It is with great sadness that we announce the accidental death of Karim Benabed on December 3, 2025, at the age of 51. Karim was an astronomer at the Institut d’Astrophysique de Paris (IAP). He completed his thesis at the IPhT from 1998 to 2001 under the supervision of Francis Bernardeau, then, after a postdoctoral fellowship at New York University, obtained a permanent position at the IAP.
First photo (portrait accompanying the headline): Karim Benabed (taken at the IAP in March 2014. Credit: Sophie Rattier)
He joined the Planck project, an ESA satellite that measured the temperature and polarization anisotropies of the cosmic microwave background with unparalleled precision. Within the project, he worked on measuring gravitational lensing effects, a subject he had addressed at the IPhT during his thesis. His work earned him the La Recherche prize in 2014, the AIAA Space System prize, the Royal Astronomical Society prize, and the Marcel Grossman prize in 2015, the Gruber prize in 2018, and the Giuseppe and Vanna Cocconi prize in 2019 as a member of the Planck scientific team.
From 2014 to 2020, he served as deputy director to Francis Bernardeau at the IAP. During this time, he initiated numerous scientific and technical projects, as well as outreach activities that have marked the history of the IAP. He had since become involved in the Euclid project.
A more detailed portrait of Karim has been posted on the IAP website : https://www.iap.fr/actualites/laune/2025/KarimBenabed/KarimBenabed-en.html
Those who knew him can pay tribute to him on the website set up for this occasion.
Ceux qui l’ont connu peuvent lui rendre hommage sur le site ouvert à cette occasion. There you will find testimonials to his scientific influence, his generosity, and his commitment to scientific outreach.