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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"

27424 results found.

  1. GRB 090202: Fermi GBM detection
  2. GRB 090131: Fermi GBM detection
  3. GRB 090201: Swift-XRT refined analysis
  4. GRB090201: Swift UVOT upper limits
  5. GRB 090201: Swift-BAT refined analysis
  6. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  7. GRB090113: MAGIC telescope GeV observation
  8. GRB 090201: ROTSE-III Optical Limits
  9. GRB 090201: Swift detection of a burst
  10. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  11. GRB 090129: Swift-BAT refined analysis
  12. GRB 090129: Swift detection of a burst
  13. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  14. GRB 090126C: Fermi GBM detection
  15. GRB 090126A: Swift-XRT Refined Analysis
  16. GRB 090126B: Fermi GBM detection
  17. GRB 090123: GROND detection
  18. GRB 090123: Swift XRT refined analysis
  19. GRB 090123: Swift/UVOT Observations
  20. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  21. GRB 090123: Swift-BAT refined analysis
  22. GRB 090123: Swift detection of a burst
  23. Swift-BAT trigger 340734 is not a GRB
  24. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  25. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  26. AXP 1E1547.0-5408: Fermi GBM observations
  27. Trigger 340734: Swift detection of a possible short burst
  28. AXP 1E1547.0-5408 activity with SGR bursts
  29. GRB 090118 (BATSS): GRT Optical Observation
  30. GRB 090118: Swift-XRT observations
  31. GRB090118 Swift/UVOT upper limits
  32. GRB 090118: GROND Upper Limits
  33. GRB 090118: Possible burst detection from Swift-BAT slew data
  34. GRB 090117B : Fermi GBM detection
  35. GRB 090117C - Fermi GRB Detection
  36. GRB 090117 - Fermi GBM Observations
  37. GRB 090117: GROND Upper Limits
  38. GRB090102: MAGIC telescope GeV observation
  39. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  40. GRB 090113: Swift UVOT upper limits
  41. GRB 090113: GROND Upper Limits
  42. GRB 090113: Swift-XRT refined analysis
  43. GRB 090113: Swift-BAT refined analysis
  44. GRB 090113: ROTSE-III Optical Limits
  45. GRB090113: XRT position
  46. GRB 090112B: Fermi GBM Detection
  47. GRB 090113: Swift detection of a burst
  48. GRB 090112: Fermi GBM detection
  49. GRB 090109: Fermi GBM detection
  50. GRB 090108B: Fermi GBM detection
  51. GRB 090111, Swift-BAT refined analysis
  52. GRB 090111: Swift UVOT Upper Limits
  53. GRB 090108: Fermi GBM Detection
  54. GRB 090111: Swift-XRT refined analysis
  55. GRB 090111: Swift detection of a burst
  56. GRB090107B: Fermi GBM Detection
  57. GRB 090107B: Swift XRT afterglow confirmation
  58. GRB 090107B: Swift/UVOT Observations
  59. GRB 090107B: Swift-XRT detection of possible afterglow
  60. GRB 090107B: ROTSE-III Optical Limits
  61. Fermi/GBM detection of GRB 081226A
  62. Fermi/GBM detection of GRB 081225
  63. GRB 090107: Swift-BAT refined analysis
  64. GRB 090107: Swift detection of a burst
  65. GRB 081231: Fermi GBM Detection
  66. GRB 090102: GRT Optical Observation
  67. Swift triggered on the HMXB 1A 1118-61
  68. Konus-Wind observation of GRB 090102
  69. GRB 081229: Fermi GBM detection
  70. Swift UVOT observations of GRB 090102
  71. GRB 090102: Swift-BAT refined analysis
  72. GRB 090102: Swift XRT refined analysis
  73. GRB 090102: TAROT Calern observatory optical light curve
  74. GRB 090102: Swift detection of a burst with an optical counterpart
  75. GRB 090102: TAROT Calern observatory optical observations
  76. GRB 081230: GROND confirmation of the afterglow
  77. GRB 081230, Swift-BAT refined analysis
  78. GRB 081230 Swift/UVOT Observations
  79. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  80. GRB 081230: ROTSE-III Detection of Optical Counterpart
  81. GRB 081230: Swift detection of a burst
  82. GRB 081228: GROND confirmation of the optical/NIR afterglow
  83. GRB 081226B: Fermi GBM observation
  84. GRB 081226C: Fermi GBM detection
  85. GRB 081228, Swift-BAT refined analysis
  86. GRB 081228: Swift/UVOT Upper Limits
  87. GRB 081228: Swift-XRT Team refined analysis
  88. GRB 081228: detection by GROND
  89. GRB 081228: TAROT Calern observatory optical observations
  90. GRB 081228: Swift detection of a burst
  91. GRB 081226B: Swift XRT and UVOT upper limits
  92. GRB 081224: Suzaku WAM observation of the prompt emission
  93. GRB 081226: Swift-XRT refined analysis
  94. GRB 081226A: Swift UVOT Upper Limits
  95. GRB 081226A: Swift-BAT refined analysis
  96. GRB 081226: ROTSE-III Optical Limits
  97. GRB 081226: Swift detection of a possible short-hard burst
  98. GRB 081224: Swift-XRT observation
  99. GRB 081224: Fermi GBM Detection & LAT Localization
  100. Konus-Wind observation of GRB 081222

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