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"5051 results found.
- GRB 080229: Swift detection of a bright burst
- GRB 080204: Suzaku WAM observation of the prompt emission
- GRB 080218B: Swift-XRT refined analysis
- GRB 080212: REM refined analysis
- GRB 080212: Gemini-South optical observations
- GRB 080212: GROND detects afterglow
- GRB 080212: REM NIR afterglow?
- GRB 080212: Swift-XRT Team refined analysis
- GRB 080212: DSS/2MASS Galaxy at XRT position
- GRB 080210: Swift-XRT Refined Analysis
- GRB 080207: Swift-XRT Refined Analysis
- GRB 080205: MASTER optical observation
- IPN localization of very hard GRB 080204
- GRB 080130: Swift-BAT refined analysis
- GRB 080123: Early afterglow detection with BATSS (BAT Slew Survey)
- GRB 080129, Swift-BAT refined analysis
- GRB 080122 : Suzaku WAM observation of the prompt emission
- GRB 080123: Swift-XRT refined analysis
- Swift UVOT Monitoring of the SN 2008D Brightening (Transient in NGC 2770)
- Swift UVOT Observations of the X-ray transient in NGC 2770
- Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
- GRB 071227: Swift-XRT refined analysis
- VLA radio detection of GRB 071122
- GRB 071122 Swift-XRT refined analysis
- GRB 071122: ROTSE-III Optical Limits
- GRB 071117: Swift-XRT refined analysis
- GRB 071112C: emission lines and refined VLT redshift
- GRB 071112C: Swift XRT refined analysis
- GRB 071112C: Palomar Pre-Imaging
- GRB 071112B: ROTSE-III Rapid Optical Limits
- GRB 071104: Swift-XRT Team Refined Analysis
- GRB 071101: Swift-XRT Team refined analysis
- GRB071101: Optical and NIR upper limits by KANATA
- GRB 071101: Swift detection of a burst
- GRB 071031: Swift-XRT Team refined analysis
- GRB071031: Rapid PROMPT Detections
- GRB 071028: Swift-XRT Team refined analysis
- GRB 071025: Kuiper Telescope Optical Observations
- GRB071020, optical upper limit
- GRB 071025: Swift-XRT Team refined analysis
- GRB 071025: Swift detection of a burst
- GRB 071021: Swift-XRT Team refined analysis
- GRB 071021: Swift detection of a burst
- GRB 071020: Swift-XRT refined analysis
- GRB 071013: 3rd TLS Epoch - constraints on variability
- GRB 071010B correction to GCN 6892 optical observations
- GRB 071010B: Super-LOTIS upper limit
- GRB 071010B optical photometry
- GRB 071010: Swift-XRT observation
- GRB 071010: Keck Observations of the Afterglow
- GRB 071010: TAROT La Silla observatory detection of the afterglow
- GRB 071003: Keck HIRES spectroscopy
- GRB 071001: Swift-XRT Team refined analysis
- Update on Swift Status
- GRB 070917: Confirmation of the X-ray afterglow
- GRB920925C: search for host galaxy
- GRB 070917: P60 Observations
- GRB 070917: Swift-XRT observations
- GRB 070917: Swift detection of a bright burst
- Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
- Konus-Wind observation of GRB 070824
- GRB 070824 - Combined SuperAGILE/IPN Localization
- GRB 070810A: ROTSE-III Refined Analysis
- GRB 070810B: Xinglong TNT optical Upper Limit
- A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
- GRB 070810: Swift-XRT Team Refined Analysis
- GRB 070809: Swift-XRT refined analysis
- GRB 070810: Swift/UVOT Optical Counterpart
- GRB 070810: Swift detection of a burst
- GRB 070809: ROTSE-III Optical Limits
- Swift trigger on 4U 1700-377 while star tracker loss-of-lock
- GRB 070802: Swift-XRT refined analysis
- GRB070729: Swift/UVOT upper limits
- GRB 070729: Swift-XRT refined analysis
- GRB 070724b: First Gamma Ray Burst Localization by SuperAGILE onboard
- GRB 070724: P60 and Gemini Observations
- GRB 070724: Swift-XRT Team refined analysis
- GRB 070721A: Swift/XRT refined analysis
- GRB 070714A: Swift XRT refined analysis
- GRB070714B: Swift-XRT refined analysis
- GRB 070704: Swift-XRT refined analysis
- GRB 070626: IPN localization and Konus spectrum of a bright long burst
- GRB070621: RTT150 optical observations
- GRB 070621: VLT optical observations
- Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
- GRB070621: Swift XRT refined analysis
- GRB 070621: Gemini South optical imaging
- GRB 070621: UVOT-enhanced XRT position
- GRB 070621: NOT observations
- GRB 070621: ROTSE-III Prompt Optical Limits
- Swift XRT observations of the INTEGRAL burst GRB070615: Possible
- SWIFT J195509.6+261406 (GRB 070610): further observations
- GRB 070612A: continued SARA observations
- GRB 070612B: SARA upper limit
- GRB 070612B: KAIT limits
- GRB 070610: TAROT Calern observatory optical observations
- GRB 070611: Swift-XRT refined analysis
- GRB 070529: Swift-XRT refined analysis
- GRB 070521: Swift-XRT refined analysis
- GRB 070520A: Subaru Observations