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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"
  1. GRB 100805A: P60 Optical Afterglow Candidate
  2. GRB 100805A: Enhanced Swift-XRT position
  3. GRB 100805A: ROTSE-III Optical Limits
  4. GRB 100805A: Swift detection of a burst with an optical counterpart
  5. GRB 100802A: Fermi GBM observation
  6. GRB 100728B: optical photometry of ISON-NM
  7. GRB 100713A: second epoch Maidanak optical observation
  8. GRB 100713A: CrAO optical limits
  9. GRB 100802A: NOT optical observation
  10. GRB100802A: MITSuME optical upper limits
  11. GRB 100802A: P60 Observations
  12. GRB 100802A: XRT refined analysis
  13. GRB 100802A: Swift/UVOT Possible Optical Afterglow
  14. GRB 100728A: Suzaku WAM observation of the prompt emission
  15. GRB 100802A: Enhanced Swift-XRT position
  16. GRB 100802A: Swift-BAT refined analysis
  17. GRB 100802A: Liverpool Telescope observations
  18. GRB 100802A: ROTSE-III Optical Limits
  19. GRB 100802A: Possible Swift/UVOT Detection of Optical Afterglow
  20. GRB 100802A: Swift detection of a burst
  21. GRB 100725B: TELMA optical observation
  22. GRB 100728B: Swift/UVOT Observations (correction to GCN 11028)
  23. GRB 100728B: Swift/UVOT Observations (correction)
  24. GRB 100728B - NOT optical observation
  25. GRB 100728B: Swift/UVOT Observations
  26. GRB 100728B: Lick Observations
  27. GRB 100728B: Continued KAIT observations
  28. GRB 100728B, Swift-BAT refined analysis
  29. GRB 100728B: Swift-XRT Refined Analysis
  30. Konus-Wind observation of GRB 100728A
  31. GRB 100728A: GROND Detection of the NIR Afterglow Candidate
  32. GRB 100727A: Swift/UVOT Upper Limits
  33. GRB 100728A, Swift-BAT refined analysis
  34. GRB 100728B: Enhanced Swift-XRT position
  35. GRB 100728A: Swift/UVOT Upper Limits
  36. GRB 100728B: Fermi GBM observation
  37. GRB 100728A: Swift-XRT refined analysis
  38. GRB 100728B: GROND Detection of the NIR Afterglow
  39. GRB 100728B: optical detection
  40. GRB 100728B: Skynet/PROMPT Detections (correction)
  41. GRB 100728B: KAIT optical afterglow detection (correction)
  42. GRB 100728B: Swift detection of a burst with an optical counterpart
  43. GRB 100728A: Skynet/PROMPT Detections
  44. GRB 100728A: KAIT optical afterglow detection
  45. GRB 100728A: Fermi GBM observation
  46. GRB 100728A: Enhanced Swift-XRT position
  47. GRB 100728A: Swift detection of a burst
  48. GRB 100727A: Swift XRT refined analysis
  49. GRB 100727A: Fermi GBM observation
  50. GRB 100727A, Swift-BAT refined analysis
  51. GRB 100727A: Enhanced Swift-XRT position
  52. GRB100727A: MOA optical upper limit
  53. GRB 100727A: Swift detection of a burst
  54. GRB100725B: MITSuME optical upper limits
  55. GRB 100724B: AGILE/GRID analysis
  56. GRB 100724B: Suzaku WAM observation of the prompt emission
  57. GRB 100724B: gamma-ray detection by AGILE
  58. GRB 100725B: Swift-BAT refined analysis
  59. GRB 100725B: refined XRT analysis
  60. GRB 100725A: GROND upper limits
  61. GRB 100725B: Swift/UVOT Upper Limits
  62. GRB 100725A: Swift/UVOT Upper Limits
  63. GRB 100725A: Swift-BAT refined analysis
  64. GRB 100725A: Swift XRT refined analysis
  65. GRB 100725B: Enhanced Swift-XRT position
  66. GRB 100725A: Enhanced Swift-XRT position
  67. GRB100725B: Faulkes Telescope North observations
  68. GRB 100725B: Swift detection of a burst
  69. GRB100725A Faulkes Telescope South observations
  70. Konus-Wind observation of GRB 100724B
  71. GRB 100725A: Prompt enhanced Swift-XRT position
  72. GRB 100725A: Swift detection of a burst
  73. GRB 100724B: Fermi LAT and GBM analysis
  74. GRB 100724B: Fermi GBM detection
  75. GRB 100724A: Swift/BAT spectral lag results
  76. GRB 100724A: Swift XRT refined analysis
  77. GRB 100724A: Enhanced Swift-XRT position
  78. GRB 100724A: Swift/UVOT observations
  79. GRB 100724A: Swift-BAT refined analysis
  80. GRB 100724A: X-shooter redshift
  81. GRB 100724A: fading afterglow seen with GROND
  82. GRB 100724A, GROND detection of an afterglow candidate
  83. GRB 100724A: Swift detection of a burst
  84. GRB 100614A: 10.4-m GTC deep-optical limit
  85. GRB 100722A: Fermi GBM detection
  86. GRB 100718A: MASTER-Net optical prompt and alert observations
  87. GRB 100719A: Swift-BAT refined analysis
  88. GRB 100719A: Swift detection of a burst
  89. GRB 100713A: optical observation in Maidanak
  90. GRB 100713A: further inspection of TNG images
  91. GRB 100713A: Swift XRT refined analysis
  92. GRB 100713A : IRSF/SIRIUS NIR upper limits
  93. Fermi GBM trigger 300794561 (100714419) is not a GRB
  94. GRB100713A: Swift/UVOT observations
  95. GRB 100713A: GROND upper limits
  96. GRB 100713A: optical upper limit
  97. GRB 100713A: TNG optical observations
  98. GRB 100713A: TELMA and 1.5m OSN optical observations
  99. GRB100713A: Swift X-ray afterglow detection
  100. GRB 100713A: a long GRB detected by INTEGRAL

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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