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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"

26309 results found.

  1. GRB 090423: Fermi GBM observation
  2. GRB 090422: Fermi GBM observation
  3. GRB 090423: Ep,i - Eiso correlation
  4. GRB 090424: SDSS Galaxy at the Swift position
  5. GRB 090424: Swift detection of a burst with an optical counterpart
  6. GRB 090423: Refined TNG analysis
  7. GRB090423: Y-band field calibration
  8. GRB 090423 limiting magnitudes
  9. GRB 090423: Near infrared observation at Okayama Observatory
  10. GRB 090423: GROND detection and preliminary photo-z
  11. GRB 090423: Swift-XRT refined analysis
  12. GRB090418A Rc-band photometry
  13. GRB090423 - Swift/UVOT upper limits.
  14. GRB 090423: NIR photometry and evidence for spectral break
  15. GRB 090422: Swift-XRT refined analysis
  16. GRB 090423: UKIRT data further analysis
  17. GRB 090423: Enhanced Swift-XRT position
  18. GRB 090423: Swift-BAT refined analysis
  19. GRB 090422: Swift/UVOT Upper Limits
  20. GRB 090423: Swift detection of a burst
  21. GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
  22. GRB 090422: Swift-BAT refined analysis
  23. GRB 090422: Enhanced Swift-XRT position
  24. GRB 090418B: Suzaku WAM observation of the prompt emission
  25. GRB 090422: Swift detection of a burst
  26. GRB 090418C: Fermi GBM Detection
  27. GRB 090419: Swift-XRT refined analysis
  28. Konus-Wind observation of GRB 090418B
  29. GRB 090419: Swift-BAT refined analysis
  30. VLA radio detection of GRB 090418
  31. VLA radio upper limit on GRB 090417B
  32. GRB 090419: Enhanced Swift-XRT position
  33. GRB 090418: Swift XRT refined analysis
  34. GRB 090419: Swift detection of a burst
  35. VLA observations of short burst GRB 090417A
  36. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  37. GRB 090418: Swift-BAT refined analysis
  38. GRB 090417B: Swift-XRT refined analysis
  39. GRB 090418: Enhanced Swift-XRT position
  40. GRB 090418: Swift detection of a burst with optical afterglow
  41. GRB 090411B: Suzaku WAM observation of the prompt emission
  42. GRB 090411A: Suzaku WAM observation of the prompt emission
  43. GRB 090417B: Subaru NIR Observations
  44. GRB 090417B: Liverpool Telescope observations
  45. GRB090417B: Xinglong TNT optical upper limit
  46. GRB 090417B: Swift-BAT refined analysis
  47. GRB 090417A: Swift-BAT refined analysis
  48. GRB 090417A: nearby galaxy redshift
  49. GRB 090417B: Swift detection of a burst
  50. GRB 090417: Swift detection of a short burst
  51. GRB 090411B: Fermi GBM detection
  52. GRB 090411A: Fermi GBM detection
  53. GRB 090410: Suzaku WAM observation of the prompt emission
  54. GRB 090408b: IPN Triangulation
  55. GRB 090328b: IPN Triangulation
  56. GRB 090410: Swift-BAT refined analysis
  57. GRB 090410: Swift detection of a burst
  58. Konus-Wind and Konus-RF observations of GRB 090408b
  59. GRB 090409: Fermi GBM detection
  60. Swift-BAT Trigger 348781 is not a GRB
  61. Swift-BAT Trigger 348720 is not a GRB
  62. GRB 090406: pseudo-z= 0.91 from prompt emission spectrum
  63. Swift-BAT trigger 348781: almost certainly not a burst
  64. GRB 090408: Swift detection of a burst
  65. GRB 090407: Swift-XRT refined analysis
  66. GRB 090407: Enhanced Swift-XRT position
  67. GRB 090407: Swift-BAT refined analysis
  68. Konus-Wind and Konus-RF observations of GRB 090406
  69. GRB 090407: Swift detection of a burst
  70. GRB 090404: millimeter detection
  71. GRB 090404: nIR observations at Calar Alto
  72. GRB 090405: Fermi GBM Detection
  73. GRB 090404: GROND upper limits
  74. GRB 090404: further NOT observations
  75. GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
  76. GRB 090404: Swift-XRT Team refined analysis
  77. GRB 090404: Swift-BAT refined analysis
  78. GRB 090404: Enhanced Swift-XRT position
  79. GRB 090404: Swift detection of a burst
  80. GRB 090401A: Suzaku WAM observation of the prompt emission
  81. GRB 090401B: Suzaku WAM observation of the prompt emission
  82. Konus-Wind observation of GRB 090401B
  83. GRB 090401B: VLA radio upper limit
  84. GRB 090401B: Upper limits of MITSuME optical observation
  85. GRB 090401B: NOT optical observations
  86. GRB 090328: Fermi-LAT refined analysis
  87. Swift/UVOT observations of GRB090401B
  88. Swift/UVOT observations of GRB090401B
  89. GRB 090401B: Swift XRT Refined Analysis
  90. Konus-Wind observation of GRB 090401A
  91. GRB 090401B: Enhanced Swift-XRT position
  92. AGILE Gamma-ray detection of GRB 090401B
  93. GRB 090401B: Swift-BAT refined analysis
  94. Swift/UVOT detection of GRB090401B
  95. GRB 090401B: Swift detection of a burst
  96. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  97. GRB 090401, Swift-BAT refined analysis
  98. GRB 090323: Further TLS detections - a break?
  99. GRB 090401: Swift detection of a burst
  100. GRB 090324: Suzaku WAM observation of the prompt emission

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