Extending the Model of KH 15D: Estimating the Effects of Forward Scattering and Curvature of the Occulting Ring Edge

Abstract

The periodic eclipses of the pre-main-sequence binary, KH 15D, have been explained by a circumbinary dust ring inclined to the orbital plane, which causes occultations of the stars as they pass behind the ring edge. We compute the extinction and forward scattering of light by the edge of the dust ring to explain (1) the gradual slope directly preceding total eclipse, (2) the gradual decline at the end of ingress, and (3) the slight rise in flux at mid-eclipse. The size of the forward scattering halo indicates that the dust grains have a radius of a ~ 6 (D/3 AU) microns, where D is the distance of the edge of the ring from the system barycenter. This dust size estimate agrees well with estimates of the dust grain size from polarimetry, adding to the evidence that the ring lies at several AU. Finally, the ratio of the fluxes inside and outside eclipse independently indicates that the ring lies at a few astronomical units.

8 pages, 6 Postscript figures, to see the mpeg file associated with figure 4 go to: http://mdbworks.net/devin/kh15d.mpg

References in corpus (3)

• Dust filtration at gap edges: Implications for the spectral energy distributions of discs with embedded planets
• The Orbit and Occultations of KH 15D
• Reflected Light from Sand Grains in the Terrestrial Zone of a Protoplanetary Disk

Cited by in corpus (4)

• Constraining the Circumbinary Disk Tilt in the KH 15D system
• Optical and Radio Observations of the T Tauri Binary KH 15D (V582 Mon): Stellar Properties, Disk Mass Limit and Discovery of a CO Outflow
• Two Candidate KH 15D-like Systems from the Zwicky Transient Facility
• Untangling the Near-IR Spectral Features in the Protoplanetary Environment of KH 15D