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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"

21459 results found.

  1. GRB 050713B: Swift-BAT Refined Analysis
  2. Swift-BAT Trigger 145729 is not a GRB
  3. GRB 050713A: Swift/UVOT observation
  4. GRB 050713A : Swift-BAT Refined Analysis
  5. GRB050712: Swift UVOT Observation of Afterglow Emission
  6. GRB 050713A XMM-Newton observation
  7. GRB050713B: Faulkes North Telescope observation
  8. RBO RI observations of GRB 050713A
  9. GRB 050713B
  10. GRB050713: Liverpool Telescope prompt observations
  11. GRB050709: Candidate X-ray Afterglow from Chandra
  12. GRB 050713, R-band observations at NOT
  13. GRB050713: possible I-band afterglow
  14. GRB 050713: Swift detection of Bright Burst
  15. GRB 050713A: ROTSE-III Optical Limits
  16. GRB050712: XRT refined analysis
  17. GRB 050709: Swift UVOT and XRT observations
  18. GRB 050712: Swift-BAT Refined Analysis
  19. GRB050712: UVOT candidate optical counterpart
  20. GRB 050712: Swift XRT afterglow position
  21. GRB 050712: Swift detection of a weak burst
  22. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  23. GRB 050626: Swift XRT observations
  24. GRB 050701
  25. GRB 050701, optical observations
  26. GRB 050701: Refined XRT analysis
  27. Swift UVOT observations of GRB 050701
  28. GRB050701: Swift-BAT Refined analysis
  29. GRB 050701: Swift XRT afterglow position
  30. Swift trigger 143708 is really GRB 050701
  31. GRB 050525A: Swift Late-Time Decay Rate
  32. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  33. GRB 050416(a): Host Galaxy Redshift Determination
  34. Swift/UVOT observations of GRB050607
  35. GRB 050607: PROMPT VRcIc Observations
  36. GRB 050607: RAPTOR-S Early Optical Limits
  37. GRB050607: KAIT optical limits
  38. GRB 050607: MDM Observations
  39. GRB050607,optical observation
  40. GRB 050607 - XRT refined data analysis
  41. Optical Afterglow of GRB 050607
  42. GRB050607 optical limit by "Pi of the Sky"
  43. GRB050607: Swift Detection of a long GRB
  44. Limits on a SN in the field of GRB 050509b
  45. GRB 050603: Redshift
  46. GRB 050603 - XRT data analysis of the first day
  47. Konus-Wind observation of GRB 050603
  48. GRB 050603: Analysis of UVOT data
  49. GRB050603: Fading Afterglow observed by Swift UVOT
  50. GRB 050603: Swift XRT Position
  51. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  52. Swift/BAT Detection of GRB050603
  53. GRB 050408: jet break in the XRT light curve
  54. GRB050528, XRT observations
  55. Correction to GCN Circ 3502 on GRB 050528
  56. Swift-BAT GRB 050528: a soft burst
  57. Update on Swift-BAT GRB 050528 (Trigger 130679)
  58. Possible GRB050528: no candidate from Liverpool Telescope
  59. Swift-BAT detection of possible GRB 050528
  60. GRB 050509b: refined XRT/Chandra afterglow position analysis
  61. GRB050525a: optical upper limits
  62. GRB 050525B: Swift-BAT observations
  63. GRB050525A,optical observation
  64. GRB050525: Super-LOTIS observations
  65. GRB 050525, spectral lag pseudo-redshift
  66. GRB050306: optical afterglow not confirmed
  67. GRB 050525A: BOOTES simultaneous optical observations
  68. GRB 050525A: Swift-BAT refined analysis
  69. Swift/UVOT UV and optical detections of GRB 050525
  70. Konus-Wind observation of GRB 050525
  71. GRB 050525: TAROT observations of the early afterglow
  72. INTEGRAL detection of GRB 050525
  73. GRB 050525: Optical observation
  74. GRB050525: ROTSE-III Refined Analysis
  75. GRB 050525 - Very Bright, Not Short
  76. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  77. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  78. XRF050522: NIR observations of XRT candidate
  79. XRF 050522: Swift XRT refined analysis
  80. Swift/UVOT observation of XRF 050522
  81. GRB 050509A: Further I-band imaging
  82. RBO Observations of GRB050522
  83. GRB050509b: optical observations
  84. GRB050520: Radio Observations
  85. XRF 050522: Swift XRT observation
  86. GRB 050520: VLT/ULTRACAM observations
  87. Swift UVOT Observations of GRB 050520
  88. GRB 050520: Swift XRT refined analysis
  89. XRF050509C: Chandra Afterglow Detection
  90. XRF 050509c: Swift XRT Upper Limit
  91. RBO Observations of GRB050520
  92. GRB 050520: P200 Observations
  93. GRB050520: Liverpool Telescope follow-up
  94. GRB 050520: TAROT optical limit
  95. GRB 050520: Swift XRT position
  96. No Swift-BAT Lightcurves in real-time for next 3 weeks
  97. Swift-BAT trigger 122203 is not a real GRB
  98. GRB 050504: Swift XRT afterglow candidate has faded
  99. GRB 050509B and short GRB-SN association? (corrected)
  100. GRB 050509B and short GRB-SN association?

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