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"19043 results found.
- GRB 171102B: Swift/UVOT Upper Limits
- GRB 171102B: Enhanced Swift-XRT position
- GRB 171102B: Swift detection of a burst
- GRB 171030A: Swift non-localization with BAT, XRT and UVOT
- GRB 171030A: Swift ToO observations
- IPN Triangulation of GRB 171030A (short)
- Swift Trigger 783893: KAIT Optical Observations
- Swift Triggers 784159 and 784160 are not bursts
- Swift Trigger 783893: LCO 1-m telescope observations
- Swift Trigger 783893 is probably not a GRB
- GRB 171027A: Swift/UVOT Upper Limits
- GRB 171027A: Enhanced Swift-XRT position
- GRB 171027A: RATIR Confirmation of Fading and Photo-z
- GRB 171027A: VLT optical upper limits
- GRB 171027A: RATIR Detection of a NIR Afterglow Candidate
- GROND observations of GRB 171027A
- GRB 171027A: Swift detection of a burst
- Swift Trigger 781740 is not a burst
- Fermi GBM Observations of IceCube-171015A
- GRB 171020A: Continued RATIR Optical and NIR Observation
- GRB 171020A: TAROT Calern observatory optical observations
- GRB 171020A: Swift/UVOT Upper Limits
- GRB 171020A: RATIR Optical and NIR Observations
- GRB 171020A: Enhanced Swift-XRT position
- GRB 171020A: Confirmation of OT fading
- GRB 171020A: Mini-MegaTORTORA upper limits on simultaneous optical emission
- GRB 171020A: NOT optical afterglow detection
- GRB 171020A: Swift detection of a burst
- Swift Trigger on AXP CXOU J164710.2-455216/PSR J1647-4552
- GRB 171010B: Swift-XRT afterglow detection
- Trigger 779762: Swift detection of Vela X-1
- Trigger 779351: Swift detection of Swift J0243.6+6124
- INTEGRAL SPI-ACS observation of IceCube-171015A
- Swift trigger 779171 is probably a noise fluctuation
- GRB 171010A : Optical observations from HCT
- GRB 171010A: RATIR Optical and NIR Observations
- BAT trigger 778435 is not a GRB.
- GRB 171013A: TAROT Calern observatory optical observations
- GRB 171013A: Swift detection of a possible burst
- GRB 171010A: Swift/UVOT Detection
- Konus-Wind observation of GRB 171010A
- IPN Triangulation of GRB 171011B (long/very bright)
- GRB 171010B: Swift ToO observations
- GRB 171011A: TAROT Calern observatory optical observations
- GRB 171010A: Swift-XRT afterglow detection
- GRB 171010A: optical observations
- GRB 171010A: OT, spectrum, and possible host galaxy
- GRB 171010A: Swift ToO observations
- GRB 171010A: Fermi-LAT detection
- GRB 171007A: Swift/UVOT Upper Limits
- LIGO/Virgo G298048/GW170817: updated localization from parameter estimation
- GRB 171007A: Enhanced Swift-XRT position
- GRB 171007A: Swift-XRT refined Analysis
- GRB 171007A: RATIR Optical and NIR Observations
- GRB 171007A: Swift detection of a burst
- LIGO/Virgo G298048: LWA radio observations
- GRB 171004A: Swift/UVOT Upper Limits
- GRB 171004A: Enhanced Swift-XRT position
- GRB 171004A: RATIR Optical and NIR Observations
- GRB 170710A: LCO Observations
- GRB 171004A: Swift detection of a burst
- GRB 171003A: Enhanced Swift-XRT position
- LIGO/Virgo G299232: MAGIC Cherenkov Telescopes observations
- LIGO/Virgo G299232: LOFAR follow-up
- GRB 171003A: LT early optical observations
- GRB 171003A: Swift detection of a burst or a Galactic Transient
- GRB 171001A: RATIR Optical and NIR Observations
- GRB 171001A: Nanshan-0.36m optical afterglow detections
- GRB 171001A: Swift/UVOT Detection
- GRB 171001A: IRSF Observation
- GRB171001A: D50 optical limit
- GRB 171001A: Enhanced Swift-XRT position
- GRB 171001A: Swift detection of a burst
- GRB 170728B: Kottamia R-band observation
- LIGO/Virgo G298048: Summary of Pi of the Sky observations
- IceCube-170922A: Swift-XRT observations
- LIGO/Virgo G298048: MWA Observations of Error Region
- IceCube-170922A: HAWC follow-up
- IPN Triangulation of GRB 170921B
- INTEGRAL SPI-ACS observation of AMON IceCube-170922A
- GRB 170921A: RATIR Optical Afterglow Detection and NIR Observations
- LIGO/Virgo G298048: SRT observations of SSS17a in NGC 4993
- GRB 170921A: Swift/UVOT Upper Limits
- GRB 170921A: NOT optical observations
- LIGO/Virgo G298048: LCO FLOYDS and Gemini Spectroscopy
- GRB 170921A: Nanshan optical upper limit
- GRB 170921A: Enhanced Swift-XRT position
- GRB 170921A: MITSuME Okayama upper limits
- GRB 170921A: Swift-XRT refined Analysis
- GRB 170921A: TAROT Calern observatory optical observations
- GRB 170921A: Swift detection of a burst
- LIGO/Virgo G298048: ATCA monitoring of SSS17a in NGC 4993
- LIGO/Virgo G298048: Milliarcsecond imaging of the NGC 4993 central radio source
- LIGO/Virgo G298048: ATLAS pre-discovery limits 601 to 16 days before first detection of SSS17a/DLT17ck
- LIGO/Virgo G298048: AST3-2 observations of SSS17a/DLT17ck from Antarctica
- LIGO/Virgo G298048: ATCA monitoring of SSS17a in NGC 4993
- GRB 170912B: Swift/UVOT Upper Limits
- GRB 170912A: Swift-XRT refined Analysis
- LIGO/Virgo G299232: Khureltogot observations
- GRB 170912A: Swift/UVOT Upper-Limits