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').
3086 results found.
- GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
- GRB 230409B: Mondy optical upper limit
- Fermi trigger No 702745263: Global MASTER-Net observations report
- MAXI GRB230408.82: Global MASTER-Net observations report
- GRB 230409B: Swift detection of a burst
- Fermi trigger No 701883729: Global MASTER-Net observations report
- GRB 230328B: Swift-BAT refined analysis
- GRB 230328B: Nanshan/NEXT optical upper limit
- Fermi GRB 230328A: Global MASTER-Net observations report
- Fermi trigger No 701321709: Global MASTER-Net observations report
- Konus-Wind detection of GRB 230309A
- GRB 230322A: Fermi GBM Final Real-time Localization
- Fermi GRB 230313A: Global MASTER-Net observations report
- GRB 230307A: soft X-ray detection with LEIA
- Further improved IPN localization for GRB 230307A
- GRB 230307A: MAXI/GSC upper limit
- Fermi GRB 230308A: Global MASTER-Net observations report
- Fermi trigger No 699294715: Global MASTER-Net observations report
- Fermi trigger No 699311646: Global MASTER-Net observations report
- GRB 230220A: Correction to GCN 33352
- Fermi GRB 230220B: Global MASTER-Net observations report
- GRB 230220A: MAXI/GSC detection
- IceCube-230217A: BOOTES-4/MET Optical Observations
- IPN triangulation of GRB 230209B
- GRB 230204B: CALET Gamma-Ray Burst Monitor detection
- GRB 230204B: ATCA radio detection
- Fermi trigger No 697926015: Global MASTER-Net observations report
- Fermi trigger No 697904388: Global MASTER-Net observations report
- GRB 230204B: MASTER early OT detection
- GRB 230204B: Swift/UVOT Upper Limits
- GRB 230204B: Fermi GBM detection
- GRB 230204B: Swift-XRT afterglow detection
- GRB 230204B: 3.6m DOT optical observation
- GRB 230204B: ATLAS detection of the optical afterglow and a projected location in a nearby galaxy group
- GRB 230204B: Swift ToO observations
- GRB 230204B: Detection by GRBAlpha
- GRB 230204B: AGILE detection
- GRB 230204B: GIT discovery of the likely optical afterglow
- GRB 230204B: AstroSat CZTI detection
- GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
- GRB 230204B: MAXI/GSC detection
- GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
- GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
- Fermi trigger No 697098930: Global MASTER-Net observations report
- GRB 221216A: Swift-BAT refined analysis
- Fermi GRB 230201A: Global MASTER-Net observations report
- Fermi-LAT Gamma-ray Observations of IceCube-Cascade-221229A
- GRB 230111A: Fermi GBM Observation
- Fermi GRB 230112A: Global MASTER-Net observations report
- GRB 230111A: MAXI/GSC detection
- Subject: IceCube-Cascade 221229A: Upper limits from a search for additional neutrino events in IceCube
- Fermi GRB 221226A: Global MASTER-Net observations report
- Fermi GRB 221221A: Global MASTER-Net observations report
- IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
- Integral GRB221218.34: Global MASTER-Net observations report
- Fermi trigger No 692713692: Global MASTER-Net observations report
- Swift Trigger 1144538 is not a GRB
- Konus-Wind detection of a burst from SGR 1935+2154 on 2022 December 13
- Fermi GRB 221211A: Global MASTER-Net observations report
- IceCube Alert 221210.36: Global MASTER-Net observations report
- IceCube Alert 221124.66: Global MASTER-Net observations report
- LAT GRB221119.63: Global MASTER-Net observations report
- GRB 221028A: CrAO/ZTSh optical upper limit
- GRB 221028B: MAXI/GSC detection
- Konus-Wind detection of GRB 221017A
- Swift GRB 221027B: Global MASTER-Net observations report
- GRB 221022B: Detection by GRBAlpha
- GRB 221017A: CALET Gamma-Ray Burst Monitor detection
- GRB 221017A: Swift-XRT observations
- GRB 221017A: Swift ToO observations
- AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
- IPN triangulation of GRB 221017A (long)
- MAXI GRB221017.24: Global MASTER-Net observations report
- GRB 221017A: MAXI/GSC detection
- MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
- MAXI GRB 221006A: Redshifts of the possible host galaxies
- Fermi trigger No 687340841: Global MASTER-Net observations report
- GRB 221006A: Swift-XRT afterglow detection
- Fermi trigger No 687281393: Global MASTER-Net observations report
- Afterglow limits of GRB 221006A from OHP
- GRB 221009A: NICER follow-up observations
- Fermi trigger No 687190301: Global MASTER-Net observations report
- GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
- GRB 221009A: Upper limits from HAWC 8 hours after trigger
- GRB 221006A: Swift ToO observations
- GRB 221006A: CALET Gamma-Ray Burst Monitor detection
- GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
- GRB 221009A BOOTES-2/TELMA and OSN optical detections
- GRB 221008A: Swift-XRT observations
- GRB 221008A: Tiled Swift observations
- GRB 221008A: MAXI/GSC detection
- GRB 221006A: Swift-XRT observations
- GRB 221006A: Tiled Swift observations
- GRB 221006A: MAXI/GSC detection
- Fermi trigger No 686588176: Global MASTER-Net observations report
- GRB 220927A: Fermi GBM Final Localization
- Fermi GRB 220925A: Global MASTER-Net observations report
- Fermi trigger No 685748699: Global MASTER-Net observations report
- Fermi trigger No 685452089: Global MASTER-Net observations report
- IceCube-220907A: No significant detection in HAWC