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"44284 results found.
- GRB 071112C: Swift/UVOT observations
- GRB 071112C: Swift XRT refined analysis
- GRB 071112C: Optical observations at Crni Vrh
- Swift UVOT upper limits of GRB071112B
- GRB 071112C: VLT redshift
- GRB 071112B: Magellan i-band imaging
- GRB 071112B: Gemini Optical Imaging (Correction)
- GRB 071112B: Gemini Optical Imaging
- GRB 071112B: Swift-XRT preliminary analysis
- GRB 071112B, Swift-BAT partial refined analysis of the SHB
- GRB071112C: NOT observations
- GRB 071112C: Palomar Pre-Imaging
- Swift-BAT trigger 296491 is not a GRB
- GRB 071112C : Lulin R-band observation
- GRB 071112C: RTT150 optical observations
- GRB 071112C: TAROT Calern observatory optical observations
- Swift XRT follow-up observations of GRB071028B
- GRB071112C Xinglong_TNT_and_EST_afterglow observations
- GRB 071112C: Optical and NIR afterglows observed with KANATA
- GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
- GRB 071112B: ROTSE-III Rapid Optical Limits
- GRB 071112C: Swift detection of a burst with an optical counterpart
- GRB 071112B: Swift detection of a short hard burst
- GRB 071112: Swift detection of a possible burst
- GRB071109: Super-LOTIS observations
- VLA IInd observation of INTEGRAL burst GRB 071109
- Swift/UVOT initial analysis of GRB071109
- GRB 071109: further Swift-XRT analysis
- GRB 071109: TAROT Calern observatory optical observations
- No radio detection at Swift-XRT position
- GRB 071109: Swift-XRT possible X-ray counterpart
- VLA prompt radio detection of the INTEGRAL burst 071109
- GRB 071109: IBIS refined analysis
- GRB 071109: BOOTES-2 prompt optical observations
- GRB 071109: A long GRB detected by INTEGRAL
- GRB 071104: Swift-XRT Team Refined Analysis
- GRB 071104: Possible Swift UVOT Afterglow Candidate
- GRB 071104: Swift-XRT position
- GRB 071104: Gamma Ray Burst Localization by SuperAGILE
- GRB071010b: optical observation
- Swift XRT and UVOT observations of GRB071028B
- GRB 071101, Swift-BAT refined analysis
- GRB 071101: Swift-XRT Team refined analysis
- GRB071101: Optical and NIR upper limits by KANATA
- GRB0711101: Two new source from Xinglong TNT observation
- GRB 071101: TAROT Calern observatory optical observations
- GRB 071101: Swift XRT position
- GRB071101 LOAO B,V,R,I observation
- GRB 071101: BOOTES-2 prompt optical observations
- GRB 071101: a nearby galaxy
- GRB 071101: Swift detection of a burst
- GRB 071031, Swift-BAT refined analysis
- GRB 071031: Swift/UVOT detection of afterglow
- GRB 071031: Swift-XRT Team refined analysis
- GRB 071020: MITSuME Akeno optical observations
- GRB 071031: REM NIR and Optical observation
- GRB 071031, SMARTS afterglow observations
- GRB 071031: VLT high-resolution spectroscopy
- GRB071031: Rapid PROMPT Detections
- GRB 071031: GROND detection in all bands
- GRB 071031: Swift detection of a burst with an optical counterpart
- GRB 071028B Swift-BAT detection of a burst
- GRB071025: Optical+NIR observations
- GRB 071028: SARA observations of variable source
- Swift UVOT upper limits to GRB071028
- GRB071028: Xinglong EST V-band upper limit
- GRB 071028: Swift-XRT Team refined analysis
- GRB 071028, Swift-BAT refined analysis
- GRB 071028: Swift detection of a burst
- GRB 071025: Kuiper Telescope Optical Observations
- GRB 071003: Infrared Photometry with Keck Adaptive Optics
- GRB 071018: Revised BAT position
- GRB 071025A: RAPTOR Observations of Complex Early Optical Behavior
- GRB071021: MARGE Optical Limits
- GRB071020, optical upper limit
- GRB 071025: SARA VRI upper limits
- GRB 071025 Milagro GeV/TeV Observations
- GRB 071025: SQIID JHK photometry
- GRB 071025A: Complex Early-Time IR Behavior, Simultaneous with Gamma- and X-rays
- GRB071025: Optical Pre-imaging from Palomar
- Swift UVOT upper limits
- GRB071025: Xinglong TNT I-band upper limit
- GRB 071025: Swift-XRT Team refined analysis
- GRB 060602A: host redshift
- GRB 071025, Swift-BAT refined analysis
- GRB 071025: Early Super-LOTIS Observations
- GRB 071025: R/I-band update
- GRB071021 : CFHT Ks-band observation
- GRB 071025: ROTSE-III Refined Analysis
- GRB 071025: I-detection, R-dropout?
- GRB 071025: Swift XRT refined position
- GRB 071025a: PAIRITEL observations
- GRB071025: REM NIR afterglow
- GRB 071025: ROTSE-III Detection of Optical Counterpart
- GRB 071025: Swift detection of a burst
- GRB 071021: R-band detection and analysis
- GRB 071020: BTA spectroscopy
- GRB071021: Optical+NIR observations
- Possible radio detection of GRB 071021 with the VLA
- Optical observations of GRB 071020