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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

45739 results found.

  1. GRB 121125A: Swift detection of a burst with optical counterpart
  2. GRB 121123A: GROND observations
  3. GRB 121123A: Enhanced Swift-XRT position
  4. GRB 121123A: Swift-BAT refined analysis
  5. GRB 121123A: Swift-XRT refined Analysis
  6. GRB 121123A: optical observations
  7. GRB 121123A: BOOTES-4 and IAC80 optical observations
  8. GRB 121123A: NOT optical observations
  9. GRB 121123A: Fermi GBM observation
  10. GRB 121123A: MASTER-NET optical limit
  11. GRB 121123A: GMG optical observation
  12. GRB 121123A: Swift detection of a burst with optical counterpart
  13. GRB 121108A: optical upper limit
  14. GRB 121117A: Optical observations
  15. Konus-Wind observation of GRB 121118B
  16. GRB 121117A: optical upper limit
  17. IPN Triangulation of GRB 121118B (long/intense)
  18. GRB 121117A: GROND confirmation of the UVOT afterglow candidate
  19. IPN Triangulation of GRB 121118A
  20. Swift-BAT trigger 538575 is not astrophysical
  21. GRB 121117A: Swift/UVOT Observations
  22. GRB 121117A: Swift-XRT refined Analysis
  23. GRB 121117A: MASTER prompt optical limit
  24. GRB 121117A, Swift-BAT refined analysis
  25. GRB 121117A: ROTSE-III Optical Limits
  26. GRB 121117A: BOOTES-3 early optical upper limit
  27. GRB 121117A: Swift detection of a burst
  28. Swift trigger 538575: Magellan Observations
  29. Fermi GBM trigger 121115.186 is not a GRB
  30. Trigger 538084: Swift detection of XTE J1739-302
  31. GRB 121108A: Swift-XRT refined Analysis
  32. GRB 121108A: Swift/UVOT Upper Limits
  33. GRB 121108A, Swift-BAT refined analysis
  34. GRB 121108A: Xinglong TNT upper limit
  35. GRB 121108A: Enhanced Swift-XRT position
  36. GRB 121108A : Lulin/TRIPOL2 Optical Limits
  37. GRB 121108A: Optical observations
  38. GRB 121108A: MITSuME Ishigakijima upper limits
  39. GRB 121108A: Weihai observatory optical observations
  40. GRB 121108A: MASTER early prompt optical limit
  41. GRB 121108A: TAROT Calern observatory optical observations
  42. GRB 121108A: Swift detection of a burst
  43. GRB 121031A: Fermi GBM detection
  44. GRB 121028A: Swift/UVOT Upper Limits
  45. GRB 121031A, Early peak observed with Swift-BAT
  46. GRB 121102A: Swift/UVOT Upper Limits
  47. GRB 121031A: Swift/UVOT Upper Limits
  48. GRB 121031A: Swift-XRT refined Analysis
  49. GRB 121102A: Enhanced Swift-XRT position
  50. GRB 121031A: Enhanced Swift-XRT position
  51. GRB 121102A: Swift-XRT refined Analysis
  52. GRB 121102A: Swift-BAT refined analysis
  53. GRB 121025A: Confirmation of the X-ray afterglow
  54. GRB 121029A Suzaku WAM observation of the prompt emission
  55. GRB 121102A : a long GRB detected by INTEGRAL
  56. GRB 121102A: Swift detection of a burst
  57. GRB 121027A: sub-mm upper limit
  58. GRB 121031A: Swift-BAT refined analysis
  59. GRB 121031A: Prompt enhanced Swift-XRT position
  60. GRB 121031A: Swift detection of a burst
  61. Swift Quick-look and HEASARC are back online
  62. GRB 121027A: Swift/UVOT Possible Detection
  63. GRB 121024A: LOAO RIzY Observation
  64. GRB 121027A: X-shooter redshift confirmation
  65. GRB 121027A - Gemini South spectroscopy
  66. GRB 121024A: SMARTS optical/IR afterglow observations
  67. GRB 121028A: near-IR observations at Calar Alto
  68. GRB 121027A: GROND Confirmation of Rebrightening
  69. GRB 121029A: Fermi GBM detection
  70. GRB 121028A: RAPTOR Limits During Gamma-Ray Emitting Interval
  71. Swift Quick-look and HEASARC will be offline for due to hurricane Sandy
  72. GRB 121027A: MASTER early prompt optical limit
  73. GRB 121027A: Swift-XRT refined Analysis
  74. GRB 121027A: Brightening IR counterpart
  75. GRB 121028A: Swift-XRT refined Analysis
  76. GRB 121028A: Enhanced Swift-XRT position
  77. GRB 121028A: Swift-BAT refined analysis
  78. GRB 121027A: Enhanced Swift-XRT position
  79. GRB 121028A: MITSuME Okayama Optical upper limits
  80. GRB 121028A: Faulkes Telescope North observations
  81. GRB 121028A: Swift detection of a burst
  82. GRB 121011A: optical observations
  83. GRB 121027A: nIR afterglow candidate with AAT
  84. GRB 121027A: Swift-BAT refined analysis
  85. GRB 121025A: Swift-XRT observation
  86. GRB 121027A: MAXI/GSC detection 40 minutes after the Swift Trigger
  87. GRB 121027A: Swift detection of a burst
  88. Swift Quick-look and HEASARC will be offline for 24 hours this weekend
  89. GRB 121024A: optical observations
  90. GRB 121024A: EVLA Detection
  91. Swift-BAT trigger 536502 is not astrophysical
  92. GRB 121024A: Swift/UVOT Observations
  93. GRB 121024A: CARMA 3mm Detection
  94. GRB 121024A: Swift-BAT refined analysis
  95. GRB 121024A: GMG optical observation
  96. GRB 121024A: MITSuME Ishigakijima upper limits
  97. GRB 121024A: MITSuME Okayama Optical upper limits
  98. GRB 121025A: MAXI/GSC detection
  99. GRB 121024A: Enhanced Swift-XRT position
  100. GRB 121024A: PAIRITEL NIR Detection

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