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"
32135 results found.
- GRB 240527B: Fermi GBM Observation
- Fermi GRB 240527A: Global MASTER-Net observations report
- GRB 240527B: Fermi-LAT detection
- Fermi GRB 240527B: Global MASTER-Net observations report
- GRB 240527B: Fermi GBM Final Localization
- GRB 240527B: BALROG localization (Fermi Trigger 738511436 / GRB 240527586)
- GRB 240527A: Fermi GBM Final Real-time Localization
- GRB 240523A: Swift-BAT refined analysis
- GRB 240523A: Swift-XRT refined Analysis
- GRB 240523A: Enhanced Swift-XRT position
- GRB 240523A: Swift detection of a burst
- GRB 240521B: Fermi GBM Observation
- Fermi GBM Sub-Threshold Detection of GRB 240516B
- GRB 240513A: Swift-XRT afterglow detection
- GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
- GRB 240521A: GECAM-B detection of a long burst
- GRB 240516B: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
- GRB 240514B: VZLUSAT-2 detection
- GRB 240504A: VZLUSAT-2 detection
- GRB 240502A: VZLUSAT-2 detection
- GRB 240519A: GRBAlpha detection
- GRB 240516A: Swift/UVOT Upper Limits
- GRB 240519A: AstroSat CZTI detection
- GRB 240519A: BALROG localization (Fermi Trigger 737788024 / GRB 240519213)
- GRB 240516A: Swift-BAT refined analysis
- Fermi GRB 240517A: Global MASTER-Net observations report
- GRB 240516A ATCA radio observations
- IPN triangulation of GRB 240514B (short)
- GRB 240513A: Swift ToO observations
- GRB 240517A: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240513A
- GRB 240516A: AstroSat CZTI detection
- GRB 240516A: Swift-XRT refined Analysis
- GRB 240514E: A possible candidate BD-21 1074
- GRB 240516A: Fermi GBM Observation
- GRB 240511A: Observations from GTC/OSIRIS+
- GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
- GRB 240516A: GOTO optical upper limit
- LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits
- GRB 240516A: Swift detection of a burst
- GRB 240514B: AT2024ixa/GOTO24bph is not consistent with the Fermi localisation
- GRB 240511A: radio detection of afterglow candidate
- GRB 240514B: GOTO candidate optical counterpart
- Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
- GRB 240514E: MAXI/GSC detection of a probable afterglow
- GRB 240514B: GRBAlpha detection
- GRB 240514B: Fermi GBM Detection
- GRB 240513A: Fermi GBM observation
- GRB 240513A: Swift-XRT observations
- GRB 240514D: AstroSat CZTI detection
- GRB 240514C: Fermi GBM Final Real-time Localization
- Fermi GRB 240514B: Global MASTER-Net observations report
- GRB 240514B: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
- GRB 240514A: Fermi GBM Final Real-time Localization
- GRB 240513A: Tiled Swift observations
- GRB 240513A: Fermi-LAT detection
- GRB 240511A: Fermi GBM Observation
- GRB 240511A: Swift-BAT refined analysis
- Fermi GRB 240513B: Global MASTER-Net observations report
- GRB 240513B: Fermi GBM Final Real-time Localization
- GRB 240513A: AstroSat CZTI detection
- GRB 240511A: J-band observations with WINTER
- GRB 240511A: Enhanced Swift-XRT position
- GRB 240511A : MITSuME Akeno optical upper limits
- GRB 240511A: Swift-XRT refined Analysis
- GRB 240511A: optical afterglow detection from the NOT
- Fermi Gamma-ray Burst Monitor trigger 737102480/240511279 is not a GRB
- Fermi Gamma-ray Burst Monitor trigger 737111207/240511380 is not a GRB
- Fermi GBM trigger 737105243/240511311 is not a GRB
- Fermi GRB 240511A: Global MASTER-Net observations report
- Swift GRB 240511A: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 737133200/240511634 is not a GRB
- GRB 240511A: Prompt enhanced Swift-XRT position
- GRB 240511A: Swift detection of a burst
- GRB 240511A: Fermi GBM Final Real-time Localization
- Fermi Gamma-ray Burst Monitor trigger 737076431/240510977 is not a GRB
- Fermi Gamma-ray Burst Monitor trigger 230925241/717313591 is not a GRB
- EP240506a: CrAO ZTSH optical upper limit
- GRB 240504A: Fermi GBM Observation
- Fermi Gamma-ray Burst Monitor trigger 736837160/240508208 is not a GRB
- IPN triangulation of GRB 240504A
- GRB 240502A: 1.3m DFOT Optical upper limit
- GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
- IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
- Fermi GRB 240504A: Global MASTER-Net observations report
- GRB 240503A: AstroSat CZTI detection
- GRB 240504A: BALROG localization (Fermi Trigger 736492377 / GRB 240504217)
- GRB 240504A: Fermi GBM Final Real-time Localization
- LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
- GRB 240502A: GOTO optical upper limit
- GRB 240502A: Fermi GBM Observation
- GRB 240415A 1.3m DFOT Optical upper limit
- GRB 240502C: GOTO possible optical counterpart candidates