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"
- Konus-Wind observation of GRB 060121
- GRB 060121: I-band Limits
- GRB 060121: Confirmation of Afterglow
- GRB 060121: candidate optical counterpart
- GRB 060121: Swift XRT refined position
- GRB060121: SARA Observations
- GRB 060121: optical observations
- GRB 060121: Infrared Observations
- GRB 060121: optical observations
- GRB 060121: Optical imaging
- GRB060121 - SDSS pre-burst observations
- GRB 060121: A short-hard GRB in a cluster?
- GRB 060121 (=H4010): Results of preliminary spectral analysis
- GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
- GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
- HETE Alert 4006: MASTER promt optical limit
- GRB 060117: PROMPT Observations
- GRB060117 - ATCA 3/6cm radio limits - correction
- GRB060117 - ATCA 3/6cm radio limits
- GRB 060116: photometric redshift - the farthest GRB?
- GRB 060117: pseudo-z from spectral parameters of the prompt emission
- Correction to GCN 4542 on GRB 060117
- Konus-Wind observation of GRB 060117
- GRB 060116: possible I-J dropout
- GRB 060116: UKIRT IR Observations
- GRB060108: photometric redshift determination
- GRB 060117: Refined analysis of the Swift-BAT burst
- GRB 060116: PROMPT Observations
- GRB 060117: FRAM refined analysis
- GRB 060117: FRAM optical afterglow candidate
- GRB 060117: nearby galaxy
- GRB 060117: Swift-BAT detection of a bright burst
- GRB 060116: VLT optical observations
- GRB 060116: Refined analysis of the Swift-BAT burst
- GRB 060115: PROMPT Observations
- GRB 060116: XRT refined analysis
- GRB 060116: IR Candidate Afterglow
- GRB 060116: Swift/UVOT upper limits
- GRB060115: REM observations
- GRB 060110: XRT position and analysis
- GRB 060116 : Lulin optical limit
- GRB 060116: ROTSE-III Optical Limits
- GRB060116: XRT position
- GRB060116: Faulkes North observation
- GRB 060115: absorption redshift
- GRB 060116: Swift-BAT detection of a burst
- GRB 060115: Refined analysis of the Swift-BAT burst
- GRB 060115: OT photometry with MITSuME
- GRB 060115: Swift/UVOT upper limits
- GRB 060114: REM observations
- GRB 060115: Swift XRT refined analysis
- GRB 060115: OT finding chart
- GRB 060114: Swift/UVOT Observations
- GRB060115, optical observation
- GRB 060115: MITSuME optical afterglow candidate
- GRB 060115: Swift detection of a burst
- GRB 060114: Swift XRT upper limit
- GRB060114, optical observation
- GRB 060114: refined position
- GRB 060114: A long GRB detected by INTEGRAL
- GRB060114: Faulkes North observation
- GRB 060108: IR observations of afterglow
- GRB060108: Faulkes North afterglow evidence
- GRB 060108: further analysis of VLT images
- GRB 060108: Evidence for an XRT Position Offset
- GRB 060110: KAIT observations
- GRB 060111B: Swift XRT refined analysis
- GRB 060111A: refined UVOT anaysis
- GRB 060111B: MITSuME detection of optical afterglow
- GRB 060111B: TAROT optical observation
- GRB060111A: RTT150 optical observations
- GRB060111B: RTT150, possible host galaxy
- GRB 060111B: Refined analysis of the Swift-BAT burst
- GRB 060110: MARGE observations
- GRB 060111(a): P60 Observations
- GRB 060111B: Gualba observatory limit
- GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
- GRB 060111B: Swift detection of a burst
- GRB 060111: Swift-BAT Refined Analysis
- GRB060111.2:_MASTER optical limit
- GRB 060108: VLT K-band observations
- GRB 060111: TAROT optical observation
- GRB 060111: possible UVOT counterpart
- GRB060111 : XRT refined analysis
- GRB 060111: ROTSE-III Optical Limits
- GRB 060111: Swift detection of a burst
- GRB 060110: Mitsume optical observations
- GRB 060110: Swift-BAT refined analysis
- GRB 060109: Swift-BAT refined analysis
- GRB 060108: z-band imaging from Gemini-North
- GRB 060110a: RAPTOR detection of early optical emission.
- GRB 060110: UKIRT K-band observations
- GRB 060110: ROTSE-III Confirmation of Optical Counterpart
- GRB 060110: IR Candidate Afterglow
- GRB060110, optical observation
- GRB 060110: Super-LOTIS observations
- GRB 060110: Optical observation
- GRB 060110: Correction
- Correction to GRB 060109 XRT analysis
- GRB 050110: IR Observations