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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"

36149 results found.

  1. GRB 050421: ROTSE-III Optical Limits
  2. GRB 050421: NIR observations re-examination
  3. GRB 050421: early Swift XRT analysis results
  4. GRB 050421: NIR observations
  5. GRB050421: P60 Observations
  6. GRB 050421: BOOTES-2 simultaneous optical observations
  7. GRB 050421: Optical observations at the INT
  8. GRB 050416b: Tentative Swift XRT Position
  9. GRB 050315: potential host galaxy
  10. GRB 050412: Chandra observations
  11. GRB050416A, optical observations
  12. GRB 050418: Swift-BAT refined analysis
  13. Swift-BAT detection of the bright and long GRB 050418
  14. GRB 050416: Mitsume optical observation
  15. GRB 050416 : optical observation at Xinglong observatory
  16. GRB 050416B: optical observations
  17. GRB 050416b: Swift-BAT refined analysis
  18. GRB 050416b: LCO observations
  19. GRB 050416b: LCO observations
  20. GRB050416B: IR observations
  21. GRB 050416: Swift/UVOT refined analysis
  22. Swift-BAT detection of GRB 050416b
  23. IBAS GRB Alert # 2463: not a GRB
  24. GRB050412: Radio Observations
  25. GRB 050416: Swift/UVOT detection of afterglow emission
  26. GRB 050416: Swift-BAT refined analysis
  27. GRB 050416: ART observations
  28. GRB 050416,optical observation
  29. GRB 050416: KAIT observations
  30. GRB050416: P200 NIR Observations
  31. GRB 050416: Swift XRT Position
  32. GRB 050416: Radio observations
  33. Confirmation of OT for GRB050416
  34. GRB050416: P60 Afterglow Candidate
  35. Swift BAT/XRT Detection of GRB 050416
  36. GRB 050412: Subaru observations
  37. GRB 050408: RTT150 optical observations
  38. GRB 050412: PROMPT VRcIc Observations
  39. GRB 050408: Kuiper 1.5m observations
  40. GRB 050412: optical limit
  41. GRB 050412: optical observations
  42. GRB 050408: refined XRT analysis, no jet break seen yet
  43. GRB 050412: early Swift XRT analysis results
  44. GRB 050412 : XingLong optical observation
  45. GRB 050412: Swift-BAT refined analysis
  46. GRB 050412: ANU 2.3m observations
  47. GRB 050412: Early Optical/Ultraviolet Observations with
  48. GRB 050412: retraction of UVOT transient report
  49. GRB 050412: UVOT transient not in XRT error circle
  50. GRB 050408: SDSS Field Calibration
  51. GRB 050412: Optical limit
  52. GRB 050412: LCO Optical Observations
  53. GRB 050412: Optical observations
  54. GRB050412: P60 Observations
  55. GRB 050412: Swift XRT Position
  56. GRB050412: optical limit before and during GRB
  57. GRB 050412: LCO optical observations
  58. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  59. GRB 050412: IR and Optical observations
  60. GRB 050412: IR Observations
  61. GRB050408: Radio Observations
  62. GRB 050401: Optical limit
  63. GRB 050408: Optical limit
  64. GRB050410: P60 Observations
  65. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  66. GRB 050410, optical observations
  67. GRB 050408: PROMPT VRcIc Observations
  68. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  69. GRB 050410 R band Optical Observations
  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. GRB050410: MASTER optical observations
  75. GRB 050410: Early observations with Swift-UVOT
  76. Swift-BAT detection of GRB 050410
  77. GRB 050410: Swift XRT Position
  78. GRB 050408: Retraction of Proposed Host Galaxy
  79. GRB 050408: Inconsistency of host galaxy identification
  80. GRB 050408: Subaru Observations
  81. GRB 050408: WIDGET simultaneous optical observations
  82. GRB 050408: SOAR UBVRc Observations
  83. GRB 050408: Properties of the Host Galaxy
  84. GRB 050408: Mercator Optical Observations
  85. GRB050408: Radio Observations
  86. GRB 050408: Swift XRT analysis
  87. GRB 050408, SMARTS optical/IR afterglow observations
  88. GRB 050408: Optical limit at 20 min after the burst
  89. GRB 050408, optical observations
  90. GRB 050408: Moderate-resolution Gemini Spectroscopy
  91. GRB 050408,optical observation
  92. GRB 050408 Optical Observations
  93. GRB 050408: Emission and absorption redshift
  94. GRB 050408: Mercator Optical Observations
  95. GRB 050408: Magellan astrometry and photometry
  96. GRB 050408: First Optical observations with TFOSC at the RTT150
  97. GRB 050408: steepening of the optical decay
  98. GRB 050408: Optical afterglow confirmed
  99. GRB 050408: opitcal observation
  100. GRB 050408, optical observations

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