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"26037 results found.
- GRB 050801: ROTSE-III Early Afterglow Break
- GRB050801: Swift-BAT detection of a burst
- GRB050801: GCN XRT position is incorrect
- GRB 050801: ROTSE-III Detection of Possible Counterpart
- GRB 050730: XRT refined analysis
- GRB 050730: early TAROT optical observations
- GRB 050726: PROMPT Rc Observations
- GRB 050730: RTT150 optical observations
- Swift/UVOT photometry of GRB050730
- GRB 050730, spectra and optical photometry
- GRB050730: Refined BAT analysis of the Swift-BAT burst
- GRB 050730: Swift XRT afterglow observations
- GRB 050730 XMM-Newton observation
- GRB 050730: PROMPT VRcIc Observations
- GRB050730, afterglow observations
- GRB050730: confirmation of redshift
- GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
- GRB 050730, SMARTS optical/IR afterglow observations
- GRB050730: Liverpool Telescope optical observations
- GRB 050730, optical candidate
- GRB050730: Swift-BAT detection of a weak burst
- GRB 050713A: Swift XRT extended light curve
- GRB 050709: PROMPT Rc Observations
- GRB050713b: Maidanak optical observations
- GRB 050724: WHT optical observations
- GRB050726: Swift UVOT observations
- GRB 050724: Chandra Observations of the X-ray Afterglow
- GRB050724: Refined Radio Position
- GRB050713: analysis of the XMM-Newton observation
- GRB 050724, SMARTS optical/IR afterglow observations
- GRB 050726, SMARTS optical/IR observations
- Swift-BAT trigger 147918 is not a real GRB
- GRB 050727: RTT150 optical observations
- GRB050724: VLT observations of the variable source
- GRB050727: KAIT optical limit
- 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
- GRB050724: Further Radio Observations
- GRB 050726: early Swift XRT analysis results
- GRB050726: Swift-BAT detection of a weak burst
- GRB 050724: J-band observations
- GRB 050724: GMOS Imaging and Spectroscopy
- GRB 050724: SWIFT XRT refined position
- GRB050724: Radio Observation
- GRB 050724: spectroscopy of object in the XRT error circle
- GRB 050724: Optical limit
- GRB 050724: optical and near-IR observations
- GRB 050724: Optical imaging/astrometry
- GRB 050724: Swift/UVOT Upper Limit
- GRB 050724: early Swift XRT analysis results
- GRB050724: Refined analysis of the Swift-BAT possible short burst
- GRB 050724: possible host galaxy in DSS
- 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 050721: early afterglow light curve
- GRB 050721A: Swift-BAT refined analysis
- GRB 050721A: Early Swift XRT analysis results
- GRB050721A: optical decay
- GRB 050721: optical afterglow confirmed
- Swift BAT Trigger 146986 is SWIFT J1753.5-0127
- GRB 050721a: Optical Observations
- GRB050721A: Swift-BAT detection of a weak burst
- GRB 050717: PROMPT RcIc Observations
- GRB050714b: Radio Observation
- GRB 050714a: Refined XRT analysis and afterglow confirmation
- 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
- GRB 050717: Additional LCO observations
- GRB050717
- GRB 050716; J-band observations
- Konus-Wind observation of GRB 050717
- GRB 050717: LCO near-IR observations
- Swift/UVOT Observations of GRB 050717
- GRB 050717: Swift-BAT refined analysis
- GRB 050717: Refined XRT analysis.
- GRB050712: optical limits
- GRB050717: Swift XRT position
- Swift detection of GRB 050717
- GRB 050716 - UKIRT identification of candidate afterglow
- Swift UVOT Observations of GRB 050716
- GRB 050716: Refined XRT analysis.
- GRB050716: Refined analysis of the Swift-BAT burst
- GRB 050716: Lulin B and R band optical observations
- GRB050716, optical observation
- GRB 050716: Optical Observations
- GRB050716: Faulkes North Telescope observation
- GRB050716: Correction to sign in XRT coordinate
- Swift/BAT detection of GRB 050716
- GRB050715: Refined analysis of the Swift-BAT burst
- GRB 050715: Swift-BAT detection
- Swift UVOT Observations of GRB 050714B
- Konus-Wind observation of GRB 050713A
- GRB 050714B: refined XRT analysis
- GRB 050714B: candidate afterglow does not fade
- GRB050714B: Refined analysis of the Swift-BAT burst