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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"

24927 results found.

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

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