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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"

21456 results found.

  1. GRB 050713A : Swift-BAT Refined Analysis
  2. GRB050712: Swift UVOT Observation of Afterglow Emission
  3. GRB 050713A XMM-Newton observation
  4. GRB050713B: Faulkes North Telescope observation
  5. RBO RI observations of GRB 050713A
  6. GRB 050713B
  7. GRB050713: Liverpool Telescope prompt observations
  8. GRB050709: Candidate X-ray Afterglow from Chandra
  9. GRB 050713, R-band observations at NOT
  10. GRB050713: possible I-band afterglow
  11. GRB 050713: Swift detection of Bright Burst
  12. GRB 050713A: ROTSE-III Optical Limits
  13. GRB050712: XRT refined analysis
  14. GRB 050709: Swift UVOT and XRT observations
  15. GRB 050712: Swift-BAT Refined Analysis
  16. GRB050712: UVOT candidate optical counterpart
  17. GRB 050712: Swift XRT afterglow position
  18. GRB 050712: Swift detection of a weak burst
  19. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  20. GRB 050626: Swift XRT observations
  21. GRB 050701
  22. GRB 050701, optical observations
  23. GRB 050701: Refined XRT analysis
  24. Swift UVOT observations of GRB 050701
  25. GRB050701: Swift-BAT Refined analysis
  26. GRB 050701: Swift XRT afterglow position
  27. Swift trigger 143708 is really GRB 050701
  28. GRB 050525A: Swift Late-Time Decay Rate
  29. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  30. GRB 050416(a): Host Galaxy Redshift Determination
  31. Swift/UVOT observations of GRB050607
  32. GRB 050607: PROMPT VRcIc Observations
  33. GRB 050607: RAPTOR-S Early Optical Limits
  34. GRB050607: KAIT optical limits
  35. GRB 050607: MDM Observations
  36. GRB050607,optical observation
  37. GRB 050607 - XRT refined data analysis
  38. Optical Afterglow of GRB 050607
  39. GRB050607 optical limit by "Pi of the Sky"
  40. GRB050607: Swift Detection of a long GRB
  41. Limits on a SN in the field of GRB 050509b
  42. GRB 050603: Redshift
  43. GRB 050603 - XRT data analysis of the first day
  44. Konus-Wind observation of GRB 050603
  45. GRB 050603: Analysis of UVOT data
  46. GRB050603: Fading Afterglow observed by Swift UVOT
  47. GRB 050603: Swift XRT Position
  48. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  49. Swift/BAT Detection of GRB050603
  50. GRB 050408: jet break in the XRT light curve
  51. GRB050528, XRT observations
  52. Correction to GCN Circ 3502 on GRB 050528
  53. Swift-BAT GRB 050528: a soft burst
  54. Update on Swift-BAT GRB 050528 (Trigger 130679)
  55. Possible GRB050528: no candidate from Liverpool Telescope
  56. Swift-BAT detection of possible GRB 050528
  57. GRB 050509b: refined XRT/Chandra afterglow position analysis
  58. GRB050525a: optical upper limits
  59. GRB 050525B: Swift-BAT observations
  60. GRB050525A,optical observation
  61. GRB050525: Super-LOTIS observations
  62. GRB 050525, spectral lag pseudo-redshift
  63. GRB050306: optical afterglow not confirmed
  64. GRB 050525A: BOOTES simultaneous optical observations
  65. GRB 050525A: Swift-BAT refined analysis
  66. Swift/UVOT UV and optical detections of GRB 050525
  67. Konus-Wind observation of GRB 050525
  68. GRB 050525: TAROT observations of the early afterglow
  69. INTEGRAL detection of GRB 050525
  70. GRB 050525: Optical observation
  71. GRB050525: ROTSE-III Refined Analysis
  72. GRB 050525 - Very Bright, Not Short
  73. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  74. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  75. XRF050522: NIR observations of XRT candidate
  76. XRF 050522: Swift XRT refined analysis
  77. Swift/UVOT observation of XRF 050522
  78. GRB 050509A: Further I-band imaging
  79. RBO Observations of GRB050522
  80. GRB050509b: optical observations
  81. GRB050520: Radio Observations
  82. XRF 050522: Swift XRT observation
  83. GRB 050520: VLT/ULTRACAM observations
  84. Swift UVOT Observations of GRB 050520
  85. GRB 050520: Swift XRT refined analysis
  86. XRF050509C: Chandra Afterglow Detection
  87. XRF 050509c: Swift XRT Upper Limit
  88. RBO Observations of GRB050520
  89. GRB 050520: P200 Observations
  90. GRB050520: Liverpool Telescope follow-up
  91. GRB 050520: TAROT optical limit
  92. GRB 050520: Swift XRT position
  93. No Swift-BAT Lightcurves in real-time for next 3 weeks
  94. Swift-BAT trigger 122203 is not a real GRB
  95. GRB 050504: Swift XRT afterglow candidate has faded
  96. GRB 050509B and short GRB-SN association? (corrected)
  97. GRB 050509B and short GRB-SN association?
  98. GRB 050509B: Subaru Optical Observations
  99. GRB050502b: Early Observation
  100. GRB050509b, Bok telescope B-band imaging

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