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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"

27039 results found.

  1. GRB 140103A: Lulin Optical r-band Observations
  2. Swift-BAT trigger 582894 is HR 1099 (Flare star)
  3. GRB140104A : Xinglong TNT observation. A bright star is located nearby
  4. GRB 140102A, Optical Observations
  5. GRB 140103A: P60 Observations
  6. GRB 140102A: P60 observations
  7. GRB 131231A: Swift/UVOT Observations of the Optical Afterglow
  8. GRB 140103A: Swift/UVOT Upper Limits
  9. GRB 140102A: Fermi/GBM Observation
  10. GRB 131229A: Suzaku WAM observation of the prompt emission
  11. Konus-Wind observation of GRB 140102A
  12. GRB 140103A: Swift-XRT refined analysis
  13. GRB 140102A: GROND observations
  14. GRB 140103A, Swift-BAT refined analysis
  15. GRB 140102A: MAXI/GSC detection
  16. GRB 140102A, Swift-BAT refined analysis
  17. GRB 140102A: Swift-XRT refined Analysis
  18. GRB 140103A: MASTER-Net optical observations
  19. GRB 140102A: Fermi-LAT detection of a burst
  20. GRB 140103A: Swift detection of a burst
  21. GRB 140102A: Early optical observations from Nanshan
  22. GRB 140102A: Swift detection of a burst with optical counterpart
  23. GRB 131231A: Gemini-South Redshift
  24. GRB 131229A: Fermi GBM detection
  25. GRB 131231A: Swift-XRT observations
  26. GRB 131231A: Fermi GBM detection
  27. GRB 131231A: iPTF optical afterglow candidate coincident with Nanshan detection
  28. GRB 131231A: afterglow confirmation from the NOT
  29. GRB 131231A: Nanshan afterglow candidate
  30. GRB 131231A: Fermi-LAT detection of a burst
  31. Konus-Wind observation of GRB 131229A
  32. GRB 131229A: Magellan upper limit
  33. GRB 131229A: GROND observations
  34. GRB 131229A: Swift-BAT refined analysis
  35. GRB 131229A: Swift-XRT refined Analysis
  36. GRB 131229A: Swift/UVOT Upper Limits
  37. GRB 131227A: GROND Upper Limits
  38. GRB 131229A: Swift detection of a burst
  39. GRB 131227A: P60 Limits
  40. GRB 131227A: Gemini-North Redshift
  41. GRB 131227A: Swift-XRT refined Analysis
  42. GRB 131227A: Xinglong optical observations
  43. GRB 131227A: Swift/UVOT Upper Limits
  44. GRB 131227A: Swift-BAT refined analysis
  45. Konus-Wind observation of GRB 131226A
  46. GRB 131227A: Swift detection of a burst
  47. GRB 131224A: Swift/UVOT Upper Limits
  48. GRB 131225A: MASTER-Net optical observations
  49. GRB 131226A, Swift-BAT refined analysis
  50. GRB 131226A: Swift detection of a burst
  51. GRB 131216A: Suzaku WAM observation of the prompt emission
  52. GRB 131224A: Swift-XRT observation
  53. GRB 131224A: MASTER-Net early optical observations
  54. GRB 131218A: GROND Upper Limits
  55. GRB 131218A: Swift XRT and UVOT observations
  56. Fermi Gamma-ray Burst Monitor trigger 409187680/131219968 is not a GRB
  57. GRB 131218A: Zadko observatory - Gingin optical candidate
  58. GRB 131218A: TAROT La Silla observatory optical observations
  59. IPN Triangulation of GRB 131216A
  60. GRB 131216A: Fermi GBM observation
  61. GRB 131216A: Fermi-LAT detection of a burst
  62. Trigger 581129: Swift-BAT triggered on noise
  63. INTEGRAL Weak trigger #6403: AROMA-N Optical Observation
  64. GRB 131209A: Swift XRT and UVOT observations
  65. GRB 131209A: Fermi GBM observation
  66. IPN Triangulation of GRB 131209A
  67. GRB 131209A: Fermi-LAT detection of a burst
  68. GRB 131205A: Swift-BAT refined analysis
  69. GRB 131205A: Swift-XRT refined Analysis
  70. Swift Trigger 580319 is not a GRB
  71. GRB 131205A: Swift/UVOT Upper Limits
  72. GRB 131205A: Zadko observatory - Gingin optical observations
  73. GRB 131205A: Swift detection of a burst
  74. GRB 131127B: rejection of optical counterpart candidates
  75. GRB 131126A: Fermi GBM observation
  76. GRB 131126A: iPTF upper limits on the afterglow of a short GRB
  77. GRB 131127A: optically dark burst
  78. GRB 131202A, Swift-BAT refined analysis
  79. GRB 131202A: Swift/UVOT Upper Limits
  80. GRB 131202A: Swift-XRT refined Analysis
  81. GRB 131202A: RATIR Optical and NIR Observations
  82. GRB 131202A: Fermi GBM Detection
  83. GRB 131202A: Bassano Bresciano Observatory optical upper limit
  84. GRB 131202A: Tautenburg observations
  85. GRB 131202A: Swift detection of a burst
  86. GRB 131122A: Swift-XRT Further Observation
  87. GRB 131128A: Bassano Bresciano Observatory optical upper limit
  88. GRB 131127A: RATIR Rejection of High-z Candidate
  89. GRB 131128A; Fermi GBM observation
  90. GRB 131125A: iPTF upper limits on the afterglow of a short GRB
  91. IPN Triangulation of GRB 131126A (short/hard)
  92. GRB 131128A: GROND observations of the afterglow
  93. IPN Triangulation of GRB 131125A (short/hard)
  94. GRB 131128A: Swift/UVOT Detection
  95. GRB 131128A: AROMA-N Optical Observation
  96. GRB 131127B: Bassano Bresciano Observatory optical observations
  97. GRB 131128A: Swift-XRT refined Analysis
  98. GRB 131128A: Kanata/HOWPol optical observation
  99. GRB 131128A: T100 observations
  100. GRB 131128A: Swift-BAT refined analysis

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