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"4046 results found.
- GRB 090418B: Detection of a bright burst from Swift-BAT slew data
- GRB 090417B: MITSuME Okayama optical upper limits
- GRB090417B: Xinglong TNT optical upper limit
- GRB 090417A: Early-type nature of the putative host
- GRB 090417A: nearby galaxy redshift
- GRB 090408b: IPN Triangulation
- GRB 090328b: IPN Triangulation
- GRB 090407: ROTSE-III Optical Limits
- GRB 090407: Swift detection of a burst
- GRB 090404: Swift detection of a burst
- GRB 090328: BOOTES-3 optical observations
- GRB 090328: Gemini South Redshift
- SGR J1550-5418: two Fermi GBM triggers on March 22
- A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
- GRB 090313: Ongoing plateau phase
- GRB 090205: Zadko Telescope late-time observations
- GRB 090309: Swift detection of a burst
- ATCA observation of SGR J1550-5418
- GRB 090306B: Burst detection from Swift-BAT slew data
- GRB 090303: Fermi GBM detection
- Konus-RF catches first GRB and SGR bursts
- SGR J1550-5418
- Ongoing activity of AXP/SGR 1E1547.0-5408
- GRB 090217: Fermi GBM detection
- SGR activity seen by BAT during ICSP Ionospheric Events
- Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
- Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
- GRB 090129: Fermi GBM detection
- ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
- GRB 090201: ROTSE-III Optical Limits
- Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
- Suzaku ToO Observation of AXP 1E 1547.0-5408
- Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
- AXP 1E1547.0-5408: RHESSI observations up to 400 keV
- Konus-Wind detection of very bright SGR-like burst on January 25, 2009
- AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
- Trigger 340734: Swift detection of a possible short burst
- AXP 1E1547.0-5408 activity with SGR bursts
- GRB 090117C - Fermi GRB Detection
- GRB 090113: LOAO Detection Limits in R, I, z, Y-band
- GRB 090108: Fermi GBM Detection
- GRB 081231: Fermi GBM Detection
- GRB 081229: Fermi GBM detection
- GRB 090102: Swift detection of a burst with an optical counterpart
- GRB 081230: GROND confirmation of the afterglow
- GRB 081230 Swift/UVOT Observations
- GRB 081230: Swift/UVOT Detection of an Optical Afterglow
- GRB 081230: ROTSE-III Detection of Optical Counterpart
- GRB 081230: Swift detection of a burst
- Konus-Wind observation of GRB 081222
- Swift/UVOT observations of GRB 081221
- GRB 081222: GROND Detection of the Optical/NIR Afterglow
- Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
- GRB 081203A: optical observations
- GRB 081206B: Fermi GBM detection
- GRB 081206: Fermi GBM detection
- GRB081203A: MITSuME optical observation
- GRB 081203A: Optical observations of Xinglong TNT telescope
- GRB 081204: Swift XRT afterglow candidate
- GRB081203A: optical observation
- GRB081203: optical observation
- GRB 081203: Swift detection of a burst with a bright optical counterpart
- Swift Trigger 335971: Swift/UVOT Observations
- GRB 081129: Fermi GBM detection
- SGR 1806-20: Fermi GBM detection.
- GRB 081126: Swift observations continuing
- GRB 081119: Fermi GBM detection
- SGR 1806-20: Fermi GBM detection
- GRB 081104: GROND found no Optical/NIR Afterglow
- SGR 0501+4516: optical observations in August
- GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
- SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
- SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
- Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
- GRB 081024B: BTA deep optical observations
- GRB 081028: CrAO optical observations
- GRB 081029, SMARTS optical/IR afterglow observations
- GRB 081029: Redshift Confirmation from Gemini-South
- GRB 081029: REM observations
- GRB 081029: UVES/VLT Absorption Redshift
- GRB 081028: Swift-XRT refined analysis
- GRB 081024: Swift detection of a burst
- GRB 081012, Swift-BAT refined analysis
- GRB081006: Fermi GBM detection
- Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
- GRB 081003B: Swift-XRT upper limit
- GRB 081003A: OSN optical observations
- GRB 081003A: Swift-XRT Team position and analysis
- AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
- SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
- Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
- Trigger 330353: Swift detection of a Galactic short soft burst
- GRB 080928: VLT redshift
- GRB080928: Gemini-South Absorption Redshift
- GRB 080928: GROND DETECTION
- GRB 080925: Fermi GBM Detection
- SGR 0501+4516: preliminary results of the Suzaku ToO observation
- GRB 080915B, Swift-BAT refined analysis
- SGR 0501+4516 : P200 i-band observations
- GRB 080905C: Fermi GBM detection