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"23442 results found.
- GRB 110928A: Swift/UVOT finding chart observation
- GRB 110928A: PAIRITEL NIR Observations
- GRB 110928A: ROTSE-III Optical Limits
- GRB 110928A: Swift detection of a burst
- Swift-BAT trigger 503926 is noise
- GRB 110924A: Swift detection of a possible burst
- GCN for GRB 110921B
- GRB 110921A: Swift/UVOT Observations
- GRB 110921A: NOT observations
- GRB 110921A: TNT astrometry
- GRB 110918A: submm observations from APEX
- GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
- GRB 110921A: Enhanced Swift-XRT position
- GRB 110921A: Swift detection of a burst
- GRB 110915B : X-ray afterglow confirmation
- GRB 110918A: Swift/UVOT Detection of the Optical Counterpart
- GRB 110918A optical observation
- GRB 110918A: GROND detection of the afterglow candidate
- GRB 110918A: INT optical detection of Swift candidate afterglow
- GRB 110918A: Swift-XRT observations
- Swift detection of short bursts from PSR J1647-4552
- GRB 110915A: Konus-Wind and Swift/BAT joint spectral analysis
- IPN triangulation of GRB 110918A (long duration, extremely intense)
- GRB 110915B: GROND Observations of the Optical/NIR Afterglow Candidate
- GRB 110915A: Swift/UVOT Upper Limits
- GRB 110915B: Swift/UVOT Upper Limits
- GRB 110915A: GROND Upper limits
- GRB 110915B: Afterglow candidate from OSN
- GRB 110915A: Deep Near-IR Limits from Magellan
- GRB 110915B: XRT afterglow candidate
- GRB 110915A: Deep Gemini-South i/z-band imaging
- GRB110915A MITSuME Okayama J-band upper-limit
- GRB 110915A: MITSuME Okayama and Ishigakijima Optical upper limits
- GRB 110915A: NOT observations
- GRB 110915A: 1.23m CAHA I-band observations
- GRB 110915A: Enhanced Swift-XRT position
- GRB 110915A: GMG optical upper limit
- GRB 110915A: MASTER-Net early limit
- GRB 110915A: Swift detection of a burst
- GRB 110825A: Further Swift/XRT Observations
- GRB 110731A: SAO RAS and Terskol observations
- GRB 110906A(?): Burst detection (unconfirmed) from Swift-BAT slew data
- GRB 110905A: Swift detection of a burst
- GRB 110903A: Fermi GBM observation
- GRB 110903A: Swift/UVOT Upper Limits
- GRB 110903A: Swift-XRT observations
- GRB 110903A: a long GRB detected by INTEGRAL
- GRB 110820A: optical upper limit
- Trigger 502024: Swift detection of KS 1741-293
- Swift detection of an SGR burst from Swift J1834.9-0846
- GRB 110825A: Suzaku WAM observation of the prompt emission
- GRB 110825A: GMG optical observation
- GRB110825A: ROTSE early time optical limit
- GRB 110827A, Swift-BAT refined analysis
- GRB 110825A: optical afterglow candidate
- GRB 110827A: Swift detection of a burst
- GRB 110825A: field inspection and possible host galaxy
- GRB110825A: Swift target of opportunity observation
- IPN triangulation of GRB110825A (very intense, long-duration)
- Swift-BAT Trigger 501485 is noise
- IPN triangulation of GRB 110820B (very long duration, extremely intense)
- GRB 110820A: Swift/UVOT Upper Limits
- GRB 110820A: Position udpate + 2nd epoch data
- GRB 110820A: CQUEAN izY Observation
- GRB110820A: MITSuME Ishigakijima Optical Upper Limits
- GRB 110820A: Enhanced Swift-XRT position
- GRB 110820A: CrAO optical upper limit
- GRB 110820A: Swift detection of a burst
- GRB 110818A: Swift/UVOT Upper Limits
- GRB 110818A: Enhanced Swift-XRT position
- GRB 110818A: Optical afterglow and redshift from VLT/X-shooter
- GRB 110818A: Swift-XRT refined Analysis
- GRB 110815A: Swift-XRT and UVOT refined Analysis
- GRB 110818A: Swift detection of a burst
- IPN triangulation of GRB110815A (long, intense)
- GRB 110801A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 110801A: optical observations at Mt. Terskol observatory
- GRB 110812A: SuperAGILE localization of a long GRB.
- IPN triangulation of GRB 110808B (short/hard/intense)
- A new photometric resource for GRB observers
- RXTE Discovery of the Spin Period of Swift J1834.9-0846
- GRB 110808A: Swift/UVOT Detection
- GRB 110808A: VLT/X-shooter spectroscopy
- GRB 110808A: Enhanced Swift-XRT position
- GRB 110808A: Swift detection of a burst with optical counterpart
- Fermi GBM detection of a SGR-like burst
- GRB 110807A: SAO RAS observations
- GRB 110807A: Swift detection of a burst or a posible new SGR
- GRB 110726A: two epochs of SAO RAS optical observations
- IPN triangulation of GRB110802A (short/hard burst)
- GRB 110801A: optical observations in CrAO
- EVLA observation for Fermi burst GRB 110721A
- GRB 110801A: SAO RAS optical observations
- GRB110801A: MITSuME Ishigakijima Optical Observation at 1 day after the burst
- GRB 110801A: MASTER OT observations
- Swift/UVOT observations of GRB110801A
- GRB 110801A: Afterglow redshift from 10.4m GTC
- GRB110801A: MITSuME Ishigakijima Optical Observation
- GRB 110801A: Enhanced Swift-XRT position
- GRB 110801A: Swift detection of a burst with an optical counterpart