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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"850 results found.
- IceCube-200227A: IceCube observation of a high-energy neutrino candidate event
- GRB 200224A: Swift-XRT refined Analysis
- GRB 200216B: Swift-XRT refined Analysis
- IPN triangulation of GRB 200130B
- Fermi trigger No 601677816: Global MASTER-Net observations report
- Konus-Wind observation of GRB 200120A
- IPN Triangulation of GRB 200120A
- IPN triangulation of GRB 200111A
- IceCube Alert 200109.99: Global MASTER-Net observations report
- IceCube Alert 200109.99: Global MASTER-Net observations report
- Konus-Wind observation of GRB200101A
- IPN triangulation of GRB 200101A
- IPN triangulation of GRB 191227B (short)
- GRB 191227A: Swift-BAT refined analysis
- Swift GRB191226.02: Global MASTER-Net observations report
- Swift trigger 946234/GRB 191226.02 : MASTER obervation
- LIGO/Virgo S191124be: Global MASTER-Net observations report
- LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, prompt observation
- Swift GRB191105.01: Global MASTER-Net observations report
- IPN triangulation of GRB 191027A
- LIGO/Virgo S190930t: Swift XRT observations, no secure afterglow found
- IPN triangulation of GRB 190928A (long/bright)
- Swift Trigger 924641 is an outburst from MAXI J1807+132
- IPN triangulation of GRB 190906A (short)
- IPN triangulation of GRB 190805B
- IPN triangulation of GRB 190810A (short)
- IPN Triangulation of GRB 190731A
- LIGO/Virgo S190728q: Optical transients from Pan-STARRS coverage during first 2 nights
- IPN triangulation of GRB 190720A
- Swift GRB190718.2 Global MASTER-Net observations report
- LIGO/Virgo S190510g: Swift UVOT - no new counterpart candidates identified
- IPN Triangulation of GRB 190611B
- GRB 190613B: Swift detection of a burst with an optical counterpart
- Fermi GRB190515.49 Global MASTER-Net observations report
- Konus-Wind observation of GRB 190510A
- Fermi GRB190505.05 Global MASTER-Net observations report
- LIGO/Virgo S190503bf: Identification of a GW compact binary merger candidate
- IPN Triangulation of GRB 190501A (long/bright)
- LIGO/Virgo S190412m: Further J-GEM optical/NIR observations
- LIGO/Virgo S190426c: J-GEM optical/NIR follow-up observations
- LIGO/Virgo S190412m: J-GEM optical/NIR follow-up observations
- LIGO-Virgo GW S190408an: J-GEM optical/NIR follow-up observations
- IPN Triangulation of GRB 190329A (long/bright)
- IPN Triangulation of GRB 190304A (long)
- Improved IPN error box for GRB 190129B
- IPN Triangulation of GRB 190129B (long/extremely bright)
- IPN Triangulation of GRB 190117A (long)
- IPN triangulation of GRB 190103A (long)
- IPN Triangulation of GRB 181227A (long)
- IPN Triangulation of GRB 181212A (long)
- GRB 181030A: MASTER Net OT detection
- IPN Triangulation of GRB 181028A (long)
- IPN Triangulation of GRB 181011A (long)
- GRB 180925A: Swift-BAT refined analysis
- IPN Triangulation of GRB 180914A (long)
- IPN Triangulation of GRB 180824A (short)
- GRB 180720C: Swift-XRT refined Analysis
- IPN Triangulation of GRB 180703A
- IPN Triangulation of GRB 180703B
- IPN Triangulation of GRB 180626B (short)
- IPN Triangulation of GRB 180611A (long)
- IPN Triangulation of GRB 180605A (long)
- GRB 180602B: Fermi GBM detection
- IPN Triangulation of GRB 180529A (short/hard)
- IPN Triangulation of GRB 180526A (long)
- IPN Triangulation of GRB 180523A
- IPN Triangulation of GRB 180427A
- IPN Triangulation of GRB 180409A
- IPN Triangulation of GRB 180404C (long)
- IPN Triangulation of GRB 180326A (long)
- IPN Triangulation of GRB 180318A (long)
- GRB 180316A: Swift/UVOT Detection
- IPN Triangulation of GRB 180223A (long)
- IPN Triangulation of GRB 180113C
- IPN Triangulation of GRB 171216B
- IPN Triangulation of GRB 171119A (long)
- GRB 171102B: Enhanced Swift-XRT position
- IPN Triangulation of GRB 171022A
- IPN Triangulation of GRB 171011B (long/very bright)
- GRB 171007A: Swift-BAT refined analysis
- IPN Triangulation of GRB 170921B
- IPN Triangulation of GRB 170904A (long/very bright)
- IPN Triangulation of GRB 170826B
- IPN Triangulation of GRB 170805A (short)
- Correction to GCN Circular 21305: Trigger 760835: Swift misidentification of GRS1716-249
- Trigger 760835: Swift misidentification of GRS1716-249
- IPN Triangulation of GRB 170616A (short/hard)
- Konus-Wind observation of GRB 170607B
- IPN Triangulation of GRB 170607B
- GRB 170526A: 15 GHz upper limits from AMI
- IPN Triangulation of GRB 170529A (long)
- IPN Triangulation of GRB 170527A
- IPN Triangulation of GRB 170522A
- IPN Triangulation of GRB 170522B (long/intense)
- LIGO/Virgo G275404: European VLBI Network (EVN) follow-up of the near-IR transient in the AGL J1914+1043 field
- GRB 170331A: Swift detection of a burst
- IPN Triangulation of GRB 170320A (long/intense)
- GRB 170317A: Swift-XRT refined Analysis
- Konus-Wind observation of GRB 170311B
- IPN Triangulation of GRB 170311B (long/very intense)