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"23436 results found.
- GRB 120802A: MASTER optical observations
- GRB 120802A: optical uper limit in ISON-NM observatory
- GRB 120802A: Swift detection of a burst
- IPN Triangulation of GRB 120728B (long/intense)
- GRB 120729A: RTT150 optical observations
- Virtual Telescope observations of GRB 120729A
- GRB 120729A: UKIRT Observation
- T100 observations of GRB 120729A
- GRB 120728A: GROND Afterglow discovery
- GRB 120729A: Swift/UVOT Detection
- GRB 120729A: Xinglong TNT optical upper limit
- GRB 120729A: Enhanced Swift-XRT position
- GRB 120728A: Swift/UVOT Upper Limits
- GRB 120729A: Swift detection of a burst with an optical afterglow
- GRB 120728A: Enhanced Swift-XRT position
- Trigger 529076: Swift possible detection of SwJ1910.2-0546
- GRB 120728A: GROND observations
- GRB 120728A: Swift detection of a burst
- GRB 120727A/Galactic source: Fermi-LAT detection of a transient source
- Swift Trigger 528925 is probably a noise fluctuation
- GRB 120722A: optical upper limit
- GRB 120724A: optical observation in Maidanak observatory
- GRB 120716A: optical observation in CrAO
- GRB 120724A: Swift/UVOT Detection of the Optical Afterglow
- GRB 120724A: Enhanced Swift-XRT position
- GRB 120724A: Swift-XRT refined Analysis
- GRB 120724A: Swift detection of a burst
- GRB 120709A: Swift re-observation of the field of the X-ray counterpart candidate.
- GRB 120722A: Swift/UVOT Upper Limits
- GRB 120722A: VLT/X-shooter redshift of the host galaxy
- GRB 120722A: GROND detection of the afterglow
- GRB 120722A: 1.5m OSN I-band observations
- GRB 120722A: Enhanced Swift-XRT position
- GRB 120722A: Correction for GCN circ.13500
- GRB 120722A: Swift detection of a burst
- GRB 120716A: Swift-XRT detection
- GRB 120716A: Swift/XRT position consistent with that of the optical counterpart
- GRB 120716A: GROND confirmation of the optical/NIR afterglow
- GRB 120716A: Optical decay from NOT
- GRB 120716A: Candidate Optical Afterglow from PTF
- Konus-Wind observation of GRB 120716A
- IPN Triangulation of unusual GRB 120716A
- GRB 120714B: Swift/UVOT Detection
- GRB120714A: Swift/UVOT upper limits
- GRB 120714A: GROND upper limits
- GRB 120714B: GROND confirmation of fading afterglow
- GRB 120714B: Redshift from VLT/X-shooter
- Trigger 526660: Swift detection of 1 E 1841-045 (aka Kes 73)
- GRB 120624B: VLA Observations
- GRB 120714B: Swift detection of a burst
- GRB 120714A: Enhanced Swift-XRT position
- GRB 120712A: Fermi GBM observation
- GRB 120711A: INTEGRAL/SPI observations
- GRB120714A: UVOT non-detection
- GRB 120714A: Swift-XRT observations
- GRB120711B: MITSuME Ishigakijima upper limits
- GRB 120714A: Swift detection of a burst
- IPN Triangulation of GRB 120709A
- GRB 120712A: Swift/UVOT Detection
- GRB 120712A: VLT/Xshooter redshift
- GRB 120712A: GROND Detection of the Optical/NIR Afterglow Candidate and photo-z
- GRB 120712A: Enhanced Swift-XRT position
- GRB 120712A: Swift detection of a burst with optical afterglow
- GRB 120711B: Swift-XRT refined Analysis
- GRB 120711A: Fermi LAT Detection
- GRB 120711B: Swift/UVOT Upper Limits
- GRB 120711A: Swift/UVOT Observations
- GRB 120709A: Swift/UVOT Observations
- Konus-Wind observation of GRB 120711A
- GRB 120711A: Fermi LAT detection
- GRB 120711A: MASTER early OT detection
- GRB 120711A: Swift-XRT observations
- GRB 120711A Gemini-S likely redshift
- GRB 120711A: REM NIR early time detection
- GRB 120711A: GROND photometric redshift
- Continued Skynet/PROMPT observations of GRB120711A
- Swift detection of GRB 120711B or a new Galactic transient
- Skynet/PROMPT Observations of GRB120711A
- GRB 120709A: Fermi GBM detection
- GRB 120709A: Swift-XRT observations
- GRB 120709A: optical afterglow limits
- IPN Triangulation of GRB 120707A
- GRB 120709A: Fermi-LAT Detection
- GRB 120707A: Fermi GBM Detection of a Bright Burst
- GRB 120624B: mm detection at PdBI
- GRB 120703A: Swift/UVOT Detection
- GRB 120703A: Enhanced Swift-XRT position
- GRB 120703A: NOT optical observation
- GRB 120701A: Swift/UVOT Detection
- GRB 120701A: GROND detection of the afterglow
- GRB 120703A: Swift detection of a bright burst with an optical afterglow
- Swift Trigger 525554 is noise
- GRB 120701A: Swift-XRT afterglow detection and analysis
- GRB 120630A: Swift-BAT/-XRT/-UVOT refined analysis
- Swift Trigger 525554 is probably not a GRB
- GRB120624B: Chandra observations and afterglow detection
- GRB 120624B: Swift/UVOT Upper Limits
- Watcher follow-up observations of IGR J17062-6143 (Swift trigger 525148)
- GRB 120624B: Further analysis of the HAWKI observations
- GRB 120624B: Swift-XRT observations