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.
Advanced Search Examples (click to copy):
subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
32140 results found.
- GRB 240712A ATCA radio observations
- GRB240715A: GRANDMA Optical Upper Limits
- IPN triangulation of GRB 240715A (short)
- GRB 240712A: Swift/UVOT Upper Limits
- GRB 240715A: Fermi GBM Final Real-time Localization
- GRB 240713A: Tiled Swift observations
- GRB 240713A: J-band upper limit from WINTER
- GRB 240713A: NOT optical upper limits on three EP/FXT candidates
- GRB 240713A: JinShan optical upper limits
- GRB 240713A: OHP/T120 optical upper limit
- GRB240713A: X-ray follow-up observation with EP-FXT
- GRB 240713B: AstroSat CZTI detection of a long burst
- Fermi Sub-threshold Observation of GRB240713A
- GRB240713A : The first probable GRB Located on-Board SVOM by ECLAIRs
- Fermi Gamma-ray Burst Monitor trigger 742413075/240711744 is not a GRB
- GRB 240712A: Swift detection of a burst
- GRB 240711A: Fermi GBM Final Real-time Localization
- EP240708a: KAIT optical upper limit
- Fermi GRB 240710A: Global MASTER-Net observations report
- GRB 240710A: Fermi GBM Final Real-time Localization
- EP240708a: SVOM/C-GFT optical upper limit
- Fermi Gamma-ray Burst Monitor trigger 741911057/240705933 is not a GRB
- GRB 240705A: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240627A
- IPN triangulation of GRB 240628B (short)
- EP240703a: KAIT optical upper limit
- EP240703a: BTA observations
- EP240703a/GRB 240703A: TRT optical candidate likely not real
- EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
- IPN triangulation of GRB 240627A
- GRB 240619A: Host galaxy redshift from VLT/X-shooter
- The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
- Konus-Wind detection of GRB 240703A (a counterpart of EP240703a)
- The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A
- GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885)
- Fermi GRB 240702A: Global MASTER-Net observations report
- GRB 240702A: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
- Fermi Gamma-ray Burst Monitor trigger 741448122/240630575 is not a GRB
- GRB 240627A: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
- Fermi GRB 240629A: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 741362867/240629589 is not a GRB
- Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
- GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
- GRB 240629A: Fermi GBM Final Real-time Localization
- Fermi Gamma-ray Burst Monitor trigger 741356809/240629519 is not a GRB
- IPN triangulation of GRB 240619C
- GRB 240628A: BALROG localization (Fermi Trigger 741288821 / GRB 240628732)
- GRB 240627A: NuSTAR Detection of the long GRB
- GRB 240615A: SAI CMO J- band observations
- GRB 240627A: AstroSat CZTI detection
- EP240626a: Montarrenti Observatory optical upper limit
- EP240626a: KAIT optical upper limit
- GRB 240624A: Swift-BAT refined analysis
- Konus-Wind detection of GRB 240619A
- Fermi GRB 240625B: Global MASTER-Net observations report
- GRB 240624B: CALET Gamma-Ray Burst Monitor detection
- GRB 240625B: Fermi GBM Final Real-time Localization
- GRB 240625A: Fermi GBM Observation
- GRB 240624B: GRBAlpha detection
- GRB 240625A: Fermi GBM Final Real-time Localization
- GRB240624A: Fermi GBM Observation
- LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
- Swift GRB 240624A: Global MASTER-Net observations report
- GRB240615A: Gemini-North observations of the BAT and XRT positions
- Fermi GRB 240624A: Global MASTER-Net observations report
- GRB 240624B: Fermi GBM Final Real-time Localization
- GRB240615A: Gemini-North observations of the BAT and XRT positions
- GRB 240624A: Fermi GBM Final Real-time Localization
- GRB 240619A: detection of a radio counterpart with AMI-LA
- GRB 240624A: Swift detection of a burst
- GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
- GRB 240619A: J-band detection with WINTER
- EP240618a: NOT optical counterpart candidate
- GRB 240529A: JinShan optical observations
- IPN triangulation of GRB 240615A (short)
- GRB 240619A: GRBAlpha detection
- GRB 240619A: Swift-XRT probable afterglow detection
- GRB 240619A: Swift ToO observations
- GRB 240619A: CALET Gamma-Ray Burst Monitor detection
- GRB 240619C: NuSTAR automated detection of the GRB
- GRB 240619A: Fermi GBM Observation
- Fermi GBM Sub-Threshold Detection of GRB 240619C
- GRB 240619A: GOTO candidate optical afterglow
- EP240618a: Abastumani optical observationsEP240618a
- GRB 240615A: NOT optical observations
- GRB 240619C: AstroSat CZTI detection
- Fermi GRB 240619A: Global MASTER-Net observations report
- GRB 240615A: possible transient detection from Wendelstein observations
- Fermi Gamma-ray Burst Monitor trigger 740474239/240619304 is not a GRB
- GRB 240619B: Fermi GBM Final Real-time Localization
- GRB240615A: 1.3m DFOT optical upper limit
- GRB 240619A: BALROG localization (Fermi Trigger 740461416 / GRB 240619155)
- GRB 240619A: Fermi GBM Final Real-time Localization
- EP240617a: BOOTES-6/DPRT optical upper limit
- EP240617a is likely a GRB event
- LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO