During the last week Chandra completed the observing schedule as planned.

A Chandra image release was issued on Dec 15 describing a new project from the Chandra X-ray Observatory, which reveals stunning connections between the vast universe and the microscopic world that we cannot see with the naked eye. Chandra’s “New Perspectives” project takes these space-based images and creates side-by-side comparisons with the winning images from the Nikon Small World contest. For details see: https://chandra.si.edu/press/25_releases/press_121525mm.html

Chandra press and image releases were issued on Dec 16, describing a luminous fast blue optical transient (LFBOT), AT 2024wpp. LFBOTs are among the more puzzling cosmic phenomena discovered over the past few decades. They are brief and very bright flashes of blue and ultraviolet light that gradually fade away, leaving behind faint X-ray and radio emissions. The analysis of AT2024wpp led the researchers to conclude that the emission likely came from an extreme event where a black hole up to 100 times the mass of the Sun tore apart a companion star that got too close. For details see: https://chandra.harvard.edu/press/25_releases/press_121625.html

Another Chandra press release was issued Dec 17, describing observations of the Perseus Cluster by NASA's Chandra X-ray Observatory and NASA's Imaging X-ray Polarimetry Explorer (IXPE). Scientists studied the polarization properties of 3C 84, the massive active galaxy located at the very center of the Perseus Cluster. IXPE measured a net polarization of 4% in the X-ray spectrum, with comparable values measured in the optical and radio data. These results strongly favor the synchrotron self-Compton model for the seed photons. For details see: https://chandra.harvard.edu/press/25_releases/press_121725.html

Of note this week was the release on Dec 18 of the Cycle 28 Call for Proposals. The proposal submission deadline is 18 March 2026. In conjunction with the call was the release on Dec 16 of the CIAO version 4.18 analysis software system, Sherpa 4.18, Chandra CalDB version 4.12.3, SAOImage DS9 version 8.7b2, and MARX version 6.0.1. For details see: https://cxc.cfa.harvard.edu/proposer
https://cxc.cfa.harvard.edu/ciao/download
https://ds9.si.edu/site/Download.html
and
https://space.mit.edu/CXC/MARX

The schedule of targets for the next week is shown below and includes an observation of AT2025aarm, which was accepted as a Director's Discretionary Time Target of Opportunity on Dec 18.