NOAO >   Observing Info >   Approved Programs >   2009A-0285

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Proposal Information for 2009A-0285


PI: Andrew Skemer, University of Arizona, askemer@as.arizona.edu
Address: Astronomy Department, 933 N. Cherry Ave, Tucson, AZ 85721, USA

CoI: Laird Close, University of Arizona
CoI: Beth Biller, University of Hawaii
CoI: Josh Eisner, University of Arizona

Title: The Periodicity of Extinction Events in VV Ser: A Map of Dust Structures in the Inner-Rim of a Herbig Be Disk

Abstract: Edge-on circumstellar disks provide a unique laboratory for probing absorption, extinction and other dust characteristics in the line-of- sight to their stars. Of particular interest is a class of objects named after UX Orionis, which exhibit variable extinction on relatively short (day-week) timescales. One exciting explanation for these events is that dust clumps resulting from the planet formation process could be obscuring their host star with Keplerian periodicity. However, this has yet to be unambiguously observed. VV Ser is a bright UX Ori type star with ~5 day long extinction events that can be adequately sampled at a cadence of once per night. What makes the object particularly interesting is that it has a small inner rim radius (resolved by PTI). Assuming Keplerian orbits, it is possible to probe the occulting dust perturbations with predicted periods of ~1-3 months as the whole rim rotates multiple times in an observing season. We propose to do a well-sampled, long-term, photometric variability study of VV Ser with the goal of observing Keplerian behavior at a ~1-3 month period. From previous semesters, we have 13 minutes of V+K data for 132 nights (NOAO-2008A-0511; NOAO-08B-0300). Our lightcurve periodogram shows a peak that is in VV Ser's Keplerian range. We propose to continue monitoring VV Ser for an additional 152 nights in 2009A. This will allow us to determine if our periodogram peak is real and to constrain its position.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



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