# Photometry of Beta Lyrae in 2018 by the BRITE satellites

## TL;DR

This study used BRITE satellites to observe Beta Lyrae in 2018, revealing correlated light-curve variability across spectral bands and suggesting differences in amplitude related to the accretion disk's temperature structure.

## Contribution

First multi-band photometric analysis of Beta Lyrae with BRITE satellites, identifying spectral-dependent variability and confirming instrumental correction methods.

## Key findings

- Blue variations have smaller amplitudes than red, indicating cooler outer disk regions.
- Light-curve variability is well correlated outside primary minima.
- Instrumental correction methods are validated by 2018 data.

## Abstract

Observations of Beta Lyr in four months of 2018 by three BRITE Constellation satellites (the red-filter BTr and BHr, and the blue-filter BLb) permitted a first, limited look into the light-curve variability in two spectral bands. The variations were found to be well correlated outside the innermost primary minima with the blue variations appearing to have smaller amplitudes than the red; this reduction may reflect their presumed origin in the cooler, outer parts of the accretion disk. This result must be confirmed with more extensive material as the current conclusions are based on observations spanning slightly less than three orbital cycles of the binary. The assumption of an instrumental problem and the applied corrections made to explain the unexpectedly large amplitude of the red-filter light-curve observed with the BTr satellite in 2016 are fully confirmed by the 2018 results.