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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"

24929 results found.

  1. GRB050502a: P60 Observations
  2. Renewal of SGR 1806-20 activity
  3. GRB 050502A: WSRT Radio Observations
  4. GRB050502B Swift-BAT refined analysis
  5. GRB050502B: I band source in XRT error circle
  6. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  7. GRB 050502: INTEGRAL results
  8. GRB 050502 - A long GRB detected with INTEGRAL
  9. GRB 050502: ROTSE-III Detection of Possible Counterpart
  10. Swift/BAT possible detection of a weak burst GRB050430
  11. GRB 050401: Rc observation
  12. GRB050416a: Radio Detection
  13. Swift Detection of GRB 050422
  14. GRB 050421: SLOTIS observations
  15. GRB 050421: Further Analysis of IR imaging
  16. GRB050421: Radio Observations
  17. GRB050421: Radio Observations
  18. GRB 050421: IR Observations
  19. GRB 050421: Swift-BAT refined analysis
  20. GRB050421
  21. GRB 050421: early Swift XRT analysis results
  22. GRB 050421: NIR observations
  23. GRB050421: P60 Observations
  24. GRB 050421: BOOTES-2 simultaneous optical observations
  25. GRB 050416b: Tentative Swift XRT Position
  26. GRB 050315: potential host galaxy
  27. GRB050326: analysis of the XMM-Newton observation
  28. GRB050418: Null Optical Observations
  29. GRB 050412: Chandra observations
  30. GRB050416A, optical observations
  31. GRB 050416: Mitsume optical observation
  32. GRB050416B: IR observations
  33. GRB050412: Radio Observations
  34. GRB 050416: Swift/UVOT detection of afterglow emission
  35. GRB050416: Refined Swift-XRT analysis
  36. GRB 050416,optical observation
  37. GRB050416: P200 NIR Observations
  38. GRB 050416: Radio observations
  39. Swift BAT/XRT Detection of GRB 050416
  40. GRB 050408: Kuiper 1.5m observations
  41. GRB 050412: early Swift XRT analysis results
  42. GRB 050412: Swift-BAT refined analysis
  43. GRB 050412: Early Optical/Ultraviolet Observations with
  44. GRB 050408: SDSS Field Calibration
  45. GRB050412: P60 Observations
  46. GRB 050412: IR and Optical observations
  47. GRB 050412: IR Observations
  48. GRB050408: Radio Observations
  49. GRB050410: P60 Observations
  50. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  51. GRB 050408: PROMPT VRcIc Observations
  52. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  53. GRB050410: Radio Observations
  54. GRB050410: MASTER optical observations
  55. GRB 050410: Early observations with Swift-UVOT
  56. GRB 050408: Inconsistency of host galaxy identification
  57. GRB 050408: Subaru Observations
  58. GRB 050408: WIDGET simultaneous optical observations
  59. GRB 050408: Properties of the Host Galaxy
  60. GRB 050408: Mercator Optical Observations
  61. GRB050408: Radio Observations
  62. GRB 050408: Swift XRT analysis
  63. GRB 050408: Optical limit at 20 min after the burst
  64. GRB050408: REM NIR and Optical observation
  65. GRB 050408,optical observation
  66. GRB 050408 Optical Observations
  67. GRB 050408: Emission and absorption redshift
  68. GRB 050408: Mercator Optical Observations
  69. GRB 050408: Optical afterglow confirmed
  70. GRB 050408: opitcal observation
  71. GRB 050408, optical observations
  72. GRB 050408 optical candidate
  73. GRB 050408: Swift XRT Position
  74. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  75. GRB050408: MASTER optical observations
  76. GRB050401: Radio Detection
  77. GRB 050406: early Swift XRT analysis results
  78. GRB 050406 BAT refined analysis
  79. GRB 050406: Early observations with Swift-UVOT
  80. GRB 050406: Swift XRT Position
  81. Swift-BAT detection of GRB 050406
  82. Konus-Wind observation of GRB 050401
  83. GRB050401: Radio observation at 610 MHz with GMRT
  84. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  85. GRB 050401: VLT spectroscopic redshift
  86. GRB 050401 BAT refined analysis
  87. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  88. GRB050401: TNG R-band observation
  89. GRB 050402: Early observations with Swift-UVOT
  90. Swift Trigger 113225: P60 Observations
  91. GRB 050401: Optical afterglow confirmed
  92. GRB050331: No Afterglow Detected
  93. GRB 050331: Swift UVOT Source
  94. Swift-BAT detection of GRB 050331
  95. GRB050319: radio observation
  96. GRB 050326: Early observations with Swift-UVOT
  97. GRB 050326 XMM-Newton observation
  98. GRB 050326: Swift XRT Position
  99. GRB 050326 BAT refined analysis
  100. GRB050326: delayed XRT observation

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