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"- GRB 080603b: optical observation
- Swift observations of BAT Slew Survey event (Trigger=010)
- GRB 080603A: final Swift-XRT observations.
- GRB 080607: AGILE-MCAL observation of the prompt emission
- GRB 080603B - TLS 2nd Epoch: Another Break
- GRB 080605: TLS 3rd Epoch - Source Confusion
- GRB080605: optical observation with the MITSuME-OAO telescope
- Konus-Wind observation of GRB 080607
- GRB080607: RTT150 optical observations
- GRB 080603A: optical observations
- GRB 080607: Swift-XRT refined analysis
- Swift/UVOT Observations of GRB080607
- GRB 080605: optical observations
- GRB 080607 KAIT observations
- VLA detection of INTEGRAL burst GRB 080603A
- Konus-Wind observation of GRB 080605
- GRB 080607: Enhanced Swift-XRT position
- GRB 080607, Swift-BAT refined analysis
- GRB 080605: GROND 2nd epoch observations
- GRB 080607 - PAIRITEL NIR detection
- GRB 080607: Keck/LRIS spectroscopy and redshift
- GRB 080607: Super-LOTIS early observations
- GRB 080607: Swift detection of a burst with optical afterglow
- GRB 080607: ROTSE-III Detection of Optical Counterpart
- GRB 080605: TLS RRM Analysis, Plateau/Rebrightening, Red OT
- GRB 080605: Swift-UVOT refined analysis
- Possible VLA radio detection on INTEGRAL burst GRB 080603A
- GRB 080604: VLA radio upper limit
- GRB 080605, Swift-BAT refined analysis
- GRB 080603B: VLA radio upper limit
- GRB 080605, Swift-BAT refined analysis
- GRB 080605: Swift-XRT refined analysis
- GRB080605: observation by BOOTES
- GRB 080605: MASTER VWF 46 s AT observation
- GRB 080605: Enhanced Swift-XRT position
- GRB 080605: GROND detection of the optical afterglow candidate
- GRB080605: optical observations
- GRB 080605: VLT redshift
- GRB 080605: Liverpool Telescope optical afterglow candidate
- GRB 080605: Swift/UVOT Position of the Optical Afterglow
- GRB 080605: TLS RRM Afterglow
- GRB 080605: Swift detection of a burst with an optical afterglow
- GRB 080603B: PAIRITEL infrared detection
- GRB 080603A: PAIRITEL infrared detection
- GRB 080604: Xinglong R band observation
- GRB 080603A: Xinglong R band observation
- GRB 080603B: TLS Afterglow Observation
- GRB 080603A: TLS Afterglow Observation
- GRB 080604: MITSuME Okayama observation
- Swift/UVOT observations of GRB080604
- GRB080604: HET redshift retraction
- GRB 080604: Gemini-North spectroscopy
- GRB 080604, Swift-BAT refined analysis
- GRB 080604: Swift-XRT refined analysis
- GRB 080603B: Hobby-Eberly Telescope redshift confirmation
- GRB 080603B : Xinglong EST observations
- GRB 080603B : Liverpool Telescope Observations
- Konus-Wind observation of GRB 080603B
- GRB 080603B: Swift-XRT refined analysis
- GRB 080603A: Swift-XRT detection of the afterglow
- GRB 080430: optical observations
- GRB 080603B: Swift/UVOT detection of the afterglow
- GRB 080604: Enhanced Swift-XRT position
- GRB 080603B, Swift-BAT refined analysis
- GRB 080604: Hobby-Eberly Telescope spectroscopy
- GRB 080603A: Swift/UVOT detection of the afterglow
- GRB080603B: RTT150 optical observations, break in light curves
- GRB 080604: Early Super-LOTIS Observations
- GRB080604: confirmation of optical afterglow
- GRB 080604: Swift detection of a burst with an optical afterglow
- GRB 080603B: TAROT Calern observatory confirmation of slow optical decay
- GRB 080516: TAROT La Silla observatory optical observations
- GRB080603B: NOT redshift
- GRB 080603B: BOOTES2/TELMA optical observations
- GRB 080603B: TAROT Calern observatory detection of a plateau in the light curve
- GRB 080603B: Swift detection of a burst with optical afterglow
- GRB080603: Super-LOTIS detection of Optical Counterpart
- GRB 080603B: ROTSE-III Detection of Optical Counterpart
- GRB 080603: Gemini-North redshift
- GRB 080603: A long GRB detected by INTEGRAL
- GRB 080603 OA candidate
- Possible GRB080603: Faulkes Telescope North optical afterglow candidate
- SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
- GRB 080602, Swift-BAT refined analysis
- GRB 080602: Swift-XRT refined analysis
- Konus-Wind observation of GRB 080602
- GRB 080602: NOT R-band upper limit
- GRB 080602: Enhanced Swift-XRT position
- GRB 080602: Swift detection of a burst
- Swift analysis of BAT Slew Survey event (Trigger=009)
- GRB 080523: afterglow confirmation and redshift constraints
- Konus-Wind observation of reactivation of SGR 1627-41
- Reactivation of SGR 1627-41
- GRB 080524: Swift XRT and UVOT analysis
- GRB 080503: 2nd Epoch Chandra X-ray Observations
- GRB 080524: Swift-BAT detection of a burst in ground analysis
- GRB 080523: Swift-XRT refined analysis
- GRB 080523, Swift-BAT refined analysis
- GRB 080520: VLT host detection
- GRB 080523: VLT optical observations