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"27776 results found.
- GRB 240805A: Fermi-LAT detection
- GRB 240805A: INTEGRAL spectral analysis
- EP240804a: LCOGT optical counterpart detection
- GRB 240805A: A long GRB detected by INTEGRAL
- EP240804a: NOT optical counterpart detection
- EP240804a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
- GRB 240805A: Swift detection of a burst
- GRB 240805A: Fermi GBM Final Real-time Localization
- GRB 240804A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 240802A / EP 240802a
- EP240802a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
- GRB 240802A: AstroSat CZTI detection of a long burst
- EP240801a: GRANDMA and Kilonova-Catcher optical observations
- GRB 240730A: Swift-BAT refined analysis
- EP240801a: GSP follow-up observations of the candidate counterpart
- EP240801a: TRT optical counterpart detection
- EP240801a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
- GRB 240801B: AstroSat CZTI detection of a bright long burst
- GRB 240801A: Fermi GBM Final Real-time Localization
- GRB 240730C: AstroSat CZTI detection of a long burst
- GRB 240731A: Fermi GBM Final Localization
- GRB 240731A: AstroSat CZTI detection
- GRB240730A: BOOTES-5/JGT early optical upper limit
- GRB 240730B: Fermi GBM Final Real-time Localization
- 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 240727C: GRBAlpha detection
- 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: Fermi GBM Final Real-time Localization
- GRB 240727C: AstroSat CZTI detection of a long burst
- GRB 240727A: Swift-XRT refined Analysis
- GRB 240720B: GRBAlpha detection
- GRB 240718A: GRBAlpha detection
- GRB 240710B: GRBAlpha detection
- GRB 240627A: GRBAlpha detection
- GRB 240727A: Enhanced Swift-XRT position
- GRB 240727B: Fermi GBM Observation
- Swift GRB240727.16: Global MASTER-Net observations report
- GRB240529A: VIRT optical transient detection
- GRB 240727B: Swift ToO observations
- GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
- GRB 240727B: AstroSat CZTI detection
- GRB 240726B: AstroSat CZTI detection of a short 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
- GRB 240726A: AstroSat CZTI detection of a short burst
- GRB 240726A: Fermi GBM Final Real-time Localization
- IceCube-240725A - IceCube observation of a high-energy neutrino candidate track-like event
- Swift Trigger 1244778 is not a GRB
- Swift GRB240725.11: Global MASTER-Net observations report
- IceCube-240721A: Two candidates from the Zwicky Transient Facility
- 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
- IceCube-240721A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 240721A: Fermi GBM Final Real-time Localization
- GRB 240720B: AstroSat CZTI detection of a short burst
- 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
- Konus-Wind detection of GRB 240718A
- GRB 240718A: Fermi-LAT Detection
- GRB 240718A: Fermi GBM Final Real-time Localization
- GRB 240712A: Swift-BAT refined analysis
- GRB 240716A: GECAM-B detection of a long burst
- GRB 240713A: 2.2m CAHA optical limit
- 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 240715A: GECAM-C detection of a short burst
- Konus-Wind detection of GRB 240715A
- 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)
- GW s240422ed: Swift UVOT follow-up
- GRB 240712A: Swift/UVOT Upper Limits
- EP-WXT flaring star and the optical flaring activity during its decay phase
- The EP-WXT source triggered on July 14th is likely a flaring star
- GRB 240715A: Fermi GBM Final Real-time Localization
- GRB 240713A: Tiled Swift observations
- GRB 240713A: OHP/T120 optical upper limit