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"35947 results found.
- GRB 230808A: Fermi GBM Detection
- GRB 230805B: Swift-BAT refined analysis
- GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
- GRB 230805B: AstroSat CZTI detection
- GRB 230808A: Swift/BAT-GUANO detection of a burst
- GRB 230808B: Fermi GBM Final Real-time Localization
- ZTF23aaoohpy/AT2023lcr: JWST observations consistent with the presence of a supernova
- GRB 230808A: Fermi GBM Final Real-time Localization
- GRB 230805B : MITSuME Akeno optical upper limits
- Fermi GRB 230807A: Global MASTER-Net observations report
- GRB 230807A: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S230805x: Upper limits from Swift/BAT-GUANO
- Konus-Wind detection of GRB 230803A
- GRB 230805B: Fermi GBM observation
- GRB 230805B : OHP/T193 optical upper limit
- GRB 230806A: Fermi GBM Final Localization
- GRB 230805B: Enhanced Swift-XRT position
- GRB 230805B: Swift/UVOT Upper Limits
- GRB 230805B: Bassano Bresciano observatory upper limit
- GRB 230805B: BOOTES-6/DPRT optical upper limit and 1.5m OSN detection
- GRB 230805B: NOT optical afterglow confirmation
- GRB 230805B: Swift-XRT refined Analysis
- Fermi GRB 230805A: Global MASTER-Net observations report
- GRB 230805B: SAO RAS optical observations
- Swift GRB 230805B: Global MASTER-Net observations report
- GRB 230805B: Swift detection of a burst
- GRB 230805A: Fermi GBM Final Real-time Localization
- GRB 230802B: AstroSat CZTI detection
- GRB 230802A: Fermi GBM observation
- GRB 230802A: Swift-BAT refined analysis
- GRB 230804A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 230803A
- GRB 230802A: Swift/UVOT Upper Limits
- GRB 230803A: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S230802aq: AstroSat CZTI non-detection and upper limits
- GRB 230803A: Fermi GBM Final Real-time Localization
- GRB 230802B: Fermi GBM Final Localization
- Swift GRB 230802A: Global MASTER-Net observations report
- GRB 230802A: BOOTES-5/JGT optical upper limit
- LIGO/Virgo/KAGRA S230802aq: Upper limits from Fermi-GBM Observations
- GRB 230802A: Swift-XRT refined Analysis
- GRB 230802A: Enhanced Swift-XRT position
- LIGO/Virgo S230802aq: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- GRB 230802A: Swift detection of a burst
- LIGO/Virgo/KAGRA S230731an: Upper limits from Swift/BAT-GUANO
- GRB 230723A: SPT-3G millimeter-band transient event inconsistent with IPN position
- LIGO/Virgo/KAGRA S230731an: AstroSat CZTI non-detection and upper limits
- GRB 230731A: Fermi GBM Final Real-time Localization
- GRB 230723A: Detection of candidate millimeter-band radiation by SPT-3G
- GRB 230728A: Swift-BAT refined analysis
- GRB 230723B: Swift-BAT refined analysis
- GRB 230723B: MITSuME Ishigaki optical observation
- GRB 230728A: BOOTES-1 optical upper limit
- GRB 230728A: Fermi GBM Observation
- GRB 230728A: LCOGT Optical Upper Limit
- GRB 230728A: Swift/UVOT Upper Limits
- GRB 230728A: Swift-XRT refined Analysis
- GRB 230728A: Enhanced Swift-XRT position
- GRB 230728A: NOT optical observations and possible host galaxy
- GRB 230727A: AstroSat CZTI detection
- GRB 230728A: Swift detection of a burst
- GRB 230727A: Swift/BAT-GUANO detection of a burst
- GRB 230727A: Fermi GBM Final Real-time Localization
- GRB 230723B: Further CAHA observations and host galaxy detection
- Konus-Wind detection of GRB 230723A
- GRB 230723B: MITSuME Akeno optical afterglow candidate detection
- GRB 230723B: ATCA rapid radio follow-up
- IBAS trigger number 10337: not a real GRB
- GRB 230723B: GAD Observatory, La Spezia, Italy upper limit
- IPN triangulation of GRB 230723A (short)
- Fermi Gamma-ray Burst Monitor trigger 711982704/230725540 is not a GRB
- GRB 230725B: Fermi GBM Final Real-time Localization
- GRB 230725A: Fermi GBM Final Real-time Localization
- GRB 230723B: Leavitt Observatory upper limit
- GRB 230723B: Osservatorio Astronomico Nastro Verde upper limit
- GRB 230723B: Montarrenti Observatory upper limit
- GRB 230723B: Optical afterglow candidate from CAHA
- GRB 230723B: Bassano Bresciano Observatory upper limit
- GRB 230723B: Fermi GBM observation
- GRB 230723B: Swift-XRT refined Analysis
- GRB 230723B: non-detections from Observatoire de Haute-Provence
- GRB 230724A: Fermi GBM Final Real-time Localization
- GRB 230723B: Optical limit from CAHA
- GRB 230723B: Swift/UVOT Upper Limits
- Swift GRB 230723B: Global MASTER-Net observations report
- Swift-XRT position for GRB 230723B
- GRB 230723A: AGILE/MCAL detection
- GRB 230723B: Swift-XRT observations
- GRB 230723B: Swift detection of a burst
- Fermi GRB 230723A: Global MASTER-Net observations report
- GRB 230723A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 230715D
- Swift Trigger 1180063 is not a GRB
- Swift Trigger 1180060 is not a GRB
- Swift Trigger 1180055 is not a GRB
- GRB 230718A: Final Localization Correction
- GRB 230718A: Fermi GBM Final Real-time Localization
- Fermi Gamma-ray Burst Monitor trigger 711329677/230717982 is not a GRB
- IPN triangulation of GRB 230712C (short)
- IPN triangulation of GRB 230712A (short)