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"27450 results found.
- GRB 130305A: P60 Observations
- GRB 100615A: HST host detection and X-shooter redshift
- GRB 130305A: Swift/XRT detection of the afterglow
- Konus-Wind observation of GRB 130305A
- GRB 130305A: Fermi GBM observation
- GRB 130305A: Fermi LAT Detection
- Fermi GBM trigger 130301.638 is not GRB
- GBM trigger 383712005 (GRB 130228A?) : Possible high-energy photon emission in Fermi/LAT data
- GRB 130305A found in ground analysis of Swift/BAT data
- GRB 121128A: optical observations in Mondy observatory
- GRB 130216A: Swift/UVOT Upper Limit
- SGR 1806-20 outburst (trigger 549841), Swift-BAT refined analysis
- Trigger 549841: Swift detection of SGR1806-20
- GRB 130216A: possible radio counterpart is steady field source
- GRB 130216A: Swift/XRT observations
- IPN Triangulation of GRB 130219A
- GRB 130215A: PTF P48 optical detection
- GRB 130219A: Fermi GBM detection
- GRB 130216B: Swift/XRT observations
- GRB 130216A: Further Swift-BAT refined analysis
- GRB 130215A: Continued RATIR Optical and NIR Monitoring
- GRB 130216A: Fermi GBM observation
- GRB 130216B: Fermi GBM observation
- GRB 130216A: possible early detection at 15 GHz
- GRB 130216A: MITSuME Ishigakijima upper limits
- GRB 130216B BAT refined analysis
- GRB 130216B: P200 NIR Observations
- GRB 130216A: P200 NIR Observations
- GRB 130216A: Swift-BAT refined analysis
- GRB 130216A: TAROT La Silla observatory optical observations
- GRB 130216B: Burst found in ground analysis of BAT data
- GRB 130216A: OSN I-band observations
- GRB 130216A: Swift detection of a burst
- GRB 130215A: GROND Detection of the Optical/NIR Afterglow
- GRB 130215A: Fermi GBM detection
- GRB 130215A: RAPTOR Measurements
- GRB 130215A: Xinglong optical observations
- GRB 130215A: Swift-BAT refined analysis
- GRB 130215A: TAROT La Silla observatory optical observations
- GRB 130215A: RATIR Optical and NIR Observations
- GRB 130215A: P60 Observations
- GRB 130215A: ROTSE-III data analysis
- GRB 130215A: Redshift estimate
- Skynet Observations of GRB130215
- GRB 130215: ROTSE-III Detection of Optical Counterpart
- GRB 130215A: Swift detection of a burst
- Swift GRB130206A: late XRT observations.
- GRB 130131B: CTIO 0.9-m optical upper-limits
- GRB 130211A: Swift/UVOT Upper Limits
- GRB 130211A: Swift-XRT refined Analysis
- GRB 130211A: Swift-BAT refined analysis
- GRB 130211A: GROND detection of the afterglow
- GRB 130211A: Swift detection of a burst
- GRB 130122A: PTF P48 optical upper limits
- GRB 130206A: GROND Observations
- GRB 130206A: Fermi LAT Observations
- GRB 130206A: Fermi GBM observation
- GRB 130206A: XRT and UVOT follow-up observations.
- GRB 130206A, Swift-BAT refined analysis
- GRB 130206A: Zadko observatory - Gingin optical observations
- Swift GRB 130206A - analysis of Swift/UVOT initial data.
- GRB 130206A: Swift-XRT observations
- GRB 130131A: optical observation in Mondy observatory
- GRB 130206A: Swift detection of a burst
- GRB 130131A: Swift/UVOT Upper Limits
- GRB 130131B: RATIR Upper Limits
- GRB 130131A: RATIR optical and infrared upper limits
- GRB 130131A: RAPTOR Limits During Gamma-Ray Emitting Interval
- GRB 130131B: Swift-XRT refined Analysis
- GRB 130131B: GROND Upper limits
- GRB 130131B: Swift/UVOT Upper Limits
- GRB 130131A: Swift-XRT refined Analysis
- GRB 130131B: Swift-BAT refined analysis
- GRB 130131A: Swift-BAT refined analysis
- GRB 130131B: TAROT Calern observatory optical observations
- GRB 130131B: Zadko observatory - Gingin optical observations
- GRB 130131B: Swift detection of a burst
- GRB 130131A - Faulkes Telescope North Observations
- GRB 130131A - UKIRT afterglow candidate
- GRB 130131A: Swift detection of a burst
- Swift/BAT trigger 547142 is new source Swift J1753.7-2544
- GRB 130127A: Fermi GBM detection
- Swift Trigger 547142: MAXI/GSC upper limit
- Swift Trigger 547142: a probable Galactic source
- GRB 130122A: Swift/UVOT Detection
- GRB 130122A: RATIR Detection
- GRB 130122A: Swift-BAT refined analysis
- GRB 130122A: Swift-XRT refined Analysis
- GRB 130122A: Xinglong optical upper limit
- GRB 130122A: T100 observations
- GRB 130122A: Swift detection of a burst with an optical counterpart
- GRB 130102B: MASTER synchronous observations
- GRB 130102A: Swift/UVOT Upper Limits
- GRB 130102A: P60 Observations
- GRB 130102A: Swift-BAT refined analysis
- GRB 130102A: Swift-XRT refined Analysis
- GRB 130102A: Swift detection of a burst
- Swift Trigger 544381 is a noise event
- GRB 121229A: Swift-XRT refined Analysis
- GRB 121229A, Swift-BAT refined analysis