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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"

22104 results found.

  1. GRB050509c: REM NIR and Optical observations
  2. GRB 050505: SARA Observations
  3. GRB 050509B: Swift/XRT refined analysis
  4. GRB 050509b: Optical observations
  5. GRB 050509b: Possible Optical Counterpart
  6. GRB 050509A: Optical observations
  7. GRB050509b: Radio Observations
  8. GRB 050509B: ROTSE-III Optical Limits
  9. Swift Detection of GRB050509b: A short duration burst
  10. Swift Detection of the Burst GRB050509
  11. Swift-BAT detection of GRB 050507
  12. GRB 050502a: Swift XRT Upper Limit
  13. GRB 050505, simultaneous optical observation
  14. GRB 050505: Further Swift UVOT observations.
  15. GRB050505: AAVSO observations
  16. GRB050416A : 1 GHz limit from GMRT
  17. GRB050505: Optical Afterglow Candidate
  18. GRB050505 Swift-BAT refined analysis
  19. GRB 050416b:Swift XRT afterglow upper limits
  20. GRB 050416b:Swift XRT afterglow upper limits
  21. Swift-BAT detection of GRB050505
  22. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  23. GRB050502b: Afterglow Confirmation
  24. GRB050502: P200 Observations (Correction)
  25. GRB050502: P200 Observations
  26. Swift UVOT observation of GRB 050504
  27. GRB050504: P60 Observations
  28. GRB (?) 050504: IR Observations, Intriguing Source
  29. GRB 050502b, Optical observations
  30. GRB050502a: P60 Observations (Correction)
  31. GRB050502a: P60 Observations
  32. GRB 050502A: WSRT Radio Observations
  33. GRB050502A: Optical Observations
  34. GRB050502B Swift-BAT refined analysis
  35. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  36. Swift Detection of the Bright Burst GRB050502b
  37. GRB050502 - Optical Candidate from the Liverpool Telescope
  38. GRB 050502: ROTSE-III Detection of Possible Counterpart
  39. Swift/BAT possible detection of a weak burst GRB050430
  40. GRB050416a: Radio Detection
  41. GRB 050422: Swift-BAT refined analysis
  42. Swift Detection of GRB 050422
  43. GRB 050421: SLOTIS observations
  44. GRB 050421: Further Analysis of IR imaging
  45. GRB050421: Radio Observations
  46. GRB050421: Radio Observations
  47. GRB 050421: IR Observations
  48. GRB 050421: ROTSE-III Optical Limits
  49. GRB 050421: NIR observations re-examination
  50. GRB050421
  51. GRB 050421: early Swift XRT analysis results
  52. GRB 050421: NIR observations
  53. GRB050421: P60 Observations
  54. GRB 050421: BOOTES-2 simultaneous optical observations
  55. Swift Detection of GRB050421
  56. GRB 050416b: Tentative Swift XRT Position
  57. GRB 050315: potential host galaxy
  58. GRB050326: analysis of the XMM-Newton observation
  59. GRB050418: Null Optical Observations
  60. GRB050416A, optical observations
  61. GRB 050418: Swift-BAT refined analysis
  62. GRB 050416: Mitsume optical observation
  63. GRB 050416b: Swift-BAT refined analysis
  64. GRB050416B: IR observations
  65. GRB050412: Radio Observations
  66. GRB 050416: Swift/UVOT detection of afterglow emission
  67. GRB 050416: Swift-BAT refined analysis
  68. GRB 050416,optical observation
  69. GRB050416: P200 NIR Observations
  70. GRB 050416: Radio observations
  71. Swift BAT/XRT Detection of GRB 050416
  72. GRB 050412: Subaru observations
  73. GRB 050412: PROMPT VRcIc Observations
  74. GRB 050408: Kuiper 1.5m observations
  75. GRB 050412 : XingLong optical observation
  76. GRB 050412: Swift-BAT refined analysis
  77. GRB 050412: Early Optical/Ultraviolet Observations with
  78. GRB 050408: SDSS Field Calibration
  79. GRB 050412: Optical limit
  80. GRB050412: P60 Observations
  81. GRB050412: ROTSE-III Optical Limits
  82. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  83. GRB 050412: IR and Optical observations
  84. GRB 050412: IR Observations
  85. GRB050408: Radio Observations
  86. GRB 050401: Optical limit
  87. GRB 050408: Optical limit
  88. GRB050410: P60 Observations
  89. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  90. GRB 050410, optical observations
  91. GRB 050408: PROMPT VRcIc Observations
  92. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  93. GRB050410: Radio Observations
  94. GRB050410: MASTER optical observations
  95. GRB 050410: Early observations with Swift-UVOT
  96. GRB 050408: Inconsistency of host galaxy identification
  97. GRB 050408: Subaru Observations
  98. GRB 050408: WIDGET simultaneous optical observations
  99. GRB 050408: Properties of the Host Galaxy
  100. GRB050408: Radio Observations

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