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"32494 results found.
- GRB240805A: Fermi GBM Observation
- GRB 240805B: JinShan optical afterglow detection
- GRB 240804B/EP240804a: Correction to the GRB name in GCN 37071
- GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
- Konus-Wind detection of GRB 240804B (a counterpart of EP240804a)
- EP240806a: EP-FXT detection of the X-ray emission
- GRB 240624B: VZLUSAT-2 detection
- GRB 240619C: VZLUSAT-2 detection
- EP 240806A: LCO optical observations
- GRB 240805B: Optical detection with 1.6m Mephisto
- GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
- GRB 240805B: Swift/UVOT Upper Limits
- GRB 240805A: Swift/UVOT Upper Limits
- GRB 240805B: BTA optical afterglow candidate
- GRB 240805A: SVOM/GRM observation
- GRB 240805B: LCOGT Optical Upper Limits
- Swift GRB 240805B: Global MASTER-Net observations report
- GRB 240805B: JinShan optical upper limits
- EP240801a: BTA BVRI photometry
- Fermi GRB 240805A: Global MASTER-Net observations report
- Swift GRB 240805A: Global MASTER-Net observations report
- GRB 240805A: Fermi-LAT detection
- GRB 240805A: INTEGRAL spectral analysis
- EP240801a: Continued optical observations at ZTSh (CraO)
- EP240804a: VLT/X-shooter spectroscopic redshift
- EP240804a: LCOGT optical counterpart detection
- GRB 240805A: A long GRB detected by INTEGRAL
- EP240804a: NOT optical counterpart detection
- EP240802a: correction of EP-WXT trigger time in GCN 37019
- Fermi GRB 240804A: Global MASTER-Net observations report
- EP240802a: Montarrenti Observatory optical upper limit
- IPN triangulation of GRB 240802A / EP 240802a
- EP240801a: Osservatorio Astronomico Nastro Verde upper limit
- EP240802A: Bassano Bresciano Observatory upper limit
- GRB 240802A: SVOM/GRM observation
- EP240802a: Time coincidence with GRB 240802A and optical upper limits with Kinder observations
- EP240801a: further SAO RAS optical observations
- EP240801a: optical observations at CrAO and AbAO
- EP240801a: GRANDMA and Kilonova-Catcher optical observations
- EP240801a: Leavitt Observatory optical observations
- EP240801a: GTC spectroscopy and absorption redshift
- EP240801a: SAO RAS optical observations
- GRB 240801B: AstroSat CZTI Updated classification - likely a solar flare
- EP240801a: JinShan optical observations
- GRB 240727C: SVOM/GRM observation
- EP240801a: NOT optical observations
- EP240801a: follow-up observation with LCOGT
- Fermi GBM trigger 744179961 / 240801194 can not be confirmed as a GRB
- GRB 240730A: Swift-BAT refined analysis
- EP240801a: GSP follow-up observations of the candidate counterpart
- EP240801a: Kinder follow-up observations of the candidate counterpart
- EP240708a: Kinder follow-up observations of the candidate counterpart (duplicate submission of GCN 37002)
- EP240801a: KAIT optical counterpart observations
- EP240801a: GMG observation
- EP240801a: TRT optical counterpart detection
- Fermi GRB 240801A: Global MASTER-Net observations report
- GRB 240731A: Fermi GBM Final Localization
- GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
- Fermi GRB 240730B: Global MASTER-Net observations report
- Swift GRB 240730A: Global MASTER-Net observations report
- GRB 240715A: Swift-XRT afterglow detection
- GRB 240730A: KAIT Optical Upper Limit
- GRB 240727C: GRBAlpha detection
- GRB 240730A: Swift/UVOT Upper Limits
- 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
- Fermi GRB 240727A: Global MASTER-Net observations report
- GRB 240727A: Swift/UVOT detection
- GRB 240727A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 240727A: NOT optical observation
- GRB 240727A: JinShan optical upper limits
- GRB 240727A Bassano Bresciano Observatory upper limit
- GRB 240727D: Correction to the GRB name in GCN 36958
- GRB 240720B: GRBAlpha detection
- GRB 240718A: GRBAlpha detection
- GRB 240627A: GRBAlpha detection
- Fermi GRB 240726A: Global MASTER-Net observations report
- GRB 240727B: Fermi GBM Observation
- GRB240529A: VIRT optical transient detection
- GRB 240727B: Swift ToO observations
- GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
- GRB 240726A: SVOM/GRM observation
- GRB240727A: Skynet Optical Afterglow Observations
- GRB 240727A: TRT optical afterglow detection
- GRB 240727A: KAIT Optical Afterglow Candidate
- GRB 240726A: AstroSat CZTI detection of a short burst
- IceCube-240725A: Upper limits from a search for additional neutrino events in IceCube
- Fermi-LAT gamma-ray observations of IceCube-240725A
- IceCube-240721A: Two candidates from the Zwicky Transient Facility
- GRB 240720A: Swift-BAT refined analysis
- IceCube-240721A: Upper limits from a search for additional neutrino events in IceCube
- Fermi-LAT gamma-ray observations of IceCube-240721A
- Fermi Gamma-ray Burst Monitor trigger 743243582/240721356 (GRB 240721A) is not a GRB
- GRB 240720B: SVOM/GRM observation
- Fermi GRB 240720A: Global MASTER-Net observations report
- GRB 240720A: AstroSat CZTI detection
- GRB 240720A: Fermi GBM observation
- Konus-Wind detection of GRB 240718A