319, marks the first time two space telescopes have collaborated to observe a microlensing event. ...
First simultaneous microlensing observations by two space telescopes:
Spitzer & Swift reveal a brown dwarf in event OGLE-2015-BLG-1319 - Y. Shvartzvald et al
- Astrophysical Journal 831/2/183 (10 Nov 2016) DOI: 10.3847/0004-637X/831/2/183
arXiv.org > astro-ph > arXiv:1606.02292 > 07 Jun 2016