GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
472 results found.
- Fermi GRB 250504A: Global MASTER-Net observations report
- GRB 250419A: LCO optical afterglow multi-band observations
- IPN triangulation of GRB 250406B (short/hard)
- IPN triangulation of GRB 250322B
- IPN triangulation of GRB 250308A (short)
- IPN triangulation of GRB 250309B
- IPN triangulation of GRB 250217C (short)
- EP250207a: EP-WXT detection and XRT follow-up observation
- IPN triangulation of GRB 250201A
- IPN triangulation of GRB 250118B
- IPN triangulation of GRB 250119B
- Improved IPN triangulation of GRB 250107C
- IPN triangulation of GRB 250113A
- IPN triangulation of GRB 250107D (short/hard)
- GRB 250101A: Swift-XRT refined Analysis
- IPN triangulation of GRB 241128B
- IPN triangulation of GRB 241117A
- IPN triangulation of GRB 241107A (short/hard)
- IPN triangulation of GRB 241022A (short/hard)
- IPN triangulation of GRB 241021A (long)
- IPN triangulation of GRB 240930B / EP 240930a
- IPN triangulation of GRB 240926A
- GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
- IPN triangulation of GRB 240918B
- IPN triangulation of GRB 240913C / EP 240913a
- IPN triangulation of GRB 240810A (short)
- Improved IPN triangulation of GRB 240802A / EP 240802a
- IPN triangulation of GRB 240715A (short)
- EP240703a: Kinder optical follow-up observations
- IPN triangulation of GRB 240627A
- IPN triangulation of GRB 240619C
- LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 240615A (short)
- Konus-Wind detection of GRB 240607A
- IPN triangulation of GRB 240607A
- IPN triangulation of GRB 240603A
- IPN triangulation of the initial episode of GRB 240529A
- Konus-Wind detection of GRB 240513A
- IPN triangulation of GRB 240504A
- IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
- GRB 240419A: Swift-XRT refined Analysis
- IPN triangulation of GRB 240410A
- IPN triangulation of GRB 240303B
- IPN triangulation of GRB 240125A (short)
- IPN triangulation of GRB 240123C (short)
- IPN triangulation of GRB 240112A (long)
- IPN triangulation of GRB 231129C
- IPN triangulation of GRB 231205A
- IPN triangulation of GRB 231020A
- IPN triangulation of GRB 230919A (short)
- IPN triangulation of GRB 230911D (long)
- IPN triangulation of GRB 230906A (short)
- IPN triangulation of GRB 230815B
- IPN triangulation of GRB 230803A
- IPN triangulation of GRB 230723A (short)
- IPN triangulation of GRB 230715D
- IPN triangulation of GRB 230625B (ultra-long)
- IPN triangulation of GRB 230616A (short)
- GRB 230524A: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S230520ae: Identification of a GW compact binary merger candidate: End-to-End Test
- IPN triangulation of GRB 230430A (short)
- GRB 230420A: Swift/UVOT Upper Limits
- IPN triangulation of GRB 230418A (short)
- GRB 230328B: AstroSat CZTI detection
- IPN triangulation of GRB 230304B
- IPN triangulation of GRB 230308A (short/bright)
- Further improved IPN localization for GRB 230307A
- Fermi GRB 230310A: Global MASTER-Net observations report
- Improved IPN localization for GRB 230307A
- IPN triangulation of GRB 230307A (long/very bright)
- IPN triangulation of GRB 230209B
- IPN triangulation of GRB 230116B (short)
- IPN triangulation of GRB 221226A
- GRB 221216A: Swift-XRT refined Analysis
- IPN triangulation of GRB 221209A (long)
- LAT GRB221119.63: Global MASTER-Net observations report
- IPN triangulation of GRB 221017A (long)
- IPN triangulation of GRB 220927A (long)
- IceCube Alert 220629.99: Global MASTER-Net observations report
- IceCube Alert 220627.74: Global MASTER-Net observations report
- IPN triangulation of GRB 220624A
- IPN triangulation of GRB 220617A (short)
- IPN triangulation of GRB 220613A
- IPN triangulation of GRB 220609B
- IPN triangulation of GRB 220601A (long)
- Konus-Wind detection of GRB 220524B
- IPN triangulation of GRB 220525A
- IPN triangulation of GRB 220524B
- IPN triangulation of GRB 220524A
- IPN triangulation of GRB 220522B
- IPN triangulation of GRB 220521B
- IPN triangulation of GRB 220519A
- IPN triangulation of GRB 220426A
- IPN triangulation of GRB 220411A
- IPN triangulation of short/soft GRB 220406A
- IPN triangulation of GRB 220403C
- IPN triangulation of GRB 220320A
- GRB 220306B: Swift/UVOT Upper Limits
- IPN triangulation of GRB 220310A
- IPN triangulation of GRB 220305B