DM Ori: A Young Star Occulted by a Disturbance in its Protoplanetary Disk

Abstract

In some planet formation theories, protoplanets grow gravitationally within a young star's protoplanetary disk, a signature of which may be a localized disturbance in the disk's radial and/or vertical structure. Using time-series photometric observations by the Kilodegree Extremely Little Telescope South (KELT-South) project and the All-Sky Automated Survey for SuperNovae (ASAS-SN), combined with archival observations, we present the discovery of two extended dimming events of the young star, DM Ori. This young system faded by $\sim$1.5 mag from 2000 March to 2002 August and then again in 2013 January until 2014 September (depth $\sim$1.7 mag). We constrain the duration of the 2000-2002 dimming to be $<$ 860 days, and the event in 2013-2014 to be $<$ 585 days, separated by $\sim$12.5 years. A model of the spectral energy distribution (SED) indicates a large infrared excess consistent with an extensive circumstellar disk. Using basic kinematic arguments, we propose that DM Ori is likely being periodically occulted by a feature (possibly a warp or perturbation) in its circumstellar disk. In this scenario, the occulting feature is located $>$6 AU from the host star, moving at $\sim$14.6 km/s, and is $\sim$4.9 AU in width. This localized structure may indicate a disturbance such as may be caused by a protoplanet early in its formation.

9 pages, 4 figures, 1 table, Accepted for publication in ApJ

References in corpus (8)

• The Dartmouth Stellar Evolution Database
• Magnetospheric accretion-ejection processes in the classical T Tauri star AA
• Results of the ROTOR-program. I. The long-term photometric variability of classical T Tauri stars
• Young Stellar Object Variability (YSOVAR): Long Timescale Variations in the Mid-Infrared
• Another deep dimming of the classical T Tauri star RW Aur A
• V409 Tau As Another AA Tau: Photometric Observations of Stellar Occultations by the Circumstellar Disk
• The Transitional Disk around IRAS 04125+2902
• Young Stellar Object candidates toward the Orion region selected from GALEX

Cited by in corpus (6)

• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• The Mysterious Dimmings of the T Tauri Star V1334 Tau
• Periodic Eclipses of the Young Star PDS 110 Discovered with WASP and KELT Photometry
• The ASAS-SN Catalog of Variable Stars VIII: "Dipper" Stars in the Lupus Star-Forming Region
• Inhomogeneous dust eclipses in young stars. The case of CQ Tauri
• The nature of ASASSN-24fw's occultation: modelling the event as dimming by optically thick rings around a sub-stellar companion