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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"

26507 results found.

  1. GRB050421: P60 Observations
  2. GRB 050421: BOOTES-2 simultaneous optical observations
  3. GRB 050416b: Tentative Swift XRT Position
  4. GRB 050315: potential host galaxy
  5. GRB050326: analysis of the XMM-Newton observation
  6. GRB050418: Null Optical Observations
  7. GRB 050412: Chandra observations
  8. GRB050416A, optical observations
  9. GRB 050416: Mitsume optical observation
  10. GRB050416B: IR observations
  11. GRB050412: Radio Observations
  12. GRB 050416: Swift/UVOT detection of afterglow emission
  13. GRB050416: Refined Swift-XRT analysis
  14. GRB 050416,optical observation
  15. GRB050416: P200 NIR Observations
  16. GRB 050416: Radio observations
  17. Swift BAT/XRT Detection of GRB 050416
  18. GRB 050408: Kuiper 1.5m observations
  19. GRB 050412: early Swift XRT analysis results
  20. GRB 050412: Swift-BAT refined analysis
  21. GRB 050412: Early Optical/Ultraviolet Observations with
  22. GRB 050408: SDSS Field Calibration
  23. GRB050412: P60 Observations
  24. GRB 050412: IR and Optical observations
  25. GRB 050412: IR Observations
  26. GRB050408: Radio Observations
  27. GRB050410: P60 Observations
  28. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  29. GRB 050408: PROMPT VRcIc Observations
  30. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  31. GRB050410: Radio Observations
  32. GRB050410: MASTER optical observations
  33. GRB 050410: Early observations with Swift-UVOT
  34. GRB 050408: Inconsistency of host galaxy identification
  35. GRB 050408: Subaru Observations
  36. GRB 050408: WIDGET simultaneous optical observations
  37. GRB 050408: Properties of the Host Galaxy
  38. GRB 050408: Mercator Optical Observations
  39. GRB050408: Radio Observations
  40. GRB 050408: Swift XRT analysis
  41. GRB 050408: Optical limit at 20 min after the burst
  42. GRB050408: REM NIR and Optical observation
  43. GRB 050408,optical observation
  44. GRB 050408 Optical Observations
  45. GRB 050408: Emission and absorption redshift
  46. GRB 050408: Mercator Optical Observations
  47. GRB 050408: Optical afterglow confirmed
  48. GRB 050408: opitcal observation
  49. GRB 050408, optical observations
  50. GRB 050408 optical candidate
  51. GRB 050408: Swift XRT Position
  52. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  53. GRB050408: MASTER optical observations
  54. GRB050401: Radio Detection
  55. GRB 050406: early Swift XRT analysis results
  56. GRB 050406 BAT refined analysis
  57. GRB 050406: Early observations with Swift-UVOT
  58. GRB 050406: Swift XRT Position
  59. Swift-BAT detection of GRB 050406
  60. Konus-Wind observation of GRB 050401
  61. GRB050401: Radio observation at 610 MHz with GMRT
  62. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  63. GRB 050401: VLT spectroscopic redshift
  64. GRB 050401 BAT refined analysis
  65. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  66. GRB050401: TNG R-band observation
  67. GRB 050402: Early observations with Swift-UVOT
  68. Swift Trigger 113225: P60 Observations
  69. GRB 050401: Optical afterglow confirmed
  70. GRB050331: No Afterglow Detected
  71. GRB 050331: Swift UVOT Source
  72. Swift-BAT detection of GRB 050331
  73. GRB050319: radio observation
  74. GRB 050326: Early observations with Swift-UVOT
  75. GRB 050326 XMM-Newton observation
  76. GRB 050326: Swift XRT Position
  77. GRB 050326 BAT refined analysis
  78. GRB050326: delayed XRT observation
  79. GRB050319, optical observations
  80. GRB050319: optical observation, March 20-22
  81. GRB050319: RTT150 Optical Observations
  82. GRB 050318: Swift-BAT refined analysis
  83. GRB050319: VLA Observations
  84. GRB050319: radio observation
  85. GRB 050319: Swift-UVOT detection of the afterglow
  86. GRB 050315: Variability Analysis of Swift BAT Time History
  87. GRB050319: Radio Observations
  88. GRB 050319: NIR afterglow candidate
  89. GRB 050319:Near IR afterglow
  90. GRB 050318: SWIFT-UVOT refined analysis
  91. GRB 050319: Swift-BAT refined analysis
  92. GRB050319,optical observation
  93. GRB 050318: Swift/UVOT detection of afterglow emission
  94. RXTE Observations of GRB050318
  95. Swift-BAT detection of GRB 050318
  96. GRB050223: analysis of the XMM-Newton observation
  97. GRB050316: MASTER before, simultanious and follow up optical
  98. GRB 050306: ROTSE-III early limits
  99. GRB050316: MASTER optical observations
  100. GRB 050315 I-band observations

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