Related papers: A Flat-Panel Brightness Model for the Starlink Sat…
Magnitudes for the VisorSat and Original-design types were analyzed separately and by time. Mean values are compared with those from other large-scale photometric studies, and some signficant differences are noted. The illumination phase…
The apparent brightness of satellites is calculated as a function of satellite position as seen by a ground-based observer in darkness. Both direct illumination of the satellite by the Sun as well as indirect illumination due to reflection…
The mean of 830 visual magnitudes adjusted to a distance of 550 km (the operational altitude) is 4.63 +/-0.02. The data on DarkSat, the low-albedo satellite, indicate that it is fainter than the others by 1.6 magnitudes or 78%. However,…
Starlink is a low-Earth orbit (LEO) satellite constellation operated by Space Exploration Technologies Corp. (SpaceX) which aims to provide global satellite internet access. Thus far, most photometric observations of Starlink satellites…
The mean of 430 visual magnitudes of VisorSats adjusted to a distance of 550-km (the operational altitude) is 5.92 +/-0.04. This is the characteristic brightness of these satellites when observed at zenith. VisorSats average 1.29 magnitudes…
We present observations of 23 Starlink satellites in the $g'$ bandpass, obtained from the Dominion Astrophysical Observatory's Plaskett 1.8 metre telescope. The targets include a mixture of satellites with and without brightness mitigation…
A large dataset of visual magnitudes for all three designs of Starlink satellites is analyzed. Brightness phase functions are derived for the Original, VisorSat and Post-VisorSat models. Similarities and differences between the functions…
The Steward Observatory LEO Satellite Photometric Survey is a comprehensive observational survey to characterize the apparent brightness of the Starlink and OneWeb low Earth orbit satellites and evaluate the potential impact on astronomy.…
Measuring photometric brightness is a common tool for characterizaing satellites. However, characterizing satellite mega-constellations and their impact on astronomy research requires a new approach and methodology. A few measurements of…
The mean visual magnitude of OneWeb satellites at the standard satellite distance of 1,000 km is 7.18 +/-0.03 . When this value is adjusted to the nominal 1,200 km altitude of a OneWeb satellite in orbit it corresponds to magnitude 7.58…
The rapid increase in satellite launches in recent years, and the pressure of launches planned into the next decade, demands an improvement in the efficiency of space domain awareness facilities. Optical facilities form an important…
The new Starlink V2 satellites incorporate improvements to the chassis brightness through dielectric mirrors, off-pointing solar arrays, and black paint on exposed components. For the general case in which the reflectivities are initially…
The mean apparent magnitude of Starlink Mini Direct-To-Cell (DTC) satellites is 4.62 while the mean of magnitudes adjusted to a uniform distance of 1000 km is 5.50. DTCs average 4.9 times brighter than other Starlink Mini spacecraft at a…
The illumination phase functions for Starlink Mini satellites are determined for times of twilight and darkness. Those functions are then evaluated to give apparent magnitudes over a grid of points across the sky and over a range of solar…
Visual magnitudes and sky coordinates are projected for the full constellation of Starlink satellites. The results are presented in the form of sky maps and numerical tables. Observer latitudes from the equator to 60 degrees are considered.…
Starlink satellites can become extremely bright when sunlight reflects specularly to an observer on the ground. The observed brightness of such flares is consistent with a bidirectional reflectance function of the Starlink satellite…
Photometric characteristics for all models of Starlink satellites launched to date are reviewed. The Original design that lacked brightness mitigation is the most luminous. SpaceX installed a sunshade on the VisorSat model which reduced its…
The mean apparent magnitude and the mean of magnitudes adjusted to a standard distance are reported. The illumination phase function for OneWeb satellites is determined and it differs strongly from that of VisorSat spacecraft. Brightness…
Observations of Starlink V2 Mini satellites during orbit-raising suggest that SpaceX applies brightness mitigation when they reach a height of 357 km. The mean apparent magnitudes for objects below that height threshold is 2.68 while the…
The impact of large-scale constellations of satellites, is a concern for ground-based astronomers. In recent years there has been a significant increase in the number of satellites in Low-Earth Orbit and this trend is set to continue. The…