The surface brightness of megaconstellation satellites trails on large telescopes

TL;DR

This paper analyzes how the defocused trails of MegaConstellation satellites appear on large telescopes, showing their brightness remains nearly constant during their sweep and assessing the impact on telescope operations.

Contribution

It provides simple relationships to estimate the apparent brightness of satellite trails, aiding in evaluating their impact on large optical telescopes.

Findings

Satellite trails appear almost constant in brightness during their sweep.

Defocusing causes trails to be significantly defocused on large telescopes.

The relationships help predict the impact of satellite trails on telescope observations.

Abstract

On large telescopes trails of MegaConstellation's satellites will appears significantly defocused because of their relatively short distance. Because of such effect their apparent surface brightness will be, under a range of conditions, almost constant during their apparent sweeping on the focal plane of such large facilities. A few simple relationships are worked out and discussed to show the apparent brightness of such trails, in order to evaluate their impact on operations of large optical ground based facilities.