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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"

19611 results found.

  1. Konus-Wind observation of GRB 090201
  2. GRB 090201: Swift-XRT refined analysis
  3. GRB090201: Swift UVOT upper limits
  4. GRB 090201: Enhanced Swift-XRT position
  5. GRB 090201: Swift-BAT refined analysis
  6. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  7. GRB 090201: ROTSE-III Optical Limits
  8. GRB 090201: Swift detection of a burst
  9. GRB 090126A: Swift/UVOT Upper Limits
  10. GRB 090129: Swift-BAT refined analysis
  11. GRB 090129: Swift detection of a burst
  12. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  13. GRB 090126A: Swift-XRT Refined Analysis
  14. GRB 090123: GROND detection
  15. 1E1547.0-5408: Swift detection of dust halo
  16. GRB 090123: Swift XRT refined analysis
  17. GRB 090123: Swift/UVOT Observations
  18. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  19. GRB 090123: Swift-BAT refined analysis
  20. GRB090123: Enhanced Swift-XRT position
  21. GRB 090123: Swift detection of a burst
  22. GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
  23. Swift-BAT trigger 340734 is not a GRB
  24. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  25. AXP 1E1547.0-5408: Fermi GBM observations
  26. Trigger 340734: Swift detection of a possible short burst
  27. AXP 1E1547.0-5408 activity with SGR bursts
  28. GRB 090118 (BATSS): GRT Optical Observation
  29. GRB 090118: Swift-XRT observations
  30. GRB090118 Swift/UVOT upper limits
  31. GRB 090118: GROND Upper Limits
  32. GRB 090118: Possible burst detection from Swift-BAT slew data
  33. GRB 090117: confirmation of the X-ray afterglow
  34. GRB 090117: GROND Upper Limits
  35. GRB090117 Swift/UVOT upper limits
  36. GRB090117: Swift-XRT detection of a possible candidate afterglow
  37. GRB 090113: Swift UVOT upper limits
  38. GRB 090113: GROND Upper Limits
  39. GRB 090113: Swift-XRT refined analysis
  40. GRB 090113: Enhanced Swift-XRT position
  41. GRB 090113: Swift-BAT refined analysis
  42. GRB 090113: ROTSE-III Optical Limits
  43. GRB090113: XRT position
  44. GRB 090113: Swift detection of a burst
  45. GRB 090111, Swift-BAT refined analysis
  46. GRB 090111: Swift UVOT Upper Limits
  47. GRB 090111: Swift-XRT refined analysis
  48. GRB 090111: Enhanced Swift-XRT position
  49. GRB 090111: Swift detection of a burst
  50. GRB 090107B: Swift XRT afterglow confirmation
  51. GRB 090107B: Swift/UVOT Observations
  52. GRB 090107B: Swift-XRT detection of possible afterglow
  53. Fermi/GBM detection of GRB 081226A
  54. GRB 090107: Swift-BAT refined analysis
  55. GRB 090107: Swift detection of a burst
  56. VLA radio upper limit on GRB 090102
  57. GRB 090102: GRT Optical Observation
  58. Swift triggered on the HMXB 1A 1118-61
  59. Konus-Wind observation of GRB 090102
  60. Swift UVOT observations of GRB 090102
  61. GRB 090102: Swift-BAT refined analysis
  62. GRB 090102: Swift burst of interest
  63. GRB 090102: Swift XRT refined analysis
  64. GRB 090102: Enhanced Swift-XRT position
  65. GRB 090102: TAROT Calern observatory optical light curve
  66. GRB 090102: Swift detection of a burst with an optical counterpart
  67. GRB 090102: TAROT Calern observatory optical observations
  68. GRB 081230: GROND confirmation of the afterglow
  69. GRB 081230, Swift-BAT refined analysis
  70. GRB081230: Swift-XRT refined analysis
  71. GRB 081230 Swift/UVOT Observations
  72. GRB 081230: Enhanced Swift-XRT position
  73. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  74. GRB 081230: ROTSE-III Detection of Optical Counterpart
  75. GRB 081230: Swift detection of a burst
  76. GRB 081228: GROND confirmation of the optical/NIR afterglow
  77. GRB 081228, Swift-BAT refined analysis
  78. GRB 081228: Swift/UVOT Upper Limits
  79. GRB 081228: Swift-XRT Team refined analysis
  80. GRB 081228: detection by GROND
  81. GRB 081228: Enhanced Swift-XRT position
  82. GRB 081228: TAROT Calern observatory optical observations
  83. GRB 081228: Swift detection of a burst
  84. GRB 081226B: Swift XRT and UVOT upper limits
  85. GRB 081226: Swift-XRT refined analysis
  86. GRB 081226A: Swift UVOT Upper Limits
  87. GRB 081226A: Swift-BAT refined analysis
  88. GRB 081226: ROTSE-III Optical Limits
  89. GRB 081226: Swift detection of a possible short-hard burst
  90. GRB 081224: Swift-XRT observation
  91. Konus-Wind observation of GRB 081222
  92. GRB 081221: GROND observations
  93. GRB 081222:Optical afterglow observation
  94. GRB 081222: Fermi GBM observation
  95. GRB081222: Swift/UVOT further observations
  96. GRB 081221: Probable host galaxy in Keck imaging
  97. GRB 081222, Swift-BAT refined analysis
  98. GRB 081221, Swift-BAT refined analysis
  99. GRB081222 optical limit by "Pi of the Sky"
  100. GRB 081222: Swift XRT refined analysis

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