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"12314 results found.
- Fermi GRB 260926A: Global MASTER-Net observations report
- GRB 260924A: Near-infrared detection with MDM/MIRAGE
- GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
- EP260924a: J-band upper limit by SYSU 80cm infrared telescope
- GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
- GRB 260925A: Swift/UVOT Upper Limits
- GRB 260925A: COLIBRÍ optical upper limits
- EP260924a: J-band upper limit with WINTER
- GRB 260924A: Swift/UVOT Detection
- GRB 260924A: Swift/UVOT Upper Limits
- Konus-Wind detection of GRB 260922A
- Konus-Wind detection of GRB 260921A (possible merger-origin)
- Fermi GRB 260923A: Global MASTER-Net observations report
- Fermi-LAT Gamma-ray Observations of IceCube-260919A
- Fermi-LAT Gamma-ray Observations of IceCube-260916A
- GRB 260922A: J-band upper limit with WINTER
- GRB 260922A: Swift/UVOT Upper Limits
- GRB 260922A: COLIBRÍ optical upper limits
- Fermi-LAT Gamma-ray Observations of IceCube-260805A
- GRB 260922A: SVOM/C-GFT optical upper limit
- GRB 260922A: Swift detection of a burst
- EP Alert 260921.58: Global MASTER-Net observations report
- Swift GRB 260921A: Global MASTER-Net observations report
- EP Alert 260921.01: Global MASTER-Net observations report
- EP260920b: Global MASTER-Net observations report
- IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
- EP Alert 260920.66: Global MASTER-Net observations report
- EP260920a: NOT early time optical upper limits
- EP260920a: NOT optical upper limits
- EP260920a: SVOM/VT optical upper limits
- EP260917a: Global MASTER-Net observations report
- EP260920a: COLIBRÍ optical upper limits
- EP260917b: EP-FXT non-detection and upper limit
- IceCube Alert 260919A: Global MASTER-Net observations report
- EP Alert 260919.40: Global MASTER-Net observations report
- GRB 260915A: VLT optical and near-infrared upper limits
- EP260806a: Yamaguchi Interferometer radio detections
- EP260917a: SVOM/VT optical upper limits
- GRB 260918A: SVOM/C-GFT optical upper limits
- EP Alert 260918.62: Global MASTER-Net observations report
- EP Alert 260918.24: Global MASTER-Net observations report
- SVOM GRB260918.16: Global MASTER-Net observations report
- Konus-Wind detection of GRB 260916B (short/hard)
- GRB 260918A: SVOM/VT optical upper limits
- GRB 260917B: Mondy optical upper limit
- EP260917A: J-band upper limit with WINTER
- EP Alert 260917.32: Global MASTER-Net observations report
- EP260917a: COLIBRÍ optical upper limits
- GRB 260918A: LCO optical upper limits
- GRB 260918A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
- IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
- SVOM GRB260917.16: Global MASTER-Net observations report
- Fermi trigger No 811304653: Global MASTER-Net observations report
- GRB 260915A: J-band upper limit with WINTER
- Fermi trigger No 811264269: Global MASTER-Net observations report
- GRB 260909A: Swift-XRT observations
- GRB 260916A: MAXI/GSC detection
- MAXI GRB260916.37: Global MASTER-Net observations report
- GRB 260915A: J-band upper limit by SYSU 80cm infrared telescope
- GRB 260915A: SVOM/C-GFT optical upper limits
- GRB 260915A: SVOM/VT refined early optical upper limits
- GRB 260915A: SVOM/VT optical upper limits
- GRB 260915A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
- GRB 260915A: NOT optical upper limit
- SVOM GRB260915.05: Global MASTER-Net observations report
- GRB 260915A: SVOM/VT optical upper limits from VHF data
- GRB 260915A: LCO optical upper limits
- EP Alert 260914.53: Global MASTER-Net observations report
- SVOM GRB260914.47: Global MASTER-Net observations report
- SVOM GRB260913.32: Global MASTER-Net observations report
- GRB 260913A: SVOM/C-GFT optical upper limit
- GRB 260909A: OSN 1.5m, CAHA 2.2m and GTC 10.4m optical upper limits
- GRB 260909A: CrAO and AbAO optical upper limits
- GRB 260909A: KAIT optical upper limit
- GRB 260903A: Swift-XRT observations
- GRB 260909A: OHP/T193 z-band upper limit
- GRB 260909A: VLT optical and near-infrared upper limits
- EP Alert 260909.53: Global MASTER-Net observations report
- GRB 260909A: SVOM/VT optical upper limits
- GRB 260909A: Mondy optical observations and afterglow candidate
- GRB 260909A: Xinglong 2.16m optical upper limit
- GRB 260909A: SVOM/C-GFT optical upper limit
- Fermi trigger No 810554827: Global MASTER-Net observations report
- EP Alert 260908.60: Global MASTER-Net observations report
- Fermi GRB 260907B: Global MASTER-Net observations report
- GRB 260903A: SAO RAS optical upper limit
- Fermi GRB 260907A: Global MASTER-Net observations report
- EP Alert 260905.11: Global MASTER-Net observations report
- GRB 260903A: J-band upper limit with WINTER
- EP Alert 260903.47: Global MASTER-Net observations report
- GRB260903A: Liverpool Telescope optical observations
- EP Alert 260903.62: Global MASTER-Net observations report
- NuSTAR Transient 260828: SOAR Optical Upper Limits
- SVOM GRB260903A: Global MASTER-Net observations report
- EP260901a: SVOM/VT optical upper limits
- EP260901a: EP-FXT follow-up observation
- Konus-Wind detection of GRB 260829A
- EP260830a: EP-FXT follow-up observation
- EP260901a: Global MASTER-Net observations report
- GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per