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"11756 results found.
- GRB 240727A: Swift detection of a burst
- GRB 240726A: AstroSat CZTI detection of a short burst
- Fermi-LAT gamma-ray observations of IceCube-240725A
- IceCube-240721A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S240716b: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240703ad: Upper limits from Swift/BAT-GUANO
- Fermi-LAT gamma-ray observations of IceCube-240721A
- Fermi trigger No 743219692: Global MASTER-Net observations report
- IceCube Alert 240721.68: Global MASTER-Net observations report
- GRB 240720B: AstroSat CZTI detection of a short burst
- Fermi GRB 240720A: Global MASTER-Net observations report
- 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
- Fermi GRB 240718A: Global MASTER-Net observations report
- LAT GRB240718.27: Global MASTER-Net observations report
- GRB 240718A: Fermi-LAT Detection
- GRB 240712A: Swift-BAT refined analysis
- GRB 240716A: GECAM-B detection of a long burst
- Fermi-LAT gamma-ray observations of IceCube-cascade-240714A
- GRB 240715A: Swift-XRT observations
- Konus-Wind detection of GRB 240715A
- IPN triangulation of GRB 240715A (short)
- The EP-WXT source triggered on July 14th is likely a flaring star
- GRB 240713A: JinShan optical upper limits
- GRB 240713B: AstroSat CZTI detection of a long burst
- LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
- EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
- EP240708a: EP-WXT detection of a fast X-ray transient
- LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
- Konus-Wind detection of GRB 240627A
- EP240703a and EP240703b: Swift/XRT upper limits
- EP240703a: BTA observations
- EP240703c: EP-WXT detection of an X-ray transient
- EP240703b: EP-WXT detection of a fast X-ray transient
- Konus-Wind detection of GRB 240703A (a counterpart of EP240703a)
- EP240702a: Swift/XRT upper limit
- Fermi GRB 240702A: Global MASTER-Net observations report
- EP240702a: EP-WXT detection of a fast X-ray transient
- LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
- Fermi trigger No 741356809: Global MASTER-Net observations report
- Fermi GRB 240629A: Global MASTER-Net observations report
- Fermi trigger No 741296200: Global MASTER-Net observations report
- GRB 240627A: NuSTAR Detection of the long GRB
- GRB 240615A: SAI CMO J- band observations
- GRB 240627A: AstroSat CZTI detection
- EP240625a: GRANDMA Optical Upper Limits
- Konus-Wind detection of GRB 240619A
- EP240625a: NOT optical counterpart candidate
- EP240625a: EP-FXT detection of the X-ray emission
- EP240625a: EP-WXT detection of a fast X-ray transient
- LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
- Fermi trigger No 740949590: Global MASTER-Net observations report
- EP240618a: NOT optical counterpart candidate
- LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
- GRB 240619C: NuSTAR automated detection of the GRB
- GRB 240615A: NOT optical observations
- GRB 240619C: AstroSat CZTI detection
- Fermi trigger No 740474239: Global MASTER-Net observations report
- EP240618a: BOOTES-6/DPRT optical upper limit
- LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
- Fermi trigger No 740430582: Global MASTER-Net observations report
- GRB240615A: 1.3m DFOT optical upper limit
- LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
- Konus-Wind detection of GRB 240615A (short/hard)
- Fermi trigger No 740166710: Global MASTER-Net observations report
- Konus-Wind detection of GRB 240607A
- Fermi GRB 240610A: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 739632045/240609556 is not a GRB
- Konus-Wind detection of GRB 240606B
- Fermi trigger No 739506569: Global MASTER-Net observations report
- GRB 240607A: AstroSat CZTI detection of bright long burst
- GRB 240606B: GECAM-B detection a long burst
- Fermi trigger No 739373591: Global MASTER-Net observations report
- GRB 240606B: Swift-XRT afterglow detection
- Konus-Wind detection of GRB 240603A
- Fermi GRB 240604A: Global MASTER-Net observations report
- GRB 240604A: GECAM detection of a long burst
- Fermi GRB 240603C: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
- GRB 240529A: MASTER prompt OT detection
- GRB 240603A: GECAM detection of a short burst
- Fermi GRB 240602A: Global MASTER-Net observations report
- GRB 240529A: further SAO RAS optical observations
- Swift Trigger 1232465 is not a GRB
- GRB 240529A: 1.3m DFOT Optical observations
- GRB 240531A: AstroSat CZTI detection of a short burst
- Konus-Wind detection of GRB 240529A
- LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
- GRB 240529A: Skynet Optical Observations
- LXT 240528A: LEIA detection of a fast X-ray transient