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"26781 results found.
- GRB 050408: ROTSE-III Optical Limits
- GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
- Swift-UVOT Optical Counterpart Candidate to XRF 050406
- GRB 050406: early Swift XRT analysis results
- GRB 050406 BAT refined analysis
- GRB 050406: Early observations with Swift-UVOT
- GRB 050406: Swift XRT Position
- Swift-BAT detection of GRB 050406
- Konus-Wind observation of GRB 050401
- GRB050401: Radio observation at 610 MHz with GMRT
- GRB 050401 Optical Observations
- GRB 050401 BAT refined analysis
- Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
- GRB 050402: Early observations with Swift-UVOT
- Swift Trigger 113225: P60 Observations
- GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
- GRB 050401: Optical afterglow candidate
- Swift-BAT detection of GRB 050401
- GRB 050401: Prompt XRT position
- Retraction of three Swift GRB triggers
- Swift-BAT detection of GRB 050331b
- GRB 050331: Swift UVOT Source
- Swift-BAT detection of GRB 050331
- GRB 050331: Swift XRT Position
- Konus-Wind observation of GRB 050326
- GRB050326: optical limit
- GRB 050326: Early observations with Swift-UVOT
- GRB 050326 : Planned XMM-Newton observation
- GRB 050326: Swift XRT Position
- GRB050326: optical limit 33min before GRB
- GRB 050326 BAT refined analysis
- GRB050326: delayed XRT observation
- Swift-BAT detection of a bright GRB 050326
- GRB050319, optical observations
- Swift-BAT detection of a bright outburst from SGR1806-20
- Swift-BAT trigger 112060 is not a real GRB
- GRB 050319: ROTSE-III Refined Analysis
- GRB 050318: Swift-BAT refined analysis
- GRB 050319 R band observations
- GRB 050319: Swift-UVOT detection of the afterglow
- GRB 050315: Variability Analysis of Swift BAT Time History
- GRB 050318: SWIFT-UVOT refined analysis
- GRB 050319: Swift-BAT refined analysis
- GRB050319,optical observation
- Swift Detection of GRB 050319
- GRB 050318: Swift/UVOT detection of afterglow emission
- GRB 050318: Magellan optical afterglow identification
- GRB050318: Swift XRT position
- RXTE Observations of GRB050318
- Swift-BAT detection of GRB 050318
- GRB 050315: Swift-BAT further refined analysis
- GRB050315: Swift-BAT Refined analysis
- GRB 050315: Swift XRT Position
- GRB 050315: Early Observations with Swift/UVOT
- Swift-BAT detection of GRB 050315
- GRB050223: No XMM-Newton OM detection of afterglow emission
- GRB050309: CONCAM pre-trigger and trigger coincident optical
- Swift-BAT trigger 107873: No Swift XRT counterpart
- GRB 050309, Early optical limits from RAPTOR
- GRB050309: Early optical limit from P60
- Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
- GRB 050309 : Lulin R-band observation
- Swift 107873: P60 Optical Observations
- GRB 050306: CORRECTION to date of observation
- GRB 050306: No Swift UVOT Optical Counterpart Detected
- GRB 050306: Possible X-ray Afterglow Position from the Swift
- Swift trigger 107518: optical observation
- GRB 050306,optical observation
- GRB 050306: Swift-BAT detection of a long burst
- Ongoing activity of SGR 1806-20 after the giant flare
- GRB 050219b: candidate NIR afterglow
- Confirmed XRF nature for GRB050215b
- GRB 050223: optical observations
- GRB050223: No Swift UVOT Detection of Afterglow Emission
- GRB050223: ROTSE-III Optical Observations
- GRB 050223 Swift/BAT detection of a burst
- GRB 050223: Swift XRT Position
- GRB050219b: CORRECTION to time of UVOT observations
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB 050219b: Swift-BAT detection of a burst
- GRB 050219b: CORRECTION: Swift XRT Position
- GRB 050219b: Swift XRT Position
- GRB 050219a, optical observations
- GRB 050219a: Refined XRT position
- GRB050219a: No Swift UVOT Detection of Afterglow Emission
- GRB 050219: Swift-BAT detection of a burst
- GRB050215b: Swift UVOT Detection of Afterglow Emission
- GRB 050219: Prompt X-ray position
- GRB 050215B: candidate afterglow
- GRB 050215b : Lulin follow-up observation
- GRB 050215b, BOOTES-2 simultaneous optical observations
- GRB 050215B: UKIRT K-band imaging
- GRB 050215b: Swift XRT Observations
- GRB050215b: No Swift UVOT Detection of Afterglow Emission
- GRB050215a: No Swift UVOT Detection of Afterglow Emission
- Swift-BAT detects two bursts: GRB050215a and GRB050215b
- GRB 050215b, BOOTES-1B optical limit
- GRB050215B: ROTSE-III optical observations
- GRB050215A: ROTSE-III Optical Observations