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"4903 results found.
- GRB 130812A: Swift-XRT refined Analysis
- GRB 130812A: Swift detection of a burst
- GRB 130806A: Swift-XRT refined Analysis
- GRB 130803A: Swift-XRT refined Analysis
- GRB 130727A: Swift-XRT refined Analysis
- GRB 130725A: Swift-XRT refined Analysis
- GRB 130725B: Swift-XRT refined Analysis
- GRB 130725B: Swift detection of a burst
- Fermi Gamma-ray Burst Monitor trigger 396447899 / 130725517 is not a GRB
- GRB 130722A: Swift-XRT refined Analysis
- GRB 130702A: Continued P60 observations
- Fermi394416326: iPTF detection of a possible optical afterglow
- GRB 130701A: MITSuME Akeno Optical observation
- GRB 130701A: Swift-XRT refined Analysis
- GRB 130627A: Swift-XRT refined Analysis
- GRB 130625A: Swift-XRT refined Analysis
- GRB 130603B: First epoch of XMM-Newton observations
- Swift Trigger 558828 is not an interesting event
- GRB 130609B: Suzaku WAM observation of the prompt emission
- GRB 130615A: Swift-XRT refined Analysis
- GRB 130612A: Swift-XRT refined Analysis
- IPN Triangulation of GRB 130610B (long/multipeaked)
- GRB 130610A: Swift-XRT refined Analysis
- GRB 130609B: Swift-XRT refined Analysis
- GRB 130606A - Liverpool Telescope and Faulkes Telescope North optical observations
- GRB 130608A: Swift-XRT refined Analysis
- GRB 130609A: Swift-XRT refined Analysis
- Swift Trigger 557674 was due to an onboard position error
- Swift Trigger 557674 is a probable new Galactic transient
- GRB 130606A: Swift-XRT refined Analysis
- GRB 130606A: AAO optical observations
- GRB 130605A: Swift-XRT refined Analysis
- GRB 130604A: Swift-XRT refined Analysis
- GRB 130603B: Swift-XRT refined Analysis
- GRB 130603A: Swift-XRT refined Analysis
- GRB 130518A: Suzaku WAM observation of the prompt emission
- GRB 130529A: Swift-XRT refined Analysis
- GRB 130528A: Swift-XRT refined Analysis
- GRB 130527A: Swift-XRT refined Analysis
- GRB 130527A: Prompt enhanced Swift-XRT position
- GRB 130521B: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 130521B
- IPN Triangulation of GRB 130521B
- GRB 130518A: P60 Afterglow Observations
- GRB 130515A: Swift-XRT refined Analysis
- GRB 130514A: Swift-XRT refined Analysis
- GRB 130514A: Skynet/PROMPT/DSO Detections
- GRB 130427A: optical observations
- GRB 130513A: Swift-XRT detection of the afterglow.
- GRB 130511A: Swift-XRT refined Analysis
- GRB 130508A: Refined Swift-XRT analysis: Correction to GCN 14612
- GRB 130504B: Suzaku WAM observation of the prompt emission
- GRB 130505A: Swift-XRT refined Analysis
- GRB 130505A: Swift detection of a burst with optical afterglow
- GRB 130504A: MITSuME Okayama upper limits
- GRB 130502B: Suzaku WAM observation of the prompt emission
- Swift-XRT X-ray afterglow candidate for GRB 130504A (BAT trigger 555096)
- GRB 130502B: Fermi GBM detection of a burst
- GRB 130427B: MITSuME Ishigakijima upper limits
- GRB 130427A: Nishi-Harima NIR Observations
- GRB 130427A: Swift-XRT refined Analysis
- GRB 130427B: Swift-XRT refined Analysis
- IPN Triangulation of GRB 130425A
- GRB 130420B: Swift-XRT refined Analysis
- GRB 130420A: Swift-XRT refined Analysis
- GRB 130420B: MASTER-Net optical observations
- GRB 130418A: SMARTS optical/IR afterglow observations
- GRB 130419B (Swift trigger Trigger 553930): MASTER-Net optical observations
- Trigger 553930: Swift detection of a possible flare from HR 5110
- GRB 130408A: SMARTS optical/IR afterglow observations
- GRB 130408A: Swift-XRT refined Analysis
- GRB 130327B: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 130320B
- IPN Triangulation of GRB 130320B (very long/bright)
- Swift/XRT observation of GRB 130327B
- GRB 130310A: RATIR Observations
- Konus-Wind observation of GRB 130327B
- GRB 130327B: Fermi-LAT detection of a burst
- GRB 130327B: Fermi GBM detection
- GRB 130327B: gamma-ray detection by AGILE
- GRB 130327A: Swift-XRT refined Analysis
- GBM trigger 383712005 (GRB 130228A?) : Possible high-energy photon emission in Fermi/LAT data
- GRB 130219A: Suzaku WAM observation of the prompt emission
- Trigger 549841: Swift detection of SGR1806-20
- IPN Triangulation of GRB 130219A
- GRB 130216A: Swift detection of a burst
- GRB 130211A: Swift-XRT refined Analysis
- GRB 130131A: optical observation in Mondy observatory
- GRB 130131B: Swift-XRT refined Analysis
- GRB 130131A: VLA 5.8 Ghz Detection
- GRB 130131A: Swift-XRT refined Analysis
- GRB 130131A - UKIRT afterglow candidate
- Swift/BAT trigger 547142 is new source Swift J1753.7-2544
- Swift Trigger 547142: MAXI/GSC upper limit
- GRB 130122A: Swift-XRT refined Analysis
- Short GRB 121226A: TNG observation of the host galaxy
- GRB 130102A: Swift-XRT refined Analysis
- GRB 121226A: 5.8 GHz VLA observations
- GRB 121229A: Swift-XRT refined Analysis
- GRB 121226A: 10.4m GTC optical observations