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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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').
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"

16306 results found.

  1. GRB 170208B: Swift/UVOT Upper Limits
  2. IPN Triangulation of GRB 170209A
  3. GRB 170208B: RATIR Optical and NIR Observations
  4. Fermi Trigger 508295323: MASTER-OAFA possible OT detection
  5. GRB 170208B WHT nIR candidate afterglow
  6. GRB 170208A: Swift/UVOT Upper Limits
  7. GRB 170208B: GROND observations
  8. GRB 170208B: NOT upper limits
  9. GRB 170208B: Etelman observatory optical observations
  10. LIGO/Virgo G270580: Gemini-South Spectroscopic Classification of Optical Transients
  11. GRB 170206B: Swift/UVOT Upper Limits
  12. GRB 170205A: NOT afterglow observations
  13. GRB 170205A: RATIR Optical and NIR Observations
  14. GRB 170202A: SMARTS optical/IR afterglow observations
  15. GRB 170205A: LCO FTN observations
  16. GRB 170205A: Swift detection of a burst with an optical counterpart
  17. GRB 170202A: SQUEAN Observation (2nd night)
  18. GRB 170202A: Zadko observatory - Gingin optical observations
  19. GRB 170202A: Etelman Observatory optical observations
  20. GRB 170202A: RATIR Optical and NIR Observations
  21. GRB 170202A: LCO FTN observations
  22. GRB 170202A VLT/X-shooter redshift [minor correction]
  23. GRB 170202A: Xinglong 2.16m photometry and spectroscopic redshift
  24. GRB 170202A: MITSuME Akeno Optical Observation
  25. GRB 170202A: NOT afterglow observations
  26. GRB 170202A: Kanata optical and infrared observations
  27. GRB 170202A: Zadko observatory - Gingin optical observations
  28. GRB 170202A: LCO Sutherland observations
  29. GRB 170202A: MASTGlobal ER-Net bright OT nonmonotonic light curve
  30. GRB 170202A : Xinglong TNT optical observation
  31. GRB 170202A: Swift detection of a burst with an optical afterglow
  32. GRB 170131A: Swift/UVOT Upper Limits
  33. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  34. GRB 170127B: Swift/UVOT Upper Limits
  35. GRB 170127A: Swift/UVOT Upper Limits
  36. GRB 170127B: NOT r-band upper limits
  37. GRB 170127B: MASTER-Kislovodsk early optical observations
  38. GRB 170126A: Swift detection of a burst with an optical counterpart
  39. LIGO/Virgo G270580: NOT observations of PS17yt
  40. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  41. GRB 170121B: AbAO optical observations
  42. GRB 170121B: MASTER early optical observations of the Swift possible XT
  43. GRB 170121B: Swift-XRT and UVOT observations
  44. GRB 170121B: LCO FTN observations
  45. LIGO/Virgo G270580: A third optical transient from CNEOST
  46. GRB 170121B: Fermi GBM detection
  47. LIGO/Virgo G270580: ATLAS coverage and 4 optical transients
  48. LIGO/Virgo G270580: Two optical counterpart candidates from CNEOST
  49. LIGO/Virgo G270580: Pan-STARRS and ATLAS observations of the skymap
  50. GRB 170117A: Swift/UVOT Upper Limits
  51. GRB 170115A : AbAO optical upper limit
  52. GRB 170115A: Swift/UVOT Upper Limits
  53. GRB 170112A : AbAO optical observations
  54. GRB 170113A: VLT/X-shooter redshift
  55. GRB 170113A: GROND afterglow observations
  56. GRB 170112A: Swift/UVOT Upper Limits
  57. GRB 170113A: LCO Sutherland observations
  58. GRB 170113A: Swift detection of a burst with an optical counterpart
  59. GRB 170112A: RATIR Optical and NIR Observations
  60. GRB 161219B: afterglow and SN2016jca optical observations
  61. GRB 170111A: Swift/UVOT Upper Limits
  62. GRB 170112A: MASTER-OAFA (Argentina) early optical observations
  63. GRB 170112A: REM optical/NIR observations
  64. GRB170111A: REM optical/NIR observations
  65. LIGO/Virgo G268556: Early SWASP limits of ATLAS17aeu
  66. GRB 170111A: SMARTS optical/IR observations
  67. LIGO/Virgo G268556: Additional GROWTH follow up observation of iPTF Optical Transient Candidates
  68. GRB 170111A: MASTER-OAFA (Argentina) prompt OT observations
  69. LIGO/Virgo G268556: AMI 15 GHz detection of ATLAS17aeu
  70. LIGO/Virgo G268556: Lijiang Observatory GMG Telescope Upper Limit on ATLAS17aeu
  71. LIGO/Virgo G268556: NOWT of EWE, Xinglong 0.6/0.9m, Xuyi 1m optical upper limits of ATLAS17aeu and a reminder of GCN 20394
  72. LIGO/Virgo G268556: Swift-XRT confirms that ATLAS17aeu is fading in X-rays
  73. LIGO/Virgo G268556/GW170104: TNG spectroscopic observations of iPTF17ck and iPTF17dz
  74. LIGO/Virgo G268556: IPN Triangulation of GRB 170105A (association with ATLAS17aeu)
  75. LIGO/Virgo G268556: Continued iPTF Observations and Additional Optical Transient Candidates
  76. LIGO/Virgo G268556: Swift/UVOT observations of ATLAS17aeu
  77. LIGO/Virgo G268556: iPTF Optical Transient Candidates
  78. Discovery Channel Telescope Imaging of ATLAS17aeu (LVCG268556)
  79. LIGO/Virgo G268556: VLA follow-up of ATLAS17aeu
  80. LIGO/Virgo G268556: SWASP optical imaging
  81. LIGO/Virgo G268556: Swift-XRT sources
  82. GRB170104.78 MASTER-Net OT detection
  83. GRB 161214B: MASTER-Kislovodsk early optical observations
  84. GRB 161214A: MASTER-IAC early optical observations
  85. GRB 161219B: Spectroscopic detection of the associated SN with OSIRIS/GTC
  86. GRB 161224A: TSHAO optical observations
  87. GRB 161224A: Swift/UVOT Upper limits
  88. GRB 161219B: UKIRT near-IR afterglow detection
  89. GRB161219.78 MASTER-Net OT detection
  90. GRB 161219B: Rapid ALMA Observations & Detection
  91. GRB 161219B: SALT observations
  92. GRB 161219B: VLT/X-shooter redshift
  93. GRB 161214B: optical spectroscopy of the foreground SDSS object
  94. GRB 161219B: MITSuME Akeno Optical Observation
  95. GRB 161219B: VLA Detection
  96. GRB 161220A: GROND Upper Limits
  97. GRB 161219B: ISON/Terskol optical observations
  98. GRB 161220A: Swift/UVOT Upper Limits
  99. GRB 161219B: Watcher optical observations
  100. GRB 161219B: LCO Sutherland observations

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