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"4180 results found.
- 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
- GRB 130912A: 5.8 GHz VLA upper limit
- GRB 130831A: Continued Skynet/PROMPT-SSO, PROMPT-CTIO and Yerkes-41 detections
- GRB 130831A: T100 observations
- GRB 130831A: THO optical observation
- GRB 130831A: Optical Observations via Virtual Telescope
- GRB 130831A: Montarrenti Observatory optical observations
- GRB 130831A: Skynet/PROMPT-SSO detections
- GRB 130831A: Swift detection of a burst with an optical counterpart
- GRB 130829A: AAO optical observations
- GRB 130829A: NOT optical observations
- GRB 130623A: GROND detection of the optical/NIR afterglow
- GRB 130806A: MITSuME Okayama upper limits
- IPN localization of GRB 130804A
- SGR 1745-29 (Swift trigger 565443), Swift-BAT refined analysis
- Trigger 565443: Swift detection of a burst from SGR J1745-29
- GRB 130803A, Swift-BAT refined analysis
- GRB 130803A: Enhanced Swift-XRT position
- GRB 130803A: Swift detection of a burst
- GRB 130722A: Faulkes Telescope South optical candidate
- Fermi GRB 130702A: Swift XRT and UVOT observations
- Swift Trigger 558631 is not a real source
- Fermi/GBM observation of the Soft Gamma Repeater SGR J1550-5418
- GRB 130612A: ISON-NM optical observations
- GRB 130608A: Further Swift-BAT analysis
- GRB 130608A: Swift-BAT refined analysis
- GRB 130608A: Swift detection of a burst
- GRB 130606A: EVLA detection
- Trigger 557640: Swift detection of burst from SGR J1745-29
- GRB 130606A:T100 observations
- GRB130606A: Montarrenti Observatory afterglow detection
- Virtual Telescope observations of GRB 130606A
- GRB 130606A: IRSF NIR Observation
- GRB 130606A: NOT afterglow detection
- GRB 130605A: Swift detection of a burst
- GRB 130603A: MITSuME Okayama Optical Observation
- Fermi Trigger 130507.091 - Detection of a SGR-like Burst
- GRB 130504C: Suzaku WAM observation of the prompt emission
- GRB 130427A: Amateur observations from Sweden
- Refined IPN Triangulation of GRB 130502B
- GRB 130505A, Swift-BAT refined analysis
- Konus-Wind observation of GRB 130504C
- Swift/UVOT observations of GRB130505A
- GRB 130505A: iTelescope T12 optical observations
- GRB 130505A: Enhanced Swift-XRT position
- GRB 130505A: MAXI/GSC detection
- GRB 130505A: Swift detection of a burst with optical afterglow
- GRB 130427A: Non-observation of VHE emission with HAWC
- GRB 130427A: KAIT optical observations
- GRB 130427A: SARA-N optical observations
- GRB 130427A: MITSuME Ishigakijima Optical Observation after 2 days
- GRB 130427A: Challis Observatory optical observations
- GRB 130427A: Continued Skynet/PROMPT Observations
- GRB 130427A: further GMG observations
- GRB 130427A: SARA-N detection
- GRB 130427A: MITSuME Okayama and Ishigakijima Optical Observation after 1 day
- GRB 130427A: Optical Observations
- GRB 130427A: Swift detection of a very bright burst with a likely bright optical counterpart
- Trigger 554491: Swift detection of a spike possibly from Sgr A*
- GRB 130420A: ROTSE-III data analysis
- GRB 130420A: Early RAPTOR Simultaneous Multi-Color Observations
- Swift Trigger 554135 is probably not a GRB or transient
- GRB 130420A: ROTSE-III Detection of Optical Counterpart
- GRB 130420A: Swift detection of a burst with an optical counterpart
- GRB 130419A: Swift detection of a burst
- Konus-Wind observation of GRB 130408A
- GRB 130211A: Retraction of afterglow candidate
- Konus-Wind observation of GRB 130320B
- IPN Triangulation of GRB 130320B (very long/bright)
- Swift XRT observations of GRB 130310A
- GRB 130306A: Swift detection of a burst