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"30653 results found.
- GRB 220408A: Swift-BAT refined analysis
- Fermi GRB 220411A: Global MASTER-Net observations report
- GRB 220408A: RATIR Optical and NIR Observations
- GRB 220403B: 1.3m DFOT Optical upper limit
- GRB 220408A: 1.3m DFOT Optical upper limit
- GRB 220408A: LOAO, DOAO, and, SAO optical upper limit
- GRB 220403C: Swift-XRT observations
- GRB 220408A: redshift lower limit estimating
- GRB 220408A: NOT optical observations and archival detection
- GRB 220408B: AstroSat CZTI detection
- GRB 220408A: LCO Optical Afterglow Detection
- GRB 220408A: Swift-XRT refined Analysis
- GRB 220403C: Swift ToO observations
- Fermi GRB 220408B: Global MASTER-Net observations report
- GRB 220408A: GIT optical upper limit
- GRB 220408A: Fermi GBM observation
- GRB 220408A: Swift/UVOT Detection
- GRB 220408A: Xinglong-2.16m optical upper limit
- Chandra upper limit at the location of GRB 220408A
- GRB 220408A: KAIT Optical Observations
- Fermi GRB 220408A: Global MASTER-Net observations report
- ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, SAO RAS, CrAO)
- Fermi-LAT Gamma-ray Observations of IceCube-220405B
- GRB 220403B: Mondy optical upper limit
- IceCube-220405A: No Candidate Counterparts from the Zwicky Transient Facility
- IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
- GRB 220404A: Swift-BAT refined analysis
- GRB 220403B: Kitab optical observations
- Fermi-LAT Gamma-ray Observations of IceCube-220405A
- GRB 220403B: Swift-BAT refined analysis
- GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
- GRB 220403B: Fermi GBM detection
- GRB 220403B: Swift-XRT refined Analysis
- GRB 220403B: LBT observations
- Swift GRB 220403B: Global MASTER-Net observations report
- GRB 220403C (or A): Swift/BAT-GUANO detection outside the coded FOV
- GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
- GRB 220403A: Tautenburg observations
- Fermi GRB 220403A: Global MASTER-Net observations report
- GRB 220401A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220401A: Fermi GBM observation
- Fermi GRB 220401B: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 220331776/670444627 is not a GRB
- Fermi GRB 220330A: Global MASTER-Net observations report
- ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
- GRB 220325A: GRANDMA observations
- GRB 220320A: Detection by VZLUSAT-2
- Konus-Wind observation of GRB 220320A
- GRB 220325A: Swift/UVOT Upper Limits
- GRB 211024B: Host galaxy redshift from X-shooter/VLT
- GRB 220325A: Swift-BAT refined analysis
- ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, TSHAO, AbAO)
- GRB 220325A: Tautenburg observations
- GRB 220325A: LCO Optical Upper Limits
- GRB 220325A: Swift-XRT refined Analysis
- GRB 220325A: 1.3m DFOT Optical upper limit
- Fermi GBM Sub-Threshold Detection of GRB 220325A
- GRB 220325A: MASTER Global Robotic Net optical observations
- GRB 220323A: AstroSat CZTI detection
- GRB 220319A: GRANDMA observations
- GRB 220323A: AGILE/MCAL detection
- IPN triangulation of GRB 220320A
- GRB 220319A: Swift-BAT refined analysis
- GRB 220316A: AstroSat CZTI detection
- GRB 220320A: AstroSat CZTI detection
- GRB 220317A: Fermi GBM detection
- GRB 220319A: MITSuME Akeno optical upper limits
- GRB220319A: Optical observations from NOT
- GRB 220319A: LCO Optical Upper Limit
- GRB 220319A: Mondy optical uper limit
- GRB 220319A: Swift-XRT refined Analysis
- GRB 220319A: MASTER Global Robotic Net optical observations
- Fermi-LAT Gamma-ray Observations of IceCube-220317A
- GRB 220317A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220310A: MITSuME Akeno optical observation
- IceCube-220317A: MASTER Global Robotic Net optical observations
- GRB 220315A: MASTER Global Robotic Net optical observations
- GRB 220311A: Fermi GBM observation
- GRB 220306B: Swift/UVOT Upper Limits
- GRB 220311A: MITSuME Akeno optical upper limits
- IPN triangulation of GRB 220310A
- GRB 220310C: Fermi GBM observation
- GRB 210722A: TAROT Reunion observatory optical light curve
- GRB 210222B: TAROT Reunion observatory optical light curve
- GRB 201021C: TAROT Reunion observatory optical light curve
- GRB 220310A: K-800 of Terskol observatory optical upper limit
- GRB 220310A: [KAO-Egypt] SDSS r, i observation
- Konus-Wind detection of GRB 220310A
- GRB 220310C: Swift ToO observations
- GRB 220310C: Swift/BAT-GUANO candidate arcminute localization
- GRB 220311A: MASTER OT retraction
- ZTF22aabjpxh/AT2022cva (GRB 220219B): evidence of supernova in LBT spectra
- GRB 220310A: GIT confirmation of optical afterglow.
- GRB 220306B: Nanshan/NEXT optical upper limit
- ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
- Fermi GBM Detection of GRB 220308A
- GRB 220308A: AGILE detection
- GRB 220310A: MASTER optical counterpart detection
- GRB 220310A: Swift ToO observations
- GRB 220310A: CALET Gamma-Ray Burst Monitor detection