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.
- GRB230618A: LCOGT Optical Observations
- GRB 230618B: Fermi GBM Final Real-time Localization
- GRB 230618A: Prompt enhanced Swift-XRT position
- GRB 230618A: Swift detection of a burst
- GRB 230616A: Swift ToO observations
- GRB 230617A: Fermi GBM Final Real-time Localization
- GRB 230614C: GRBAlpha detection
- GRB 230616A: AstroSat CZTI detection
- GRB 230616A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
- GRB 230614C: AstroSat CZTI detection
- GRB 230614B: Fermi GBM Observation
- GRB 230614C: Fermi GBM Detection
- GRB 230614B: Swift/BAT-GUANO detection outside the coded FOV
- GRB 230614B: Fermi GBM Final Real-time Localization
- GRB 230614A: Fermi GBM Final Real-time Localization
- GRB 230606A: LCOGT Optical Observations
- GRB 230608A: CALET Gamma-Ray Burst Monitor detection
- GRB 230608A: AstroSat CZTI detection
- GRB 230608A: AGILE detection
- Fermi GRB 230603A: Global MASTER-Net observations report
- GRB 230506B: Chandra localization of the X-ray afterglow
- GRB 230606A: Swift-BAT refined analysis
- GRB 230606A: Gaoyazi/GOT optical upper limit
- GRB 230606A: Fermi GBM Observation
- GRB 230606A: BOOTES-5/JGT optical upper limit
- GRB 230606A: Swift-XRT refined Analysis
- GRB 230604A: GRBAlpha detection
- GRB 230606A: Swift/UVOT Upper Limits
- GRB 230606A: Enhanced Swift-XRT position
- GRB 230606A: Swift detection of a burst
- GRB 230604A: AstroSat CZTI detection of a short GRB
- GRB 230603A: Fermi GBM Final Real-time Localization
- GRB 230521A: VZLUSAT-2 detection
- GRB 230522A: GRBAlpha and VZLUSAT-2 joint detection
- GRB 230525A: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo/KAGRA S230529ay: Upper limits from Fermi-GBM Observations
- LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- GRB 230529A: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S230518h: Upper limits from Glowbug gamma-ray observations
- GRB 230510A: Swift-BAT refined analysis
- GRB 230525A: Fermi GBM Detection
- GRB 230525A: Fermi GBM Final Localization
- GRB 230523B: GRBAlpha detection
- GRB 230524A: Fermi GBM Observation
- GRB 230524B: AstroSat CZTI detection
- GRB 230524A: AstroSat CZTI detection
- GRB 230524A: AGILE detection
- GRB 230524A: Fermi GBM Final Real-time Localization
- GRB 230523B: Name correction from GCN Circular 33859
- GRB 230523A: Swift/BAT-GUANO detection of a short hard burst
- Fermi Gamma-ray Burst Monitor trigger 706536788/230523509 is not a GRB
- GRB 230523A: Fermi GBM Final Real-time Localization
- GRB 230518B: VZLUSAT-2 detection
- Fermi Gamma-ray Burst Monitor trigger 706338208/230521211 is not a GRB
- IPN triangulation of GRB 230518A (short)
- GRB 230520A: CALET Gamma-Ray Burst Monitor detection
- GRB 230521A: Fermi GBM Final Real-time Localization
- GRB 230520B is not a GRB
- GRB 230520B: Fermi GBM Final Real-time Localization
- GRB 230520A: MAXI/GSC detection
- GRB 230518A: Fermi GBM Observation
- LIGO/Virgo/KAGRA S230518h: Upper limits from Konus-Wind observations
- GRB 230518A: Swift/BAT-GUANO detection
- GRB 230518A: Fermi GBM Final Real-time Localization
- Fermi Gamma-ray Burst Monitor trigger 706068974/230518095 is not a GRB
- LIGO/Virgo/KAGRA S230518h: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- GRB 230513A: Zwicky Transient Facility continuous observations of a Fermi Short GRB (Trigger 705709044)
- GRB 230510B: GRBAlpha detection
- GRB 230517A: BALROG localization (Fermi Trigger 706014351 / GRB 230517462)
- Improved IPN triangulation of GRB 230512A
- GRB 230517A: Fermi GBM Final Real-time Localization
- GRB 230510B: Fermi GBM detection
- GRB 230516A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 230511D (short)
- IPN triangulation of GRB 230512A
- GRB 230513A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
- GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate
- GRB 230512A: Zwicky Transient Facility non-detection of GRB afterglow candidate
- GRB 230512A: Liverpool Telescope observations
- GRB 230512A: GIT non detection of afterglow candidate
- GRB 230512A: Kitab possible afterglow candidate
- GRB 230512A: GRBAlpha detection
- GRB 230510A: GRBAlpha detection
- GRB 230513A: Fermi GBM Final Real-time Localization
- GRB 230510A: OHP/T193 and OHP/T120 optical observations
- GRB 230512A: Swift-XRT observations
- GRB 230512A: GIT optical follow-up ZTF candidates
- GRB 230512A: Fermi GBM detection
- GRB 230512A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705565670)
- GRB 230430A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 704533643)
- GRB 230511D: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705537623)
- GRB 230512A: Tiled Swift observations
- GRB 230512A: Fermi-LAT detection
- GRB 230512A: AstroSat CZTI detection
- GRB 230512A: Fermi GBM Final Localization
- GRB 230510A: GIT optical upper limits
- GRB 230510A: LCOGT Optical Upper Limit
- GRB 230511D: Fermi GBM Final Real-time Localization
- GRB 230510A: Swift/UVOT Observations