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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').
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"

19550 results found.

  1. GRB 180904A: OSN observations
  2. GRB 180904A: Enhanced Swift-XRT position
  3. GRB 180904A: NOT optical observations, candidate host galaxy
  4. GRB 180904A: Swift detection of a burst
  5. GRB 180829A: Swift-XRT observations
  6. GRB 180828A: Swift/UVOT Upper Limits
  7. GRB 180828A: RATIR Optical and NIR Observations
  8. GRB 180829A: Tiled Swift observations
  9. GRB 180829A/MAXI J0406-019: MAXI/GSC detection
  10. GRB 180828A: Swift-XRT refined Analysis
  11. GRB 180828A / Swift J1754.9-2548: Enhanced Swift-XRT position
  12. GRB 180828A: Swift detection of a GRB or possible Galactic Transient Swift J1754.9-2548
  13. GRB 180728A: classification of the associated SN 2018fip
  14. GRB 180818B: TSHAO optical upper limit
  15. GRB 180823A, Swift-BAT refined analysis
  16. IPN Triangulation of GRB 180824A (short)
  17. GRB 180823A: Swift/UVOT Upper Limits
  18. GRB 180823A: RATIR Optical and NIR Observations
  19. GRB 180823A: Enhanced Swift-XRT position
  20. GRB 180823A: Swift detection of a burst
  21. GRB 180821A: VLT observations
  22. GRB 180821A: Swift/UVOT Upper Limits
  23. GRB 180821A: Enhanced Swift-XRT position
  24. GRB 180818B: 1.5m OSN optical afterglow candidate
  25. GRB 180821A: iTelescope optical afterglow detection
  26. GRB 180821A: Swift detection of a burst
  27. GRB180806A: confirmation of the X-ray afterglow
  28. GRB 180818B: Swift/UVOT Upper Limits
  29. GRB 180818B: Enhanced Swift-XRT position
  30. GRB 180818A: Swift/UVOT Upper Limits
  31. GRB 180818B: Swift detection of a burst
  32. GRB 180818A: Enhanced Swift-XRT position
  33. GRB 180818A: Swift detection of a burst
  34. GRB 180809A: further Swift/XRT observations
  35. Correction: Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
  36. GRB 180812A: Swift/UVOT Detection
  37. Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
  38. GRB 180809B: ePESSTO NTT NIR observations
  39. GRB 180812A: COATLI Detection and Light Curve
  40. GRB 180812A: Enhanced Swift-XRT position
  41. GRB 180812A: Swift detection of a burst
  42. GRB180809B TUG T60 observations
  43. GRB 180809B: Swift-XRT refined Analysis
  44. GRB 180809B: CrAO optical observations
  45. GRB 180809B: Swift/UVOT Detection
  46. Swift Trigger 852625: a possible GRB
  47. GRB 180809B: VLT optical upper limits
  48. GRB 180809B: GROND Detection of the NIR Afterglow
  49. GRB 180809B: RATIR Optical Observations and Confirmation of Rapid Fading
  50. GRB 180805B: Teide LCO optical observations
  51. GRB 180809A: iTelescope optical limit
  52. GRB 180809A: Swift-XRT afterglow detection
  53. GRB 180809A: Tiled Swift observations
  54. GRB 180806A/180806.98: RATIR Optical Observations of MASTER OT J004613.05+242014.1
  55. GRB 180806A/180806.94: Refined COATLI Photometry of MASTER OT J004613.05+242014.1
  56. GRB 180806A: Swift ToO observations
  57. GRB 180806.94: COATLI Detection of MASTER OT J004613.05+242014.1 and Confirmation of Fading
  58. GRB 180805B: ESO/NTT optical observations
  59. GRB 180805B: COATLI Optical Observations
  60. GRB 180805B: GOTO optical limits
  61. GRB 180805B: VLT optical and near-infrared observations
  62. GRB 180805B: Swift/UVOT Upper Limits
  63. GRB 180805B: Enhanced Swift-XRT position
  64. GRB 180805B: Swift detection of a burst
  65. GRB 180805A: Enhanced Swift-XRT position
  66. GRB 180805A: Swift detection of a burst
  67. GRB 180728B: MASTER optical observations short GRB IPN error box
  68. GRB 180728A: Swift/UVOT Detection
  69. GRB 180727A: Swift/UVOT Upper Limits
  70. Konus-Wind observation of the bright nearby GRB 180728A
  71. IPN Triangulation of GRB 180728B (short)
  72. GRB 180728A: Enhanced Swift-XRT position
  73. GRB 180728A: Swift-XRT observations
  74. GRB 180727A: Swift-XRT refined Analysis
  75. GRB 180727A: Swift detection of a burst
  76. GRB 180720B: OAJ optical observations
  77. GRB 180720B: KAIT Optical Observations
  78. GRB 180722A: Swift-XRT observations
  79. GRB 180718A: Swift-XRT observations
  80. GRB 180720B: MASTER Global Net OT observations
  81. GRB 180720B: REM photometry
  82. GRB 180720B: ISON-Castelgrande optical observations
  83. GRB 180720B: COATLI Optical Detection
  84. GRB 180720C: BOOTES-2/TELMA optical observations
  85. GRB 180722A: Tiled Swift observations
  86. GRB 180721A: Swift/UVOT Upper Limits
  87. FRB 180714: MASTER optical inspection of the Fast Rado Burst Transient
  88. ANTARES neutrino Alert180713.02: MASTER optical observation
  89. GRB 180720B: Swift-BAT refined analysis
  90. GRB 180721A: Enhanced Swift-XRT position
  91. GRB 180721A: Swift detection of a burst
  92. GRB 180720C: Swift/UVOT Upper Limits
  93. GRB 180720C: Enhanced Swift-XRT position
  94. GRB 180720C: Swift detection of a burst or possible Galactic Transient
  95. GRB 180720B : TSHAO optical observations
  96. GRB 180715A: MASTER optical observation
  97. GRB 180720B: Kanata 1.5m optical/NIR observation
  98. GRB 180720B: Swift detection of a burst
  99. GRB 180715A: Gemini imaging upper limits
  100. GRB 180715A: Swift/UVOT Upper Limits

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