| Issue |
A&A
Volume 704, December 2025
|
|
|---|---|---|
| Article Number | A217 | |
| Number of page(s) | 10 | |
| Section | Interstellar and circumstellar matter | |
| DOI | https://doi.org/10.1051/0004-6361/202555615 | |
| Published online | 16 December 2025 | |
Brightness variability in polar circumbinary disks
1
Dipartimento di Fisica, Università degli Studi di Milano,
Via Celoria 16,
20133
Milano,
Italy
2
Department of Physics and Astronomy, University of Nevada,
Las Vegas 4505 S. Maryland Parkway,
Las Vegas,
NV
89154,
USA
★ Corresponding author: ian.rabago@unimi.it
Received:
21
May
2025
Accepted:
29
October
2025
In binary systems with a strongly misaligned disk, the central binary stars can travel a significant vertical distance above and below the disk’s orbital plane. This can cause large changes in illumination of the disk over the course of the binary orbital period. We use both analytic and radiative transfer models to examine the effect of changes in stellar illumination on the appearance of the disk, specifically in the case of the polar disk HD 98800B. We find that the observed flux from the disk can vary significantly over the binary orbital period, producing a periodically varying light curve that peaks twice each binary orbit. The amount of flux variation is strongly influenced by the disk geometry. We suggest that these flux variations produce several observable signatures, and that these observables may provide constraints on different properties of the disk, such as its vertical structure, geometry, and cooling rate.
Key words: accretion, accretion disks / radiation mechanisms: general / radiative transfer / protoplanetary disks / binaries: general / stars: individual: HD 98800
© The Authors 2025
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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