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').
- GRB foobar
- GRB foobar test
- GRB testing 3
- GRB testing 2
- GRB testing
- GRB test 4
- GRB test 3
- GRB test 2
- GRB test
- GRB foobar
- GRB foobar
- LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
- LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
- GRB foobar
- GRB foobar
- PKS2326-505, millimeter wavelength flare, transient
- GRB foo 3
- GRB foo 2
- GRB foo
- GRB foo
- GRB foo
- GRB foo
- GRB test
- GRB foo
- GRB foobar
- GRB foobar
- GRB foobar
- GRB foobar
- GRB foobar
- GRB test
- MAGIC test
- GRB test
- GRB foo
- Test GCN GW submission
- GRB test 2
- GRB test
- GRB test
- Test GW GCN hermes submission 2
- Test GW GCN hermes submission
- Test GW GCN hermes submission
- A GRB test
- TEST GW GCN hermes submission
- GRB 170817A: an awesome GCN Circular
- VIRT optical transient detection
- GRB 230414B: 3.6m DOT Optical observations, slow decay at early epochs
- GRB 230307A: iTelescope optical upper limit (likely)
- GRB 230414B: Montarrenti Observatory late time optical afterglow detection
- IceCube-230416A: IceCube observation of a high-energy neutrino candidate
- Fermi trigger No 703284533: Global MASTER-Net observations report
- GRB 230414B: Lulin 40cm-SLT optical limit
- GRB 230414B: Bassano Bresciano Observatory optical observations
- GRB 230414B: Redshift from OSIRIS/GTC
- GRB 230414B: AbAO optical observations
- GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
- GRB 230414B: Swift-XRT refined Analysis
- GRB 230414B: Dabancheng/GHOST optical observations
- AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230414A
- GRB 230414B: slow optical light curve decay
- GRB 230414B: SAO RAS optical observations
- GRB 230414B: Enhanced Swift-XRT position
- GRB 230414B: 1.3m DFOT Optical observations
- Fermi GRB 230414A: Global MASTER-Net observations report
- GRB 230414B: GROWTH India Telescope afterglow confirmation
- GRB 230414B (correction GRB name in the GCN 33615): Mondy optical afterglow candidate
- GRB 230414B: Nanshan/HMT optical afterglow detection
- GRB 230414A: Mondy optical afterglow candidate
- Swift GRB 230414B: Global MASTER-Net observations report
- GRB 230414B: Prompt enhanced Swift-XRT position
- GRB 230414B: Swift detection of a burst
- IceCube-230405A: BOOTES-4/MET Optical Upper Limits
- GRB 230414A: Fermi GBM Final Real-time Localization
- GRB 230328B: redshift lower limit estimating
- GRB 230409B: Mondy optical upper limit
- GRB 230409B: OHP/T193 optical upper limit
- GRB 230410B: VZLUSAT-2 detection
- GRB 230409D: VZLUSAT-2 detection
- GRB 230410B: AGILE detection of a burst
- GRB 230410A: Fermi GBM Final Real-time Localization
- Fermi GRB 230409C: Global MASTER-Net observations report
- Fermi GRB 230409A: Global MASTER-Net observations report
- GRB 230409C: Fermi GBM Final Real-time Localization
- GRB 230409B: Swift-XRT refined Analysis
- GRB 230409B: Swift-BAT refined analysis
- Fermi trigger No 702745263: Global MASTER-Net observations report
- Swift GRB 230409B: Global MASTER-Net observations report
- GRB 230409B: Swift/UVOT Detection
- GRB 230409B: Enhanced Swift-XRT position
- MAXI GRB230408.82: Global MASTER-Net observations report
- GRB 230409B: Swift detection of a burst
- GRB 230409A: Fermi GBM Final Real-time Localization
- GRB 230405B: VZLUSAT-2 detection
- IceCube-230405A: Upper limits from a search for additional neutrino events in IceCube
- Fermi-LAT gamma-ray observations of IceCube-230405A
- Konus-Wind detection of GRB 230405B
- GRB 230405B: AGILE detection
- GRB 230405B: Swift-XRT refined Analysis
- GRB 230405B: Fermi GBM Observation
- GRB 230405B: MeerLICHT upper limits
- IceCube Alert 230405.56: Global MASTER-Net observations report
- GRB 230307A: JWST NIRSpec observations, possible higher redshift