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 240821A: PRIME near-infrared observations
- GRB 240825A: VLA detection
- Fermi GRB 240828A: Global MASTER-Net observations report
- Fermi trigger No 746438824: Global MASTER-Net observations report
- SVOM GRB 240821A: optical afterglow discovery
- GRB 240828B : Detection of a possible very soft X-ray transient by SVOM/ECLAIRs
- GRB 240828A: Fermi GBM Final Real-time Localization
- GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
- GRB 240825A: GECAM detection
- GRB 240825A: ALMA detection
- GRB 240825A: SAO RAS optical observations
- GRB 240824A: GIT optical upper limit
- GRB 240819A: Swift afterglow confirmation
- GRB 240825A: TNG optical photometry and spectroscopy
- LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
- LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
- GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
- GRB 240825A: GMG Continued Optical Observation on the Second Night
- GRB 240824B: Ondrejov D50 optical limit
- GRB 240825A: KAIT optical observations
- GRB 240825A: PRIME near-infrared detection
- Konus-Wind detection of GRB 240825A (bright/long)
- GRB 240825A: Fermi GBM Observation
- GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
- GRB 240825A: AKO Optical Follow-Up Observations
- GRB 240825A: AstroSat CZTI detection of the long bright burst
- SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
- GRB 240825A: Swift/UVOT Detection
- GRB 240825A: REM detection of the optical/NIR afterglow
- GRB 240825A: Swift-XRT refined Analysis
- GRB 240825A: VLT/X-shooter redshift
- GRB 240825A: SVOM/C-GFT optical observations
- GRB 240825A: Montarrenti Observatory optical observations
- GRB 240825A: Enhanced Swift-XRT position
- GRB 240825A: MASTER optical counterpart observation
- GRB 240825A: Fermi-LAT detection
- GRB 240825A: LCO optical observations
- GRB 240824B: KAIT optical upper limit
- SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
- GRB 240824B: Fermi GBM Observation
- Fermi GRB 240825A: Global MASTER-Net observations report
- SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
- GRB 240824B: NOT optical upper limit
- GRB 240825A: GMG Optical Observation
- Swift GRB 240825A: Global MASTER-Net observations report
- GRB 240825A: 1.6m Mephisto multi-band detection
- GRB 240825A: AKO Optical Afterglow Detection
- GRB 240825A: Skynet Optical Afterglow observations
- GRB 240825A: Nanshan/HMT optical afterglow observations
- GRB 240825A: Swift detection of a burst with a bright optical counterpart
- GRB 240825A: Fermi GBM Final Real-time Localization
- GRB 240824A: Swift-BAT refined analysis
- GRB 240824A: SVOM/C-GFT optical upper limit
- GRB 240824B: Swift-XRT afterglow detection
- GRB 240824A: Swift-XRT observations
- LIGO/Virgo/KAGRA S240825ar: Identification of a GW compact binary merger candidate
- GRB 240824B: Swift/BAT arcminute localization of a burst
- GRB 240824B: Swift ToO observations
- Fermi GRB 240824C: Global MASTER-Net observations report
- GRB 240824C: Fermi GBM Final Localization
- GRB 240824A: Swift/UVOT Upper Limits
- GRB 240821A: Swift/UVOT observations of the XRT sources.
- GRB 240824B: MAXI/GSC detection
- GRB 240824B: Fermi GBM Final Real-time Localization
- GRB 240824A: Retraction of GCN 37255
- GRB240824A: GRANDMA/TAROT-TCA Upper Limit
- SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
- GRB 240824A: KAIT optical upper limit
- GRB 240824A: Skynet Optical Afterglow Discovery
- GRB 240824A: Swift detection of a burst
- Swift GRB240824.04: Global MASTER-Net observations report
- SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
- GRB 240821A: Colibri Optical Upper Limit
- EP240820a: PRIME J-band Observations
- GRB 240821A: Swift-XRT observations
- GRB 240822A: AstroSat CZTI detection of a short burst
- GRB 240821A: REM optical/NIR upper limits
- GRB 240821A: LCO optical observations
- GRB 240821A: JinShan optical upper limits
- GRB 240809A: Mondy and AbAO Optical Observations
- GRB 240821A: SVOM/VT follow-up and optical upper limit
- GRB 240821A: GMG Optical Upper Limit
- Fermi GRB 240821A: Global MASTER-Net observations report
- GECAM-B observation of a short burst from SGR 1E 1841-045 / Kes 73
- GRB 240821A: Fermi GBM Observation
- Fermi trigger No 745964969: Global MASTER-Net observations report
- Fermi trigger No 745925274: Global MASTER-Net observations report
- GRB 240821A: Swift ToO observations
- Fermi trigger No 746019401: Global MASTER-Net observations report
- Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
- Fermi trigger No 745935375: Global MASTER-Net observations report
- GRB240821A: EIRSAT-1 GMOD Detection
- GRB240821B: First GRB Detected by EIRSAT-1 GMOD
- GRB 240821A: EP-FXT follow-up observation and afterglow candidates
- Fermi GRB 240821B: Global MASTER-Net observations report
- EP240801a: Keck/LRIS spectroscopic redshift confirmation
- GRB 240821A: SVOM/GRM observation
- GRB 240821A: SVOM/GRM observation
- GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
- GRB 240821B: Fermi GBM Final Localization