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"32494 results found.
- GRB 240529A: 1.3m DFOT Optical observations
- LIGO/Virgo/KAGRA S240527en: Updated Sky localization
- LIGO/Virgo/KAGRA S240601aj: Identification of a GW compact binary merger candidate
- GRB 240529A : Mondy optical observations
- Konus-Wind detection of GRB 240529A
- IPN triangulation of the initial episode of GRB 240529A
- GRB 240529A: SAO RAS optical observations
- LIGO/Virgo/KAGRA S240531bp: Updated Sky localization
- LIGO/Virgo/KAGRA S240531bp: Identification of a GW compact binary merger candidate
- 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 S240530a: Identification of a GW compact binary merger candidate
- GRB 240529A: J-band detections with WINTER
- GRB 240529A: Skynet Optical Observations
- GRB 240529A: Swift-BAT refined analysis
- LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
- GRB 240529A: Swift/UVOT Detection
- GRB 240529A: NOT optical observations
- GRB 240529A: AstroSat CZTI detection
- GRB 240529A: GOTO optical afterglow detection
- LIGO/Virgo/KAGRA S240527fv: Updated Sky localization
- GRB 240527B: Fermi GBM Observation
- Fermi GRB 240527A: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S240527fv: Identification of a GW compact binary merger candidate
- GRB 240527B: Fermi-LAT detection
- LIGO/Virgo/KAGRA S240527en: Identification of a GW compact binary merger candidate
- Fermi GRB 240527B: Global MASTER-Net observations report
- GRB 240523A: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S240525p: Updated Sky localization
- LIGO/Virgo/KAGRA S240525p: Identification of a GW compact binary merger candidate
- GRB 240521B: Fermi GBM Observation
- Fermi GBM Sub-Threshold Detection of GRB 240516B
- GRB 240513A: Swift-XRT afterglow detection
- LIGO/Virgo/KAGRA S240520cv: Updated Sky localization and EM Bright Classification
- EP240518a: GSP optical upper limit
- LIGO/Virgo/KAGRA S240520cv: Identification of a GW compact binary merger candidate
- 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
- EP240518a: possibly identified with a flare star by EP-FXT
- LIGO/Virgo/KAGRA S240514c: Updated Sky localization
- 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
- 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
- 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 240514B: GRBAlpha detection
- LIGO/Virgo/KAGRA S240514x: Updated Sky localization
- LIGO/Virgo/KAGRA S240515m: Identification of a GW compact binary merger candidate
- GRB 240514B: Fermi GBM Detection
- GRB 240513A: Fermi GBM observation
- LIGO/Virgo/KAGRA S240513ei: Updated Sky localization
- LIGO/Virgo/KAGRA S240514x: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate
- Fermi GRB 240514B: Global MASTER-Net observations report
- GRB 240513A: Tiled Swift observations
- GRB 240513A: Fermi-LAT detection
- LIGO/Virgo/KAGRA S240513ei: Identification of a GW compact binary merger candidate
- GRB 240511A: Fermi GBM Observation
- GRB 240511A: Swift-BAT refined analysis
- Fermi GRB 240513B: Global MASTER-Net observations report
- GRB 240511A: J-band observations with WINTER
- GRB 240511A : MITSuME Akeno optical upper limits
- LIGO/Virgo/KAGRA S240512r: Updated Sky localization and EM Bright Classification
- GRB 240511A: optical afterglow detection from the NOT
- LIGO/Virgo/KAGRA S240512r: Identification of a GW compact binary merger candidate
- Fermi GRB 240511A: Global MASTER-Net observations report
- Swift GRB 240511A: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S240511i: Updated Sky localization
- LIGO/Virgo/KAGRA S240511i: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
- LIGO/Virgo/KAGRA S240422ed: Candidates from the latest GW-MMADS DECam Observations
- EP240506a: Xinglong optical upper limit
- EP240506a: CrAO ZTSH optical upper limit
- GRB 240504A: Fermi GBM Observation
- EP240506a: Archival radio searching
- EP240506a: TRT optical upper limit
- LIGO/Virgo/KAGRA S240507p: Updated Sky localization and EM Bright Classification
- EP240506a: Optical upper limit with Kinder observations
- IPN triangulation of GRB 240504A