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.
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"20985 results found.
- GRB 170203A: 15 GHz upper limits from AMI
- GRB 170202A: 15 GHz upper limits from AMI
- GRB 170209A: Swift-XRT observations
- GRB 170209A: Swift ToO observations
- GRB 170208B: Swift/UVOT Upper Limits
- GRB 170208B: RATIR Optical and NIR Observations
- GRB 170209A: Fermi GBM Detection
- Correction to GCN 20640: GRB 170208B: GROND observations
- Fermi Trigger 508295323: MASTER-OAFA possible OT detection
- GRB 170208A: Swift/UVOT Upper Limits
- GRB 170208B: GROND observations
- GRB 170208B: NOT upper limits
- GRB 170208B: Etelman observatory optical observations
- GRB 170206B: Swift/UVOT Upper Limits
- GRB 170206A: POLAR observation
- GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
- GRB 170205A: NOT afterglow observations
- GRB 170205A: RATIR Optical and NIR Observations
- GRB 170202A: SMARTS optical/IR afterglow observations
- GRB 170205A: LCO FTN observations
- GRB 170202A: SQUEAN Observation (2nd night)
- GRB 170202A: Zadko observatory - Gingin optical observations
- GRB 170202A: Etelman Observatory optical observations
- GRB 170202A: RATIR Optical and NIR Observations
- GRB 170202A: SQUEAN Observation
- GRB 170202A: LCO FTN observations
- GRB 170202A: T100 observations
- GRB 170202A VLT/X-shooter redshift [minor correction]
- GRB 170202A: Swift/UVOT Detection
- GRB 170202A: Redshift from OSIRIS/GTC
- GRB 170202A: NOT afterglow observations
- GRB 170202A: Kanata optical and infrared observations
- GRB 170202A: Zadko observatory - Gingin optical observations
- GRB 170202A: LCO Sutherland observations
- GRB 170202A : Xinglong TNT optical observation
- GRB 170131A: Swift/UVOT Upper Limits
- GRB 170131A: Swift-XRT observations
- GRB 170131A: Swift ToO observations
- LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
- GRB 170127C: Swift-XRT observations
- GRB 170127A: GROND Upper limits
- GRB 170127B: Swift/UVOT Upper Limits
- GRB 170127A: Swift/UVOT Upper Limits
- GRB 170127C: Tiled Swift observations
- LIGO/Virgo G270580: HAWC follow-up observations
- GRB 170127B: MASTER-Kislovodsk early optical observations
- LIGO/Virgo G270580: Swift/UVOT follow-up of PS17yt
- GRB 170126A: Swift/UVOT Detection of a Fading Afterglow
- LIGO/Virgo G270580: Fermi GBM Observations
- GRB 170115A: 15 GHz upper limits from AMI
- LIGO/Virgo G270580: MAXI/GSC observations
- LIGO/Virgo G270580: NOT observations of PS17yt
- LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G270580: Asiago 1.82m observations of PS17ua and PS17yt
- LIGO/Virgo G270580: 10.4m GTC spectroscopic observations of PS17yt
- LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
- GRB 170121B: AbAO optical observations
- LIGO/Virgo G270580: UL50 observations
- GRB 170121B: MASTER early optical observations of the Swift possible XT
- LIGO/Virgo G270580: CALET Observations
- GRB 170121B: Swift-XRT and UVOT observations
- LIGO/Virgo G270580/GW170120 : Asiago observations
- GRB 170121B: LCO FTN observations
- LIGO/Virgo G268556/GW170104: MAXI/GSC observations
- GRB 170121B: Swift ToO observations
- LIGO/Virgo G270580: ATLAS coverage and 4 optical transients
- GRB 170121B/Fermi trigger 506702667 MASTER-Amur OT detection
- LIGO/Virgo G270580: Two optical counterpart candidates from CNEOST
- LIGO/Virgo G270580: INTEGRAL search of temporally coincident prompt hard X-ray
- LIGO/Virgo G270580: Swift-XRT sources
- LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
- LIGO/Virgo G270580: Mini-MegaTORTORA follow-up observations
- LIGO/Virgo G270580: Pan-STARRS and ATLAS observations of the skymap
- LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
- LIGO/Virgo G270580: AGILE MCAL and Super-AGILE Observations
- GRB 170117A: Swift/UVOT Upper Limits
- GRB 170117A: Swift-XRT observations
- GRB 170117A: Swift ToO observations
- GRB 170115A: Swift/UVOT Upper Limits
- GRB 170115B: Swift-XRT observations
- LIGO/Virgo G268556: Swift-XRT observations of iPTF17cw
- GRB 170112A : AbAO optical observations
- GRB 170115B: Tiled Swift observations
- GRB 170113A: VLT/X-shooter redshift
- GRB 170113A: GROND afterglow observations
- GRB 170113A: Swift/UVOT Observations
- GRB 161214B: 15 GHz upper limits from AMI
- GRB 170113A: Fermi GBM observations
- GRB 170112A: Swift/UVOT Upper Limits
- GRB 170101A: 15 GHz upper limits from AMI
- GRB 170113A: LCO Sutherland observations
- GRB 161217A: 15 GHz upper limits from AMI
- LIGO/Virgo G268556: TZAC TAROT network observations with TRE/TCA/TCH
- GRB 170112A: RATIR Optical and NIR Observations
- GRB 161219B: afterglow and SN2016jca optical observations
- GRB 170111A: Swift/UVOT Upper Limits
- GRB 170112A: Swift-XRT observations
- GRB 170112A: MASTER-OAFA (Argentina) early optical observations
- GRB 170112A: REM optical/NIR observations