Eclipsing Disks in the Galactic Bulge Time-Domain Survey
| Program ID | 19071 |
|---|---|
| Science Category | Stellar Physics |
| Program Type | Analysis |
| Category | Small |
| Principal Investigator | Eric Gaidos |
| PI Institution | University of Hawaii |
| Co-Investigators |
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| Abstract | We propose to search for eclipsing circumstellar disks among systems of older and evolved stars in the Roman Space Telescope's Galactic Bulge Time-Domain Survey. These systems manifest themselves as deep, long-duration (months) dimming events in the light curves of otherwise unremarkable stars. These disks produce similar light curves but are vastly older than the eclipsing disks in binary T Tauri stars or young massive stars where the presence of primordial disks can be readily explained. These older disks are optically thick and not the debris disks detected by infrared surveys around some main sequence stars. Instead they could represent a new class of object which informs us about rare, catastrophic dust-producing events in planetary systems, or the final stages of planetary evolution under the influence of the post main-sequence host star. Only a handful of these systems are known from ground-based surveys, which are biased towards towards more luminous and observationally accessible stars. The GBTDS is an opportunity to carry out a homogeneous survey for these eclipsing disk systems among a very large number of older main sequence and evolved stars to determine their statistical occurrence and the distribution of stellar types, important clues to the underlying mechanism. We will identify ingress or egress events in individual seasons and validate them against other types of stellar variability using inferred stellar properties, light curve shape, and -- exploiting the multi-filter photometry obtained at lower cadence -- color changes. We will compare our detections to simulations of binary systems in the Bulge population to estimate the intrinsic occurrence of such disks. Our investigation will provide added value to the GBTDS and has the potential for the serendipitous discoveries of other kinds of deep dimming events such as those produced by circumstellar or circum-planetary rings or exocomets. |