First simultaneous microlensing observations by two space telescopes: $Spitzer$ & $Swift$ reveal a brown dwarf in event OGLE-2015-BLG-1319
Abstract
Simultaneous observations of microlensing events from multiple locations allow for the breaking of degeneracies between the physical properties of the lensing system, specifically by exploring different regions of the lens plane and by directly measuring the "microlens parallax". We report the discovery of a 30-55 brown dwarf orbiting a K dwarf in microlensing event OGLE-2015-BLG-1319. The system is located at a distance of 5 kpc toward the Galactic bulge. The event was observed by several ground-based groups as well as by and , allowing the measurement of the physical properties. However, the event is still subject to an 8-fold degeneracy, in particular the well-known close-wide degeneracy, and thus the projected separation between the two lens components is either 0.25 AU or 45 AU. This is the first microlensing event observed by , with the UVOT camera. We study the region of microlensing parameter space to which is sensitive, finding that while for this event could not measure the microlens parallax with respect to ground-based observations, it can be important for other events. Specifically, for detecting nearby brown dwarfs and free-floating planets in high magnification events.
Cite
@article{arxiv.1606.02292,
title = {First simultaneous microlensing observations by two space telescopes: $Spitzer$ & $Swift$ reveal a brown dwarf in event OGLE-2015-BLG-1319},
author = {Y. Shvartzvald and Z. Li and A. Udalski and A. Gould and T. Sumi and R. A. Street and S. Calchi Novati and M. Hundertmark and V. Bozza and C. Beichman and G. Bryden and S. Carey and J. Drummond and M. Fausnaugh and B. S. Gaudi and C. B. Henderson and T. G. Tan and B. Wibking and R. W. Pogge and J. C. Yee and W. Zhu and Y. Tsapras and E. Bachelet and M. Dominik and D. M. Bramich and A. Cassan and R. Figuera Jaimes and K. Horne and C. Ranc and R. Schmidt and C. Snodgrass and J. Wambsganss and I. A. Steele and J. Menzies and S. Mao and R. Poleski and M. Pawlak and M. K. Szymański and J. Skowron and P. Mróz and S. Kozłowski and Ł. Wyrzykowski and P. Pietrukowicz and I. Soszyński and K. Ulaczyk and F. Abe and Y. Asakura and R. K. Barry and D. P. Bennett and A. Bhattacharya and I. A. Bond and M. Freeman and Y. Hirao and Y. Itow and N. Koshimoto and M. C. A. Li and C. H. Ling and K. Masuda and A. Fukui and Y. Matsubara and Y. Muraki and M. Nagakane and T. Nishioka and K. Ohnishi and H. Oyokawa and N. J. Rattenbury and To. Saito and A. Sharan and D. J. Sullivan and D. Suzuki and P. J. Tristram and A. Yonehara and U. G. Jørgensen and M. J. Burgdorf and S. Ciceri and G. D'Ago and D. F. Evans and T. C. Hinse and N. Kains and E. Kerins and H. Korhonen and L. Mancini and A. Popovas and M. Rabus and S. Rahvar and G. Scarpetta and J. Skottfelt and J. Southworth and N. Peixinho and P. Verma and B. Sbarufatti and J. A. Kennea and N. Gehrels},
journal= {arXiv preprint arXiv:1606.02292},
year = {2016}
}
Comments
28 pages, 6 figures, 2 tables. Submitted to ApJ