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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"- GRB 100728A: Skynet/PROMPT Detections
- GRB 100728A: KAIT optical afterglow detection
- GRB 100728A: Fermi GBM observation
- GRB 100728A: Enhanced Swift-XRT position
- GRB 100728A: Swift detection of a burst
- GRB 100727A: Swift XRT refined analysis
- GRB 100727A: Fermi GBM observation
- GRB 100727A, Swift-BAT refined analysis
- GRB 100727A: Enhanced Swift-XRT position
- GRB100727A: MOA optical upper limit
- GRB 100727A: Swift detection of a burst
- GRB100725B: MITSuME optical upper limits
- GRB 100724B: AGILE/GRID analysis
- GRB 100724B: Suzaku WAM observation of the prompt emission
- GRB 100724B: gamma-ray detection by AGILE
- GRB 100725B: Swift-BAT refined analysis
- GRB 100725B: refined XRT analysis
- GRB 100725A: GROND upper limits
- GRB 100725B: Swift/UVOT Upper Limits
- GRB 100725A: Swift/UVOT Upper Limits
- GRB 100725A: Swift-BAT refined analysis
- GRB 100725A: Swift XRT refined analysis
- GRB 100725B: Enhanced Swift-XRT position
- GRB 100725A: Enhanced Swift-XRT position
- GRB100725B: Faulkes Telescope North observations
- GRB 100725B: Swift detection of a burst
- GRB100725A Faulkes Telescope South observations
- Konus-Wind observation of GRB 100724B
- GRB 100725A: Prompt enhanced Swift-XRT position
- GRB 100725A: Swift detection of a burst
- GRB 100724B: Fermi LAT and GBM analysis
- GRB 100724B: Fermi GBM detection
- GRB 100724A: Swift/BAT spectral lag results
- GRB 100724A: Swift XRT refined analysis
- GRB 100724A: Enhanced Swift-XRT position
- GRB 100724A: Swift/UVOT observations
- GRB 100724A: Swift-BAT refined analysis
- GRB 100724A: X-shooter redshift
- GRB 100724A: fading afterglow seen with GROND
- GRB 100724A, GROND detection of an afterglow candidate
- GRB 100724A: Swift detection of a burst
- GRB 100614A: 10.4-m GTC deep-optical limit
- GRB 100722A: Fermi GBM detection
- GRB 100718A: MASTER-Net optical prompt and alert observations
- GRB 100719A: Swift-BAT refined analysis
- GRB 100719A: Swift detection of a burst
- GRB 100713A: optical observation in Maidanak
- GRB 100713A: further inspection of TNG images
- GRB 100713A: Swift XRT refined analysis
- GRB 100713A : IRSF/SIRIUS NIR upper limits
- Fermi GBM trigger 300794561 (100714419) is not a GRB
- GRB100713A: Swift/UVOT observations
- GRB 100713A: GROND upper limits
- GRB 100713A: optical upper limit
- GRB 100713A: TNG optical observations
- GRB 100713A: TELMA and 1.5m OSN optical observations
- GRB100713A: Swift X-ray afterglow detection
- GRB 100713A: a long GRB detected by INTEGRAL
- GRB 100707A: Suzaku WAM observation of the prompt emission
- Fermi GBM trigger 300370702 (100709513) is not a GRB
- Konus-Wind observation of GRB 100707A
- IPN triangulation of GRB 100707A
- GRB 100628A: Keck/LRIS Spectroscopy of Host Galaxy Candidate
- GRB 100707A: Fermi LAT detection
- GRB 100707A: Fermi GBM detection
- GRB 100628A: Near-IR sources coincident with the possible X-ray afterglow
- GRB 100628A: Chandra observations
- GRB 100628A: Swift XRT/UVOT refined analysis
- Tentative redshift of GRB100704A from Swift-XRT data
- Konus-Wind observation of GRB 100701B
- IPN triangulation of GRB 100701B
- Konus-Wind observation of GRB 100704A
- GRB 100703A: a short GRB detected by INTEGRAL
- GRB 100704A: Swift XRT refined analysis
- GRB 100704: Swift/UVOT Upper Limits
- GRB 100704A: Fermi GBM observation
- GRB 100704A: Swift-BAT refined analysis
- GRB100704A: MOA optical upper limit
- GRB 100704A: Enhanced Swift-XRT position
- GRB 100704A: Swift detection of a burst
- GRB 100615A: Additional Gemini/NIRI observations
- GRB 100526A: Gemini/NIRI afterglow confirmation and host galaxy
- GRB 100702A, Swift-BAT refined analysis
- Fermi GBM trigger 299767472 (100702531) is not a GRB
- GRB 100702A: Swift XRT refined analysis
- Swift/UVOT observations of GRB100702A - correction
- Swift/UVOT observations of GRB100702A
- GRB 100702A: Second epoch of Magellan near-IR observations and afterglow limits
- GRB 100701B: Fermi GBM detection
- GRB 100702A: Magellan near-IR observations
- GRB 100702A: VLT optical observations
- GRB 100702: ROTSE-III Optical Limits
- GRB 100702A: Swift detection of a short burst
- GRB 100615A: Chandra X-ray ToO Observation
- XRF 100701A : MAXI/GSC detection of a probable XRF
- GRB 100213B: Detection of Fading Optical Afterglow
- GRB 100625A: Fermi GBM detection
- GRB 100628A: Second epoch of Magellan near-IR observations
- GRB 100628A: GROND optical/NIR observations of the host candidate
- GRB 100628A: Gemini North Observations