Two Candidate KH 15D-like Systems from the Zwicky Transient Facility

TL;DR

This paper reports the discovery of two new systems similar to KH 15D, exhibiting long, periodic dimming caused by tilted circumbinary disks, expanding understanding of such phenomena.

Contribution

It introduces two candidate KH 15D-like systems from Zwicky Transient Facility data and models their photometric behavior with a tilted, warped circumbinary disk.

Findings

Large-amplitude, long-duration dimming events observed

Potential precession periods longer than 10 years suggested

A one-sided screen model effectively explains the photometric behavior

Abstract

KH 15D contains a circumbinary disk that is tilted relative to the orbital plane of the central binary. The precession of the disk and the orbital motion of the binary together produce rich phenomena in the photometric light curve. In this work, we present the discovery and preliminary analysis of two objects that resemble the key features of KH 15D from the Zwicky Transient Facility. These new objects, Bernhard-1 and Bernhard-2, show large-amplitude ($>1.5\,$mag), long-duration (more than tens of days), and periodic dimming events. A one-sided screen model is developed to model the photometric behaviour of these objects, the physical interpretation of which is a tilted, warped circumbinary disk occulting the inner binary. Changes in the object light curves suggest potential precession periods over timescales longer than 10 years. Additional photometric and spectroscopic observations are encouraged to better understand the nature of these interesting systems.