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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. Swift/UVOT refined analysis of GRB070529
  2. GRB 070529: MARGE Observations
  3. GRB 070529: Optical aterglow from MIRO
  4. GRB 070529: Gemini Redshift
  5. GRB 070529: Swift-XRT refined analysis
  6. GRB 070529, Swift-BAT refined analysis
  7. GRB 070529: Xinglong TNT Optical Upper Limit
  8. GRB 070529: Swift detection of a burst with an optical aterglow
  9. GRB 070412: Deep Keck imaging
  10. Swift Triggers 280447, 280450 and 280451 are invalid
  11. Swift trigger 280447 is probably a Galactic transient
  12. GRB 070518, deep LBT photometry
  13. GRB 070518: MARGE Observations
  14. GRB 070521: pseudo-z ~ 2.28 from prompt emission spectrum
  15. Konus-Wind observation of GRB 070521
  16. GRB 070518: optical observation
  17. GRB070521: Second Epoch Gemini Imaging
  18. GRB070521: NIR observations
  19. GRB070520B: NIR observations
  20. GRB 070521: Swift/UVOT Upper Limits
  21. GRB 070521, optical observation
  22. GRB 070521: Swift-XRT refined analysis
  23. GRB 070521: Keck imaging
  24. GRB070521: Gemini Observations
  25. GROND upper limits of GRB 070521
  26. GRB 070521 Milagro GeV/TeV Observations
  27. GRB 070520B: SARA upper limit
  28. GRB 070520A: SARA upper limit
  29. GRB 070521: SARA upper limit
  30. GRB 070521: Subaru observations and possible host detection
  31. GRB070518: Optical/NIR observation
  32. GRB 070520B: Swift/UVOT Upper Limits
  33. GRB 070520A: Subaru Observations
  34. GRB 070521, Swift-BAT refined analysis
  35. GRB 070520A: Swift UVOT Upper Limits
  36. GRB 070520B: Swift-XRT refined analysis
  37. GRB 070521: optical limit by Pi of the Sky
  38. GRB070521: P200 Observations
  39. GRB070521 : Faulkes Telescope North Observations
  40. GRB 070521: TAROT La Silla observatory optical observations
  41. GRB070521: Bright SDSS Galaxy Near XRT Error Circle
  42. GRB070521 - SDSS Pre-Burst Observations
  43. GRB 070521: Swift detection of a burst
  44. GRB 070520A: MITSuME Akeno optical upper limits
  45. GRB 070520B, Swift-BAT refined analysis
  46. GRB 070520A, Swift-BAT refined analysis
  47. GRB 070520A: Swift-XRT refined analysis
  48. GRB 070518: TNG observations
  49. GRB 070520B: Swift detection of a burst
  50. GRB 070520: Xinglong EST optical Upper Limit
  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. GRB070518: OSN observation
  57. GRB 070518, Swift-BAT refined analysis
  58. GRB 070518: OT confirmed form Xinglong TNT observation
  59. GRB 070518: Swift detection of a burst with optical afterglow
  60. GRB070517: Swift-XRT Refined Analysis
  61. GRB 070517, Swift-BAT refined analysis
  62. GRB 070517: Optical search
  63. GRB 070517: Swift detection of a burst
  64. GRB 070509: objects inside XRT error circle
  65. GRB 070512: pseudo-z ~ 1.39 from prompt emission spectrum
  66. GRB 070512: IPN localization and Konus spectrum of a bright burst
  67. GRB070419A: optical observations
  68. GRB 070419A, Deep LBT photometry
  69. GRB 070508: pseudo-z from 4 different spectral analyses
  70. GRB 070509: Swift/UVOT Upper Limits
  71. Konus-Wind and Konus-A observation of GRB 070508
  72. Swift-BAT trigger 278987 is not a GRB
  73. GRB 070510: Swift detection of a possible burst
  74. GRB070509: Swift-XRT Refined Analysis
  75. RHESSI Spectrum of GRB070508
  76. GRB 070508: OA fading and tentative redshift
  77. GRB 070509, Swift-BAT refined analysis
  78. GRB 070508: Suzaku/WAM observation of the prompt emission
  79. GRB 070509: REM observations
  80. GRB 070509: Swift detection of a burst
  81. GRB 070509: ROTSE-III Optical Limits
  82. GRB070508: Swift/UVOT Observations
  83. GRB 070508, SMARTS optical afterglow observation
  84. GRB 070508, Swift-BAT refined analysis
  85. GRB 070508: Multicolor optical observations and possible redshift limit
  86. GRB 070508: Swift-XRT refined analysis
  87. GRB 070508: Optical observation limiting magnitude
  88. GRB 070508: Optical afterglow detection
  89. GRB 070508: REM observations
  90. GRB 070508: TAROT La Silla observatory optical observations
  91. GRB 070508: Swift detection of an intense burst with an optical counterpart
  92. GRB070412: MAGIC telescope GeV observation
  93. Swift-BAT trigger 278809 is not a GRB
  94. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  95. GRB 070506: VLT redshift
  96. GRB070506: Swift/UVOT Observations
  97. GRB070506: Swift XRT refined analysis
  98. GRB 070506, Swift-BAT Refined Analysis
  99. GRB 070506: Swift detection of a burst with optical afterglow
  100. GRB 070412, deep LBT imaging

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