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.
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"
32101 results found.
- GRB 240222A: GRBAlpha detection
- VLA X-band observation of EPW20240219aa
- Transient EPW20240219aa: Mondy optical observations
- Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
- Swift BAT Sub-Threshold Detection of EPW20240219aa
- GRB 240222A: GECAM detection of a burst
- GRB 240222A: Swift-BAT refined analysis
- GRB 240222A: Swift-XRT refined Analysis
- GRB 240222A: Fermi GBM Observation
- GRB 240222A: Swift/UVOT Upper Limits
- Fermi GBM Sub-Threshold Detection of EPW20240219aa as a likely GRB
- Swift GRB 240222A: Global MASTER-Net observations report
- Fermi GRB 240222A: Global MASTER-Net observations report
- EPW20240219aa is Likely a GRB Event
- GRB 240222A: REM optical and NIR early-time observations
- GRB 240222A: Swift detection of a burst
- GRB 240222A: Fermi GBM Final Real-time Localization
- GRB 240218A: MeerLICHT upper limits
- GRB 240216A: Glowbug gamma-ray detection
- GRB 240215B: Fermi GBM Observation
- GRB 240218A: LBT H-band detection
- GRB 240218A: Swift-BAT refined analysis
- Fermi GRB 240220A: Global MASTER-Net observations report
- GRB 240220A: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240218A
- GRB 240218A: Swift-XRT refined Analysis
- GRB 240218A: VLT/X-shooter redshift of z = 6.782
- GRB 240218A: Fermi GBM Detection
- GRB 240215A: Fermi GBM Observation
- GRB 240216A: GRBAlpha detection
- GRB 240215B: GRBAlpha detection
- IPN triangulation of GRB 240209A
- GRB 240218A: VLT/FORS2 z-band detection
- GRB 240218A: Enhanced Swift-XRT position
- GRB 240218A: REM detection of a NIR afterglow candidate
- GRB 240213A: GRBAlpha detection
- GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
- GRB240218A: VLT/X-shooter upper limits
- GRB 240218A: Swift detection of a burst
- GRB 240215C: Fermi GBM Final Real-time Localization
- GRB 240215B: Swift/BAT-GUANO detection of a burst outside the coded FOV
- Fermi GRB 240216A: Global MASTER-Net observations report
- GRB 240216A: Fermi GBM Final Real-time Localization
- GRB 240215A: Tiled Swift observations
- GRB 240215A: Swift/BAT-GUANO localization of a burst
- GRB 240209A: Classification of AT2024cew/GOTO24pw as Type Ia-pec supernova
- GRB 240209A: Fermi GBM observation
- GRB 240213A: Glowbug gamma-ray detection
- GRB240209A: OHP/T193 detection of the GOTO afterglow candidate AT2024cew / GOTO24pw
- GRB 240209A: Wendelstein Optical Observations
- GRB 240128A: Further Swift-XRT observations
- GRB 240214A: Tiled Swift observations
- GRB 240214A/1H 0451-560: MAXI/GSC detection
- GRB 240213A: BALROG localization (Fermi Trigger / GRB 240213841)
- Fermi GRB 240213A: Global MASTER-Net observations report
- GRB 240213A: Fermi GBM Final Real-time Localization
- GRB 240209A: NOEMA non-detection of AT2024cew / GOTO24pw counterpart candidate
- GRB 240209A: NOT photometry of the AT2024cew / GOTO24pw counterpart candidate
- GRB 240209A: GOTO optical counterpart candidate
- Konus-Wind detection of GRB 240204A
- Konus-Wind detection of GRB 240205A (short)
- GRB 240209A: Fermi GBM Final Localization
- IPN triangulation of GRB 240205A (short)
- GRB 240205B: PRIME near infrared detection
- GRB 240205A (short): Glowbug gamma-ray detection
- GRB240204A: Swift/UVOT Upper Limits
- GRB 240205B: AstroSat CZTI detection
- GRB 240205B: Swift-BAT refined analysis
- Konus-Wind detection of GRB 240205B (long / very soft)
- GRB 240207A: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240125A
- GRB 240205B: VLT/X-shooter redshift
- GRB 240205B: CALET Gamma-Ray Burst Monitor detection
- GRB 240205B: BOOTES-6 optical afterglow follow-up
- GRB 240205B: ATCA detection of radio counterpart
- GRB 240205B: REM detection of the optical/NIR afterglow
- GRB 240205B: Fermi GBM Observation
- GRB 240204A: AstroSat CZTI detection
- GRB 240204A: Mondy optical afterglow observations
- GRB 240204A : OHP/T193/T120 optical afterglow fading detection
- GRB 240205B: GECAM detection of a long burst
- GRB 240204A: Swift-BAT refined analysis
- GRB 240205B: Skynet Optical Afterglow Observations
- GRB 240205B: BOOTES-7 optical afterglow follow-up
- GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
- GRB 240205B: Swift detection of a burst
- GRB 240205B: Fermi GBM Final Real-time Localization
- GRB 240204A: Fermi GBM Observation
- GRB 240205A: Fermi GBM Final Real-time Localization
- GRB 240204a: Liverpool Telescope optical afterglow detection
- GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
- Fermi Gamma-ray Burst Monitor trigger 728740048/240204491 is not a GRB
- GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
- GRB 240204A: Montarrenti Observatory optical observations
- GRB 240204A: Enhanced Swift-XRT position
- GRB 240204A: Mondy optical afterglow candidate
- Fermi Gamma-ray Burst Monitor trigger 728706420/240204102 is not a GRB
- Fermi GRB 240204A: Global MASTER-Net observations report
- GRB 240204A: Swift detection of a burst
- GRB 240204A: Fermi GBM Final Real-time Localization