Photometric Variability at the L/T Dwarf Boundary
Abstract
We have monitored the photometric variability of nine field L and T brown dwarfs for 10 nights during the course of 1 month. Observations were obtained in the K_s band with the Palomar 60 inch (1.5 m) telescope Near-Infrared Camera. Results of statistical analyses indicate that at least three of the nine targets show significant evidence for variability, and three more are possibly variable. Fractional deviations from the median flux vary from 5% to 25%. Two of the variable targets, 2MASS 0030-14 (L7) and SDSS 0151+12 (T1), have marginally significant peaks in their periodograms. The phased light curves show evidence for periodic behavior on timescales of 1.5 and 3.0 hr, respectively. No significant correlations between variability amplitude and spectral type or J-K_s color are found. While it is clear that variability exists in objects near the L/T dwarf boundary, we find no evidence that variability near the L/T boundary is more likely than it is for early L dwarfs.
Additional Information
© 2003 American Astronomical Society. Received 2003 January 29; accepted 2003 April 29. The authors are grateful to Antonin Bouchez, Jean-Luc Margot, and the Palomar Observatory staff for their time and help in obtaining these observations. We also thank the referee for helpful comments on the manuscript. M. L. E. acknowledges support from a NSF Graduate Research Fellowship. A. J. B. acknowledges support by NASA through Hubble Fellowship grant HST-HF-01137.01 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. This publication makes use of data from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center, funded by NASA and the NSF.Attached Files
Published - 1538-3881_126_2_1006.pdf
Accepted Version - 0305048.pdf
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Additional details
- Eprint ID
- 34414
- Resolver ID
- CaltechAUTHORS:20120926-094752428
- NSF Graduate Research Fellowship
- HST-HF-01137.01
- NASA Hubble Fellowship
- NAS 5-26555
- NASA
- NASA/JPL/Caltech
- Created
-
2012-09-26Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC), Division of Geological and Planetary Sciences