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').
17080 results found.
- LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
- LVK S240422ed: Further Swift-XRT followup of three sources
- LIGO/Virgo/KAGRA S240422ed: Magellan Follow-up Observations of Swift/XRT candidates
- LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
- LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
- LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limits for Swift/XRT candidates
- GRB 240419B: Swift-BAT refined analysis
- GRB 240421B: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101
- IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event
- LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
- LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
- LIGO/Virgo/KAGRA S240422ed: NOT J-band upper limit on the Swift/XRT source S240422ed_X61
- LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Three Potential Electromagnetic Counterparts Reported So Far
- GRB 240421B: GRBAlpha detection
- LIGO/Virgo/KAGRA S240422ed: WINTER J-band upper limits on the Swift/XRT source S240422ed_X61
- LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61
- GRB 240419A: Swift-BAT refined analysis
- GRB 240418A: Swift-BAT refined analysis
- LXT240402A/GRB240402B: Chandra X-ray detection
- LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
- GRB 240419B : MITSuME Akeno optical upper limits
- GRB 240415B: Swift-XRT observations
- GRB 240415A: Swift-XRT refined Analysis
- GRB 240421B: AstroSat CZTI detection
- GRB240421B: Zadko Observations
- Swift GRB 240421B: Global MASTER-Net observations report
- GRB 240421B: Fermi GBM Observation
- GRB 240421B: Swift-XRT refined Analysis
- GRB240421B: BOOTES-5/JGT optical upper limit
- GRB 240421B: Swift/UVOT Upper Limits
- GRB 240421B: Enhanced Swift-XRT position
- GRB 240421B: Swift detection of a burst
- GRB240419A: Skynet Optical Afterglow Analysis
- GRB 240419B: Swift/UVOT Upper Limits
- GRB 240419A: Swift/UVOT Upper Limits
- GRB 240419B: Swift-XRT refined Analysis
- Swift GRB 240419B: Global MASTER-Net observations report
- GRB 240419B: Enhanced Swift-XRT position
- Swift GRB 240419A: Global MASTER-Net observations report
- GRB 240418A: Swift/UVOT Upper Limits
- GRB 240419A: Swift-XRT refined Analysis
- GRB 240418A: Swift-XRT refined Analysis
- GRB 240419B: Swift detection of a burst
- GRB 240411B: Swift/UVOT Detection
- GRB240418A: YAHPT Upper Limits
- GRB 240419A: Enhanced Swift-XRT position
- GRB 240419A: Prompt enhanced Swift-XRT position
- GRB 240419A: Swift detection of a burst
- GRB 240418A: TSHAO Zeiss-1000 optical upper limit
- GRB 240418A: Enhanced Swift-XRT position
- Swift GRB240418.85: Global MASTER-Net observations report
- GRB 240418A: Swift detection of a burst
- Improved IPN triangulation of GRB 240411A
- GRB 240415A: Glowbug gamma-ray detection
- GRB 240414A: Glowbug gamma-ray detection
- GRB 240415B: GECAM-B detection
- GRB 240415A: Swift-BAT refined analysis
- GRB 240411A: Glowbug gamma-ray detection
- GRB 240414A: Swift-BAT refined analysis
- GRB 240414A: AbAO optical upprer limit
- GRB 240415A: Swift/UVOT Detection
- GRB 240415A: Fermi GBM Observation
- GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
- GRB 240415A: Enhanced Swift-XRT position
- GRB 240415B: Swift ToO observations
- GRB 240415B: Swift/BAT-GUANO Correction
- GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
- GRB 240414A: Fermi GBM Observation
- GRB 240414A: Swift/UVOT Detection
- LXT 240402A/GRB 240402B: Swift follow-up observations
- GRB 240414A: Mondy optical observations
- GRB 240415A: Prompt Swift-XRT observations
- GRB 240415A: Swift detection of a burst
- GRB 240414A: Swift-XRT refined Analysis
- GRB 240414A: Enhanced Swift-XRT position
- GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
- GRB 240414A: Skynet Optical Afterglow Observations
- Swift GRB 240414A: Global MASTER-Net observations report
- IPN triangulation of GRB 240410A
- IPN triangulation of GRB 240411A
- GRB 240414A : MITSuME Akeno optical upper limits
- GRB 240414A: Swift detection of a burst
- GRB 240411B: Swift-BAT refined analysis
- GRB 240411B: Swift-XRT refined Analysis
- GRB 240411B: 1.3m DFOT Optical observations
- GRB 240411B: Enhanced Swift-XRT position
- GRB 240411B: Swift detection of a burst
- EP240408A: MASTER optical observations
- EP240408a: GROND detection of a candidate counterpart
- EP240408a: Swift follow-up observation
- Swift Trigger 1220736: detection of 4U 1543-62.
- Swift satellite resumes pointed science observations
- GRB 240318A: Fermi GBM Observation
- Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
- GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
- GRB 240318A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
- GRB 240317B: Swift/BAT-GUANO Angular Error Correction
- GRB 240317B: Fermi GBM Observation