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"11757 results found.
- Konus-Wind observation of GRB 170219A (short/hard)
- IPN Triangulation of GRB 170219A (short/hard)
- LIGO/Virgo G274296: Optical Observation
- LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
- LIGO/Virgo G274296: SWASP optical imaging coverage
- LIGO/Virgo G274296: Observations of initial skymap by project Mini-GWAC of SVOM
- LIGO/Virgo G274296: REM optical/NIR observations
- GRB 170214A: Mondy optical upper limit
- Konus-Wind observation of GRB 170214A
- GRB 170214A: Fermi-LAT detection
- LIGO/Virgo G270580: DLT40 follow-up observation
- Konus-Wind observation of GRB 170210A
- GRB 170210A: POLAR observation
- GRB 170208C: POLAR Observation
- IPN Triangulation of GRB 170210A
- Konus-Wind observation of GRB 170209A
- GRB 170208B: Swift-BAT refined analysis
- LIGO/Virgo G270580: AstroSat CZTI upper limits
- GRB 170207A: POLAR Observation
- Konus-Wind observation of GRB 170208B
- Konus-Wind observation of GRB 170208A
- GRB 170206C: POLAR Observation
- GRB 170208B: Swift-XRT refined Analysis
- GRB 170208B: Swift detection of a burst
- Konus-Wind observation of GRB 170207A
- Konus-Wind observation of GRB 170206A
- GRB 170206A: POLAR observation
- IPN Triangulation of GRB 170206A (short/hard)
- GRB 170206A: Fermi-LAT detection
- Konus-Wind observation of GRB 170205A
- Konus-Wind observation of GRB 170202A
- GRB 170202B POLAR Observation
- GRB 170131A: POLAR Observation
- GRB 170202A: Swift-XRT refined Analysis
- GRB 170202A: T100 observations
- GRB 170131A detected in Swift/BAT ground processing
- LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
- GRB 170130A: POLAR Observation
- Konus-Wind observation of GRB 170127C (short/hard GRB with extended emission)
- GRB 170127B: Swift-BAT refined analysis
- GRB 170127C: POLAR Observation
- GRB 170127B: Swift-XRT refined Analysis
- GRB 170127A: Swift-XRT refined Analysis
- GRB 170124A: CALET Gamma-Ray Burst Monitor detection
- Konus-Wind observation of GRB 170126A
- GRB 170127C (Fermi/GBM trigger 507173752): AGILE analysis
- GRB 170127C: Fermi-LAT detection
- GRB 170127B: Swift detection of a short burst
- GRB 170126A: Swift-XRT refined Analysis
- LIGO/Virgo G270580: MAXI/GSC observations
- LIGO/Virgo G270580: No change to estimate of LIGO false alarm probability
- LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
- LIGO/Virgo G270580: UL50 observations
- GRB 170121B: MASTER early optical observations of the Swift possible XT
- LIGO/Virgo G270580: CALET Observations
- LIGO/Virgo G268556/GW170104: MAXI/GSC observations
- GRB 170120A: POLAR Observation
- LIGO/Virgo G270580: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G270580: Two optical counterpart candidates from CNEOST
- LIGO/Virgo G270580: INTEGRAL search of temporally coincident prompt hard X-ray
- LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
- LIGO/Virgo G270580: Mini-MegaTORTORA follow-up observations
- LIGO/Virgo G270580: Pan-STARRS and ATLAS observations of the skymap
- LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
- LIGO/Virgo G270580: AGILE MCAL and Super-AGILE Observations
- LIGO/Virgo G270580: Identification of a GW Burst Candidate
- Konus-Wind observation of GRB 170115B
- GRB 170115A: Swift-XRT refined Analysis
- GRB 170115B: Fermi-LAT detection
- GRB 170115A: Swift detection of a burst
- LIGO/Virgo G268556: spectra of two nuclear transients PS17fr and PS17er
- GRB 161219B: afterglow and SN2016jca optical observations
- GRB 170111A: Swift-BAT refined analysis
- GRB 170111A: Swift-XRT refined Analysis
- LIGO/Virgo G268556/GW170104: Campo Imperatore Observatory observations
- LIGO/Virgo G268556: AMI 15 GHz detection of ATLAS17aeu
- GRB 170111A: Swift detection of a burst
- LIGO/Virgo G268556: Spectroscopic observations of ATLAS17aeu and iPTF17cw
- LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
- LIGO/Virgo G268556: IPN Triangulation of GRB 170105A (association with ATLAS17aeu)
- LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
- LIGO/Virgo G268556: CALET Observations
- LIGO/Virgo G268556: iPTF Optical Transient Candidates
- LIGO/Virgo G268556/GW170104: Global MASTER Net second OT detection
- LIGO/Virgo G268556: SWASP optical imaging
- LIGO/Virgo G268556/GW170104: Global MASTER Net observations and first OT detection
- LIGO/Virgo G268556: ATLAS imaging of the skymap
- LIGO/Virgo G268556: AGILE MCAL and Super-AGILE Observations
- LIGO/Virgo G268556: Fermi-LAT search for high-energy gamma-ray counterpart
- LIGO/Virgo G211117 / GW151226: LOFAR follow-up
- LIGO/Virgo G268556: observation regions by Project Mini-GWAC of SVOM
- Konus-Wind observation of GRB 170101A
- GRB161219B - Anticipated hyperluminal evidence
- Fermi GBM trigger 504043585/161221838 is not a GRB
- Konus-Wind observation of GRB 161219B
- GRB 161219B: SALT observations
- GRB 161220A: Swift-XRT refined Analysis
- GRB 161220A: LCO-FTS observations
- GRB 161219B: MITSuME Akeno Optical Observation