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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"25891 results found.
- GRB240615A: 1.3m DFOT optical upper limit
- LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
- GRB 240615A: J-band upper limits from WINTER
- GRB 240615A: Fermi GBM Observation
- GRB 240615A: Swift-XRT observations
- GRB 240615A: GECAM detection
- GRB 240615A: FLWO-1.2m optical upper limits
- Konus-Wind detection of GRB 240615A (short/hard)
- GRB 240615A: GOTO optical upper limits
- GRB 240615A: Swift ToO observations
- GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
- EXO 0748-676: Swift-BAT refined analysis
- GRB240529A: 3.6m TNG NIR detection 8d after the burst
- GRB 240529A: LBT optical detection and late temporal decay
- GRB 240529A : MITSuME Akeno optical afterglow detection
- Trigger 1236151: Swift detection of EXO 0748-676
- IPN triangulation of GRB 240607A
- Konus-Wind detection of GRB 240606B
- GRB 240529A: NOEMA detection
- GRB 240606B: Fermi GBM Observation
- Swift Trigger 1235109: consistent with noise and not astrophysical
- GRB 240529A: radio detection with AMI-LA
- GRB 240606B: GECAM-B detection a long burst
- GRB 240606B: Swift-XRT afterglow detection
- Swift GRB240606.15: Global MASTER-Net observations report
- GRB 240606B: Swift ToO observations
- GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
- Swift Trigger 1235109: a possible GRB 240606A
- IPN triangulation of GRB 240531A (short)
- Swift Trigger 1232755: likely consistent with noise and not astrophysical
- LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
- Swift Trigger 1232465: consistent with noise
- GRB 240603B: Swift detection of a possible burst
- GRB 240529A: MASTER prompt OT detection
- GRB 240529A: OSN optical detection
- Swift Trigger 1232465 is not a GRB
- GRB 240529A: AKO Optical Afterglow Follow-Up Observations
- GRB 240529A: 1.3m DFOT Optical observations
- GRB 240529A : Mondy optical observations
- Konus-Wind detection of GRB 240529A
- IPN triangulation of the initial episode of GRB 240529A
- GRB 240529A: MAAO 0.7m telescope optical afterglow detection
- GRB 240529A: Insight-HXMT/HE detection
- GRB 240529A: optical photometry from Konkoly
- GRB 240529A: GROWTH-India optical follow-up
- GRB 240529A: T193/MISTRAL observations
- GRB 240529A: Redshift from GTC/OSIRIS+
- GRB 240529A: AKO Optical Afterglow Detection
- LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
- GRB 240529A: Skynet Optical Observations
- GRB 240529A: Swift-BAT refined analysis
- GRB 240529A: Swift-XRT refined Analysis
- GRB240529A: BOOTES-6/DPRT optical detection
- GRB 240529A: Swift/UVOT Detection
- GRB 240529A: NOT optical observations
- GRB 240529A: AstroSat CZTI detection
- GRB 240529A: GOTO optical afterglow detection
- GRB 240527B: Swift-XRT afterglow detection
- GRB 240529A: Enhanced Swift-XRT position
- GRB 240529A: Swift detection of a burst with an optical counterpart
- Swift GRB240529.12: Global MASTER-Net observations report
- GRB 240527B: Fermi-LAT detection
- 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
- GRB 240513A: Swift-XRT afterglow detection
- GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
- 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 240504A: VZLUSAT-2 detection
- GRB 240516A: Swift/UVOT Upper Limits
- GRB 240516A: Swift-BAT refined analysis
- GRB 240516A ATCA radio observations
- IPN triangulation of GRB 240514B (short)
- GRB 240513A: Swift ToO observations
- 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
- GRB 240516A: Swift detection of a burst
- Swift GRB240516.15: Global MASTER-Net observations report
- GRB 240511A: radio detection of afterglow candidate
- GRB 240514E: MAXI/GSC detection of a probable afterglow
- GRB 240513A: Swift-XRT observations
- 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 240513A: Tiled Swift observations
- GRB 240513A: Fermi-LAT detection
- GRB 240511A: Fermi GBM Observation
- GRB 240511A: Swift-BAT refined analysis