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"26179 results found.
- Swift-BAT detection of GRB 050410
- GRB 050410: Swift XRT Position
- GRB 050408: Swift XRT analysis
- GRB 050408,optical observation
- GRB 050408: Magellan astrometry and photometry
- 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
- Swift-BAT detection of GRB 050406
- Konus-Wind observation of GRB 050401
- 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
- Swift-BAT detection of GRB 050331b
- GRB 050331: Swift UVOT Source
- Konus-Wind observation of GRB 050326
- GRB050326: optical limit
- GRB 050326: Early observations with Swift-UVOT
- GRB 050326 : Planned XMM-Newton observation
- GRB 050326 BAT refined analysis
- 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 050319: Swift-UVOT detection of the afterglow
- GRB 050318: SWIFT-UVOT refined analysis
- GRB050319,optical observation
- GRB 050318: Swift/UVOT detection of afterglow emission
- RXTE Observations of GRB050318
- Swift-BAT detection of GRB 050318
- GRB 050315: Swift-BAT further refined analysis
- 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
- 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
- Swift trigger 107518: optical observation
- GRB 050306,optical observation
- Ongoing activity of SGR 1806-20 after the giant flare
- GRB 050219b: candidate NIR afterglow
- GRB050223: No Swift UVOT Detection of Afterglow Emission
- GRB050223: ROTSE-III Optical Observations
- GRB050219b: CORRECTION to time of UVOT observations
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB050219a: No Swift UVOT Detection of Afterglow Emission
- GRB050215b: Swift UVOT Detection of Afterglow Emission
- GRB 050215b: XRT confirmation of IR afterglow candidate
- GRB 050215b: Swift XRT Source Variability
- 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
- GRB050209: REM optical observations
- GRB 050209 Optical observations
- GRB050209: P60 Optical Observations
- GRB 050209: Optical observation
- GRB050128,optical observations
- GRB 050124 I-band observation
- GRB050124,optical observation
- GRB050124: Refined BAT position, spectral and fluence information
- GRB050123,optical observation
- GRB 050123: KAIT observations
- GRB 050123(=H3666): A GRB Localized in Real Time by HETE
- GRB 050117, I-band observations
- SGR1806: Detection of a Sudden Ionospheric Disturbance
- SGR1806-20: RXTE-PCA observation of the 041227 super-flare
- The giant outburst from SGR 1806-20
- Swift-BAT Time History of GRB041219
- GRB041220: Swift-BAT burst
- Deep RAPTOR observations during GRB 041219
- GRB041219c: Third Burst in One Day from Swift-BAT
- GRB 041219 ,optical observation
- GRB 041218: R-band optical observations
- Swift-BAT detection of the bright long burst GRB041219
- GRB041219: Prompt Optical Observations from ROTSE-IIIb
- GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
- GRB041211: Continued P60 Observations
- GRB041211: RAPTOR observations
- GRB041211, BVRcIc field calibration
- GRB041211,optical observation
- GRB 041211: Infrared Observations
- GRB 041211: KAIT observations