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').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Lucene Examples (click to copy):
subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
3035 results found.
- GRB 241229A: EP-FXT afterglow candidates
- GRB 241228B: Swift-XRT afterglow detection
- GRB 241229B: Swift-XRT refined Analysis
- GRB 241228A: Swift-XRT refined Analysis
- GRB 241223A: Swift-XRT observations
- EP 241217a: NIR detection with P200/WIRC
- GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
- GRB 241218A: Swift-XRT refined Analysis
- GRB 241217A: Swift-XRT afterglow detection
- EP241217a: Swift-XRT Detection
- GRB 241212A: Swift-XRT observations
- GRB 241213B: Swift-XRT observations
- GRB 241213A: Swift-XRT refined Analysis
- EP241213a: EP detection of An X-ray Transient
- GRB 241209A: Chandra X-ray Detection
- GRB 241209B: Swift-XRT afterglow detection
- GRB 241209A: Swift-XRT refined Analysis
- EP241208a: EP-FXT follow-up observations
- GRB 241209D: Swift-XRT refined Analysis
- GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
- AT2024adec: X-ray Upper Limits from EP-FXT Observation
- EP241201a: EP-FXT follow-up observations
- Fermi trigger No 754701230: Global MASTER-Net observations report
- Swift-XRT observations of IceCube -241127A
- GRB 241128A: Swift-XRT refined Analysis
- GRB 241128A: Swift-XRT afterglow detection
- GRB 241127A: Swift-XRT refined Analysis
- LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
- LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
- LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
- GRB 241115A: Swift-XRT afterglow detection
- GRB 241113B: Swift-XRT observations
- GRB 241113A: Swift-XRT refined Analysis
- GRB 241112B: Swift-XRT afterglow detection
- GRB 241108A: Swift-XRT observations
- GRB 241105A: Swift/UVOT Detection
- GRB 241105A: Swift-XRT afterglow detection
- GRB 241104A: Swift-XRT observations
- EP241104a: EP detection of GRB 241104A X-ray emission
- EP241101a: EP-FXT observations update
- LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
- EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
- EP241101a: EP-WXT detection of a fast X-ray transient
- GRB 241030B: Swift-XRT refined Analysis
- EP241030a: EP detection of GRB 241030A X-ray Afterglow
- GRB 241029A: SVOM/VT optical afterglow observations
- EP241021a: Swift-UVOT detection
- GRB 241030A: Swift-XRT refined Analysis
- EP 241021a: further Swift-XRT observations and X-ray counterpart detection
- GRB 241029A: Swift-XRT observations
- GRB 241026A: Swift-XRT refined Analysis
- GRB 241025A: Swift-XRT refined Analysis
- EP 241021a: Swift-XRT observations
- GRB 241018A: Swift-XRT observations
- GRB 241017A: Swift-XRT observations
- GRB 241001A: EP-FXT afterglow detection
- GRB 241009A: Swift-XRT afterglow detection
- GRB 241010A: Swift-XRT refined Analysis
- GRB 241002B: Swift-XRT afterglow detection
- GRB 241006A: Swift-XRT refined Analysis
- GRB 241001A: Swift-XRT afterglow detection
- GRB 241002B: Swift-XRT observations
- GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
- GRB 241002A: Swift-XRT refined Analysis
- GRB 241001A: Swift-XRT observations
- EP240919a / GRB 240919A: SVOM/VT upper limit
- LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
- GRB 240910A: further Swift observations and confirmation of afterglow
- GRB 240916A: Swift-XRT afterglow detection
- LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
- EP240913a: VLT/HAWK-I near-infrared upper limits
- GRB 240914A: Swift-XRT observations
- GRB 240910A: SVOM/VT optical observations
- EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
- GRB 240911A: Swift-XRT observations
- GRB 240912A: Swift-XRT refined Analysis
- GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
- GRB 240905E: SVOM/VT optical observations
- EP240908a: EP detection of a fast X-ray transient
- GRB 240905B: Swift-XRT observations
- GRB 240905E: Swift-XRT refined Analysis
- GRB 240905B: AstroSat CZTI detection and localization
- GRB 240828A: Swift-XRT afterglow detection
- GRB 240828B: Swift-XRT afterglow detection
- GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
- GRB 240819A: Swift afterglow confirmation
- GRB 240825A: Swift-XRT refined Analysis
- GRB 240824B: Swift-XRT afterglow detection
- GRB 240824A: Swift-XRT observations
- GRB 240821A: Swift/UVOT observations of the XRT sources.
- GRB 240821A: Swift-XRT observations
- GRB 240821A: EP-FXT follow-up observation and afterglow candidates
- GRB 240819A: Swift-XRT observations
- EP240820a: EP detection of a fast X-ray transient
- GRB 240819A: X-ray follow-up observation with EP-FXT
- GRB 240811A: Swift-XRT refined Analysis
- GRB 240809A: Swift-XRT refined Analysis
- The EP-WXT trigger 01709018832 on August 7th is likely a flaring star
- GRB 240805B: Swift-XRT refined Analysis
- GRB 240805A: Swift-XRT refined Analysis