The GCN Team is pleased to announce a new Notice Type and a schema release. BOOM Cross-Correlated Optical Transient Notices The Burst & Outburst Observations Monitor (BOOM)/Babamul Team (https://www.ztf.caltech.edu/ztf-boom-babamul.html) and the GCN Team are pleased to announce the availability of a new notice type via the new GCN in JSON format. BOOM provides real-time brokering, archival context, and coordination tools that enable rapid identification, vetting, and follow-up of astrophysical transients. BOOM is the software stack operating to enable a multi-survey alert broker and data archive (Babamul) that ingests and combines alerts from the Zwicky Transient Facility (ZTF) and the Vera C. Rubin Observatory alert stream. BOOM is contributing a GCN Notices stream, where cross-matches from the BOOM fast transient stream (which analyzes ZTF and LSST alert streams) are checked for (i) gravitational-wave alert candidates consistent with a binary neutron star merger or neutron star-black hole merger and (ii) gamma-ray bursts detected by Fermi, SVOM, and Swift. This enables rapid cross-identification of events across experiments and observatories, enhancing situational awareness and time-critical response for the broader transient astronomy community. Alert includes localization, photometry, cross-matches with other GCN Notices, and classification scores from machine-learning models. BOOM notices are published on the GCN Kafka topic gcn.notices.boom.alert. See the BOOM mission page (https://gcn.nasa.gov/missions/boom) for a more extensive description of the information provided in these new notices. Schema v7.0.0 GCN Schema v7.0.0 is available with recent changes including new Notice types and a modified and generalized Spectral core schema (Release Notes; https://github.com/nasa-gcn/gcn-schema/releases/tag/v7.0.0). For more details on this new feature and an archive of GCN news and announcements, see https://gcn.nasa.gov/news. For questions, issues, or bug reports, please contact us via: - Contact form: https://gcn.nasa.gov/contact - GitHub issue tracker: https://github.com/nasa-gcn/gcn.nasa.gov/issues --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...