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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. GRB 070520A, Swift-BAT refined analysis
  2. GRB 070520A: Swift-XRT refined analysis
  3. GRB 070518: TNG observations
  4. GRB 070520B: Swift detection of a burst
  5. GRB 070520: Xinglong EST optical Upper Limit
  6. GRB 070520: Swift detection of a burst
  7. VLA observation of GRB 070518
  8. GRB 070518: Swift-XRT refined analysis
  9. GRB 070517: Gemini optical imaging
  10. GRB070518: UVOT refined analysis
  11. GRB070518: OSN observation
  12. GRB 070518, Swift-BAT refined analysis
  13. GRB 070518: OT confirmed form Xinglong TNT observation
  14. GRB 070518: Swift detection of a burst with optical afterglow
  15. GRB070517: Swift-XRT Refined Analysis
  16. GRB 070517, Swift-BAT refined analysis
  17. GRB 070517: Optical search
  18. GRB 070517: Swift detection of a burst
  19. GRB 070509: objects inside XRT error circle
  20. GRB 070512: pseudo-z ~ 1.39 from prompt emission spectrum
  21. GRB 070512: IPN localization and Konus spectrum of a bright burst
  22. GRB070419A: optical observations
  23. GRB 070419A, Deep LBT photometry
  24. GRB 070508: pseudo-z from 4 different spectral analyses
  25. GRB 070509: Swift/UVOT Upper Limits
  26. Konus-Wind and Konus-A observation of GRB 070508
  27. Swift-BAT trigger 278987 is not a GRB
  28. GRB 070510: Swift detection of a possible burst
  29. GRB070509: Swift-XRT Refined Analysis
  30. RHESSI Spectrum of GRB070508
  31. GRB 070508: OA fading and tentative redshift
  32. GRB 070509, Swift-BAT refined analysis
  33. GRB 070508: Suzaku/WAM observation of the prompt emission
  34. GRB 070509: REM observations
  35. GRB 070509: Swift detection of a burst
  36. GRB 070509: ROTSE-III Optical Limits
  37. GRB070508: Swift/UVOT Observations
  38. GRB 070508, SMARTS optical afterglow observation
  39. GRB 070508, Swift-BAT refined analysis
  40. GRB 070508: Multicolor optical observations and possible redshift limit
  41. GRB 070508: Swift-XRT refined analysis
  42. GRB 070508: Optical observation limiting magnitude
  43. GRB 070508: Optical afterglow detection
  44. GRB 070508: REM observations
  45. GRB 070508: TAROT La Silla observatory optical observations
  46. GRB 070508: Swift detection of an intense burst with an optical counterpart
  47. GRB070412: MAGIC telescope GeV observation
  48. Swift-BAT trigger 278809 is not a GRB
  49. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  50. GRB 070506: VLT redshift
  51. GRB070506: Swift/UVOT Observations
  52. GRB070506: Swift XRT refined analysis
  53. GRB 070506, Swift-BAT Refined Analysis
  54. GRB 070506: Swift detection of a burst with optical afterglow
  55. GRB 070412, deep LBT imaging
  56. GRB 070429A: Swift XRT further analysis
  57. GRB070429B: VLT observations
  58. GRB 070429A: optical observations
  59. GRB070429B: position correction
  60. GRB 070309: Swift-XRT afterglow confirmation
  61. GRB070429B: possible host galaxy detection
  62. VLA observation of GRB 070429B
  63. Swift/UVOT observations of GRB070429B
  64. GRB 070429B, Swift-BAT refined analysis
  65. Swift/UVOT observations of GRB070429A
  66. GRB 070429A: Swift XRT refined analysis
  67. GRB 070429A, Swift-BAT refined analysis
  68. GRB 070429A: optical and NIR observations
  69. GRB 070429B: Swift XRT refined analysis
  70. GRB 070429B: ROTSE-III Optical Limits
  71. GRB 070429B: Swift detection of a short burst
  72. GRB 070429: What's the temperature?
  73. GRB 070429: ROTSE-III Optical Limits
  74. GRB 070429: Swift detection of a burst
  75. GRB 070427, Swift-BAT Refined Analysis
  76. LT monitoring of GRB070412
  77. GRB 070427: Swift detection of a burst
  78. GRB 070411, further deep LBT photometry
  79. GRB 070411: Late-time Keck imaging
  80. GRB 070411 : Planned XMM-Newton observation
  81. GRB070419B: Suzaku WAM observation of the prompt emission
  82. GRB 070420, SMARTS optical/IR afterglow observations
  83. GRB 070411, deep LBT photometry
  84. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  85. Konus-Wind observation of GRB 070420
  86. GRB 070411: break in the optical light curve
  87. GRB 070420 Swift-BAT Refined Analysis
  88. GRB070419A: Kuiper Optical detection
  89. GRB070419a: Swift UVOT observations
  90. GRB 070419A: MARGE Observations
  91. GRB 070420: optical rebrightening observed at Mt. John
  92. GRB 070420: Swift XRT refined analysis
  93. GRB070420: Swift UVOT continuing observations
  94. GRB 070411: BART early limit
  95. GRB 070420: Faulkes Telescope South Observations
  96. GBR 070419A: Swift/XRT refined analysis
  97. GRB 070420: TAROT La Silla observatory optical observations
  98. GRB 070420: NIR and optical afterglow confirmed
  99. GRB 070420: Swift detection of a burst with optical afterglow
  100. GRB 070419A: MITSuME Okayama Observations

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