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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"

42241 results found.

  1. GRB 050421: BOOTES-2 simultaneous optical observations
  2. GRB 050421: Optical observations at the INT
  3. Swift Detection of GRB050421
  4. GRB 050416b: Tentative Swift XRT Position
  5. GRB 050315: potential host galaxy
  6. GRB050326: analysis of the XMM-Newton observation
  7. GRB050418: Null Optical Observations
  8. GRB 050412: Chandra observations
  9. GRB050416A, optical observations
  10. GRB 050418: Swift-BAT refined analysis
  11. GRB 050416: Mitsume optical observation
  12. GRB 050416 : optical observation at Xinglong observatory
  13. GRB 050416B: optical observations
  14. GRB 050416b: LCO observations
  15. GRB 050416b: LCO observations
  16. GRB 050416: Swift/UVOT refined analysis
  17. Swift-BAT detection of GRB 050416b
  18. IBAS GRB Alert # 2463: not a GRB
  19. GRB050412: Radio Observations
  20. GRB 050416: Swift/UVOT detection of afterglow emission
  21. GRB050416: Refined Swift-XRT analysis
  22. GRB050416: Maidanak optical observations
  23. GRB 050416: ART observations
  24. GRB 050416,optical observation
  25. GRB 050416: KAIT observations
  26. GRB050416: P200 NIR Observations
  27. GRB 050416: Swift XRT Position
  28. Confirmation of OT for GRB050416
  29. GRB050416: P60 Afterglow Candidate
  30. Swift BAT/XRT Detection of GRB 050416
  31. GRB 050412: Subaru observations
  32. GRB 050408: RTT150 optical observations
  33. GRB050408: optical observation
  34. GRB 050412: PROMPT VRcIc Observations
  35. GRB 050408: Kuiper 1.5m observations
  36. GRB 050412: optical limit
  37. GRB 050412: optical observations
  38. GRB 050408: refined XRT analysis, no jet break seen yet
  39. GRB 050412: early Swift XRT analysis results
  40. GRB 050412 : XingLong optical observation
  41. GRB 050412: Swift-BAT refined analysis
  42. GRB 050412: ANU 2.3m observations
  43. GRB 050412: Early Optical/Ultraviolet Observations with
  44. GRB 050412: UVOT transient not in XRT error circle
  45. GRB 050408: SDSS Field Calibration
  46. GRB 050412: Optical limit
  47. GRB 050412: LCO Optical Observations
  48. GRB 050412: Optical observations
  49. GRB050412: P60 Observations
  50. GRB 050412: Swift XRT Position
  51. GRB050412: optical limit before and during GRB
  52. GRB 050412: LCO optical observations
  53. GRB050412: ROTSE-III Optical Limits
  54. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  55. GRB 050412: IR and Optical observations
  56. GRB 050412: IR Observations
  57. GRB050408: Radio Observations
  58. GRB 050401: Optical limit
  59. GRB 050408: Optical limit
  60. GRB050410: P60 Observations
  61. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  62. GRB 050410, optical observations
  63. GRB 050408: PROMPT VRcIc Observations
  64. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  65. GRB 050410 R band Optical Observations
  66. GRB 050410, optical observations
  67. GRB050410: Radio Observations
  68. GRB 050408: Swift XRT measurement of possible jet break
  69. GRB050410: MASTER optical observations
  70. GRB 050410: Early observations with Swift-UVOT
  71. Swift-BAT detection of GRB 050410
  72. GRB 050410: Swift XRT Position
  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. GRB050408: REM NIR and Optical observation
  85. GRB 050408: Moderate-resolution Gemini Spectroscopy
  86. GRB 050408,optical observation
  87. GRB 050408 Optical Observations
  88. GRB 050408: Emission and absorption redshift
  89. GRB 050408: Mercator Optical Observations
  90. GRB 050408: Magellan astrometry and photometry
  91. GRB 050408: First Optical observations with TFOSC at the RTT150
  92. GRB 050408: steepening of the optical decay
  93. GRB 050408: Optical afterglow confirmed
  94. GRB 050408: opitcal observation
  95. GRB 050408, optical observations
  96. GRB 050408 optical candidate
  97. GRB 050408: Swift XRT Position
  98. GRB 050408: ROTSE-III Optical Limits
  99. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  100. GRB050408: MASTER optical observations

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