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"28083 results found.
- GRB 050820a - corrections to GCN 3846
- Swift/UVOT UV Photometry of GRB 050820B
- GRB 050822: ROTSE-III Prompt Optical Limits
- GRB 050822: Swift detection of a long burst
- GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
- GRB 050820a: NIR Observations by WIRO
- GRB 050820B: Swift XRT position
- GRB050820B: Refined analysis of the Swift-BAT burst
- GRB050820B: BAT-Swift detection of a bright GRB
- Swift/UVOT photometry of GRB050820
- GRB050820: refined XRT analysis
- GRB 050820: Early RAPTOR detections
- GRB 050820 Swift-BAT refined analysis
- GRB050819: refined XRT analysis
- GRB 050820: Swift detection of a GRB
- GRB050820: Optical afterglow from P60
- GRB 050819 Swift-BAT refined analysis
- GRB050819: Swift XRT position
- GRB050819: Swift-BAT detection of a weak burst
- Swift-BAT trigger 150993 is not a GRB
- Swift Trigger 150823 is HETE J1900.1-2455
- GRB050817: Swift-BAT Detection of a burst
- GRB050815: Optical afterglow detection by Swift UVOT
- GRB050815: XRT refined analysis
- GRB050815: Refined analysis of the Swift-BAT burst
- GRB 050815: ROTSE-III Optical Limits
- GRB050815: Swift XRT afterglow localization
- GRB050815: Swift-BAT detection of a burst
- GRB 050814: XRT refined analysis
- GRB050814: SWIFT/UVOT observation
- GRB050814: Refined analysis of the Swift-BAT burst
- GRB 050814: Swift XRT Afterglow Localization
- GRB 050814: Swift detection of a burst
- GRB050813, SDSS pre-burst observations
- GRB 050813: KAIT optical limit
- GRB 050813: Swift-BAT refined analysis
- GRB050813: SWIFT/UVOT observation
- RBO GRB 050714A and GRB 050716 observations
- GRB 050813: Possible Short Swift-BAT GRB
- GRB050813 (Swift 150139): P60 Observations
- Swift-BAT trigger 150131 is not a GRB
- GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
- Detection of an intermediate burst from SGR 1806-20 on August 8
- GRB 050807: ROTSE-III Optical Limits
- GRB050805b: CrAO optical limit
- GRB050805a : Null detection report
- Swift-BAT trigger 149118 is very likely not a GRB
- Retraction of Swift Trigger 149131 (GRB 050805B)
- GRB 050805b: OHP optical limits
- GRB 050805b: TAROT optical limits
- GRB050805b: MASTER optical observations
- Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
- GRB050805a: MASTER optical candidat
- Swift-BAT trigger 149118 is probably not a GRB
- GRB050803: Optical/UV Upper Limits from Swift-UVOT
- GRB 050803: Swift-BAT refined analysis
- GRB050803: MASTER further analys
- GRB 050803: early Swift XRT analysis results
- GRB 050803: TAROT optical limits
- GRB050803: Swift-BAT detection of a very long burst
- GCN GRB observation 050713A
- GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
- GRB 050802: Swift/UVOT optical and UV detections
- GRB050802 radio non-detection
- GRB 050802: early Swift XRT analysis results
- GRB 050802: Swift/UVOT observations
- GRB 050802: Swift-BAT refined analysis
- GRB 050802: Swift Gamma-ray Burst
- GRB050801: Swift/UVOT Optical and UV detections
- GCN 050801: early Swift XRT analysis results
- GRB 050801: Swift-BAT refined analysis
- GRB 050801: ROTSE-III Early Afterglow Break
- GRB050801: Swift-BAT detection of a burst
- GRB 050801: ROTSE-III Detection of Possible Counterpart
- GRB 050730: XRT refined analysis
- Swift/UVOT photometry of GRB050730
- GRB050730: Refined BAT analysis of the Swift-BAT burst
- GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
- GRB 050730, optical candidate
- GRB050730: Swift-BAT detection of a weak burst
- GRB 050713A: Swift XRT extended light curve
- GRB050713b: Maidanak optical observations
- Swift-BAT trigger 147918 is not a real GRB
- GRB 050727: RTT150 optical observations
- GRB050727: KAIT optical limit
- GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
- GRB 050726: early Swift XRT analysis results
- GRB050726: Swift-BAT detection of a weak burst
- GRB 050724: Optical limit
- GRB 050724: Swift/UVOT Upper Limit
- GRB 050724: early Swift XRT analysis results
- GRB050724: Refined analysis of the Swift-BAT possible short burst
- GRB050724: a short-burst detected by Swift
- Swift-BAT trigger 147325 is not due to a real GRB
- GRB050723: XRT distributed coordinates are not related to the burst
- GRB 050721A: Swift-BAT refined analysis
- GRB 050721A: Early Swift XRT analysis results
- Swift BAT Trigger 146986 is SWIFT J1753.5-0127
- GRB 050721a: Optical Observations
- GRB050721A: Swift-BAT detection of a weak burst