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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. GRB070521: P200 Observations
  2. GRB070521 : Faulkes Telescope North Observations
  3. GRB 070521: TAROT La Silla observatory optical observations
  4. GRB070521: Bright SDSS Galaxy Near XRT Error Circle
  5. GRB070521 - SDSS Pre-Burst Observations
  6. GRB 070521: Swift detection of a burst
  7. GRB 070520A: MITSuME Akeno optical upper limits
  8. GRB 070520B, Swift-BAT refined analysis
  9. GRB 070520A, Swift-BAT refined analysis
  10. GRB 070520A: Swift-XRT refined analysis
  11. GRB 070518: TNG observations
  12. GRB 070520B: Swift detection of a burst
  13. GRB 070520: Xinglong EST optical Upper Limit
  14. GRB 070520: Swift detection of a burst
  15. VLA observation of GRB 070518
  16. GRB 070518: Swift-XRT refined analysis
  17. GRB 070517: Gemini optical imaging
  18. GRB070518: UVOT refined analysis
  19. GRB070518: OSN observation
  20. GRB 070518, Swift-BAT refined analysis
  21. GRB 070518: OT confirmed form Xinglong TNT observation
  22. GRB 070518: Swift detection of a burst with optical afterglow
  23. GRB070517: Swift-XRT Refined Analysis
  24. GRB 070517, Swift-BAT refined analysis
  25. GRB 070517: Optical search
  26. GRB 070517: Swift detection of a burst
  27. GRB 070509: objects inside XRT error circle
  28. GRB 070512: pseudo-z ~ 1.39 from prompt emission spectrum
  29. GRB 070512: IPN localization and Konus spectrum of a bright burst
  30. GRB070419A: optical observations
  31. GRB 070419A, Deep LBT photometry
  32. GRB 070508: pseudo-z from 4 different spectral analyses
  33. GRB 070509: Swift/UVOT Upper Limits
  34. Konus-Wind and Konus-A observation of GRB 070508
  35. Swift-BAT trigger 278987 is not a GRB
  36. GRB 070510: Swift detection of a possible burst
  37. GRB070509: Swift-XRT Refined Analysis
  38. RHESSI Spectrum of GRB070508
  39. GRB 070508: OA fading and tentative redshift
  40. GRB 070509, Swift-BAT refined analysis
  41. GRB 070508: Suzaku/WAM observation of the prompt emission
  42. GRB 070509: REM observations
  43. GRB 070509: Swift detection of a burst
  44. GRB 070509: ROTSE-III Optical Limits
  45. GRB070508: Swift/UVOT Observations
  46. GRB 070508, SMARTS optical afterglow observation
  47. GRB 070508, Swift-BAT refined analysis
  48. GRB 070508: Multicolor optical observations and possible redshift limit
  49. GRB 070508: Swift-XRT refined analysis
  50. GRB 070508: Optical observation limiting magnitude
  51. GRB 070508: Optical afterglow detection
  52. GRB 070508: REM observations
  53. GRB 070508: TAROT La Silla observatory optical observations
  54. GRB 070508: Swift detection of an intense burst with an optical counterpart
  55. GRB070412: MAGIC telescope GeV observation
  56. Swift-BAT trigger 278809 is not a GRB
  57. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  58. GRB 070506: VLT redshift
  59. GRB070506: Swift/UVOT Observations
  60. GRB070506: Swift XRT refined analysis
  61. GRB 070506, Swift-BAT Refined Analysis
  62. GRB 070506: Swift detection of a burst with optical afterglow
  63. GRB 070412, deep LBT imaging
  64. GRB 070429A: Swift XRT further analysis
  65. GRB070429B: VLT observations
  66. GRB 070429A: optical observations
  67. GRB070429B: position correction
  68. GRB 070309: Swift-XRT afterglow confirmation
  69. GRB070429B: possible host galaxy detection
  70. VLA observation of GRB 070429B
  71. Swift/UVOT observations of GRB070429B
  72. GRB 070429B, Swift-BAT refined analysis
  73. Swift/UVOT observations of GRB070429A
  74. GRB 070429A: Swift XRT refined analysis
  75. GRB 070429A, Swift-BAT refined analysis
  76. GRB 070429A: optical and NIR observations
  77. GRB 070429B: Swift XRT refined analysis
  78. GRB 070429B: ROTSE-III Optical Limits
  79. GRB 070429B: Swift detection of a short burst
  80. GRB 070429: What's the temperature?
  81. GRB 070429: ROTSE-III Optical Limits
  82. GRB 070429: Swift detection of a burst
  83. GRB 070427, Swift-BAT Refined Analysis
  84. LT monitoring of GRB070412
  85. GRB 070427: Swift detection of a burst
  86. GRB 070411, further deep LBT photometry
  87. GRB 070411: Late-time Keck imaging
  88. GRB 070411 : Planned XMM-Newton observation
  89. GRB070419B: Suzaku WAM observation of the prompt emission
  90. GRB 070420, SMARTS optical/IR afterglow observations
  91. GRB 070411, deep LBT photometry
  92. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  93. Konus-Wind observation of GRB 070420
  94. GRB 070411: break in the optical light curve
  95. GRB 070420 Swift-BAT Refined Analysis
  96. GRB070419A: Kuiper Optical detection
  97. GRB070419a: Swift UVOT observations
  98. GRB 070419A: MARGE Observations
  99. GRB 070420: optical rebrightening observed at Mt. John
  100. GRB 070420: Swift XRT refined analysis

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