Initial Observations of the First BlueBird Spacecraft and a Model of Their Brightness

TL;DR

This paper reports initial observations of BlueBird satellites, noting their brightness levels, and presents a model explaining their brightness based on design changes from previous satellites, highlighting their potential impact on astronomy.

Contribution

It provides the first observational data on BlueBird satellites and introduces a brightness model linking their design to observed luminosity.

Findings

Mean apparent magnitude is 3.44

Brightness can reach magnitude 0.5 near zenith

Design changes explain brightness variations

Abstract

Based on a large set of visual observations, the mean apparent magnitude of BlueBird satellites is 3.44, while the mean of magnitudes adjusted to a uniform distance of 1000 km is 3.84. Near zenith the spacecraft can be as bright as magnitude 0.5. While these spacecraft are bright enough to impact astronomical observations, they can for periods be fainter than the BlueWalker 3 prototype satellite. A model for their brightness shows that design changes since the BlueWalker 3 mission can explain the behavior of BlueBird.