Modeling Transiting Circumstellar Disks: Characterizing the Newly Discovered Eclipsing Disk System OGLE LMC-ECL-11893

TL;DR

This paper models the eclipsing behavior of OGLE LMC-ECL-11893, a star with a circumstellar dust disk causing long-period eclipses, and compares it to similar systems, providing insights into disk structures around evolved stars.

Contribution

It introduces a detailed model of the eclipsing disk system OGLE LMC-ECL-11893, highlighting the debris disk as the best fit and exploring its origin and characteristics.

Findings

Eclipses caused by a debris disk around a low-mass companion.

Disk has an outer radius of ~0.2 AU and temperature of 1100-1400 K.

System shows similarities to EE Cep with a dense circumstellar dust disk.

Abstract

We investigate the nature of the unusual eclipsing star OGLE LMC-ECL-11893 (OGLE J05172127-6900558) in the Large Magellanic Cloud recently reported by Dong et al. 2014. The eclipse period for this star is 468 days, and the eclipses exhibit a minimum of ~1.4 mag, preceded by a plateau of ~0.8 mag. Spectra and optical/IR photometry are consistent with the eclipsed star being a lightly reddened B9III star of inferred age ~150 Myr and mass of ~4 solar masses. The disk appears to have an outer radius of ~0.2 AU with predicted temperatures of ~1100-1400 K. We model the eclipses as being due to either a transiting geometrically thin dust disk or gaseous accretion disk around a secondary object; the debris disk produces a better fit. We speculate on the origin of such a dense circumstellar dust disk structure orbiting a relatively old low-mass companion, and on the similarities of this system to the previously discovered EE Cep.