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').
17519 results found.
- GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
- GRB 240819A: Swift ToO observations
- GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
- GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
- EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
- Konus-Wind detection of GRB 240811A
- GRB 240811A: Swift-BAT refined analysis
- GRB 240809A: Swift-BAT refined analysis
- GRB 240811A: Bassano Bresciano Observatory upper limit
- GRB 240811A: Swift-XRT refined Analysis
- GRB 240811A: Swift/UVOT Upper Limits
- GRB 240811A: LCOGT Optical Upper Limit
- GRB 240811A: Enhanced Swift-XRT position
- Konus-Wind detection of GRB 240809A
- Swift GRB 240811A: Global MASTER-Net observations report
- GRB 240811A: Swift detection of a burst
- GRB 240809A: Bassano Bresciano Observatory optical observations
- GRB 240809A: KAIT optical observations
- GRB 240809A: GIT afterglow observations
- GRB 240809A: Swift/UVOT Detection
- GRB 240809A: Swift-XRT refined Analysis
- IPN triangulation of GRB 240807A / EP 240807a
- Swift GRB 240809A: Global MASTER-Net observations report
- GRB 240809A: JinShan optical observations
- GRB 240809A: Enhanced Swift-XRT position
- GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
- GRB 240809A: SVOM/GRM observation
- GRB 240809A: Swift detection of a burst with a bright optical counterpart
- GRB 240805A: ATCA Radio Upper Limits
- GRB 240805B: GIT optical upper limit
- GRB 240805B: Swift-BAT refined analysis
- GRB 240805A: Swift-BAT refined analysis
- Konus-Wind detection of GRB 240805A
- GRB 240805B Bassano Bresciano Observatory upper limit
- GRB240805A: Fermi GBM Observation
- GRB 240805B: JinShan optical afterglow detection
- GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
- GRB 240805B: Swift-XRT refined Analysis
- GRB 240805B: Swift/UVOT Upper Limits
- GRB 240805A: Swift/UVOT Upper Limits
- GRB 240805A: SVOM/GRM observation
- GRB 240805B: Enhanced Swift-XRT position
- GRB 240805B: LCOGT Optical Upper Limits
- Swift GRB 240805B: Global MASTER-Net observations report
- GRB 240805B: JinShan optical upper limits
- Swift GRB 240805A: Global MASTER-Net observations report
- GRB 240805A: Swift-XRT refined Analysis
- GRB 240805B: Swift detection of a burst
- GRB 240805A: Fermi-LAT detection
- GRB 240805A: INTEGRAL spectral analysis
- GRB 240805A: A long GRB detected by INTEGRAL
- GRB 240805A: Swift detection of a burst
- GRB 240730A: Swift-BAT refined analysis
- GRB240730A: BOOTES-5/JGT early optical upper limit
- Swift GRB 240730A: Global MASTER-Net observations report
- GRB 240730A: Swift-XRT refined Analysis
- GRB 240715A: Swift-XRT afterglow detection
- GRB 240730A: KAIT Optical Upper Limit
- GRB 240730A: Swift/UVOT Upper Limits
- GRB 240730A: Enhanced Swift-XRT position
- GRB 240730A: Swift detection of a burst
- GRB 240727A: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
- GRB 240727A: observations of optical counterpart.
- GRB 240727B: Swift-XRT observations
- GRB 240727A: Swift/UVOT detection
- GRB 240727A: NOT optical observation
- GRB 240727A: JinShan optical upper limits
- GRB 240727A Bassano Bresciano Observatory upper limit
- GRB 240727A: Swift-XRT refined Analysis
- GRB 240727A: Enhanced Swift-XRT position
- GRB 240727B: Fermi GBM Observation
- Swift GRB240727.16: Global MASTER-Net observations report
- GRB 240727B: Swift ToO observations
- GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
- GRB240727A: Skynet Optical Afterglow Observations
- GRB 240727A: TRT optical afterglow detection
- GRB 240727A: KAIT Optical Afterglow Candidate
- GRB 240727A: Swift detection of a burst
- Swift Trigger 1244778 is not a GRB
- Swift GRB240725.11: Global MASTER-Net observations report
- GRB 240720A: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S240716b: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240703ad: Upper limits from Swift/BAT-GUANO
- GRB 240720A: AstroSat CZTI detection
- GRB 240720A: Fermi GBM observation
- GRB 240720A: Swift detection of a burst
- Swift GRB240720.02: Global MASTER-Net observations report
- GRB 240718A: Fermi-LAT Detection
- GRB 240712A: Swift-BAT refined analysis
- GRB 240715A: Swift/UVOT observations of the XRT sources.
- GRB 240715A: Swift-XRT observations
- GRB240713A: Swift/UVOT Upper LImits
- EP240708a: X-ray follow-up observations with Swift/XRT
- GRB 240713A: Swift-XRT observations
- GRB 240715A: TRT optical upper limit on one Swift/XRT candidate
- GRB 240712A: Swift-XRT refined Analysis
- GRB 240715A: Swift ToO observations
- GRB 240712A ATCA radio observations
- IPN triangulation of GRB 240715A (short)