6 papers
Polarimetry and albedo of the Near-Earth Asteroid 2025 FA22
J. -P. Rivet, S. Bagnulo, P. Bendjoya +17
We report spectropolarimetric and broadband polarimetric observations of the near-Earth asteroid 2025 FA22 during its close approach of 18 September 2025 (about two Moon distances)…
Detection of a weak magnetic field in the Balmer emission line white dwarf WDJ1653-1001
Abbigail Elms, Stefano Bagnulo, Pier-Emmanuel Tremblay +8
The small DAHe and DAe spectral classes comprise isolated, hydrogen-dominated atmosphere white dwarfs that exhibit variable photometric flux and Balmer line emission. These mysteri…
Polarimetric and spectropolarimetric observations with FoReRo2: Instrument overview and standard star monitoring
Yanko Nikolov, Galin Borisov, Stefano Bagnulo +3
In this paper, we present a description and characterisation of the 2-Channel Focal Reducer Rozhen (FoReRo2), with an emphasis on its polarimetric and spectropolarimetric observati…
Rapid-response characterization of near-Earth asteroid 2024 YR4 during a Torino Scale 3 alert
Maxime Devogèle, Olivier R. Hainaut, Marco Micheli +32
On 27 December 2024, near-Earth object (NEO) 2024 YR was discovered by the ATLAS survey and identified as a virtual impactor. A few weeks later, it eventually reached level 3 o…
JWST detection of a carbon dioxide dominated gas coma surrounding interstellar object 3I/ATLAS
Martin A. Cordiner, Nathaniel X. Roth, Michael S. P. Kelley +10
3I/ATLAS is the third confirmed interstellar object to visit our Solar System, and only the second to display a clear coma. Infrared spectroscopy with the James Webb Space Telescop…
Extreme Negative Polarisation of New Interstellar Comet 3I/ATLAS
Zuri Gray, Stefano Bagnulo, Galin Borisov +13
We present the first polarimetric observations of the third discovered interstellar object, 3I/ATLAS (C/2025 N1), obtained pre-perihelion with FORS2/VLT, ALFOSC/NOT, and FoReRo2/RC…