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"35360 results found.
- Fermi GRB 240814B: Global MASTER-Net observations report
- GRB 240812B: SVOM/GRM observation
- EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
- GRB 240814B: Fermi GBM Final Real-time Localization
- GRB 240814A: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240811A
- Konus-Wind detection of GRB 240810A
- Fermi Gamma-ray Burst Monitor trigger 745220784/240813240 is not a GRB
- GRB 240809A: Correction to the VLA source position in GCN 37158
- GRB 240810A: SVOM/GRM observation
- Fermi Gamma-ray Burst Monitor trigger 240812940/745194848 is not a GRB
- Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
- Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
- GRB 240809A: ATA radio non-detection
- GRB 240812D: Fermi GBM Final Real-time Localization
- GRB 240812C: Fermi GBM Final Real-time Localization
- GRB 240809A : RAPAS follow-up observations
- GRB 240809A: VLA detection
- GRB 240809A: ALMA detection
- IPN triangulation of GRB 240810A (short)
- GRB 240811A: Swift-BAT refined analysis
- GRB 240809A: Swift-BAT refined analysis
- GRB 240812B: AstroSat CZTI detection of a long burst
- IceCube-240808A: Upper limits from a search for additional neutrino events in IceCube
- GRB 240811A: Bassano Bresciano Observatory upper limit
- GRB 240811A: Swift-XRT refined Analysis
- Fermi Gamma-ray Burst Monitor trigger 745135620/240812255 is not a GRB
- GRB 240811A: Swift/UVOT Upper Limits
- EP240801a: Assy-Turgen optical observations
- Fermi GRB 240810A: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 240812094/745121685 is not a GRB
- GRB 240812A: Fermi GBM Final Real-time Localization
- GRB 240811A: LCOGT Optical Upper Limit
- GRB 240811A: Enhanced Swift-XRT position
- GRB 240811A: Upper limits with Mephisto
- Konus-Wind detection of GRB 240809A
- Swift GRB 240811A: Global MASTER-Net observations report
- GRB 240811A: Swift detection of a burst
- Fermi Gamma-ray Burst Monitor trigger 745050426/240811269 is not a GRB
- GRB 240810A: Fermi GBM Final Real-time Localization
- GRB 240809A: REM detection of the optical afterglow
- GRB 240809A: Bassano Bresciano Observatory optical observations
- Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
- GRB 240809A: Conclusive redshift from VLT
- GRB 240809A: KAIT optical observations
- GRB 240808A: AstroSat CZTI detection
- GRB 240809A: GIT afterglow observations
- GRB 240809B: MAXI/GSC detection
- GRB 240809A: Swift/UVOT Detection
- GRB 240809A: Tentative redshift from NOT
- GRB 240809A: Swift-XRT refined Analysis
- IPN triangulation of GRB 240807A / EP 240807a
- Swift GRB 240809A: Global MASTER-Net observations report
- GRB 240809A: JinShan optical observations
- GRB 240809A: Enhanced Swift-XRT position
- GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
- GRB 240809A: SVOM/GRM observation
- GRB 240808A: SVOM/GRM observation
- GRB 240807A: SVOM/GRM observation
- GRB 240809A: Swift detection of a burst with a bright optical counterpart
- EP-WXT trigger 01709018832: SVOM/C-GFT observations of the star flare
- EP240807a: STEP/T80S optical limits
- GRB 240807B: AstroSat CZTI detection of a short burst
- GRB 240801A: GRBAlpha detection
- GRB 240807B: Fermi GBM Final Localization
- GRB 240710B: VZLUSAT-2 detection
- GRB 240805A: ATCA Radio Upper Limits
- EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
- EP-WXT trigger 01709018832: KAIT optical observations of the star flare
- EP240802a/GRB240802A: KAIT optical upper limit
- GRB 240720B: VZLUSAT-2 detection
- GRB 240710A: VZLUSAT-2 detection
- GRB 240807A: Fermi GBM Final Localization
- GRB 240805B: GIT optical upper limit
- EP240806a: KAIT optical observations
- GRB 240805B: Swift-BAT refined analysis
- GRB 240805A: Swift-BAT refined analysis
- EP240804a (GRB 240804B): NOT optical observations
- Konus-Wind detection of GRB 240802A (EP240802a)
- Improved IPN triangulation of GRB 240802A / EP 240802a
- Konus-Wind detection of GRB 240805A
- GRB 240805B Bassano Bresciano Observatory upper limit
- GRB240805A: Fermi GBM Observation
- GRB 240805B: JinShan optical afterglow detection
- GRB 240804B/EP240804a: Correction to the GRB name in GCN 37071
- GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
- Konus-Wind detection of GRB 240804B (a counterpart of EP240804a)
- Fermi Gamma-ray Burst Monitor trigger 240806402/744629911 is not a GRB
- GRB 240626B: VZLUSAT-2 detection
- GRB 240624B: VZLUSAT-2 detection
- GRB 240619C: VZLUSAT-2 detection
- EP 240806A: LCO optical observations
- GRB 240805B: Optical detection with 1.6m Mephisto
- GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
- GRB 240805B: Swift-XRT refined Analysis
- GRB 240805B: Swift/UVOT Upper Limits
- GRB 240805A: Swift/UVOT Upper Limits
- GRB 240805B: BTA optical afterglow candidate
- GRB 240805A: SVOM/GRM observation
- GRB 240805B: Enhanced Swift-XRT position