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').
9625 results found.
- GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 231216A: Swift-XRT refined Analysis
- GRB 231215A: Swift-BAT refined analysis
- GRB 231216A: Swift detection of a burst
- Konus-Wind detection of GRB 231215A
- GRB 231215A: NOT optical observations
- GRB 231204A: VZLUSAT-2 detection
- GRB 231215A: AKO Optical Upper Limit
- GRB 231214A: Fermi GBM observation
- Konus-Wind detection of GRB 231210B
- GRB 231215A: AstroSat CZTI detection
- GRB 231214A: Swift-XRT refined Analysis
- GRB 231214A: AstroSat CZTI detection
- Swift GRB231215.41: Global MASTER-Net observations report
- GRB 231214A: Fermi-LAT detection
- GRB 231214B: Swift/BAT-GUANO detection of a burst
- GRB231214A: BOOTES-6/DPRT optical upper limit
- Fermi trigger No 724278269: Global MASTER-Net observations report
- Fermi trigger No 724233240: Global MASTER-Net observations report
- Swift GRB231214.85: Global MASTER-Net observations report
- GRB 231214A: Swift detection of a burst
- GRB 231214A: Fermi GBM Final Real-time Localization
- Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
- LIGO/Virgo/KAGRA S231206cc: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231206ca: Upper limits from Swift/BAT-GUANO
- GRB 231212A: GECAM-C detection of a likely short burst
- Fermi trigger No 724035412: Global MASTER-Net observations report
- GRB 231210B: MeerLICHT afterglow observations
- GRB 231210B: Swift-BAT refined analysis
- GRB 231210B: Swift-XRT refined Analysis
- Fermi trigger No 723906955: Global MASTER-Net observations report
- GRB 231208A: AstroSat CZTI detection of a faint burst
- Fermi trigger No 723581802: Global MASTER-Net observations report
- GRB 231205B: Ondrejov D50 optical upper limit
- Fermi-LAT gamma-ray observations of IceCube-231202A
- GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
- GRB 231206A: GECAM-B detection of a short burst (correction)
- GRB 231206A: GECAM-B detection of a short burst
- GRB 231205B: Nanshan/HMT optical upper limit
- GRB 231205B: GECAM-B detection of a long burst
- GRB 231204A: Glowbug gamma-ray detection
- GRB 231204A: CALET Gamma-Ray Burst Monitor detection
- Fermi-LAT daily aperture light curve of T CrB now available
- GRB 231204A: AstroSat CZTI detection
- GRB 231205A: GECAM-B detection of a short burst
- Fermi trigger No 723435916: Global MASTER-Net observations report
- Fermi trigger No 723326169: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
- Fermi trigger No 723412808: Global MASTER-Net observations report
- GRB 231204A: Fermi GBM Final Real-time Localization
- GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- Konus-Wind detection of GRB 231129C
- Fermi trigger No 723149952: Global MASTER-Net observations report
- GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
- GRB 231129C: Fermi-LAT detection
- GRB 231129C: GECAM-B detection of a bright burst
- GRB 231129C: AstroSat CZTI detection
- GRB 231127A: GRBAlpha detection
- GRB 231129C: MAXI/GSC detection
- Fermi trigger No 722977823: Global MASTER-Net observations report
- GRB 231129B: MAXI/GSC detection
- Fermi-LAT gamma-ray observations of IceCube-231125A
- GRB 231129A: GECAM-C detection of a long burst
- GRB 231129A: INTEGRAL detection of a long GRB
- GRB 231127A: AstroSat CZTI detection
- GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
- GRB 231124A: GRBAlpha detection
- GRB 231125A: AstroSat CZTI detection of a short burst
- GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
- GRB230506B: VIRT optical upper limit
- Fermi trigger No 722462310: Global MASTER-Net observations report
- GRB 231115A: XMM-Newton observation
- GRB 231123A: AstroSat CZTI detection
- GRB 231117A: Mondy optical observations
- GRB 231118A: REM optical afterglow detection
- GRB 231122B: AstroSat CZTI detection
- GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
- GRB 231117A: Continued GTC Observations
- Fermi trigger No 722349867: Global MASTER-Net observations report
- GRB 231122A: GECAM detection
- GRB 231122B: GECAM detection
- GRB 231118A: ATCA detection of radio counterpart
- LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
- Konus-Wind detection of GRB 231020A
- GRB 231117A: LDT Confirmation of Optical Fading
- 231118A: Swift-UVOT Detection
- LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
- GRB 231120A: Fermi GBM Final Real-time Localization
- GRB 231117A: Swift-XRT refined Analysis
- GRB 231118A: Swift-XRT refined Analysis
- GRB 231118A: AstroSat CZTI detection
- GRB 231118A: LCOGT Optical Observations
- GRB 231118A: MASTER OT observation
- Swift GRB231118.72: Global MASTER-Net observations report
- GRB 231115A: JinShan optical upper limits
- Konus-Wind detection of GRB 231117A (short/hard)
- GRB 231115A: optical observations from INAF observatories