sci25004 — Announcement

The story behind the image

17 June 2025

-By Chris Evans-

Following Webb’s launch on an Ariane 5 rocket in December 2021, the ESA/Webb science outreach team has featured a new image each month in the ESA/Webb Picture of the Month series. The series showcases remarkable Webb images from across the broad range of its scientific targets, alongside the popular ESA/Hubble Picture of the Week series, which recently celebrated its fifteenth anniversary.

The ESA/Webb March 2025 Picture of the Month was of a particularly striking Einstein Ring, with a beautiful example of strong lensing in the galaxy cluster field SMACSJ0028.2-7537. The NIRCam data were obtained as part of the Strong Lensing and Cluster Evolution (SLICE) survey, a Cycle 3 Survey programme led by Guillaume Mahler at the University of Liege. For the image release, the NIRCam observations were combined with visible Hubble-ACS observations from a past Snapshot programme (PI: Harald Ebeling).

The ESA/Webb outreach team is always on the look out for compelling targets for our image releases, and for the discovery of this Einstein Ring, this is owed to the six year-old son of Michael McDonald, one of the SLICE team co-Is at the Massachusetts Institute of Technology. Michael was having a first look through the reduced Webb images with his son on a Sunday morning, and the spectacular Einstein Ring immediately caught his son’s eye, prompting many questions to Michael of what they had found! This system was not the primary target of the Webb nor Hubble observations and is near the edge of the observed field. As such, it was unnoticed until now, and is a great example of the type of serendipitous discoveries enabled by Webb’s unprecedented capabilities.

Contacts

Chris Evans
ESA/HST & ESA/JWST Project Scientist
ESA Office, STScI Baltimore, USA
Email: [email protected]