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"11070 results found.
- GRB051006: Refined analysis of the Swift-BAT burst
- GRB 051006: XRT position
- GRB051006: Swift detection of a burst
- GRB 051001: Swift XRT refined analysis
- GRB 051001: AAT infra-red observations
- GRB 051001: ROTSE-III Optical Limits
- GRB050922C: optical observation
- GRB050922C: UVES/VLT high resolution spectroscopy
- GRB050925: Swift/XRT limits
- GRB050925: Swift-BAT detection of a short burst
- GRB 050922B: Correction to BAT refined analysis, longer burst
- Konus-Wind observation of GRB 050922C
- GRB050922C: Optical Observations
- GRB 050922C: Swift XRT refined analysis
- GRB 050922C: optical obserations
- GRB 050922C: ROTSE-IIId Refined Analysis
- GRB 050922B: ROTSE-III Optical Limits
- Possible GRB 050922 detected by INTEGRAL
- GRB050820B: analysis of the XMM-Newton observation
- GRB050916: Swift/UVOT Upper Limits
- GRB 050918 - A long GRB detected by INTEGRAL
- Swift-BAT trigger 155535 is definitely not a GRB
- GRB 050916: XRT position
- GRB050916: Swift-BAT detection of a long weak burst
- GRB 050915B: XRT position
- GRB050915B: Swift-BAT detection of a long bright burst
- GRB 050915: Swift-BAT refined analysis
- GRB050915: P60 Optical Observations
- GRB 050915: ROTSE-III optical limits
- Swift is in normal operation
- GRB 050911: Swift-BAT refined analysis
- GRB 050911: z~0.16 cluster in the field
- GRB050911: Swift-BAT detection of a long burst
- GRB 050910a: TAROT early optical limits
- GRB 050906: Possible X-ray Counterpart
- GRB 050908: Swift-BAT refined analysis
- GRB 050908: Optical observations
- GRB 050908: Prompt PROMPT Observations
- Swift trigger 154073 is not a GRB
- GRB050904: CrAO optical observations
- GRB 050906: Radio Observations
- GRB 050906: Bright galaxy in BAT error box
- GRB 050904: Swift/UVOT observations
- GRB 050904: early Swift XRT analysis results
- GRB 050827: P200 NIR Observations
- GRB050824, HETE-2 Observation
- GRB050824: decay of the XRT light curve and updated X-ray spectrum
- GRB050824, I-band imaging
- GRB 050822: refined XRT analysis
- GRB 050824: XRT refined analysis and possible afterglow detection
- GRB 050824: ROTSE-III Optical Limits
- GRB050820A: RTT150 optical observations
- GRB 050822: Swift-BAT refined analysis
- GRB050820A: RTT150 optical observations
- GRB 050820a - corrections to GCN 3846
- GRB 050822: ROTSE-III Prompt Optical Limits
- GRB050820B: BAT-Swift detection of a bright GRB
- GRB 050820: High Resolution Spectroscopy from Keck
- GRB 050820: Swift detection of a GRB
- Swift-BAT trigger 150993 is not a GRB
- GRB 050815: ROTSE-III Optical Limits
- GRB050814: Fading red source
- GRB050814: P60 Optical Afterglow Candidate
- GRB 050814: XRT refined analysis
- GRB050814: Refined analysis of the Swift-BAT burst
- GRB 050814: Swift XRT Afterglow Localization
- GRB050813: RTT150 optical observations
- GRB 050813: KAIT optical limit
- GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
- Ongoing activity of SGR 1806-20: an intermediate burst 050811
- Detection of an intermediate burst from SGR 1806-20 on August 8
- GRB 050807: ROTSE-III Optical Limits
- GRB050803, optical observations
- Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
- GRB 050803: RTT150 optical observations
- GRB050803: CrAO optical observations, possible OT candidate
- GRB 050803: Swift-BAT refined analysis
- GRB050803: MASTER further analys
- GRB 050803: early Swift XRT analysis results
- GCN GRB observation 050713A
- GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
- GRB050802: CrAO optical observations
- GRB 050802: Swift Gamma-ray Burst
- GRB 050801: Swift-BAT refined analysis
- GRB 050730, corrected photometry and break?
- GRB050730: Refined BAT analysis of the Swift-BAT burst
- GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
- GRB050730: Liverpool Telescope optical observations
- GRB 050730, optical candidate
- GRB050730: Swift-BAT detection of a weak burst
- GRB050713b: Maidanak optical observations
- GRB 050724: Chandra Observations of the X-ray Afterglow
- GRB 050724, SMARTS optical/IR afterglow observations
- GRB 050726, SMARTS optical/IR observations
- GRB 050724: J-band observations
- GRB 050724: SWIFT XRT refined position
- GRB050721A: Swift-BAT detection of a weak burst
- GRB 050712, Tautenburg optical afterglow observations
- Konus-Wind observation of GRB 050717
- Swift detection of GRB 050717