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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"

19591 results found.

  1. GRB 050713: Swift detection of Bright Burst
  2. GRB 050713A: ROTSE-III Optical Limits
  3. GRB050712: XRT refined analysis
  4. GRB 050709: Swift UVOT and XRT observations
  5. GRB 050712: Swift-BAT Refined Analysis
  6. GRB050712: UVOT candidate optical counterpart
  7. GRB 050712: Swift XRT afterglow position
  8. GRB 050712: Swift detection of a weak burst
  9. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  10. GRB 050626: Swift XRT observations
  11. GRB 050701
  12. GRB 050701, optical observations
  13. GRB 050701: Refined XRT analysis
  14. Swift UVOT observations of GRB 050701
  15. GRB050701: Swift-BAT Refined analysis
  16. GRB 050701: Swift XRT afterglow position
  17. Swift trigger 143708 is really GRB 050701
  18. GRB 050525A: Swift Late-Time Decay Rate
  19. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  20. GRB 050416(a): Host Galaxy Redshift Determination
  21. Swift/UVOT observations of GRB050607
  22. GRB 050607: RAPTOR-S Early Optical Limits
  23. GRB050607: KAIT optical limits
  24. GRB 050607: MDM Observations
  25. GRB050607,optical observation
  26. GRB 050607 - XRT refined data analysis
  27. GRB050607 optical limit by "Pi of the Sky"
  28. GRB050607: Swift Detection of a long GRB
  29. GRB 050603 - XRT data analysis of the first day
  30. Konus-Wind observation of GRB 050603
  31. GRB 050603: Analysis of UVOT data
  32. GRB050603: Fading Afterglow observed by Swift UVOT
  33. GRB 050603: Swift XRT Position
  34. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  35. Swift/BAT Detection of GRB050603
  36. GRB 050408: jet break in the XRT light curve
  37. GRB050528, XRT observations
  38. Correction to GCN Circ 3502 on GRB 050528
  39. Swift-BAT GRB 050528: a soft burst
  40. Update on Swift-BAT GRB 050528 (Trigger 130679)
  41. Possible GRB050528: no candidate from Liverpool Telescope
  42. Swift-BAT detection of possible GRB 050528
  43. GRB 050509b: refined XRT/Chandra afterglow position analysis
  44. GRB050525a: optical upper limits
  45. GRB 050525B: Swift-BAT observations
  46. GRB050525A,optical observation
  47. GRB050525: Super-LOTIS observations
  48. GRB 050525, spectral lag pseudo-redshift
  49. GRB050306: optical afterglow not confirmed
  50. GRB 050525A: BOOTES simultaneous optical observations
  51. GRB 050525A: Swift-BAT refined analysis
  52. Swift/UVOT UV and optical detections of GRB 050525
  53. Konus-Wind observation of GRB 050525
  54. GRB 050525: TAROT observations of the early afterglow
  55. INTEGRAL detection of GRB 050525
  56. GRB 050525: Optical observation
  57. GRB050525: ROTSE-III Refined Analysis
  58. GRB 050525 - Very Bright, Not Short
  59. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  60. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  61. XRF 050522: Swift XRT refined analysis
  62. Swift/UVOT observation of XRF 050522
  63. GRB 050509A: Further I-band imaging
  64. RBO Observations of GRB050522
  65. XRF 050522: Swift XRT observation
  66. GRB 050520: VLT/ULTRACAM observations
  67. Swift UVOT Observations of GRB 050520
  68. GRB 050520: Swift XRT refined analysis
  69. XRF050509C: Chandra Afterglow Detection
  70. XRF 050509c: Swift XRT Upper Limit
  71. RBO Observations of GRB050520
  72. GRB 050520: TAROT optical limit
  73. GRB 050520: Swift XRT position
  74. No Swift-BAT Lightcurves in real-time for next 3 weeks
  75. Swift-BAT trigger 122203 is not a real GRB
  76. GRB 050504: Swift XRT afterglow candidate has faded
  77. GRB 050509B: Subaru Optical Observations
  78. GRB050502b: Early Observation
  79. Refined Chandra analysis of GRB 050509b
  80. GRB050509b, SDSS pre-burst observations
  81. Chandra observation of GRB 050509b
  82. GRB 050509b: RAPTOR deep, early limits.
  83. GRB050509B: Optical/Infared observations
  84. GRB 050509b: Swift/UVOT follow-up measurements
  85. GRB 050509b Milagro GeV/TeV Observations
  86. GRB050509B: Optical observations at the Very Large Telescope
  87. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  88. GRB 050509a: Swift-BAT refined analysis
  89. GRB 050509B: WSRT Radio Observations
  90. GRB 050505: SARA Observations
  91. Swift UVOT Follow-up Observations of GRB 050509B
  92. GRB 050509B, Optical Observations
  93. GRB 050509B: Swift/XRT refined analysis
  94. GRB050509a: Swift UVOT observations
  95. GRB 050509b: Optical observations
  96. GRB 050509b: Possible Optical Counterpart
  97. GRB 050509A: Optical observations
  98. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  99. GRB 050509b: optical observations
  100. GRB 050509b: Swift XRT Position

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