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"2796 results found.
- IPN triangulation of short hard GRB 081209
- GRB 081203A: optical observations
- Swift-XRT observations of GRB 081203B
- Swift-BAT Trigger 334129: possible burst
- SGR 1806-20: Fermi GBM detection
- GRB 081024: Swift detection of a burst
- GRB 081017, Swift-BAT refined analysis
- GRB 081016B: ROTSE-III Optical Limits
- GRB 081016B: Swift detection of a burst
- Swift detection of flare on CC Eri
- Detection of flare star Algol in Swift-BAT slew data
- Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
- GRB 080928: Swift-XRT refined analysis
- GRB 080916B: Swift detection of a burst
- GRB 080903: optical observations
- GRB 080903: Liverpool Telescope observations
- GRB 080903: Astrotel-Caucasus optical observations
- GRB 080903: Optical afterglow candidate
- SGR 0501+4516: Decline in Activity
- Konus-Wind observations of new SGR 0501+4516
- INTEGRAL ToO Observation of SGR0501+4516
- Trigger 321551: Continued Large Flaring of SGR 0501+4516
- Swift Trigger 321481: A Large Flare from SGR 0501+4516
- GRB080810: optical observations
- GRB 080810: Swift/UVOT Refined Analysis
- GRB 080810: Liverpool Telescope observations
- GRB 080810: D50 optical observation
- GRB 080810: Observations from NOT
- GRB 080810: ROTSE-III Prompt Detection of Optical Counterpart
- GRB 080810: Keck/HIRES Spectroscopy
- GRB 080810: Swift detection of a burst with a bright optical afterglow
- GRB 080723B: XMM-Newton observation
- GRB 080727B: IR photometry
- GRB 080723B - Swift-XRT position
- GRB 080710: REM afterglow confirmation & brightening
- GRB 080707: VLT redshift
- GRB 080703: UVOT Follow-Up Observation
- GRB 080703: VLT observations of the afterglow
- GRB 080703: Swift detection of a burst with optical afterglow
- GRB 080703A: ROTSE-III Detection of Optical Counterpart
- GRB 080623: Swift XRT prompt analysis
- GRB 080613B: GROND Upper Limits
- GRB 080605: MASTER VWF 46 s AT observation
- GRB 080605: Swift detection of a burst with an optical afterglow
- Swift/UVOT observations of GRB080604
- GRB 080604: Early Super-LOTIS Observations
- GRB080604: confirmation of optical afterglow
- GRB 080604: Swift detection of a burst with an optical afterglow
- Konus-Wind observation of reactivation of SGR 1627-41
- Reactivation of SGR 1627-41
- IPN triangulation of bright GRB 080513
- GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
- GRB 080503: Late-time Optical rebrightening (possible mini-SN)
- GRB 080503: Enhanced Swift-XRT position
- GRB 080503: New candidate afterglow/host in Gemini imaging
- GRB 080503: Swift detection of a short burst
- Swift-BAT trigger 309665 is not a GRB
- GRB 080420?: Swift detection of a possible short burst
- GRB 080413A, Swift-BAT refined analysis
- GRB080330: MAGIC telescope GeV observation
- GRB 080405: Swift-BAT refined analysis
- GRB 080328: Swift detection of a burst with an optical counterpart
- GRB 080320: Early Super-LOTIS Observations
- GRB 080319A/B/C: INTEGRAL SPI-ACS light curves available
- GRB 080319b light curve by Pi-of-the-Sky
- GRB 080319b prompt optical observation by Pi-of-the-Sky
- GRB080310: Optical observation by MITSuME telescope
- GRB080307: Optical upper limits
- GRB 080218B: Swift detection of a burst
- GRB080212: Optical afterglow candidate observed by MITSuME Telescope
- GRB 080205: Swift/UVOT observations
- GRB 080205: Enhanced Swift-XRT position
- GRB 080205: KAIT OA detection
- GRB 080205: Swift detection of a burst
- GRB 080129: GROND detection in all bands, and fading
- GRB 080129: GROND detection of the optical/NIR afterglow, and fading
- IPN triangulation of GRB080122
- GRB 080121: Nearby SDSS galaxies
- GRB 080120: Swift-XRT refined analysis
- GRB080120: Swift XRT position
- GRB 071227: Swift detection of a burst
- GRB071020: optical observations
- GRB 071122 Swift-XRT refined analysis
- GRB 071122: Corrected P60 Coordinates
- GRB 071122: P60 Optical Afterglow Candidate
- GRB 071122: Swift detection of a burst
- GRB 071118, Swift-BAT refined analysis
- VLT FORS2 observations of short hard GRB071112B
- ATCA radio observations of short hard burst GRB 071112B
- GRB 071112C: SARA upper limit
- GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
- GRB 071028B Swift-BAT detection of a burst
- GRB 071025: Kuiper Telescope Optical Observations
- GRB 071025, Swift-BAT refined analysis
- GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
- GRB 071013: TNT optical data refined analysis
- GRB 071010B: Photometry after 1.6 days
- GRB 071010A: Continued Keck Imaging
- GRB 071006, Swift-BAT refined analysis
- GRB 071010B: Swift detection of a burst