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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"

27403 results found.

  1. GRB 050509b: Keck/Chandra Cross-Correlation
  2. GRB 050509b: Keck/Chandra Cross-Correlation
  3. Chandra observation of GRB 050509b
  4. GRB 050509b: RAPTOR deep, early limits.
  5. GRB050509B: Optical observations at the Very Large Telescope
  6. GRB 050509b: No Optical Variability in XRT Error Circle
  7. GRB 050509a: Swift-BAT refined analysis
  8. GRB 050509c: ROTSE-III Optical Limits
  9. GRB 050505, early TAROT observation
  10. GRB050509c: REM NIR and Optical observations
  11. GRB 050509b: Physical Properties of the Candidate Host galaxy
  12. GRB 050505: SARA Observations
  13. GRB 050509B, Optical Observations
  14. GRB 050509B: Swift/XRT refined analysis
  15. GRB 050509b: Optical observations
  16. GRB 050509A: Optical observations
  17. GRB050509b: Radio Observations
  18. GRB 050509b: PAIRITEL and WIYN Observations
  19. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  20. Swift Detection of GRB050509b: A short duration burst
  21. Swift Detection of the Burst GRB050509
  22. GRB 050505: early time observations
  23. GRB 050505, simultaneous optical observation
  24. GRB050505: AAVSO observations
  25. GRB050416A : 1 GHz limit from GMRT
  26. GRB050505: Optical Afterglow Candidate
  27. GRB050505 Swift-BAT refined analysis
  28. GRB 050416b:Swift XRT afterglow upper limits
  29. GRB 050416b:Swift XRT afterglow upper limits
  30. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  31. GRB050502b: Afterglow Confirmation
  32. GRB050502: P200 Observations (Correction)
  33. GRB050502: P200 Observations
  34. GRB 050504 : R band observation at Lulin observatory
  35. Swift UVOT observation of GRB 050504
  36. GRB 050504, R band Observations
  37. GRB 050502b, V band Observations
  38. GRB050504: P60 Observations
  39. GRB 050504: A long GRB detected with INTEGRAL
  40. GRB (?) 050504: IR Observations, Intriguing Source
  41. GRB 050502b, Optical observations
  42. GRB050502a: P60 Observations (Correction)
  43. GRB050502a: P60 Observations
  44. Renewal of SGR 1806-20 activity
  45. GRB050502B Swift-BAT refined analysis
  46. Swift UVOT refined analysis
  47. GRB 050502a : R band observation at Lulin observatory
  48. GRB 050502b : optical observation at Lulin observatory
  49. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  50. Swift Detection of the Bright Burst GRB050502b
  51. GRB 050502: INTEGRAL results
  52. GRB 050502: ROTSE-III Detection of Possible Counterpart
  53. Swift/BAT possible detection of a weak burst GRB050430
  54. GRB050416a: Radio Detection
  55. GRB 050422: Swift-UVOT observation
  56. GRB 050422: Swift-BAT refined analysis
  57. Swift Detection of GRB 050422
  58. GRB 050421: SLOTIS observations
  59. GRB 050421: Further Analysis of IR imaging
  60. GRB050421: Radio Observations
  61. GRB050421: Radio Observations
  62. GRB 050421: IR Observations
  63. GRB 050421: Swift-BAT refined analysis
  64. GRB050421
  65. GRB 050421: early Swift XRT analysis results
  66. GRB 050421: NIR observations
  67. GRB050421: P60 Observations
  68. GRB 050421: BOOTES-2 simultaneous optical observations
  69. GRB 050416b: Tentative Swift XRT Position
  70. GRB 050315: potential host galaxy
  71. GRB050326: analysis of the XMM-Newton observation
  72. GRB050418: Null Optical Observations
  73. GRB050416A, optical observations
  74. GRB 050418: Swift-BAT refined analysis
  75. GRB 050416: Mitsume optical observation
  76. GRB050416B: IR observations
  77. GRB050412: Radio Observations
  78. GRB 050416: Swift/UVOT detection of afterglow emission
  79. GRB050416: Refined Swift-XRT analysis
  80. GRB 050416,optical observation
  81. GRB050416: P200 NIR Observations
  82. GRB 050416: Radio observations
  83. Swift BAT/XRT Detection of GRB 050416
  84. GRB 050412: PROMPT VRcIc Observations
  85. GRB 050408: Kuiper 1.5m observations
  86. GRB 050412: early Swift XRT analysis results
  87. GRB 050412: Early Optical/Ultraviolet Observations with
  88. GRB 050408: SDSS Field Calibration
  89. GRB050412: P60 Observations
  90. GRB 050412: Swift XRT Position
  91. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  92. GRB 050412: IR and Optical observations
  93. GRB 050412: IR Observations
  94. GRB050408: Radio Observations
  95. GRB 050401: Optical limit
  96. GRB050410: P60 Observations
  97. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  98. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  99. GRB050410: Radio Observations
  100. GRB050410: MASTER optical observations

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