Observed magnitudes of Qianfan spacecraft range from 4 when they are near zenith to 8 when low in the sky. Nearly all of the observations can be modeled with a nadir-facing flat antenna panel and the underside of a zenith-facing solar array, both with Lambertian reflectance properties. These satellites will impact astronomical research unless their brightness is reduced.
@article{arxiv.2409.20432,
title = {Brightness of the Qianfan Satellites},
author = {Anthony Mallama and Richard E. Cole and Bram Dorreman and Scott Harrington and Nick James},
journal= {arXiv preprint arXiv:2409.20432},
year = {2024}
}