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.
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"20951 results found.
- GRB050408: MASTER optical observations
- GRB050401: Radio Detection
- Swift-UVOT Optical Counterpart Candidate to XRF 050406
- GRB 050406: Magellan optical observations
- GRB 050406: Early observations with Swift-UVOT
- GRB050401: Radio observation at 610 MHz with GMRT
- GRB050401, radio observation at 4.8 GHz and 8.64 GHz
- GRB 050401 Optical Observations
- GRB050401: TNG R-band observation
- GRB 050402A: IR Observations
- GRB 050402: Early observations with Swift-UVOT
- Swift Trigger 113225: P60 Observations
- GRB 050401: Optical afterglow confirmed
- GRB 050401: Optical afterglow candidate
- GRB050331: No Afterglow Detected
- GRB 050331: Swift UVOT Source
- GRB050319: radio observation
- GRB 050326: Early observations with Swift-UVOT
- GRB 050326: Swift XRT Position
- GRB050326: delayed XRT observation
- GRB050319, optical observations
- GRB050319, color indices
- GRB050319: optical observation, March 20-22
- GRB050319: RTT150 Optical Observations
- GRB 050319: ROTSE-III Refined Analysis
- GRB 050318: Swift-BAT refined analysis
- GRB050319: VLA Observations
- GRB 050319 R band observations
- GRB 050319: Swift-UVOT detection of the afterglow
- GRB050319: Radio Observations
- GRB 050319: NIR afterglow candidate
- GRB 050319:Near IR afterglow
- GRB 050318: Absorption redshift from Magellan
- GRB 050319 : Confirmation of optical afterglow decay
- GRB 050319: Detection of Possible Optical Counterpart
- GRB 050318: Swift/UVOT detection of afterglow emission
- GRB 050318: Magellan optical afterglow identification
- RXTE Observations of GRB050318
- GRB 050315, SMARTS optical afterglow decay
- GRB050316: MASTER before, simultanious and follow up optical
- GRB050316: MASTER optical observations
- GRB 050315: Swift-BAT further refined analysis
- GRB 050315, SMARTS optical/IR afterglow observations
- GRB 050315 I-band observations
- GRB050315: Radio afterglow
- GRB 050315: Absorption redshift
- GRB 050315: Optical afterglow identification
- Non-detection of GRB050315 in ATCA Radio Observations
- GRB 050315: Swift XRT Position
- GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
- GRB 050315: Early Observations with Swift/UVOT
- Swift-BAT detection of GRB 050315
- GRB050223: No XMM-Newton OM detection of afterglow emission
- GRB 050306: Radio Observations
- GRB 050306: optical afterglow
- Swift-BAT trigger 107873: No Swift XRT counterpart
- GRB050309: Early optical limit from P60
- Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
- Swift 107873: P60 Optical Observations
- GRB 050306: CORRECTION to date of observation
- GRB 050306: R-band observations
- GRB 050306: No Swift UVOT Optical Counterpart Detected
- GRB 050306: REM optical-infrared observations
- GRB 050306: Possible X-ray Afterglow Position from the Swift
- GRB 050306: TAROT optical observations
- GRB050215B: Late-Time Swift UVOT Observations
- PROMPT VRcIc Observations of GRB 050223
- XRF/GRB 050215B: Radio Observations
- GRB 050219b: candidate NIR afterglow
- GRB 050223: optical observations
- GRB050223: No Swift UVOT Detection of Afterglow Emission
- GRB050223: ROTSE-III Optical Observations
- GRB 050223: Swift XRT Position
- HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
- GRB050219b: CORRECTION to time of UVOT observations
- GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB 050219a: Optical observations from LCO
- GRB 050219b: Optical and near-IR observations from LCO
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- 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
- GRB050215b: Swift UVOT Detection of Afterglow Emission
- GRB 050215B: Radio Observations
- GRB 050215b: XRT confirmation of IR afterglow candidate
- GRB050215b: P60 Optical Observations
- GRB 050215b: Swift XRT Source Variability
- GRB 050215b : Lulin follow-up observation
- GRB 050215b, BOOTES-2 simultaneous optical observations
- 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
- GRB050215B: ROTSE-III optical observations
- GRB050215A: ROTSE-III Optical Observations
- GRB050209: TAROT optical observations
- short/hard GRB 050202, optical observations