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"3850 results found.
- GRB 140629A: MITSuME Akeno Optical observation
- GRB 140629A: MASTER-Net preliminary light curve
- GRB 140629A: SAO RAS monitoring
- Fermi 425667201: optical counterpart search
- GRB 140629A: Nishi-Harima NIR Observations
- GRB 140629A: BTA redshift
- GRB 140629A: MITSuME Ishigakijima Optical Observation
- GRB 140629A: T100 observations
- GRB 140629A: KWFC z-band photometry
- GRB 140629A: RTT150 optical observations
- GRB 140629A: MASTER OT detection
- GRB 140628A: GROND observation of the afterglow
- GRB 140619B: Suzaku WAM observation of the prompt emission
- IPN Triangulation of GRB 140621A
- GRB 140606B / iPTF 14bfu: SAO RAS optical observations
- GRB 140606B / iPTF 14bfu: Mondy optical observations
- Konus-Wind observation of GRB 140610A
- GRB 140610A: Swift-XRT observations
- GRB 140610A: Swift detection of a burst
- IPN Triangulation of GRB 140606B
- Fermi423717114: iPTF optical transient candidates
- Konus-Wind observation of GRB 140523A
- GRB 140512A: MASTER prompt and afterglow optical observations
- Trigger 599041: Swift detection of SFXT IGR J16479-4514
- GRB 140423A: AAO optical upper limits
- Fermi GBM Trigger 140429551 - Detection of a burst from SGR 1806-20
- GRB 140428A: GROND observations
- Trigger 597570: Swift detection of SGR 1806-20
- GRB 140428A: 1.5m OSN I-band detection
- GRB 140428A: Keck detection of a red optical afterglow candidate
- GRB 140423A: Nishi-Harima NIR Observations
- GRB 140423A pODI/WIYN afterglow photometry
- GRB 140414A: Short burst found in ground analysis of BAT slew data
- Fermi418277210: iPTF optical observations
- Retraction of the Fermi/LAT high-energy counterpart for GRB 140330A
- GRB 140129B: AAO optical upper limit
- GRB 140129A: Mondy optical observations
- GRB 140329A: Fermi GBM observation of a bright burst
- GRB 140311A: Mondy optical limits
- GRB 140311C: MASTER before, during and after trigger optical observations
- GRB 140311B: final MASTER OT light curve
- GRB 140311A: Recalibration of photometry of OT detected with Kottamia 188cm telescope
- GRB 140311A: Optical follow-up observation with Kottamia 188cm telescope
- GRB 140311B: MASTER early optical observations
- GRB 140311B: Swift detection of a burst
- GRB 140306A: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 140306A
- IPN Triangulation of GRB 140306A
- GRB 140306A: Fermi GBM detection
- GRB 140305A: Swift detection of a burst
- GRB 140304A: Khureltogot optical observations
- GRB 140304A: Swift detection of a burst
- GRB 140304A: MASTER OT detecton
- GRB 140219A: Mondy optical observations of XRT source #5
- IPN triangulation of GRB 140226A, a possible GRB counterpart to iPTF14yb
- GRB 140219A: XRT afterglow candidate
- GRB 140219A: MASTER before and after GRB observational arguments of the exceptionally Dark GRB
- GRB 140211A: Khureltogot optical upper limits
- GRB140211A : Xinglong TNT upper limit
- GRB 140209A: Swift-XRT observations
- GRB 140209A, Swift-BAT refined analysis
- GRB 140209A: P60 optical afterglow detection
- GRB 140206A: Mondy optical observations
- GRB 140129A: Khureltogot optical limit
- GRB 140129B: MASTER OT early light curve
- GRB 140129A: MITSuME Okayama upper limits
- GRB 140129B: MASTER OT confirmation
- GRB 140114A: optical upper limit
- Swift Trigger 584155 is MAXI J1421-613
- GRB 140103A: MASTER-Net early OT detection
- GRB 140110A: Swift XRT observations
- Fermi410578384: iPTF optical afterglow candidates for a possible short GRB
- GRB 131229A: Fermi GBM detection
- GRB 131231A: P60 observations
- GRB 131231A : xinglong TNT optical observation
- GRB 131231A: MDM afterglow observation
- GRB 131227A: GROND Upper Limits
- GRB 131227A: Enhanced Swift-XRT position
- GRB 131227A: OT candidate from KAIT Optical observations
- GRB 131215A: MAXI/GSC detection
- Konus-Wind observation of GRB 131209A
- GRB 131127B: rejection of optical counterpart candidates
- GRB 131122A: Swift-XRT Further Observation
- IPN Triangulation of GRB 131126A (short/hard)
- GRB 131127A: CQUEAN riz Observation
- GRB 131128A: GROND observations of the afterglow
- IPN Triangulation of GRB 131125A (short/hard)
- GRB 131127B: MASTER-Net optical observations
- IPN Triangulation of GRB 131118A
- GRB 131031A: Mondy optical observations
- GRB 131029A: Fermi GBM observation
- GRB 131029A: Fermi-LAT detection of a burst
- Swift Trigger 575905/ GRB 131026A: MITSuME Okayama and Ishigakijima Optical upper limits
- Swift Trigger 575905: a possible GRB
- Fermi403206457: Weihai optical upper limit
- GRB 130831A: VLT/FORS2 spectroscopic detection of a supernova
- IPN Triangulation of SGR-like burst 130913 - probable association with SGR/AXP 1E1841-045
- INTEGRAL detection of a SGR-like burst likely from SGR J1745-29
- GRB 130919A: Skynet PROMPT-CTIO optical upper limits
- Fermi/GBM Detection of two SGR-like bursts possibly associated with SGR J1833-0832