Cloud Atlas: Discovery of Rotational Spectral Modulations in a Low-mass, L-type Brown Dwarf Companion to a Star
Lew, Ben W. P.
Cowan, Nicolas B.
Metchev, Stanimir A.
Miles-Páez, Paulo A.
Burgasser, Adam J.
Bedin, Luigi R.
Lowrance, Patrick J.
Marley, Mark S.
AffiliationUniv Arizona, Dept Astron, Steward Observ
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationCloud Atlas: Discovery of Rotational Spectral Modulations in a Low-mass, L-type Brown Dwarf Companion to a Star 2017, 155 (1):11 The Astronomical Journal
JournalThe Astronomical Journal
Rights© 2017. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractObservations of rotational modulations of brown dwarfs and giant exoplanets allow the characterization of condensate cloud properties. As of now, rotational spectral modulations have only been seen in three L-type brown dwarfs. We report here the discovery of rotational spectral modulations in LP261-75B, an L6-type intermediate surface gravity companion to an M4.5 star. As a part of the Cloud Atlas Treasury program, we acquired time-resolved Wide Field Camera 3 grism spectroscopy (1.1-1.69 mu m) of LP261-75B. We find gray spectral variations with the relative amplitude displaying only a weak wavelength dependence and no evidence for lower-amplitude modulations in the 1.4. mu m water band than in the adjacent continuum. The likely rotational modulation period is 4.78 +/- 0.95. hr, although the rotational phase is not well sampled. The minimum relative amplitude in the white light curve measured over the whole wavelength range is 2.41% +/- 0.14%. We report an unusual light curve, which seems to have three peaks approximately evenly distributed in rotational phase. The spectral modulations suggests that the upper atmosphere cloud properties in LP261-75B are similar to two other mid-L dwarfs of typical infrared colors, but differ from that of the extremely red L-dwarf WISE0047.
VersionFinal published version
SponsorsNASA [NAS 5-26555, GO-14241]; National Aeronautics and Space Administration; National Science Foundation