AT2025byf in NGC 5525

AT2025byf was detected by ZTF at 19.1 mag on 2025 February 18.449 UT. Image taken 38 hours after detection. No object is visible at the position reported by ZTF. Any supernova should have gained at least one magnitude of brightness in that time, especially when considering the distance of NGC 5525 of about 250 million light years.

Copy of Panstarrs image from TNS. The cross indicates the position of the object reported by ZTF.

Discovery image of ZTF (left), reference image (middle) and differential image (right). Note that the dim "star" northeast of the supposed supernova is not seen in the reference image but also in the differential image and marked by a yellow circle.