Plaskett 1.8 m Observations of Starlink Satellites

Abstract

Abstract We present observations of 23 Starlink satellites in the g′ bandpass, obtained from the Dominion Astrophysical Observatory’s Plaskett 1.8 m telescope. The targets include a mixture of satellites with and without brightness mitigation measures (i.e., visors). At the time of the observations (2021 July 16), Starlink satellites were sunlit throughout the night, and, even with strict elevation and azimuth limits, there were over 800 candidate Starlink arcs. The satellites altogether have a median range corrected brightness (550 km) of H ¯ g 550 = 5.3 mag. Dividing the targets into those without and with visors, their median range corrected magnitudes are H ¯ g 550 ( no visor ) = 5.1 and H ¯ g 550 ( visor ) = 5.7 mag, respectively. While the visor sample is dimmer in aggregate, the range corrected brightness distribution ranged from H g 550 = 4.3 mag to 9.4 mag. The two brightest satellites have similar H g 550 to within the uncertainty, but one is visored and the other nonvisored. The dimmest satellite we observed is one without mitigations. The intrinsic brightness dispersion among the full sample is σ g = 0.5 mag.