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"2747 results found.
- GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
- GRB070429B: possible host galaxy detection
- GRB 070429A: Swift XRT refined analysis
- GRB 070429B: ROTSE-III Optical Limits
- GRB 070429B: Swift detection of a short burst
- Trigger 276045: Swift detection of a possible burst
- GRB 070411: TLS data shows plateau, flares
- GRB 070406: Astrometrically Refined XRT Position, Unfading Source
- GRB 070406: Bright galaxy in XRT error circle is a quasar
- Short GRB 070406 - Possible Bright Host Galaxy
- GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
- IPN triangulation of GRB070402
- UVOT observations of GRB070330
- GRB 070311: Optical Brightening
- GRB 070306: possible emission-line redshift
- GRB 070309: variability of the XRT afterglow candidate
- GRB 070311: MDM Optical Follow-up
- GRB 070311: PAIRITEL confirmation of variability of REM candidate
- GRB 070311: REM candidate afterglow
- GRB070309: Swift/XRT possible afterglow detection
- GRB 070125: X-ray light curve analysis
- GRB070227: possible X-ray afterglow detection
- GRB 920925C: optical afterglow candidate
- VLA observation of GRB 070223
- GRB070224: Swift-XRT Refined Analysis
- GRB 070223: Swift-XRT Refined Analysis
- GRB 070223: Liverpool Telescope Possible Afterglow Candidate
- GRB 070125 observations with the GMRT
- GRB 070208: MDM Optical Decay
- GRB070126: Swift-XRT Observation
- GRB 070125: optical observation
- GRB 070129, Swift-BAT refined analysis of a particularly long
- GRB 070126: VLT observations
- GRB070126: Swift-XRT possible detection of an afterglow
- Possible GRB 070126: Swift/UVOT Upper Limit
- GRB070125: Swift-XRT Refined Analysis
- GRB 070126?: Swift detection of a possible burst
- GRB 070110: Continued Detection and Request for Ground Followup
- GRB 070110: Ep,i - Eiso correlation
- Trigger 255685: Swift detection of a possible burst
- GRB 070110: Swift detection of a burst with a possible optical afterglow
- GRB 070107: Possible UVOT Afterglow
- Retractions of previous Swift-BAT triggers
- GRB 061210: Possible Host Galaxy (S2-G2) Keck Spectrum
- GRB 061218: REM prompt observations
- Swift triggers (#251863) on a possible burst
- GRB 061210: MDM Follow-up Observation
- GRB 061210: Swift XRT analysis - Possible counterparts
- GRB 061214(?): ROTSE-III Optical Limits
- GRB 061214(?): Swift detection of a possible burst
- 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