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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"

27416 results found.

  1. GRB 090201: Swift detection of a burst
  2. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  3. GRB 090129: Swift-BAT refined analysis
  4. GRB 090129: Swift detection of a burst
  5. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  6. GRB 090126C: Fermi GBM detection
  7. GRB 090126A: Swift-XRT Refined Analysis
  8. GRB 090126B: Fermi GBM detection
  9. GRB 090123: GROND detection
  10. GRB 090123: Swift XRT refined analysis
  11. GRB 090123: Swift/UVOT Observations
  12. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  13. GRB 090123: Swift-BAT refined analysis
  14. GRB 090123: Swift detection of a burst
  15. Swift-BAT trigger 340734 is not a GRB
  16. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  17. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  18. AXP 1E1547.0-5408: Fermi GBM observations
  19. Trigger 340734: Swift detection of a possible short burst
  20. AXP 1E1547.0-5408 activity with SGR bursts
  21. GRB 090118 (BATSS): GRT Optical Observation
  22. GRB 090118: Swift-XRT observations
  23. GRB090118 Swift/UVOT upper limits
  24. GRB 090118: GROND Upper Limits
  25. GRB 090118: Possible burst detection from Swift-BAT slew data
  26. GRB 090117B : Fermi GBM detection
  27. GRB 090117C - Fermi GRB Detection
  28. GRB 090117 - Fermi GBM Observations
  29. GRB 090117: GROND Upper Limits
  30. GRB090102: MAGIC telescope GeV observation
  31. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  32. GRB 090113: Swift UVOT upper limits
  33. GRB 090113: GROND Upper Limits
  34. GRB 090113: Swift-XRT refined analysis
  35. GRB 090113: Swift-BAT refined analysis
  36. GRB 090113: ROTSE-III Optical Limits
  37. GRB090113: XRT position
  38. GRB 090112B: Fermi GBM Detection
  39. GRB 090113: Swift detection of a burst
  40. GRB 090112: Fermi GBM detection
  41. GRB 090109: Fermi GBM detection
  42. GRB 090108B: Fermi GBM detection
  43. GRB 090111, Swift-BAT refined analysis
  44. GRB 090111: Swift UVOT Upper Limits
  45. GRB 090108: Fermi GBM Detection
  46. GRB 090111: Swift-XRT refined analysis
  47. GRB 090111: Swift detection of a burst
  48. GRB090107B: Fermi GBM Detection
  49. GRB 090107B: Swift XRT afterglow confirmation
  50. GRB 090107B: Swift/UVOT Observations
  51. GRB 090107B: Swift-XRT detection of possible afterglow
  52. GRB 090107B: ROTSE-III Optical Limits
  53. Fermi/GBM detection of GRB 081226A
  54. Fermi/GBM detection of GRB 081225
  55. GRB 090107: Swift-BAT refined analysis
  56. GRB 090107: Swift detection of a burst
  57. GRB 081231: Fermi GBM Detection
  58. GRB 090102: GRT Optical Observation
  59. Swift triggered on the HMXB 1A 1118-61
  60. Konus-Wind observation of GRB 090102
  61. GRB 081229: Fermi GBM detection
  62. Swift UVOT observations of GRB 090102
  63. GRB 090102: Swift-BAT refined analysis
  64. GRB 090102: Swift XRT refined analysis
  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. GRB 081230 Swift/UVOT Observations
  71. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  72. GRB 081230: ROTSE-III Detection of Optical Counterpart
  73. GRB 081230: Swift detection of a burst
  74. GRB 081228: GROND confirmation of the optical/NIR afterglow
  75. GRB 081226B: Fermi GBM observation
  76. GRB 081226C: Fermi GBM detection
  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: TAROT Calern observatory optical observations
  82. GRB 081228: Swift detection of a burst
  83. GRB 081226B: Swift XRT and UVOT upper limits
  84. GRB 081224: Suzaku WAM observation of the prompt emission
  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. GRB 081224: Fermi GBM Detection & LAT Localization
  92. Konus-Wind observation of GRB 081222
  93. GRB 081223: Fermi GBM detection
  94. GRB 081221: GROND observations
  95. GRB 081222: Fermi GBM observation
  96. Fermi Gamma-ray Burst Monitor trigger 251687595 reclassification
  97. GRB081222: Swift/UVOT further observations
  98. GRB 081204C: Fermi GBM detection
  99. GRB 081222, Swift-BAT refined analysis
  100. GRB 081221, Swift-BAT refined analysis

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