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"19089 results found.
- GRB 171205A: SMARTS optical/IR afterglow observations
- Possible blackbody component in the X-ray spectrum of GRB171205A
- GRB 171205A: GOTO detection of the optical counterpart
- GRB 171205A: TNG NIR detections
- GRB 171205A: LSGT optical afterglow follow-up observation
- GRB 171205A: GMG observation
- GRB 171205A: RATIR Optical and NIR Observations
- GRB 171205A: Swift/UVOT Detection
- GRB 171205A: Enhanced Swift-XRT position
- GRB 171205A: Swift detection of a burst
- GRB 171124A: TShAO optical observations
- GRB 171124A: Swift-XRT afterglow detection
- Pan-STARRS follow-up of IceCube-171106A
- LIGO/Virgo G299232: LOFAR follow-up
- GRB 171123A: TShAO optical upper limit
- GRB 171123A: OSN Upper Limit
- GRB 171123A: Tautenburg observations
- GRB 171123A: Nanshan-1m optical upper limit
- GRB 171123A: RATIR Optical and NIR Observations
- GRB 171123A: Swift/UVOT Upper Limits
- GRB 171123A: GMG observation limit
- GRB 171124A: Swift ToO observations
- GRB 171123A: Confirmation of the X-ray afterglow
- GRB 171123A: Enhanced Swift-XRT position
- GRB 171123A: Swift detection of a burst
- GRB 171120A: Xinglong-2.16m optical upper limit
- GRB 171120A: Swift/UVOT Upper Limits
- GRB 171120A: Enhanced Swift-XRT position
- GRB 171120A: Swift detection of a burst
- Fermi-LAT Gamma-ray Observations of IceCube-171106A
- GRB 171115A: RATIR Optical and NIR Observations
- GRB 171115A: Enhanced Swift-XRT position
- GRB 171115A: Swift detection of a burst
- IPN Triangulation of GRB 171108A (short)
- IceCube-171106A: Swift Observations
- HAWC follow-up of IceCube-171106A
- GRB 171010A: afterglow and SN 2017htp optical observations
- GRB 171108A: Fermi GBM detection
- INTEGRAL observation of IceCube-171106A
- GRB 171010A: possible SN component
- GRB 171103A: Swift-BAT refined analysis of a short GRB
- GRB 171102B: AbAO optical upper limit
- GRB 171102B: TShAO optical upper limit
- IPN Triangulation of GRB 171102A
- GRB 171102B: Nanshan 0.36m and 0.60m optical upper limits
- GRB 171102B: RATIR Optical and NIR Observations
- 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