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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"

37743 results found.

  1. GRB 070529, Swift-BAT refined analysis
  2. GRB 070529: Xinglong TNT Optical Upper Limit
  3. GRB 070529: Swift detection of a burst with an optical aterglow
  4. GRB 070412: Deep Keck imaging
  5. Swift Triggers 280447, 280450 and 280451 are invalid
  6. Swift trigger 280447 is probably a Galactic transient
  7. GRB 070518, deep LBT photometry
  8. GRB 070518: MARGE Observations
  9. GRB 070521: pseudo-z ~ 2.28 from prompt emission spectrum
  10. Konus-Wind observation of GRB 070521
  11. GRB 070518: optical observation
  12. GRB070520B: NIR observations
  13. GRB 070521: Swift/UVOT Upper Limits
  14. GRB 070521, optical observation
  15. GRB 070521: Swift-XRT refined analysis
  16. GRB 070521: Keck imaging
  17. GROND upper limits of GRB 070521
  18. GRB 070521 Milagro GeV/TeV Observations
  19. GRB 070520B: SARA upper limit
  20. GRB 070520A: SARA upper limit
  21. GRB 070521: SARA upper limit
  22. GRB 070521: Subaru observations and possible host detection
  23. GRB 070520B: Swift/UVOT Upper Limits
  24. GRB 070520A: Subaru Observations
  25. GRB 070521, Swift-BAT refined analysis
  26. GRB 070520A: Swift UVOT Upper Limits
  27. GRB 070520B: Swift-XRT refined analysis
  28. GRB 070521: optical limit by Pi of the Sky
  29. GRB070521 : Faulkes Telescope North Observations
  30. GRB 070521: TAROT La Silla observatory optical observations
  31. GRB070521: Bright SDSS Galaxy Near XRT Error Circle
  32. GRB070521 - SDSS Pre-Burst Observations
  33. GRB 070521: Swift detection of a burst
  34. GRB 070520A: MITSuME Akeno optical upper limits
  35. GRB 070520B, Swift-BAT refined analysis
  36. GRB 070520A, Swift-BAT refined analysis
  37. GRB 070520A: Swift-XRT refined analysis
  38. GRB 070518: TNG observations
  39. GRB 070520B: Swift detection of a burst
  40. GRB 070520: Xinglong EST optical Upper Limit
  41. GRB 070520: Swift detection of a burst
  42. VLA observation of GRB 070518
  43. GRB 070518: Swift-XRT refined analysis
  44. GRB 070517: Gemini optical imaging
  45. GRB070518: UVOT refined analysis
  46. GRB070518: OSN observation
  47. GRB 070518, Swift-BAT refined analysis
  48. GRB 070518: OT confirmed form Xinglong TNT observation
  49. GRB 070518: Swift detection of a burst with optical afterglow
  50. GRB070517: Swift-XRT Refined Analysis
  51. GRB 070517, Swift-BAT refined analysis
  52. GRB 070517: Optical search
  53. GRB 070517: Swift detection of a burst
  54. GRB 070509: objects inside XRT error circle
  55. GRB 070512: pseudo-z ~ 1.39 from prompt emission spectrum
  56. GRB 070512: IPN localization and Konus spectrum of a bright burst
  57. GRB070419A: optical observations
  58. GRB 070419A, Deep LBT photometry
  59. GRB 070508: pseudo-z from 4 different spectral analyses
  60. GRB 070509: Swift/UVOT Upper Limits
  61. Konus-Wind and Konus-A observation of GRB 070508
  62. Swift-BAT trigger 278987 is not a GRB
  63. GRB 070510: Swift detection of a possible burst
  64. GRB070509: Swift-XRT Refined Analysis
  65. GRB 070508: OA fading and tentative redshift
  66. GRB 070509, Swift-BAT refined analysis
  67. GRB 070508: Suzaku/WAM observation of the prompt emission
  68. GRB 070509: REM observations
  69. GRB 070509: Swift detection of a burst
  70. GRB 070509: ROTSE-III Optical Limits
  71. GRB070508: Swift/UVOT Observations
  72. GRB 070508, SMARTS optical afterglow observation
  73. GRB 070508, Swift-BAT refined analysis
  74. GRB 070508: Multicolor optical observations and possible redshift limit
  75. GRB 070508: Swift-XRT refined analysis
  76. GRB 070508: Optical observation limiting magnitude
  77. GRB 070508: Optical afterglow detection
  78. GRB 070508: REM observations
  79. GRB 070508: TAROT La Silla observatory optical observations
  80. GRB 070508: Swift detection of an intense burst with an optical counterpart
  81. GRB070412: MAGIC telescope GeV observation
  82. Swift-BAT trigger 278809 is not a GRB
  83. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  84. GRB 070506: VLT redshift
  85. GRB070506: Swift/UVOT Observations
  86. GRB070506: Swift XRT refined analysis
  87. GRB 070506, Swift-BAT Refined Analysis
  88. GRB 070506: Swift detection of a burst with optical afterglow
  89. GRB 070412, deep LBT imaging
  90. GRB 070429A: Swift XRT further analysis
  91. GRB070429B: VLT observations
  92. GRB 070429A: optical observations
  93. GRB 070309: Swift-XRT afterglow confirmation
  94. GRB070429B: possible host galaxy detection
  95. VLA observation of GRB 070429B
  96. Swift/UVOT observations of GRB070429B
  97. GRB 070429B, Swift-BAT refined analysis
  98. Swift/UVOT observations of GRB070429A
  99. GRB 070429A: Swift XRT refined analysis
  100. GRB 070429A, Swift-BAT refined analysis

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