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"23700 results found.
- GRB050709: Second Epoch Chandra Observation
- GRB 050726: PROMPT Rc Observations
- GRB050709: Second Epoch Chandra Observation
- GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
- GRB050726: Swift-BAT detection of a weak burst
- RXTE ASM Detection of GRB050724
- GRB 050724: spectroscopy of object in the XRT error circle
- GRB 050724: optical and near-IR observations
- GRB 050724: early Swift XRT analysis results
- Swift-BAT trigger 147325 is not due to a real GRB
- GRB 050721A: Swift-BAT refined analysis
- GRB 050709: Refined Spectral and Temporal Properties
- GRB 050717: PROMPT RcIc Observations
- Swift-BAT trigger 146731 is not a real GRB
- GRB 050712, Tautenburg optical afterglow observations
- Swift-BAT detection of a possible GRB
- GRB 050714B: VLT R-band observations
- Konus-Wind observation of GRB 050717
- GRB 050717: Swift-BAT refined analysis
- GRB 050717: Refined XRT analysis.
- GRB050712: optical limits
- GRB 050716: Refined XRT analysis.
- GRB050716, optical observation
- GRB050716: Faulkes North Telescope observation
- Swift UVOT Observations of GRB 050714B
- Konus-Wind observation of GRB 050713A
- GRB 050713b: RTT150 optical observations
- GRB050714B: Refined analysis of the Swift-BAT burst
- Swift detection of a long transient (GRB 050714B?)
- GRB 050714, optical observations
- GRB 050714A: ROTSE-III Optical Limits
- GRB 050714 - A long GRB detected with INTEGRAL
- GRB050712: TNG R-band observations
- Swift-BAT Trigger 145729 is not a GRB
- GRB 050713A : Swift-BAT Refined Analysis
- GRB050712: Swift UVOT Observation of Afterglow Emission
- GRB 050713b : Lulin R-band observations
- GRB050713B: Faulkes North Telescope observation
- RBO RI observations of GRB 050713A
- GRB050713: Liverpool Telescope prompt observations
- GRB050709: Candidate X-ray Afterglow from Chandra
- GRB 050713: ARC NIR Detections and Identification of Fading
- GRB 050713A: ROTSE-III Optical Limits
- GRB 050709: Swift UVOT and XRT observations
- GRB 050712: Swift detection of a weak burst
- GRB 050709: LCO40 Observations
- GRB050709, optical observations
- GRB050709: A Possible Short-Hard GRB Localized by HETE
- PROMPT Rc Observations of GRB 050709
- GRB 050525a: PROMPT VRcIc Detections
- GRB 050525a: ARC 3.5-meter Optical and NIR Observations
- GRB 050701: Refined XRT analysis
- GRB050701: Swift-BAT Refined analysis
- Swift trigger 143708 is really GRB 050701
- GRB 050626 - Correction to GCN 3552
- GRB 050626 - a long GRB detected with INTEGRAL
- GRB 050525A: Swift Late-Time Decay Rate
- CORRECTION: GRB050603 Swift UVOT Afterglow Observations
- H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
- Konus-Wind observation of an intermediate burst from SGR 1806-20
- IBAS Alert #2512 is NOT a GRB
- GRB 050607 optical decay
- Swift/UVOT observations of GRB050607
- GRB 050607: PROMPT VRcIc Observations
- GRB 050607: RAPTOR-S Early Optical Limits
- GRB 050607: MDM Observations
- GRB050607,optical observation
- GRB050607: P60 Observations
- Konus-Wind observation of GRB 050603
- GRB050603: Fading Afterglow observed by Swift UVOT
- GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
- GRB 050603: INTEGRAL shows it is not a short GRB
- Swift/BAT Detection of GRB050603
- GRB 050525a, SMARTS optical/IR afterglow observations
- GRB050528, XRT observations
- Swift-BAT GRB 050528: a soft burst
- Update on Swift-BAT GRB 050528 (Trigger 130679)
- Possible GRB050528: no candidate from Liverpool Telescope
- Swift-BAT detection of possible GRB 050528
- GRB 050509b: refined XRT/Chandra afterglow position analysis
- GRB050525a: optical upper limits
- GRB 050525B: Swift-BAT observations
- GRB050525A,optical observation
- GRB 050525 : Lulin optical afterglow observations
- GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
- Konus-Wind observation of GRB 050525
- INTEGRAL detection of GRB 050525
- GRB 050525A: ROTSE-III Detection of Possible Counterpart
- XRF050522: NIR observations of XRT candidate
- GRB050522,optical observation
- GRB050520,optical observation
- XRF 050522: Continued NIR P200 Monitoring
- RBO Observations of GRB050522
- XRF050522, BVRcIc field photometry
- XRF050522: Optical Observations
- XRF050522: Near-infrared Observations
- XRF 050522 detected with INTEGRAL
- Swift UVOT Observations of GRB 050520
- GRB 050520: Swift XRT refined analysis
- RBO Observations of GRB050520