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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"

22916 results found.

  1. GRB 090407: VLT observations
  2. GRB 090407: Swift UVOT Upper Limits
  3. GRB 090407: Enhanced Swift-XRT position
  4. Konus-Wind and Konus-RF observations of GRB 090406
  5. GRB 090407: ROTSE-III Optical Limits
  6. GRB 090407: Swift detection of a burst
  7. GRB 090405: Fermi GBM Detection
  8. GRB 090403: Fermi GBM detection
  9. GRB 090404: GROND upper limits
  10. GRB 090404: further NOT observations
  11. Swift/UVOT observations of GRB090404
  12. GRB 090404: NOT observations
  13. GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
  14. GRB 090404: Swift-XRT Team refined analysis
  15. GRB 090404: Xinglong TNT optical Upper Limit
  16. GRB 090404: Enhanced Swift-XRT position
  17. GRB 090404: Swift detection of a burst
  18. GRB 090401A: Suzaku WAM observation of the prompt emission
  19. GRB 090401B: Xinglong TNT optical Upper Limit
  20. GRB 090401B: VLA radio upper limit
  21. GRB 090401B: Upper limits of MITSuME optical observation
  22. GRB090401B, RIMOTS optical upper limits
  23. Swift/UVOT observations of GRB090401B
  24. Swift/UVOT observations of GRB090401B
  25. GRB 090331: Fermi GBM detection
  26. GRB 090401B: Enhanced Swift-XRT position
  27. AGILE Gamma-ray detection of GRB 090401B
  28. GRB 090401B: Swift detection of a burst
  29. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  30. GRB 090401: Swift detection of a burst
  31. GRB 090328: Radio afterglow detection
  32. GRB 090326: Fermi GBM detection
  33. GRB 090328: BOOTES-3 optical observations
  34. GRB 090328B: Fermi GBM Detection
  35. GRB 090330: Fermi GBM detection
  36. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  37. GRB090323: Optical observations from NOT
  38. GRB 090328: IPN Triangulation
  39. GRB 090328: Swift UVOT observations
  40. GRB 090328: Updated position/optical afterglow candidate
  41. GRB 090323: Radio afterglow detection
  42. GRB 090327: Fermi GBM detection
  43. GRB 090320B: MASTER-Net prompt optical observations
  44. GRB 090323: UVOT Detection of Afterglow
  45. GRB 090323: Swift-XRT refined analysis
  46. GRB 090324: SuperAGILE Localization of a Long GRB
  47. GRB 090323: P60 Afterglow Confirmation
  48. GRB 090323: GROND Detection of the Afterglow and Photo-z
  49. GRB 090323: Possible XRT Counterpart
  50. IPN triangulation of GRB090323
  51. GRB 090320C: Fermi GBM Detection
  52. GRB 090320B: Fermi GBM detection.
  53. GRB 090319: Fermi GBM detection
  54. GRB 090320A: Fermi GBM detection
  55. Further 15GHz observations of GRB090313
  56. X-shooter observations of GRB 090313
  57. GRB090313: radio detection with the VLA
  58. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  59. Further radio observation of GRB 090313
  60. Further Swift/UVOT observations of GRB 090313
  61. GRB 090313: detection with CARMA in 3mm band
  62. GRB090305B: MASTER-net prompt optical short burst observations
  63. GRB 090313: MITSuME Okayama observation
  64. GRB 090313: Additional Gemini-S photometry
  65. GRB 090313: TAROT La Silla observatory optical detection
  66. GRB 090313: Zadko Telescope observations
  67. GRB 090313 optical observations
  68. GRB 090313: Ongoing plateau phase
  69. GRB 090313: Swift-XRT refined analysis
  70. GRB 090313: Swift/UVOT upper limits
  71. GRB 090313: Sustained optical brightness (correction)
  72. GRB 090306B: Confirmation of the X-ray afterglow
  73. GRB 090313, GROND observations
  74. GRB 090309, Swift-BAT lag analysis
  75. GRB 090313: Swift detection of a burst
  76. GRB 090313: Swift detection of a burst
  77. Swift trigger 346250 is probably not a burst
  78. GRB090310: Fermi GBM detection
  79. GRB 090205: Zadko Telescope late-time observations
  80. GRB 090309A: GROND upper limits
  81. GRB 090307A: TAROT Calern observatory optical observations
  82. GRB 090309: Swift/UVOT Upper Limits
  83. GRB090305B: Fermi GBM detection
  84. GRB 090309B: Fermi GBM detection
  85. GRB 090309: Enhanced Swift-XRT position
  86. GRB 090308: GROND observations
  87. GRB 090308: Gemini GMOS Observations
  88. GRB 090309: Swift detection of a burst
  89. GRB 090308B: Fermi GBM detection
  90. GRB 090308: Swift/UVOT Upper Limits
  91. GRB 090307B: Fermi GBM detection
  92. GRB 090306C: Fermi GBM detection
  93. GRB 090307: GROND Upper Limits
  94. GRB 090306B: GROND Upper Limits
  95. GRB 090308: Swift-XRT refined analysis
  96. GRB 090308: Swift detection of a burst
  97. GRB 090306B: Possible XRT afterglow
  98. GRB 090307: Swift-XRT afterglow confirmation and analysis
  99. Swift Trigger 345551 is probably not a GRB
  100. IPN localization of short GRB 090305C

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