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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"

19188 results found.

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

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