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 080825B: pseudo-z= 0.83 from prompt emission spectrum
- Konus-Wind observation of GRB 080825B
- GRB080825C: GLAST Burst Monitor detection
- GRB 080825B: Swift-XRT team analysis
- SGR 0501+4516: Fermi GBM (formerly GLAST Burst Monitor) observations of three exceptionally intense outbursts
- Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
- GRB080825: Afterglow confirmation and redshift estimate
- Suzaku ToO Observation of SGR 0501+4516
- GRB 080825B - optical counterpart candidate
- SGR 0501+4516: radio pulsar searches with GBT and WSRT
- GRB 080825B: GRB Localization by SuperAGILE
- Konus-Wind observations of new SGR 0501+4516
- INTEGRAL ToO Observation of SGR0501+4516
- Radio Detection of SGR 0501+4516
- SGR 0501+4516: MDM Optical Observations
- GRB 080822B, Swift-BAT refined analysis
- SGR 0501+4516: Astrotel-Caucasus optical observations
- SGR 0501+4516: UKIRT detection of possible infra-red counterpart
- SGR 0501+4516: WSRT Radio Observations
- Trigger 321551: Continued Large Flaring of SGR 0501+4516
- GRB 080822B: MASTER optical observation
- New Soft Gamma Repeater 0501+4516 (GRB 080822): GLAST Burst Monitor detection
- SGR 0501+4516: optical observations
- Swift Trigger 321481: A Large Flare from SGR 0501+4516
- SGR 0501+4516: Swift-BAT refined analysis of the 3 discovery events
- Discovery of the Spin Period of the New Soft Gamma Repeater SGR 0501+4516
- GRB 080822B: Swift detection of a burst
- GRB080818B: GLAST Burst Monitor detection
- Third event from SGR 0501+4516
- GRB 080822 (SGR 0501+4516): archival optical observations
- New Soft Gamma Repeater 0501+4516 was GRB 080822
- GRB 080822: Swift detection of a short burst
- GLAST Burst Monitor detection of a GRB: 080816B
- GLAST Burst Monitor detection of GRB 080818
- GLAST Burst Monitor detection of GRB080817B
- GLAST Burst Monitor detection of GRB 080817
- GLAST Burst Monitor detection of GRB080816
- GRB080810 - optical observations
- GRB080810: optical observations
- GLAST Burst Monitor detection of GRB 080812
- Radio detection of GRB 080810 with the VLA
- GRB 080810: RTT150 optical observations
- GRB 080810: Konus-Wind and Swift/BAT joint spectral analysis
- GLAST Burst Monitor detection of GRB 080810
- GRB 080810: Liverpool and Faulkes North observations
- GRB 080810: RTT150 optical observations
- GRB080810: MITSuME optical observation
- First GLAST Burst Monitor GRB Circulars
- GRB 080810: Swift/UVOT Refined Analysis
- GRB 080810: optical observations
- GRB 080810: Liverpool Telescope observations
- GRB 080810: D50 optical observation
- GRB 080810: Kanazawa optical observation
- GRB 080810: OSN follow-up
- GRB 080810: Observations from NOT
- GRB 080810: RTT150 optical observations
- GRB 080810: Swift-XRT Team refined analysis
- GRB 080810: Enhanced Swift-XRT position
- GRB 080810: KANATA optical-NIR observation, update
- GRB 080810: ROTSE-III Prompt Detection of Optical Counterpart
- GRB 080810: Keck/HIRES Spectroscopy
- GRB 080810, Swift-BAT refined analysis
- GRB 080810 : optical observation with KANATA
- GRB 080810: Swift detection of a burst with a bright optical afterglow
- GRB 080723B: GROND upper limits
- GRB 080723B: XMM-Newton observation
- GRB 080805: VLT redshift update
- GRB 080805: Faulkes Telescope South optical observations
- GRB 080804: GROND observations
- GRB 080727B: Late VLT imaging
- GRB 080804: ATCA Radio Observations
- GRB 080805: Swift-XRT Refined Analysis
- GRB 080805: Swift/UVOT Upper Limits
- GRB 080804: Swift-XRT Refined Analysis
- GRB 080804: Swift/UVOT Refined Analysis
- GRB 080805, Swift-BAT refined analysis
- GRB 080804, Swift-BAT refined analysis
- GRB 080804: Enhanced Swift-XRT position
- GRB080804: Gemini South redshift confirmation
- GRB 080804: Faulkes Telescope South observations
- GRB080805 optical limit by "Pi of the Sky"
- GRB 080805: VLT redshift
- GRB 080805: Afterglow confirmation
- GRB 080805: GROND detection of possible afterglow
- GRB 080805: Swift detection of a burst
- GRB 080804: UVES redshift
- GRB 080804: Swift detection of a burst with optical afterglow
- GRB 080804: ROTSE-III Detection of Optical Counterpart
- GRB 080802: Swift/UVOT Upper Limits
- GRB 080802: Swift-XRT Refined Analysis
- GRB 080802: UVI Telescope Upper Limit
- GRB 080802, Swift-BAT refined analysis
- GRB 080802: Swift detection of a probable burst
- GRB 080727C: Suzaku WAM observation of the prompt emission
- GRB 080727B: IR photometry
- GRB 080727A: Early IR observations
- GRB 080727C: TAROT Calern observatory optical observations
- GRB 080727B: KAIT photometry and an early lightcurve break
- GRB 080727B: GROND redshift limit
- GRB 080727C, Swift-BAT refined analysis