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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"

42757 results found.

  1. GRB 070521, Swift-BAT refined analysis
  2. GRB 070520A: Swift UVOT Upper Limits
  3. GRB 070520B: Swift-XRT refined analysis
  4. GRB 070521: optical limit by Pi of the Sky
  5. GRB070521: P200 Observations
  6. GRB070521 : Faulkes Telescope North Observations
  7. GRB 070521: TAROT La Silla observatory optical observations
  8. GRB070521: Bright SDSS Galaxy Near XRT Error Circle
  9. GRB070521 - SDSS Pre-Burst Observations
  10. GRB 070521: Swift detection of a burst
  11. GRB 070520A: MITSuME Akeno optical upper limits
  12. GRB 070520B, Swift-BAT refined analysis
  13. GRB 070520A, Swift-BAT refined analysis
  14. GRB 070520A: Swift-XRT refined analysis
  15. GRB 070518: TNG observations
  16. GRB 070520B: Swift detection of a burst
  17. GRB 070520: Xinglong EST optical Upper Limit
  18. GRB 070520: Swift detection of a burst
  19. VLA observation of GRB 070518
  20. GRB 070518: Swift-XRT refined analysis
  21. GRB 070517: Gemini optical imaging
  22. GRB070518: UVOT refined analysis
  23. GRB070518: OSN observation
  24. GRB 070518, Swift-BAT refined analysis
  25. GRB 070518: OT confirmed form Xinglong TNT observation
  26. GRB 070518: Swift detection of a burst with optical afterglow
  27. GRB070517: Swift-XRT Refined Analysis
  28. GRB 070517: Swift detection of a burst
  29. GRB 070509: objects inside XRT error circle
  30. GRB 070512: IPN localization and Konus spectrum of a bright burst
  31. GRB070419A: optical observations
  32. GRB 070419A, Deep LBT photometry
  33. GRB 070509: Swift/UVOT Upper Limits
  34. Konus-Wind and Konus-A observation of GRB 070508
  35. GRB 070510: Swift detection of a possible burst
  36. GRB070509: Swift-XRT Refined Analysis
  37. RHESSI Spectrum of GRB070508
  38. GRB 070508: OA fading and tentative redshift
  39. GRB 070509, Swift-BAT refined analysis
  40. GRB 070508: Suzaku/WAM observation of the prompt emission
  41. GRB 070509: REM observations
  42. GRB 070509: Swift detection of a burst
  43. GRB 070509: ROTSE-III Optical Limits
  44. GRB070508: Swift/UVOT Observations
  45. GRB 070508, Swift-BAT refined analysis
  46. GRB 070508: Multicolor optical observations and possible redshift limit
  47. GRB 070508: Swift-XRT refined analysis
  48. GRB 070508: Optical observation limiting magnitude
  49. GRB 070508: Optical afterglow detection
  50. GRB 070508: REM observations
  51. GRB 070508: TAROT La Silla observatory optical observations
  52. GRB 070508: Swift detection of an intense burst with an optical counterpart
  53. GRB070412: MAGIC telescope GeV observation
  54. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  55. GRB 070506: VLT redshift
  56. GRB070506: Swift/UVOT Observations
  57. GRB070506: Swift XRT refined analysis
  58. GRB 070506, Swift-BAT Refined Analysis
  59. GRB 070506: Swift detection of a burst with optical afterglow
  60. GRB 070412, deep LBT imaging
  61. GRB 070429A: Swift XRT further analysis
  62. GRB070429B: VLT observations
  63. GRB 070429A: optical observations
  64. GRB070429B: position correction
  65. GRB 070309: Swift-XRT afterglow confirmation
  66. GRB070429B: possible host galaxy detection
  67. VLA observation of GRB 070429B
  68. Swift/UVOT observations of GRB070429B
  69. GRB 070429B, Swift-BAT refined analysis
  70. Swift/UVOT observations of GRB070429A
  71. GRB 070429A: Swift XRT refined analysis
  72. GRB 070429A: optical and NIR observations
  73. GRB 070429B: Swift XRT refined analysis
  74. GRB 070429B: ROTSE-III Optical Limits
  75. GRB 070429B: Swift detection of a short burst
  76. GRB 070429: What's the temperature?
  77. GRB 070429: ROTSE-III Optical Limits
  78. GRB 070429: Swift detection of a burst
  79. LT monitoring of GRB070412
  80. GRB 070427: Swift detection of a burst
  81. GRB 070411, further deep LBT photometry
  82. GRB 070411: Late-time Keck imaging
  83. GRB 070411 : Planned XMM-Newton observation
  84. GRB070419B: Suzaku WAM observation of the prompt emission
  85. GRB 070420, SMARTS optical/IR afterglow observations
  86. GRB 070411, deep LBT photometry
  87. Konus-Wind observation of GRB 070420
  88. GRB 070411: break in the optical light curve
  89. GRB 070420 Swift-BAT Refined Analysis
  90. GRB070419A: Kuiper Optical detection
  91. GRB070419a: Swift UVOT observations
  92. GRB 070419A: MARGE Observations
  93. GRB 070420: optical rebrightening observed at Mt. John
  94. GRB 070420: Swift XRT refined analysis
  95. GRB070420: Swift UVOT continuing observations
  96. GRB 070411: BART early limit
  97. GRB 070420: Faulkes Telescope South Observations
  98. GBR 070419A: Swift/XRT refined analysis
  99. GRB 070420: TAROT La Silla observatory optical observations
  100. GRB 070420: NIR and optical afterglow confirmed

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