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"6184 results found.
- GRB 080514B: Swift-XRT analysis
- Swift detection of a possible galactic transient
- GRB 080506: NAYUTA Optical Observation
- GRB 080507: Swift XRT analysis confirms the X-ray afterglow
- GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
- GRB 080507: Swift-XRT position of a possible afterglow
- GRB 080506: TLS 2nd Epoch - possible light curve break
- GRB 080506: Swift XRT refined analysis
- GRB 080506: Optical observation with KANATA/TRISPEC
- GRB080503 XRT refined analysis
- GRB 080411: Continued Swift Monitoring
- GRB 080430: Swift-XRT refined analysis
- GRB 080426: Swift-XRT refined analysis
- GRB 080426, Swift-BAT refined analysis
- Possible GRB 080315: XRT non-detection of afterglow
- GRB080319A: MAGIC telescope GeV observation
- GRB 080420?: Swift detection of a possible short burst
- Swift XRT and UVOT observations of GRB080414
- GRB 080413B: Swift XRT refined analysis
- GRB 080413A: Swift-XRT refined analysis
- GRB 080411, Swift-BAT refined analysis
- GRB 080411: Swift-XRT Refined Analysis
- GRB080330: MAGIC telescope GeV observation
- GRB 080330 optical observations
- GRB 080409: Swift XRT refined analysis
- GRB 080408: Swift-XRT position of a possible afterglow
- GRB 080330: RAPTOR detection of prompt optical flash
- GRB 080319B: Potential Jet Break Observed by Swift-XRT and UVOT
- GRB080330: Swift XRT refined analysis
- GRB 080330A: ROTSE-III Detection of Optical Counterpart
- GRB 080328: Swift XRT refined analysis
- GRB 080325: Subaru detection of NIR afterglow candidate
- GRB080325: XRT Refined Analysis
- GRB 080319D: Swift XRT refined analysis
- Konus-Wind observation of GRB 080319B
- GRB 080319B: Swift-XRT Team Refined Analysis
- Swift trigger 306323: Swift-BAT/XRT refined analysis
- GRB080310 : Optical observations by LOAO and Lulin
- GRB 080310: Swift/UVOT Refined Analysis
- GRB 080307: Swift-XRT Team refined analysis
- Swift UVOT observations of GRB080229B
- GRB080229B: Swift XRT afterglow observation
- GRB080229: Swift XRT refined analysis
- ESO optical and NIR observations of GRB 080218B
- GRB 080218B: Swift-XRT refined analysis
- GRB 080212: Swift-XRT Team refined analysis
- GRB 080207, Swift-BAT refined analysis
- GRB 080207: Swift-XRT Refined Analysis
- GRB 080205: Swift XRT refined analysis
- GRB 080130: further Swift XRT observations confirm fading source
- GRB 080129: Swift-XRT refined analysis
- GRB 080129: Gemini-South Imaging Observations
- GRB 080121: Upper limit on X-ray afterglow
- SNe 2008D and 2007uy: Chandra Detections
- Transient 080109/SN 2008D: Spectroscopic Evolution and Re-Classification
- GRB 080123: Swift-XRT refined analysis
- GRB 080120: Swift-XRT refined analysis
- GRB080120: Swift XRT position
- Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
- Refined Swift-XRT analysis of the transient in NGC 2770
- X-ray transient in NGC 2770: Optical observations with Astrotel-Caucasus
- GRB 071227: Magellan observations
- GRB 071129, Swift-BAT refined analysis
- IPN triangulation of very bright GRB 071125
- GRB 071122 Swift-XRT refined analysis
- GRB 071117: Swift-XRT revised position
- Swift XRT follow-up observations of GRB071008
- GRB071118: Swift XRT refined analysis
- GRB 071117: Las Campanas optical observations
- GRB 071117: Swift-XRT refined analysis
- GRB 071112C: Optical and NIR data observed with KANATA
- GRB 071112C : Second Epoch Lulin R-band observations
- GRB 071112C: Swift XRT refined analysis
- GRB 071112B: Swift-XRT preliminary analysis
- Swift XRT follow-up observations of GRB071028B
- GRB 071109: further Swift-XRT analysis
- GRB 071109: Swift-XRT possible X-ray counterpart
- GRB 071104: Swift-XRT Team Refined Analysis
- GRB 071104: Possible Swift UVOT Afterglow Candidate
- GRB 071104: Swift-XRT position
- Swift XRT and UVOT observations of GRB071028B
- GRB071101: Optical and NIR upper limits by KANATA
- GRB 071101: Swift XRT position
- GRB071101 LOAO B,V,R,I observation
- GRB 071031: Swift-XRT Team refined analysis
- GRB 071028: Swift-XRT Team refined analysis
- GRB 071025A: Complex Early-Time IR Behavior, Simultaneous with Gamma- and X-rays
- GRB 071025: Swift-XRT Team refined analysis
- GRB071021 : CFHT Ks-band observation
- GRB 071025: I-detection, R-dropout?
- GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
- GRB 071021: Swift-XRT Team refined analysis
- GRB 071020, Swift-BAT refined analysis
- GRB 071018: Swift-XRT observation
- GRB 071017 - Swift XRT observations
- GRB 071013: 3rd TLS Epoch - constraints on variability
- GRB 071013: TLS 2nd epoch - Kornienko candidate constant
- GRB 071011: Swift-XRT refined analysis
- GRB 071011: NAYUTA Optical Observation, correction to GCN6886
- GRB 071011, Optical afterglow