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"2797 results found.
- GRB 061210: Swift-BAT detection of a short burst
- GRB061126: update on the Swift-XRT afterglow light curve
- GRB 061201: Initial UVOT Observations
- GRB 061126: Possible Jet Break
- GRB 061110B: Swift/XRT position
- GRB 061110B : Liverpool Telescope Optical Afterglow Detection
- GRB 061109: optical observation
- GRB 061109: Swift detection of a possible burst
- GRB 061102B: Swift detection of a possible burst
- GRB 061027, Swift refined analysis of a possible burst
- GRB 061027: Swift detection of a possible burst
- GRB061019: Swift XRT refined analysis
- GRB 060928: Swift observations
- GRB 060908: Detection of a possible host
- GRB 060807: Detection of a possible host galaxy
- GRB 060729: An update on the late-time Swift observations
- GRB 060927: Possible host galaxy (star?) in the SDSS
- GRB 060923, Swift-BAT refined analysis
- GRB 060919: Swift detection of a burst
- GRB 060912: Swift detection of a burst with an optical afterglow
- GRB 060906 (?): P60 Optical Afterglow Candidate
- GRB 060906: Swift detection of a probable burst
- GRB 060901: SMARTS optical/IR observations update
- GRB 060826(?): Swift detection of a possible burst
- GRB060813: Break in the XRT light curve
- GRB 060814: P200 NIR Observations
- GRB 060814: Possible IR counterpart
- GRB060807: Possible Highly Significant X-ray Emission Lines
- GRB 060729: An update on the Swift XRT and UVOT observations
- GRB 060804: Swift detection of a burst with a possible UVOT counterpart
- GRB 060801: optical observations at FORS2/VLT
- GRB 060801: Refined analysis of the Swift-BAT short hard burst
- GRB 060729: Swift detection of a burst with an UVOT optical counterpart
- GRB 060719: prompt PROMPT observations
- GRB 060719: VLT observations
- GRB 060714: OA fading and a possible host detection
- GRB 060714: REM infrared observations
- GRB 060714 : Liverpool Telescope Observations
- Correction to Circular 5314: Circular refers to GRB 060714
- GRB060707 possible optical confirmation
- GRB060707 possible optical confirmation
- GRB060614: Possible SN Bump in UVOT U Band Light Curve
- GRB 060614: Detection of a Possible, Late-Time Rebrightening
- Trigger 215279: Swift detection of a possible burst (GRB 060619)
- GRB050124: Possible Host Galaxy
- GRB 060602A: Swift/XRT analysis
- GRB 060604: Swift detection of a burst with possible optical counterpart
- GRB 060602A: Swift-BAT Refined Analysis: Correction
- GRB 060602B: XMM-Newton Survey Source
- GRB060602B: BOOTES-IR candidate afterglow
- GRB060526: possible break in the optical light curve
- GRB 060526: Optical Flare
- GRB060505: VLT observations of the optical afterglow
- GRB 060522: Swift detection of a burst with possible optical afterglow
- GRB 060512: reanalysis of optical spectra
- GRB 060515: NIR observation
- GRB060515: P200 NIR Observations
- GRB 060515 BAT refined analysis
- GRB 060515: Swift/XRT Team refined analysis
- GRB 060515: Swift/XRT position
- GRB 060515: TAROT optical observation
- GRB060418: optical observations
- GRB 060510B: Swift detection of a burst
- GRB060502B: improvement in the XRT afterglow position
- GRB 060505: Swift XRT Team Refined Analysis
- GRB 060502B: Refined analysis of the Swift-BAT short burst
- Short GRB 060502B: Tautenburg Observation
- GRB 060502B: Swift detection of a short burst
- GRB 060501: MDM Observations
- GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
- GRB 060428: Swift detection of a burst
- GRB060425:MASTER survey observations
- Possible GRB060421: BART limits
- GRB(?) 060421: Swift detection of a burst
- GRB 060322: IAC80 optical observations
- GRB 060323: Swift/UVOT Observations
- GRB 060323: Optical Observations
- GRB 060323: Tautenburg OT candidate retraction
- GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
- GRB 060323: Swift detection of a burst with a possible optical afterglow
- GRB060206: optical observation
- GRB060218: Refined photometric calibration of comparison stars
- GRB 060319: WHT K-band candidate afterglow
- GRB060313:Gemini South Observations
- GRB 060313, SMARTS optical counterpart?
- GRB 060313: Possible optical counterpart
- GRB 060223B: Swift XRT possible afterglow
- GRB 060218/SN 2006aj: ABT observations
- GRB 060223B: Swift-BAT refined analysis
- GRB 060223: Swift-BAT refined analysis
- GRB 060218: rebrightening
- Spectral properties of GRB060218/SN2006aj
- GRB060218: VLT spectroscopy
- GRB 051221B: Swift-XRT Team Refined Analysis
- Oddball GRB 060218, transient or GRB?
- GRB060218: Swift/XRT Team preliminary analysis of the possible burst
- Brightening of the Optical Counterpart of the Possible GRB 060218
- GRB 060218: Pre-burst detection of a possible host galaxy
- GRB 060218A: ROTSE-III Possible Optical Flare
- GRB060218: Swift/XRT refined position of a possible burst