Migration of Circulars Archive from GCN Classic

The GCN Circulars archive was migrated from the GCN Classic Circulars archive page on April 17, 2023. The new GCN Circulars archive on this site is the authoritative record of all past Circulars and is updated in real time with new Circulars. The old GCN Classic Circulars archive page is preserved, but is no longer updated.

During the migration, we made some minor adjustments to some Circulars to adapt them to the structured format of the new database:

• There were two instances where the old archive added a letter suffix to a Circular ID to distinguish multiple Circulars that were initially assigned the same ID. In the new archive, we have replaced these with half-integer IDs. GCN 18448a became GCN 18448.5 and GCN 18453a became GCN 18453.5.
• Some Circulars listed both a "date" and a "revised submission date". Where applicable, the date presented in the new archive is the revised submission date.
• The very earliest Circulars (before GCN 31) did not record a subject, submission date, or submitter email address. Where these fields were missing, we set the subject to Untitled, the date to January 1, 1970 (the start of the UNIX epoch), and the submitter email address to circulars@gcn.nasa.gov.
• Some Circulars submitted by Scott Barthelmy did not display an email address. In these cases, we have rendered the submitter as Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>.
• Some Circulars have editorial remarks indicated by the text [GCN OP NOTE ...]. In most cases, this text was at the bottom of the Circular below the body text, but in a few cases it was at the top, before the headers. We have moved all [GCN OP NOTE ...] remarks to the bottom.
• Some Circulars that were submitted by mistake and removed from the archive still had entries in the old archive that were hyperlinks to URLs of the format https://gcn.gsfc.nasa.gov/gcn3/mistakeN.gcn3 where N is an integer. These Circulars are removed entirely from the new archive.