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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"

28076 results found.

  1. GRB 050401: Rc observation
  2. GRB050416a: Radio Detection
  3. GRB 050422: Swift-UVOT observation
  4. GRB 050422: Swift XRT Position
  5. Swift Detection of GRB 050422
  6. GRB 050421: NIR observations
  7. GRB 050416: Optical/NIR observations
  8. GRB 050421: Further Analysis of IR imaging
  9. GRB050421: Radio Observations
  10. GRB050421: Radio Observations
  11. GRB 050421: Swift-UVOT observation
  12. GRB 050421: IR Observations
  13. GRB 050421: ROTSE-III Optical Limits
  14. GRB 050421: NIR observations re-examination
  15. GRB050421
  16. GRB 050421: early Swift XRT analysis results
  17. GRB 050421: NIR observations
  18. GRB050421: P60 Observations
  19. GRB 050421: Optical observations at the INT
  20. Swift Detection of GRB050421
  21. GRB 050416b: Tentative Swift XRT Position
  22. GRB 050315: potential host galaxy
  23. GRB050326: analysis of the XMM-Newton observation
  24. GRB 050412: Chandra observations
  25. Swift-BAT detection of the bright and long GRB 050418
  26. GRB 050416: Mitsume optical observation
  27. GRB 050416 : optical observation at Xinglong observatory
  28. GRB 050416B: optical observations
  29. GRB 050416: Swift/UVOT refined analysis
  30. Swift-BAT detection of GRB 050416b
  31. GRB050412: Radio Observations
  32. GRB 050416: Swift/UVOT detection of afterglow emission
  33. GRB050416: Refined Swift-XRT analysis
  34. GRB050416: Maidanak optical observations
  35. GRB 050416: Swift-BAT refined analysis
  36. GRB 050416: ART observations
  37. GRB 050416: KAIT observations
  38. GRB050416: P200 NIR Observations
  39. GRB 050416: Swift XRT Position
  40. GRB 050416: Radio observations
  41. Confirmation of OT for GRB050416
  42. GRB050416: P60 Afterglow Candidate
  43. Swift BAT/XRT Detection of GRB 050416
  44. GRB 050412: Subaru observations
  45. GRB050408: optical observation
  46. GRB 050412: PROMPT VRcIc Observations
  47. GRB 050412: optical limit
  48. GRB 050412: optical observations
  49. GRB 050408: refined XRT analysis, no jet break seen yet
  50. GRB 050412: early Swift XRT analysis results
  51. GRB 050412 : XingLong optical observation
  52. GRB 050412: Swift-BAT refined analysis
  53. GRB 050412: ANU 2.3m observations
  54. GRB 050412: Early Optical/Ultraviolet Observations with
  55. GRB 050412: UVOT transient not in XRT error circle
  56. GRB 050412: LCO Optical Observations
  57. GRB 050412: Optical observations
  58. GRB050412: P60 Observations
  59. GRB 050412: Swift XRT Position
  60. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  61. GRB 050412: IR Observations
  62. GRB050408: Radio Observations
  63. GRB 050401: Optical limit
  64. GRB 050408: Optical limit
  65. GRB050410: P60 Observations
  66. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  67. GRB 050410, optical observations
  68. GRB 050408: PROMPT VRcIc Observations
  69. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  70. GRB050410 : Null detection report
  71. GRB 050410, optical observations
  72. GRB050410: Radio Observations
  73. GRB 050408: Swift XRT measurement of possible jet break
  74. GRB 050410: Early observations with Swift-UVOT
  75. Swift-BAT detection of GRB 050410
  76. GRB 050410: Swift XRT Position
  77. GRB 050408: Retraction of Proposed Host Galaxy
  78. GRB 050408: Inconsistency of host galaxy identification
  79. GRB 050408: Subaru Observations
  80. GRB 050408: WIDGET simultaneous optical observations
  81. GRB 050408: SOAR UBVRc Observations
  82. GRB 050408: Properties of the Host Galaxy
  83. GRB 050408: Mercator Optical Observations
  84. GRB050408: Radio Observations
  85. GRB 050408: Swift XRT analysis
  86. GRB 050408, SMARTS optical/IR afterglow observations
  87. GRB 050408: Optical limit at 20 min after the burst
  88. GRB 050408, optical observations
  89. GRB050408: REM NIR and Optical observation
  90. GRB 050408: Moderate-resolution Gemini Spectroscopy
  91. GRB 050408 Optical Observations
  92. GRB 050408: Emission and absorption redshift
  93. GRB 050408: Mercator Optical Observations
  94. GRB 050408: Magellan astrometry and photometry
  95. GRB 050408: Optical afterglow confirmed
  96. GRB 050408, optical observations
  97. GRB 050408 optical candidate
  98. GRB 050408: Swift XRT Position
  99. GRB050401: Radio Detection
  100. Swift-UVOT Optical Counterpart Candidate to XRF 050406

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