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"27450 results found.
- GRB 080928, Swift-BAT initial refined analysis
- GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
- GRB 080928: Swift detection of a burst with an optical counterpart
- GRB 080925: Fermi GBM Detection
- GRB 080920: Fermi GBM detection
- GRB080922, optical upper limit
- Swift-BAT trigger 325707 is not a GRB
- Swift trigger 325707: Swift/UVOT Upper Limits
- Swift trigger 325707: Swift-XRT upper limit
- Swift detection of a possible GRB (trigger 325707)
- GRB080916A: Suzaku WAM observation of the prompt emission
- GRB080922: Swift-XRT upper limit
- GRB 080913B: Fermi GBM detection
- Trigger 324561: IGR J08408-4503 detected by Swift
- GRB 080919: Swift/UVOT Refined Analysis
- GRB 080919: Swift-XRT refined analysis
- GRB 080919, Swift-BAT refined analysis
- GRB 080916C: GROND Confirmation of the Optical Afterglow
- GRB 080916C: GROND Confirmation of the Optical Afterglow
- GRB 080919: Swift detection of a short burst
- GRB 080915A: GROND upper limits
- GRB080913: Swift-BAT spectral lag
- GRB 080916A: GROND lightcurve
- GRB 080916A: Rapid PROMPT Observations
- GRB 080916A: Fermi GBM detection
- GRB 080916C: Swift XRT refined analysis
- GRB 080916B: Swift-XRT refined analysis
- Konus-Wind observation of GRB 080916A
- Konus-Wind observation of GRB 080916C
- GRB 080916C: GROND Detection of the Optical Afterglow Candidate
- GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 080916B: Swift UVOT Refined Analysis
- GRB 080916B, Swift-BAT refined analysis
- GRB080916A: Refined Swift/UVOT Observations
- GRB 080916C: Fermi LAT observation
- GRB 080916C: Fermi GBM Detection
- GRB 080916A, Swift-BAT refined analysis
- GRB 080916B: Swift-XRT afterglow detection
- GRB 080916B: Swift detection of a burst
- GRB 080916: Swift detection of a burst with optical afterglow
- GRB 080915B, Swift-BAT refined analysis
- GRB 080912 : Fermi GBM detection
- GRB 080915B: Swift detection of a burst
- GRB 080915: Swift/UVOT Upper Limits
- GRB 080915: Swift-XRT afterglow detection and analysis
- GRB 080915, Swift-BAT refined analysis
- GRB 080915: ROTSE-III Optical Limits
- GRB 080915: Swift detection of a burst
- GRB 080913: Swift-XRT refined analysis
- GRB080913: Swift/UVOT Upper Limits
- GRB 080913, Swift-BAT refined analysis
- GRB 080913: VLT/FORS2 observations
- GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
- GRB 080913: Swift detection of a burst
- GRB 080906: Watcher observations
- Swift-BAT/-XRT refined analysis on trigger 324362 (LS I +61 303)
- GRB 080906B: Fermi GBM detection
- GRB 080905C: Fermi GBM detection
- SGR J0501+4516: radio pulsar searches with GBT and WSRT
- Swift trigger 324362 (LS I +61 303 ?): XRT
- Swift trigger 324362 (LS I +61 303 ?)
- GRB080905A: Swift/UVOT Upper Limits
- GRB 080905B: Watcher optical detection
- GRB 080904: Fermi Gamma-ray Burst Monitor detection
- GRB 080905B: Fermi Gamma-ray Burst Monitor detection
- GRB 080905A: Fermi Gamma-ray Burst Monitor detection
- GRB 080905A: MITSuME Akeno optical upper limits
- Swift Trigger 324122 is again known source Swift J1842.5-1124
- Swift Trigger 324116 is known source again
- Swift Trigger 324112 is known source Swift J1842.5-1124
- GRB 080906: Refined Swift/UVOT Observations
- GRB 080906: Swift-XRT Refined Analysis
- GRB 080906, Swift-BAT refined analysis
- GRB 080906: GROND observations of the optical/NIR afterglow
- GRB 080905B: Refined UVOT Analysis
- GRB 080905B, Swift-BAT refined analysis
- GRB 080905A, Swift-BAT refined analysis
- GRB 080906: Swift detection of a burst with optical afterglow
- GRB 080905A: Swift-XRT Refined Analysis
- GRB080825C: Fermi-LAT observations
- GRB 080905B: Swift detection of a burst with possible optical counterpart
- GRB 080905: Swift detection of a probably-short burst
- GRB 080903: Swift/UVOT Observations
- GRB 080903: Swift-XRT Refined Analysis
- GRB 080903, Swift-BAT refined analysis
- GRB 080903: Astrotel-Caucasus optical observations
- GRB 080903: TAROT Calern observatory optical observations
- GRB 080903: ROTSE-III Optical Limits
- GRB 080903: Swift detection of a burst
- GRB 080830: Fermi Gamma-ray Burst Monitor detection
- SGR 0501+4516: preliminary results of the first XMM-Newton observation
- Swift-BAT trigger 322590 is not a GRB
- Swift trigger 322590: BAT detection of a possible burst
- SGR 0501+4516: XMM-Newton monitoring schedule
- SGR 0501+4516: Decline in Activity
- GRB080823: Fermi Gamma-ray Burst Monitor detection
- GRB 080824: Fermi Gamma Ray Burst Monitor detection
- GRB080825C: GLAST Burst Monitor detection
- Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
- SGR 0501+4516: radio pulsar searches with GBT and WSRT