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"27392 results found.
- GRB 060502B MDM Follow-up Observation
- GRB 060502b: Gemini imaging and spectroscopy
- GRB060502A, optical observation
- GRB 060502B: Swift/UVOT upper limits
- GRB 060502A: Swift/UVOT source detection
- GRB 060502B: MDM Optical Observation
- GRB 060502B: Refined analysis of the Swift-BAT short burst
- GRB060502B: Swift XRT Team refined analysis
- GRB 060501: P60 Observations and Candidate Retraction
- GRB 060502B: Xinglong optical observation
- GRB060502: Swift-XRT refined analysis
- GRB 060502: Swift-BAT refined analysis
- GRB060501: Swift UVOT followup observations
- GRB 060502: P60 Afterglow Confirmation
- GRB 060502: Swift detection of a burst with an optical counterpart
- GRB060501: P60 imaging and afterglow candidate
- GRB 060501: Refined analysis of the Swift-BAT burst
- GRB060428B - SDSS Pre-Burst Observations
- GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
- GRB 060428B: MDM Observations
- GRB060428B: Swift XRT Team refined analysis
- GRB 060427B: IPN localization of a short hard burst
- GRB 060428B: Refined analysis of the Swift-BAT burst
- GRB 060428B: Xinglong I-band limit
- GRB 051117A: Bright host galaxy not confirmed
- GRB060428A: Swift/UVOT observations.
- GRB060428B, optical observation
- GRB 060428A: Refined analysis of the Swift-BAT burst
- GRB 060428b : Kiso R-band limit
- GRB 060428b: Optical afterglow candidate
- GRB060428A: Swift XRT Team refined analysis
- GRB 060428B: Swift detection of a burst
- GRB 060427: NIR observations
- GRB060427: Xinglong optical Observations
- GRB 060428: Swift detection of a burst
- GRB 060427: Swift/UVOT upper limits.
- GRB 060427: Refined analysis of the Swift-BAT burst
- GRB060427: Swift XRT Team refined analysis
- GRB060418: Swift XRT Team Further Refined Analysis
- GRB060425:MASTER survey observations
- GRB 060427, optical observation
- GRB 060427: Swift detection of a burst
- GRB060418: Further Analysis of MIKE Spectroscopy
- GRB 060424: Refined analysis of the Swift-BAT burst
- GRB 060421: TTT Observations
- GRB060421: Swift/UVOT observations
- GRB 060421: Swift-BAT Refined Analysis
- GRB 060421: Swift-XRT refined analysis
- GRB 060418: prediction of t_break
- GRB(?) 060421: Swift detection of a burst
- Erratum of GCN 4983 for GRB 060418 IR follow-up
- GRB 060418 : IR afterglow observations
- GRB 060418: Radio Observations
- GRB060418, BVRcIc field calibration
- GRB060418: Swift/UVOT Observations
- GRB060418: Optical Observations
- GRB 060418: Refined Analysis of the Swift-BAT burst
- GRB 060418, SMARTS continuing afterglow observations
- GRB 060418, SMARTS optical/IR afterglow observations
- GRB060418 : LT optical afterglow observation
- GRB 060418: REM candidate afterglow
- GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
- GRB060413: Swift/UVOT upper limits
- GRB 060413: REM NIR Observations
- GRB 060413: Refined analysis of the Swift-BAT burst
- GRB 060403: MITSuME optical observation
- GRB060403: Optical Limit
- GRB060403: XRT refined analysis
- GRB 060403: Swift/UVOT upper limits
- SGR 1900+14: BAT observations
- GRB 060403: Refined analysis of the Swift-BAT burst
- Konus-Wind observation of the recent SGR 1900+14 activity. Will
- GRB 060403: Swift detection of a burst
- HETE trigger H4044: RTT150 optical observations
- GRB060331: Swift/UVOT upper limits
- Swift XRT observations of the HETE transient H4043
- H4043, an unusual high-energy transient observed by HETE
- GRB 060322: LNA optical limit
- SGR 1900+14: bright burst detected by Konus-Wind on March 28
- INTEGRAL and XMM ToO observations of SGR1900+14
- SGR 1900+14: Swift-BAT detection of a bright outburst
- GRB 060323 : WIDGET simultaneous optical observations
- GRB 060323: Early optical observation at Xinglong
- GRB 060322: Confirmation of Swift XRT afterglow
- GRB060323: NOT optical observations
- GRB 060322: IAC80 optical observations
- GRB 060322: Swift XRT afterglow candidate
- GRB060323: P60 Observations
- GRB 060323: Swift/UVOT Observations
- GRB 060323: optical afterglow confirmed
- GRB060323: NOT observations
- GRB 060323: Optical Observations
- GRB 060323: Refined analysis of the Swift-BAT burst
- GRB 060323: optical observations at TNG
- GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
- GRB 060322: Refined analysis of the Swift-BAT burst
- GRB060323, optical observation
- GRB060323 - SDSS Pre-Burst Observations
- GRB 060323: Swift detection of a burst with a possible optical afterglow
- GRB 060322: Swift-BAT detection of a 200-sec burst