In memoriam: Sahar Allam

Sahar Allam in the control room of the 0.9-meter telescope at Cerro Tololo Interamerican Observatory. Photo: Douglas Tucker

It is with regret that we announce the passing of Sahar Allam on March 29, after a long battle with cancer. Sahar, beloved wife of Fermilab astrophysicist Douglas Tucker, was a member of the experimental astrophysics group at Fermilab and a long-time valued contributor to the Sloan Digital Sky Survey and Dark Energy Survey experiments.

Sahar was an enthusiastic supporter of the lab’s cosmic frontier experiments – always at the front of the line to volunteer for the most difficult to staff observing shifts (Christmas and New Year’s) on the mountaintop in Chile. She and Douglas were the observers on duty when the Dark Energy Survey scanned Comet Lovejoy in 2016.

Specializing in photometric calibration, she made invaluable contributions to the SDSS and DES projects, uncovering numerous issues with her painstaking analysis.

Sahar loved scientific discovery and was rightfully proud of uncovering several gravitationally lensed galaxies in the distant universe, found by carefully scanning by eye thousands of SDSS and DES images. She treasured the discoveries that the astrophysics survey projects enabled.

Dark Energy Survey scanned Comet Lovejoy in 2016.

Perhaps the most exciting happening was on the night of Aug. 17, 2017, when she was on shift duty at the ROC-West observing station in Wilson Hall when the optical counterpart to the LIGO gravitational wave oscillation was detected by the DECam imaging camera in Chile – a brilliant flash of light resulting from the merger of two neutron stars 120 million light years distant!

Sahar was a constant presence among the experimental astro group on 7th floor of Wilson hall for nearly 20 years, welcoming to all. Students and postdocs from all lands fondly recalled Sahar’s tips for working in a cubicle surrounded by vocal physicists and noted that she was always available for a chat day or late into the night. Many colleagues expressed the sentiment felt by all all those who knew her: “It is very sad to lose a friend.”

A celebration of life will be held online at 11:00 a.m. CDT on Saturday, Sept. 3, 2022. For further information, please see or contact Douglas Tucker (