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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"

21455 results found.

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

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