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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"

26499 results found.

  1. GRB 050416: Mitsume optical observation
  2. GRB050416B: IR observations
  3. GRB050412: Radio Observations
  4. GRB 050416: Swift/UVOT detection of afterglow emission
  5. GRB050416: Refined Swift-XRT analysis
  6. GRB 050416,optical observation
  7. GRB050416: P200 NIR Observations
  8. GRB 050416: Radio observations
  9. Swift BAT/XRT Detection of GRB 050416
  10. GRB 050408: Kuiper 1.5m observations
  11. GRB 050412: early Swift XRT analysis results
  12. GRB 050412: Swift-BAT refined analysis
  13. GRB 050412: Early Optical/Ultraviolet Observations with
  14. GRB 050408: SDSS Field Calibration
  15. GRB050412: P60 Observations
  16. GRB 050412: IR and Optical observations
  17. GRB 050412: IR Observations
  18. GRB050408: Radio Observations
  19. GRB050410: P60 Observations
  20. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  21. GRB 050408: PROMPT VRcIc Observations
  22. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  23. GRB050410: Radio Observations
  24. GRB050410: MASTER optical observations
  25. GRB 050410: Early observations with Swift-UVOT
  26. GRB 050408: Inconsistency of host galaxy identification
  27. GRB 050408: Subaru Observations
  28. GRB 050408: WIDGET simultaneous optical observations
  29. GRB 050408: Properties of the Host Galaxy
  30. GRB 050408: Mercator Optical Observations
  31. GRB050408: Radio Observations
  32. GRB 050408: Swift XRT analysis
  33. GRB 050408: Optical limit at 20 min after the burst
  34. GRB050408: REM NIR and Optical observation
  35. GRB 050408,optical observation
  36. GRB 050408 Optical Observations
  37. GRB 050408: Emission and absorption redshift
  38. GRB 050408: Mercator Optical Observations
  39. GRB 050408: Optical afterglow confirmed
  40. GRB 050408: opitcal observation
  41. GRB 050408, optical observations
  42. GRB 050408 optical candidate
  43. GRB 050408: Swift XRT Position
  44. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  45. GRB050408: MASTER optical observations
  46. GRB050401: Radio Detection
  47. GRB 050406: early Swift XRT analysis results
  48. GRB 050406 BAT refined analysis
  49. GRB 050406: Early observations with Swift-UVOT
  50. GRB 050406: Swift XRT Position
  51. Swift-BAT detection of GRB 050406
  52. Konus-Wind observation of GRB 050401
  53. GRB050401: Radio observation at 610 MHz with GMRT
  54. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  55. GRB 050401: VLT spectroscopic redshift
  56. GRB 050401 BAT refined analysis
  57. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  58. GRB050401: TNG R-band observation
  59. GRB 050402: Early observations with Swift-UVOT
  60. Swift Trigger 113225: P60 Observations
  61. GRB 050401: Optical afterglow confirmed
  62. GRB050331: No Afterglow Detected
  63. GRB 050331: Swift UVOT Source
  64. Swift-BAT detection of GRB 050331
  65. GRB050319: radio observation
  66. GRB 050326: Early observations with Swift-UVOT
  67. GRB 050326 XMM-Newton observation
  68. GRB 050326: Swift XRT Position
  69. GRB 050326 BAT refined analysis
  70. GRB050326: delayed XRT observation
  71. GRB050319, optical observations
  72. GRB050319: optical observation, March 20-22
  73. GRB050319: RTT150 Optical Observations
  74. GRB 050318: Swift-BAT refined analysis
  75. GRB050319: VLA Observations
  76. GRB050319: radio observation
  77. GRB 050319: Swift-UVOT detection of the afterglow
  78. GRB 050315: Variability Analysis of Swift BAT Time History
  79. GRB050319: Radio Observations
  80. GRB 050319: NIR afterglow candidate
  81. GRB 050319:Near IR afterglow
  82. GRB 050318: SWIFT-UVOT refined analysis
  83. GRB 050319: Swift-BAT refined analysis
  84. GRB050319,optical observation
  85. GRB 050318: Swift/UVOT detection of afterglow emission
  86. RXTE Observations of GRB050318
  87. Swift-BAT detection of GRB 050318
  88. GRB050223: analysis of the XMM-Newton observation
  89. GRB050316: MASTER before, simultanious and follow up optical
  90. GRB 050306: ROTSE-III early limits
  91. GRB050316: MASTER optical observations
  92. GRB 050315 I-band observations
  93. GRB050315: Radio afterglow
  94. GRB 050315: Absorption redshift
  95. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  96. GRB 050315: Early Observations with Swift/UVOT
  97. Swift-BAT detection of GRB 050315
  98. GRB 050306: Radio Observations
  99. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  100. GRB 050306: optical afterglow

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