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.
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subject:"Swift"body:"GRB"submitter:"Judith Racusin"- GRB 170317A: Mondy optical observations
- GRB 170318B: Swift-BAT refined analysis
- GRB 170317A: POLAR observation
- GRB 170318B: RATIR Optical and NIR Observations
- GRB 170317A: RATIR Optical and NIR Observations
- GRB 170318B: Swift/UVOT Upper Limits
- GRB 170318B: Swift-XRT refined Analysis
- GRB 170318A: Swift-XRT refined Analysis
- LIGO/Virgo G277583: CALET Observations
- GRB 170318A: RATIR Optical and NIR Observations
- GRB 170318A: Swift/UVOT Upper Limits
- GRB 170318B: Fermi GBM observation
- GRB 170318A: Swift-BAT refined analysis
- GRB 170317A: RATIR Optical and NIR Observations
- GRB 170318B: Enhanced Swift-XRT position
- GRB 170318B: Prompt enhanced Swift-XRT position
- GRB 170318B: Swift detection of a burst
- GRB 170318A: Enhanced Swift-XRT position
- GRB 170315A: POLAR observation
- GRB 170318A: Prompt enhanced Swift-XRT position
- GRB 170318A: Swift detection of a burst
- IceCube-170312A: MASTER follow-up observations
- LIGO/Virgo G277583: Asiago spectroscopic classification of ATLAS17byo and ATLAS17cgg
- GRB 170317A: LCO FTN observations
- LIGO/Virgo G277583 : MAXI/GSC observations
- GRB 170317A: MITSuME Okayama Optical Observation
- LIGO/Virgo G275404: P200/DBSP Classification of iPTF Candidates
- LIGO/Virgo G277583: P200/DBSP Classification of ATLAS Candidates
- GRB 170317A: Swift-BAT refined analysis
- LIGO/Virgo G277583: AstroSat CZTI upper limits
- GRB 170317A: Swift/UVOT Detection
- GRB 170317A: Mondy optical observations
- GRB 170317A: MITSuME Okayama Ks-band upper-limit
- GRB 170317A: Swift-XRT refined Analysis
- IceCube-170312A: Swift-XRT observations
- GRB 170317A: GMG observation
- GRB 170317A : Xinglong TNT optical observation
- GRB 170317A: Enhanced Swift-XRT position
- GRB 170317A: ISON-Ussuriysk aferglow confirmation
- GRB 170317A: Swift detection of a burst with an optical counterpart
- LIGO/Virgo G275697: Swift-XRT source 23 no longer fading
- LIGO/Virgo G277583: Swift/BAT data search
- LIGO/Virgo G277583: Discovery Channel Telescope Follow-Up of ATLAS17cck
- LIGO/Virgo G277583: ATLAS coverage and transients over the first 2 days
- GRB 170307A: 15 GHz upper limit from AMI
- LIGO/Virgo G277583: ATLAS17cck is likely a minor planet
- LIGO/Virgo G277583: GROND follow up of ATLAS17cck
- LIGO/Virgo G277583: ATLAS17cck - a fast declining transient
- LIGO/Virgo G275697: DLT40 follow-up observation
- LIGO/Virgo G274296: DLT40 follow-up observation
- LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G277583: ERRATUM LV GCN 20871: TAROT Calern (TCA) observations
- GRB 170311B: AstroSat CZTI detection
- LIGO/Virgo G277583: TAROT Calern (TCA) observations
- LIGO/Virgo G277583: SVOM/Mini-GWAC observations of the initial skymap
- LIGO/Virgo G275404: Medicina radio follow-up of near-infrared
- Fermi GBM trigger 510642159/170308210 is not a GRB
- LIGO/Virgo G277583: INTEGRAL was inactive at the time of the event
- LIGO/Virgo G277583 ANTARES search
- Konus-Wind observation of GRB 170311B
- LIGO/Virgo G277583: AGILE GRID observations
- LIGO/Virgo G277583: AGILE MCAL observations
- LIGO/Virgo G270580: optical observations and classification of PS and MASTER sources
- LIGO/Virgo G277583: IceCube neutrino observations
- LIGO/Virgo G277583: Identification of a GW Burst Candidate
- IPN Triangulation of GRB 170311B (long/very intense)
- GRB 170311A: VLT observations
- IceCube-170312A - IceCube update on a high-energy neutrino candidate event
- INTEGRAL observation of IceCube HESE 65274589 129281
- GRB 170311A: Swift-BAT refined analysis
- LIGO/Virgo G275697: GRAWITA NOT optical observations of Swift/XRT Source 23
- GRB 170311A: Further GROND analysis
- GRB 170311A: Swift-XRT refined Analysis
- GRB 170311A: Swift/UVOT Upper Limits
- GRB 170311A: Enhanced Swift-XRT position
- SN MASTER OT J042250.16-820415.4 is the possible optical counterpart of the gravitational waves event LIGO/Virgo G274296
- GRB 170311A: GROND upper limits
- GRB 170311A: MASTER-OAFA early optical observations
- GRB 170311A: Swift detection of a burst
- GRB 170309A: POLAR Observation
- GRB170306A: SALT observations
- GRB 170306A: GROND afterglow detection
- LIGO/Virgo G275404: Swift-XRT observations of sources in the AGILE error region
- LIGO/Virgo G275697: Swift-XRT source 23 is fading
- LIGO/Virgo G275404: Updated localization from LIGO data
- GRB 170306B: POLAR observation
- GRB 170307A (trigger 741528): Swift-BAT refined analysis
- GRB 170305A: POLAR observation
- Swift trigger 741567: MASTER red star flare detection
- GRB 170307A: Fermi GBM observation
- LIGO/Virgo G275404 and AGL J1914+1043: INTEGRAL follow-up
- LIGO/Virgo G275697: Updated localization from LIGO data
- Swift Trigger 741528: a possible GRB
- Konus-Wind observation of GRB 170306B
- GRB 170306B: Swift-XRT observations
- GRB 170306A, Swift-BAT refined analysis
- GRB 170306A: Swift-XRT refined Analysis
- GRB 170306B: Fermi GBM detection
- GRB 170306B: Fermi-LAT detection
- GRB 170306B: Tiled Swift observations