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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"

21392 results found.

  1. GRB 070411: TAROT Calern observatory optical observations
  2. GRB070520B: optical observations
  3. GRB070520: optical observation
  4. GRB070521: optical observation
  5. Swift/UVOT refined analysis of GRB070531
  6. GRB 070531: NOT nIR observations
  7. GRB 070531: Swift-BAT refined analysis
  8. GRB 070531: I-band observations from IAC80
  9. GRB 070531: Swift-XRT position
  10. GRB 070531: Liverpool Telescope Optical Observations
  11. GRB 070531: Swift detection of a burst
  12. Swift/UVOT refined analysis of GRB070529
  13. GRB 070529: MARGE Observations
  14. GRB 070529: Optical aterglow from MIRO
  15. GRB 070529: Swift-XRT refined analysis
  16. GRB 070529, Swift-BAT refined analysis
  17. GRB 070529: Swift detection of a burst with an optical aterglow
  18. GRB 070412: Deep Keck imaging
  19. Swift Triggers 280447, 280450 and 280451 are invalid
  20. Swift trigger 280447 is probably a Galactic transient
  21. GRB 070518: MARGE Observations
  22. GRB 070521: pseudo-z ~ 2.28 from prompt emission spectrum
  23. Konus-Wind observation of GRB 070521
  24. GRB070521: Second Epoch Gemini Imaging
  25. GRB070521: NIR observations
  26. GRB070520B: NIR observations
  27. GRB 070521: Swift/UVOT Upper Limits
  28. GRB 070521: Swift-XRT refined analysis
  29. GRB 070521: Keck imaging
  30. GROND upper limits of GRB 070521
  31. GRB 070521 Milagro GeV/TeV Observations
  32. GRB 070521: SARA upper limit
  33. GRB 070521: Subaru observations and possible host detection
  34. GRB 070520B: Swift/UVOT Upper Limits
  35. GRB 070520A: Subaru Observations
  36. GRB 070521, Swift-BAT refined analysis
  37. GRB 070520A: Swift UVOT Upper Limits
  38. GRB 070520B: Swift-XRT refined analysis
  39. GRB 070521: optical limit by Pi of the Sky
  40. GRB070521: P200 Observations
  41. GRB070521 : Faulkes Telescope North Observations
  42. GRB 070521: TAROT La Silla observatory optical observations
  43. GRB070521: Bright SDSS Galaxy Near XRT Error Circle
  44. GRB070521 - SDSS Pre-Burst Observations
  45. GRB 070521: Swift detection of a burst
  46. GRB 070520A: MITSuME Akeno optical upper limits
  47. GRB 070520B, Swift-BAT refined analysis
  48. GRB 070520A, Swift-BAT refined analysis
  49. GRB 070520A: Swift-XRT refined analysis
  50. GRB 070520B: Swift detection of a burst
  51. GRB 070520: Swift detection of a burst
  52. VLA observation of GRB 070518
  53. GRB 070518: Swift-XRT refined analysis
  54. GRB 070517: Gemini optical imaging
  55. GRB070518: UVOT refined analysis
  56. GRB 070518, Swift-BAT refined analysis
  57. GRB 070518: Swift detection of a burst with optical afterglow
  58. GRB070517: Swift-XRT Refined Analysis
  59. GRB 070517, Swift-BAT refined analysis
  60. GRB 070517: Swift detection of a burst
  61. GRB 070509: objects inside XRT error circle
  62. GRB 070512: IPN localization and Konus spectrum of a bright burst
  63. GRB 070508: pseudo-z from 4 different spectral analyses
  64. GRB 070509: Swift/UVOT Upper Limits
  65. Konus-Wind and Konus-A observation of GRB 070508
  66. Swift-BAT trigger 278987 is not a GRB
  67. GRB 070510: Swift detection of a possible burst
  68. GRB070509: Swift-XRT Refined Analysis
  69. GRB 070509, Swift-BAT refined analysis
  70. GRB 070508: Suzaku/WAM observation of the prompt emission
  71. GRB 070509: REM observations
  72. GRB 070509: Swift detection of a burst
  73. GRB 070509: ROTSE-III Optical Limits
  74. GRB070508: Swift/UVOT Observations
  75. GRB 070508, Swift-BAT refined analysis
  76. GRB 070508: Swift-XRT refined analysis
  77. GRB 070508: Optical afterglow detection
  78. GRB 070508: TAROT La Silla observatory optical observations
  79. GRB 070508: Swift detection of an intense burst with an optical counterpart
  80. GRB070412: MAGIC telescope GeV observation
  81. Swift-BAT trigger 278809 is not a GRB
  82. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  83. GRB070506: Swift/UVOT Observations
  84. GRB070506: Swift XRT refined analysis
  85. GRB 070506, Swift-BAT Refined Analysis
  86. GRB 070506: Swift detection of a burst with optical afterglow
  87. GRB 070412, deep LBT imaging
  88. GRB 070429A: Swift XRT further analysis
  89. GRB070429B: VLT observations
  90. GRB 070429A: optical observations
  91. GRB070429B: position correction
  92. GRB 070309: Swift-XRT afterglow confirmation
  93. GRB070429B: possible host galaxy detection
  94. VLA observation of GRB 070429B
  95. Swift/UVOT observations of GRB070429B
  96. GRB 070429B, Swift-BAT refined analysis
  97. Swift/UVOT observations of GRB070429A
  98. GRB 070429A: Swift XRT refined analysis
  99. GRB 070429A, Swift-BAT refined analysis
  100. GRB 070429A: optical and NIR observations

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