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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"

36143 results found.

  1. GRB 050421: Optical observations at the INT
  2. GRB 050416b: Tentative Swift XRT Position
  3. GRB 050315: potential host galaxy
  4. GRB 050412: Chandra observations
  5. GRB050416A, optical observations
  6. GRB 050418: Swift-BAT refined analysis
  7. Swift-BAT detection of the bright and long GRB 050418
  8. GRB 050416: Mitsume optical observation
  9. GRB 050416 : optical observation at Xinglong observatory
  10. GRB 050416B: optical observations
  11. GRB 050416b: Swift-BAT refined analysis
  12. GRB 050416b: LCO observations
  13. GRB 050416b: LCO observations
  14. GRB050416B: IR observations
  15. GRB 050416: Swift/UVOT refined analysis
  16. Swift-BAT detection of GRB 050416b
  17. IBAS GRB Alert # 2463: not a GRB
  18. GRB050412: Radio Observations
  19. GRB 050416: Swift/UVOT detection of afterglow emission
  20. GRB 050416: Swift-BAT refined analysis
  21. GRB 050416: ART observations
  22. GRB 050416,optical observation
  23. GRB 050416: KAIT observations
  24. GRB050416: P200 NIR Observations
  25. GRB 050416: Swift XRT Position
  26. GRB 050416: Radio observations
  27. Confirmation of OT for GRB050416
  28. GRB050416: P60 Afterglow Candidate
  29. Swift BAT/XRT Detection of GRB 050416
  30. GRB 050412: Subaru observations
  31. GRB 050408: RTT150 optical observations
  32. GRB 050412: PROMPT VRcIc Observations
  33. GRB 050408: Kuiper 1.5m observations
  34. GRB 050412: optical limit
  35. GRB 050412: optical observations
  36. GRB 050408: refined XRT analysis, no jet break seen yet
  37. GRB 050412: early Swift XRT analysis results
  38. GRB 050412 : XingLong optical observation
  39. GRB 050412: Swift-BAT refined analysis
  40. GRB 050412: ANU 2.3m observations
  41. GRB 050412: Early Optical/Ultraviolet Observations with
  42. GRB 050412: retraction of UVOT transient report
  43. GRB 050412: UVOT transient not in XRT error circle
  44. GRB 050408: SDSS Field Calibration
  45. GRB 050412: Optical limit
  46. GRB 050412: LCO Optical Observations
  47. GRB 050412: Optical observations
  48. GRB050412: P60 Observations
  49. GRB 050412: Swift XRT Position
  50. GRB050412: optical limit before and during GRB
  51. GRB 050412: LCO optical observations
  52. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  53. GRB 050412: IR and Optical observations
  54. GRB 050412: IR Observations
  55. GRB050408: Radio Observations
  56. GRB 050401: Optical limit
  57. GRB 050408: Optical limit
  58. GRB050410: P60 Observations
  59. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  60. GRB 050410, optical observations
  61. GRB 050408: PROMPT VRcIc Observations
  62. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  63. GRB 050410 R band Optical Observations
  64. GRB050410 : Null detection report
  65. GRB 050410, optical observations
  66. GRB050410: Radio Observations
  67. GRB 050408: Swift XRT measurement of possible jet break
  68. GRB050410: MASTER optical observations
  69. GRB 050410: Early observations with Swift-UVOT
  70. Swift-BAT detection of GRB 050410
  71. GRB 050410: Swift XRT Position
  72. GRB 050408: Retraction of Proposed Host Galaxy
  73. GRB 050408: Inconsistency of host galaxy identification
  74. GRB 050408: Subaru Observations
  75. GRB 050408: WIDGET simultaneous optical observations
  76. GRB 050408: SOAR UBVRc Observations
  77. GRB 050408: Properties of the Host Galaxy
  78. GRB 050408: Mercator Optical Observations
  79. GRB050408: Radio Observations
  80. GRB 050408: Swift XRT analysis
  81. GRB 050408, SMARTS optical/IR afterglow observations
  82. GRB 050408: Optical limit at 20 min after the burst
  83. GRB 050408, optical observations
  84. GRB 050408: Moderate-resolution Gemini Spectroscopy
  85. GRB 050408,optical observation
  86. GRB 050408 Optical Observations
  87. GRB 050408: Emission and absorption redshift
  88. GRB 050408: Mercator Optical Observations
  89. GRB 050408: Magellan astrometry and photometry
  90. GRB 050408: First Optical observations with TFOSC at the RTT150
  91. GRB 050408: steepening of the optical decay
  92. GRB 050408: Optical afterglow confirmed
  93. GRB 050408: opitcal observation
  94. GRB 050408, optical observations
  95. GRB 050408 optical candidate
  96. GRB 050408: Swift XRT Position
  97. GRB 050408: ROTSE-III Optical Limits
  98. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  99. GRB050408: MASTER optical observations
  100. GRB050401: Radio Detection

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