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Comment by porphyra | Hacker News Reader

> If these LEO satellites can be darkened to 7th magnitude, then a new instrument signature removal algorithm can remove some of the residual artifacts.

The current generation of Starlink satellites is already above the 7th magnitude, so it no longer saturates the CCD. [1] Of course, darkening them further would always be good.

[1] http://arxiv.org/abs/2306.06657

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There's however more considerations than just saturated pixels,

https://www.lsst.org/content/lsst-statement-regarding-increa... ("Vera C. Rubin Observatory – Impact of Satellite Constellations")

That's true, but this article was also from before the Starlink Generation 2 Mini satellites with magnitude > 7 came out.

> Darkening satellites to 7th magnitude would simplify removal of some artifacts in LSST images, but there is no guarantee most of the satellites will be limited in brightness to fainter than 7th magnitude.

I'm curious if they were indeed able to implement the artifact removal or if it remains challenging even then.

“Removal” here means “masking”—the pixels under the bright streaks will always be scientifically unusable because the streaks inflate the noise irrevocably. (You can’t see stars in the daytime by “removing” the sun.)

The 7th magnitude limit just minimizes the streak signal cross-talk through the rest of the camera. It also means the satellites are invisible to the naked eye.

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