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.
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18802 results found.
- Fermi-LAT detection of increased gamma-ray activity of blazar PKS 0446+11, located inside the IceCube-240105A error region
- GRB 240108A: Glowbug gamma-ray detection
- GRB 231214A: ATCA Radio Upper Limits
- GRB 240106B: Glowbug gamma-ray detection
- GRB 240106A: Glowbug gamma-ray detection
- GRB 231215A: radio detection with the VLA
- GRB 230818A: further radio observations with the VLA
- GRB 230812B: further radio observations with the VLA
- GRB 240107A: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S240109a: Identification of a GW compact binary merger candidate
- GRB 240109A: Swift detection of a short burst
- LIGO/Virgo/KAGRA S240107b: Updated Sky localization and Source Classification
- LIGO/Virgo/KAGRA S240107b: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 240101C (short)
- GRB 240101A: 1.3m DFOT optical observations
- GRB 240102A: 1.3m DFOT optical upper limit
- GRB 240101B: 1.3m DFOT optical upper limit
- LIGO/Virgo/KAGRA S240104bl: Identification of a GW compact binary merger candidate
- GRB 240102C: AstroSat CZTI detection
- GRB 231220A: Swift-UVOT upper limit
- GRB 240102A: Swift/UVOT Upper Limits
- GRB 240102A: Enhanced Swift-XRT position
- GRB 240102A: Swift-XRT refined Analysis
- GRB 240102A: LCOGT Optical Upper Limits
- GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
- GRB 240102A: Swift detection of a burst
- GRB 240101B: Swift/UVOT Upper Limits
- GRB 240101A: Swift/UVOT Upper Limits
- GRB 240101A: Swift-XRT refined Analysis
- GRB 240101B: Enhanced Swift-XRT position
- GRB 240101A: Enhanced Swift-XRT position
- GRB 240101B: Swift detection of a burst
- LIGO/Virgo/KAGRA S231231ag: Identification of a GW compact binary merger candidate
- GRB 231230A: Swift-XRT refined Analysis
- GRB 231230A: Enhanced Swift-XRT position
- GRB 231230A: Swift/UVOT Upper Limits
- GRB 231230A: NOT optical upper limits
- GRB 231230A: Swift detection of a burst
- IPN triangulation of GRB 231224A (short)
- LIGO/Virgo/KAGRA S231226av: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231224e: Identification of a GW compact binary merger candidate
- GRB 231222B: Swift-XRT afterglow detection
- LIGO/Virgo/KAGRA S231223j: Identification of a GW compact binary merger candidate
- IceCube-231211A: GRANDMA observations of PKS2047+098
- GRB 231220A: Swift-XRT follow-up observations
- GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
- GRB 231216A: optical upper limits from the INAF Asiago Observatory
- GRB 231216A: 10.4 m GTC optical upper limit
- GRB 231215A: AMI-LA radio detection
- GRB 231216A: Nanshan/HMT optical upper limit
- GRB 231216A: LCOGT Optical Upper Limits
- GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 231216A: Swift-XRT refined analysis correction
- GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 231216A: AST3-3 YaoAn Optical Upper Limit
- GRB 231216A: REM NIR upper limits
- GRB 231216A: Swift/UVOT Upper Limits
- GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
- GRB 231216A: GIT optical upper limit
- GRB 231216A: Swift detection of a burst
- GRB 231214A: Swift/UVOT Upper Limits
- GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
- GRB 231215A : OHP/T193 optical afterglow detection
- GRB 231215A: Swift/UVOT Detection
- LIGO/Virgo/KAGRA S231215i: 3 counterpart neutrino candidate events from an IceCube neutrino search
- GRB 231215A: Swift-XRT refined Analysis
- GRB 231215A: AKO Optical Upper Limit
- ATCA observations of GRB 231210B
- GRB 231215A: Enhanced Swift-XRT position
- GRB 231214A: REM optical/NIR upper limits
- GRB 231215A: GROWTH-India optical follow-up
- GRB 231215A : Nanshan/HMT optical observations
- GRB 231215A: AstroSat CZTI detection
- GRB 231215A : MITSuME Akeno optical afterglow candidate detection
- GRB 231214A: Swift-XRT refined Analysis
- GRB 231215A: Mondy optical bright afterglow detection
- GRB 231214A: AstroSat CZTI detection
- GRB 231215A: Swift-XRT observations
- GRB 231215A: Swift detection of a burst
- GRB 231214A: Enhanced Swift-XRT position
- GRB 231214A: Swift detection of a burst
- GRB 231210B: REM optical/NIR upper limits
- LIGO/Virgo/KAGRA S231213ap: Identification of a GW compact binary merger candidate
- Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
- GRB 231210B: MeerLICHT afterglow observations
- GRB 231210B: Swift-XRT refined Analysis
- GRB 231210B: Enhanced Swift-XRT position
- GRB 231210B: VLT/X-shooter redshift
- GRB 231210B: Swift detection of a burst with optical counterpart
- IPN triangulation of GRB 231129C
- GRB 231208A: GRBAlpha detection
- GRB231205B: Swift/UVOT Upper Limits
- GRB 231208A: Glowbug gamma-ray detection
- GRB 231208A: AstroSat CZTI detection of a faint burst
- IPN triangulation of GRB 231205A
- GRB 231205B: 1.3m DFOT Optical upper limit
- GRB 231205B: optical upper limit in TSHAOand AbAO
- LIGO/Virgo/KAGRA S231206cc: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231206ca: Identification of a GW compact binary merger candidate
- GRB231115A: TURBO Pre-Burst Optical Upper Limits