| Title: |
Brightness evolution of LEO Starlink mega-constellation satellites from 2021 to 2023: A multi-year ground-based photometric study |
| Authors: |
Longa-Peña, P; Tregloan-Reed, J; Adam, C; Chamoun-Contreras, J; Unda-Sanzana, E; Ávalos-Vega, C; Amadio, F; Andersen, M; Bonavita, M; Bozza, V; Estrada, B Campos; Dominik, M; Donaldson, A; Jaimes, R Figuera; Fynbo, J; Hinse, T C; Hundertmark, M; Jørgensen, U G; Khalouei, E; Kretlow, M; Molina, V; Peixinho, N; Rabus, M; Rahvar, S; Rajkumar, A R; Romero-Colmenares, M I; Rota, P; Sajadian, S; Skottfelt, J.; Snodgrass, C; Southworth, J; Alarcon, H; Blanc, G; Bocaz, P; Colque, J P; Cortes, J; Quintana, C Flores; Garcia, P; González, R; Kim, S; Martín, S; Nakos, T; Ortiz, E; Otarola, A; Hernández, J Plaza; Sanhueza, P; Siringo, G; Soto, M |
| Publisher Information: |
Oxford University Press (OUP) |
| Publication Year: |
2026 |
| Collection: |
The Open University: Open Research Online (ORO) |
| Description: |
We report a multi-epoch V-band campaign (2021–2023) with uniform processing and a common 550 km normalisation across Starlink generations. Median magnitudes (68% confidence intervals; N in brackets) are: v1.0: 5.365,[5.084,5.553] (34), Gen-2: 6.012,[5.801,6.173] (6), v1.5: 6.106,[6.065,6.154] (164), VisorSat: 6.618,[6.403,6.804] (54), DarkSat: 8.431,[5.916,10.947] (2). This yields the ordering v1.0 < Gen-2 ≲ v1.5 < VisorSat ≪ DarkSat, i.e. mitigation-era designs are typically fainter than the original v1.0. The Gen-2–v1.5 difference is small (0.094,mag) and Gen-2 has limited coverage (N = 6), so the trend is not strictly monotonic. We use an open, Python-based processing pipeline built on astropy for standard image calibration (bias, dark and flat-field correction), astrometric and photometric calibration against Gaia DR3, and derivation of the viewing geometry (solar phase angle, range, elongation and airmass). Satellite tracks are identified from TLE-based ephemerides, matched to the detections, and then used to measure a brightness value for each track in a reproducible way. At a common height, the medians are 5.37 (v1.0), 6.01 (Gen-2), 6.11 (v1.5), 6.62 (VisorSat) and 8.43 (DarkSat; N = 2), which are ∼0.4–1.6 mag brighter (numerically smaller) than the target of V ≈ 7. Thus, mitigation shows clear progress but does not yet meet the IAU CPS/SATCON goal of V ≥ 7 at ∼550 km. These benchmarks can guide future satellite designs, survey planning and avoidance strategies, with the main uncertainties arising from the very small samples for DarkSat and Gen-2. |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
https://oro.open.ac.uk/109558/1/109558.pdf; Longa-Peña, P; Tregloan-Reed, J; Adam, C; Chamoun-Contreras, J; Unda-Sanzana, E; Ávalos-Vega, C; Amadio, F; Andersen, M; Bonavita, M; Bozza, V; Estrada, B Campos; Dominik, M; Donaldson, A; Jaimes, R Figuera; Fynbo, J; Hinse, T C; Hundertmark, M; Jørgensen, U G; Khalouei, E; Kretlow, M; Molina, V; Peixinho, N; Rabus, M; Rahvar, S; Rajkumar, A R; Romero-Colmenares, M I; Rota, P; Sajadian, S; Skottfelt, J. ; Snodgrass, C ; Southworth, J; Alarcon, H; Blanc, G; Bocaz, P; Colque, J P; Cortes, J; Quintana, C Flores; Garcia, P; González, R; Kim, S; Martín, S; Nakos, T; Ortiz, E; Otarola, A; Hernández, J Plaza; Sanhueza, P; Siringo, G and Soto, M (2026). Brightness evolution of LEO Starlink mega-constellation satellites from 2021 to 2023: A multi-year ground-based photometric study. Monthly Notices of the Royal Astronomical Society (Early access). |
| DOI: |
10.1093/mnras/stag552 |
| Availability: |
https://oro.open.ac.uk/109558/; https://oro.open.ac.uk/109558/1/109558.pdf; https://doi.org/10.1093/mnras/stag552 |
| Rights: |
cc_by_4 |
| Accession Number: |
edsbas.392A78E |
| Database: |
BASE |