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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"

25953 results found.

  1. INTEGRAL observation of IceCube-180908A
  2. IceCube-180908A: HAWC follow-up
  3. Search for counterpart to IceCube-180908A with ANTARES
  4. GRB 180715A: 15 GHz upper limits from the AMI Short GRB Program
  5. GRB 180718A: 15 GHz upper limits from the AMI Short GRB Program
  6. GRB 180905A: Swift/UVOT Upper Limits
  7. GRB 180905A, Swift-BAT refined analysis
  8. GRB 180905A: RATIR Optical and NIR Observations
  9. GRB 180905A: Swift-XRT refined Analysis
  10. GRB 180905A: Enhanced Swift-XRT position
  11. GRB 180904A: AbAO optical upper limit
  12. GRB 180904A: Swift/UVOT Upper Limits
  13. GRB 180904A: RATIR Optical and NIR Observations
  14. GRB 180904A: Swift-BAT refined analysis
  15. GRB 180905A: Swift detection of a burst
  16. GRB 180904A: Swift-XRT refined Analysis
  17. GRB 180904A: SAO RAS optical observations
  18. GRB 180904A: OSN observations
  19. GRB 180904A: Enhanced Swift-XRT position
  20. GRB 180904A: NOT optical observations, candidate host galaxy
  21. GRB 180904A: Swift detection of a burst
  22. GRB 180829A: Swift-XRT observations
  23. GRB 180828A: Swift/UVOT Upper Limits
  24. GRB 180828A: RATIR Optical and NIR Observations
  25. GRB 180828A: Swift-BAT refined analysis
  26. GRB 180829A/MAXI J0406-019: MAXI/GSC detection
  27. GRB 180828A: Swift-XRT refined Analysis
  28. GRB 180828A / Swift J1754.9-2548: Enhanced Swift-XRT position
  29. GRB 180828A: Fermi GBM observation
  30. GRB 180828A: Swift detection of a GRB or possible Galactic Transient Swift J1754.9-2548
  31. GRB 180818B: TSHAO optical upper limit
  32. GRB 180823A, Swift-BAT refined analysis
  33. IPN Triangulation of GRB 180824A (short)
  34. GRB 180823A: Swift/UVOT Upper Limits
  35. GRB 180823A: RATIR Optical and NIR Observations
  36. GRB 180823A: Swift-XRT refined Analysis
  37. GRB 180823A: Enhanced Swift-XRT position
  38. GRB 180823A: Swift detection of a burst
  39. GRB 180821A: VLT observations
  40. GRB 180821A: Swift/UVOT Upper Limits
  41. GRB 180821A: Swift-XRT refined Analysis
  42. GRB 180821A: Enhanced Swift-XRT position
  43. GRB 180818B: 1.5m OSN optical afterglow candidate
  44. GRB 180821A: iTelescope optical afterglow detection
  45. GRB 180821A: Swift detection of a burst
  46. GRB180806A: confirmation of the X-ray afterglow
  47. GRB 180818B: Swift-XRT refined Analysis
  48. GRB 180818B: Swift-BAT refined analysis
  49. GRB 180818A: Swift-BAT refined analysis
  50. GRB 180818B: Fermi GBM observations
  51. GRB 180818B: Swift/UVOT Upper Limits
  52. GRB 180818B: Enhanced Swift-XRT position
  53. GRB 180818A: Swift/UVOT Upper Limits
  54. GRB 180818B: Swift detection of a burst
  55. GRB 180818A: Swift-XRT refined Analysis
  56. GRB 180818A: Enhanced Swift-XRT position
  57. GRB 180818A: Swift detection of a burst
  58. GRB 180728A: discovery of the associated supernova
  59. GRB 180809A: further Swift/XRT observations
  60. Correction: Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
  61. GRB 180812A: Swift/UVOT Detection
  62. Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
  63. GRB 180812A: Swift-BAT refined analysis
  64. GRB 180812A: Fermi GBM detection
  65. GRB 180812A: Swift-XRT refined Analysis
  66. GRB 180809B: ePESSTO NTT NIR observations
  67. GRB 180812A: COATLI Detection and Light Curve
  68. GRB 180812A: Enhanced Swift-XRT position
  69. GRB 180812A: Swift detection of a burst
  70. GRB180809B TUG T60 observations
  71. MASTER: OT detection during two Fermi GBM triggers (555263883 and 555263883) error boxes inspection in 22.5 mag SDSS galaxy direction
  72. GRB 180809B: Swift-XRT refined Analysis
  73. GRB 180809B: CrAO optical observations
  74. GRB 180809B, Swift-BAT refined analysis
  75. Swift Trigger 852625: Swift/BAT/XRT/UVOT observations
  76. GRB 180809B: Swift/UVOT Detection
  77. GRB 180809A: Fermi GBM observation
  78. Swift Trigger 852625: a possible GRB
  79. GRB 180809B: VLT optical upper limits
  80. GRB180809B: MASTER Triple Independent Automatic OT Detection
  81. GRB 180809B: LCO Sutherland observations
  82. GRB 180809B: GROND Detection of the NIR Afterglow
  83. GRB 180809B: RATIR Optical Observations and Confirmation of Rapid Fading
  84. GRB180809B: MASTER OT observation
  85. GRB 180805B: Teide LCO optical observations
  86. GRB 180809A: iTelescope optical limit
  87. GRB 180809A: Swift-XRT afterglow detection
  88. GRB 180809B: Swift detection of a burst with an optical afterglow
  89. GRB 180809A: MAXI/GSC detection
  90. GRB180806A: correction to Circular 23097
  91. GRB 180806A: Swift-XRT afterglow detection
  92. GRB 180806A/180806.98: RATIR Optical Observations of MASTER OT J004613.05+242014.1
  93. GRB 180806A: Fermi GBM detection
  94. GRB 180806A/180806.94: Refined COATLI Photometry of MASTER OT J004613.05+242014.1
  95. GRB 180806.94: COATLI Detection of MASTER OT J004613.05+242014.1 and Confirmation of Fading
  96. GRB 180805B: ESO/NTT optical observations
  97. GRB 180805B: COATLI Optical Observations
  98. GRB 180805B: GOTO optical limits
  99. GRB 180805B: VLT optical and near-infrared observations
  100. GRB 180805A: Swift-XRT refined Analysis

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