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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"

43611 results found.

  1. GRB 121128A - Gemini North redshift
  2. GRB 121128A: FTN optical afterglow confirmation
  3. GRB 121128A: Swift detection of a burst with an optical counterpart
  4. GRB 121123A: Suzaku WAM observation of the prompt emission
  5. Konus-Wind observation of GRB 121122A
  6. GRB 121117A: Terskol obseravtions
  7. GRB 121123A: Swift/UVOT Observations
  8. GRB 121125A: Swift/UVOT Detection
  9. IPN Triangulation of GRB 121122A (long/intense)
  10. GRB 121118B: Suzaku WAM observation of the prompt emission
  11. GRB 121125A: Swift-XRT refined Analysis
  12. GRB 121125A: Enhanced Swift-XRT position
  13. GRB 121125A: Fermi GBM Observation
  14. GRB 121125A: Swift-BAT refined analysis
  15. GRB 121125A: LOAO Observation
  16. GRB 121125A: MASTER-NET optical observations
  17. GRB 121125A: Swift detection of a burst with optical counterpart
  18. GRB 121123A: GROND observations
  19. GRB 121123A: Enhanced Swift-XRT position
  20. GRB 121123A: Swift-BAT refined analysis
  21. GRB 121123A: Swift-XRT refined Analysis
  22. GRB 121123A: optical observations
  23. GRB 121123A: BOOTES-4 and IAC80 optical observations
  24. GRB 121123A: NOT optical observations
  25. GRB 121123A: Fermi GBM observation
  26. GRB 121123A: MASTER-NET optical limit
  27. GRB 121123A: GMG optical observation
  28. GRB 121123A: Swift detection of a burst with optical counterpart
  29. GRB 121108A: optical upper limit
  30. GRB 121117A: Optical observations
  31. Konus-Wind observation of GRB 121118B
  32. GRB 121117A: optical upper limit
  33. IPN Triangulation of GRB 121118B (long/intense)
  34. GRB 121117A: GROND confirmation of the UVOT afterglow candidate
  35. IPN Triangulation of GRB 121118A
  36. Swift-BAT trigger 538575 is not astrophysical
  37. GRB 121117A: Swift-XRT refined Analysis
  38. GRB 121117A: MASTER prompt optical limit
  39. GRB 121117A, Swift-BAT refined analysis
  40. GRB 121117A: ROTSE-III Optical Limits
  41. GRB 121117A: BOOTES-3 early optical upper limit
  42. GRB 121117A: Swift detection of a burst
  43. Swift trigger 538575: Magellan Observations
  44. Fermi GBM trigger 121115.186 is not a GRB
  45. Trigger 538084: Swift detection of XTE J1739-302
  46. GRB 121108A: Swift-XRT refined Analysis
  47. GRB 121108A, Swift-BAT refined analysis
  48. GRB 121108A: Xinglong TNT upper limit
  49. GRB 121108A: Enhanced Swift-XRT position
  50. GRB 121108A: Optical observations
  51. GRB 121108A: Weihai observatory optical observations
  52. GRB 121108A: MASTER early prompt optical limit
  53. GRB 121108A: TAROT Calern observatory optical observations
  54. GRB 121108A: Swift detection of a burst
  55. GRB 121031A: Fermi GBM detection
  56. GRB 121028A: Swift/UVOT Upper Limits
  57. GRB 121031A, Early peak observed with Swift-BAT
  58. GRB 121031A: Swift-XRT refined Analysis
  59. GRB 121102A: Enhanced Swift-XRT position
  60. GRB 121031A: Enhanced Swift-XRT position
  61. GRB 121102A: Swift-XRT refined Analysis
  62. GRB 121102A: Swift-BAT refined analysis
  63. GRB 121025A: Confirmation of the X-ray afterglow
  64. GRB 121029A Suzaku WAM observation of the prompt emission
  65. GRB 121102A : a long GRB detected by INTEGRAL
  66. GRB 121102A: Swift detection of a burst
  67. GRB 121027A: sub-mm upper limit
  68. GRB 121031A: Swift-BAT refined analysis
  69. GRB 121031A: Prompt enhanced Swift-XRT position
  70. GRB 121031A: Swift detection of a burst
  71. Swift Quick-look and HEASARC are back online
  72. GRB 121027A: Swift/UVOT Possible Detection
  73. GRB 121024A: LOAO RIzY Observation
  74. GRB 121027A: X-shooter redshift confirmation
  75. GRB 121027A - Gemini South spectroscopy
  76. GRB 121028A: near-IR observations at Calar Alto
  77. GRB 121027A: GROND Confirmation of Rebrightening
  78. GRB 121029A: Fermi GBM detection
  79. GRB 121028A: RAPTOR Limits During Gamma-Ray Emitting Interval
  80. Swift Quick-look and HEASARC will be offline for due to hurricane Sandy
  81. GRB 121027A: MASTER early prompt optical limit
  82. GRB 121027A: Swift-XRT refined Analysis
  83. GRB 121027A: Brightening IR counterpart
  84. GRB 121028A: Swift-XRT refined Analysis
  85. GRB 121028A: Enhanced Swift-XRT position
  86. GRB 121028A: Swift-BAT refined analysis
  87. GRB 121027A: Enhanced Swift-XRT position
  88. GRB 121028A: Faulkes Telescope North observations
  89. GRB 121028A: Swift detection of a burst
  90. GRB 121011A: optical observations
  91. GRB 121027A: nIR afterglow candidate with AAT
  92. GRB 121027A: Swift-BAT refined analysis
  93. GRB 121025A: Swift-XRT observation
  94. GRB 121027A: MAXI/GSC detection 40 minutes after the Swift Trigger
  95. GRB 121027A: Swift detection of a burst
  96. Swift Quick-look and HEASARC will be offline for 24 hours this weekend
  97. GRB 121024A: EVLA Detection
  98. Swift-BAT trigger 536502 is not astrophysical
  99. GRB 121024A: CARMA 3mm Detection
  100. GRB 121024A: Swift-BAT refined analysis

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