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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"

19586 results found.

  1. GRB050712: UVOT candidate optical counterpart
  2. GRB 050712: Swift XRT afterglow position
  3. GRB 050712: Swift detection of a weak burst
  4. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  5. GRB 050626: Swift XRT observations
  6. GRB 050701
  7. GRB 050701, optical observations
  8. GRB 050701: Refined XRT analysis
  9. Swift UVOT observations of GRB 050701
  10. GRB050701: Swift-BAT Refined analysis
  11. GRB 050701: Swift XRT afterglow position
  12. Swift trigger 143708 is really GRB 050701
  13. GRB 050525A: Swift Late-Time Decay Rate
  14. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  15. GRB 050416(a): Host Galaxy Redshift Determination
  16. Swift/UVOT observations of GRB050607
  17. GRB 050607: RAPTOR-S Early Optical Limits
  18. GRB050607: KAIT optical limits
  19. GRB 050607: MDM Observations
  20. GRB050607,optical observation
  21. GRB 050607 - XRT refined data analysis
  22. GRB050607 optical limit by "Pi of the Sky"
  23. GRB050607: Swift Detection of a long GRB
  24. GRB 050603 - XRT data analysis of the first day
  25. Konus-Wind observation of GRB 050603
  26. GRB 050603: Analysis of UVOT data
  27. GRB050603: Fading Afterglow observed by Swift UVOT
  28. GRB 050603: Swift XRT Position
  29. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  30. Swift/BAT Detection of GRB050603
  31. GRB 050408: jet break in the XRT light curve
  32. GRB050528, XRT observations
  33. Correction to GCN Circ 3502 on GRB 050528
  34. Swift-BAT GRB 050528: a soft burst
  35. Update on Swift-BAT GRB 050528 (Trigger 130679)
  36. Possible GRB050528: no candidate from Liverpool Telescope
  37. Swift-BAT detection of possible GRB 050528
  38. GRB 050509b: refined XRT/Chandra afterglow position analysis
  39. GRB050525a: optical upper limits
  40. GRB 050525B: Swift-BAT observations
  41. GRB050525A,optical observation
  42. GRB050525: Super-LOTIS observations
  43. GRB 050525, spectral lag pseudo-redshift
  44. GRB050306: optical afterglow not confirmed
  45. GRB 050525A: BOOTES simultaneous optical observations
  46. GRB 050525A: Swift-BAT refined analysis
  47. Swift/UVOT UV and optical detections of GRB 050525
  48. Konus-Wind observation of GRB 050525
  49. GRB 050525: TAROT observations of the early afterglow
  50. INTEGRAL detection of GRB 050525
  51. GRB 050525: Optical observation
  52. GRB050525: ROTSE-III Refined Analysis
  53. GRB 050525 - Very Bright, Not Short
  54. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  55. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  56. XRF 050522: Swift XRT refined analysis
  57. Swift/UVOT observation of XRF 050522
  58. GRB 050509A: Further I-band imaging
  59. RBO Observations of GRB050522
  60. XRF 050522: Swift XRT observation
  61. GRB 050520: VLT/ULTRACAM observations
  62. Swift UVOT Observations of GRB 050520
  63. GRB 050520: Swift XRT refined analysis
  64. XRF050509C: Chandra Afterglow Detection
  65. XRF 050509c: Swift XRT Upper Limit
  66. RBO Observations of GRB050520
  67. GRB 050520: TAROT optical limit
  68. GRB 050520: Swift XRT position
  69. No Swift-BAT Lightcurves in real-time for next 3 weeks
  70. Swift-BAT trigger 122203 is not a real GRB
  71. GRB 050504: Swift XRT afterglow candidate has faded
  72. GRB 050509B: Subaru Optical Observations
  73. GRB050502b: Early Observation
  74. Refined Chandra analysis of GRB 050509b
  75. GRB050509b, SDSS pre-burst observations
  76. Chandra observation of GRB 050509b
  77. GRB 050509b: RAPTOR deep, early limits.
  78. GRB050509B: Optical/Infared observations
  79. GRB 050509b: Swift/UVOT follow-up measurements
  80. GRB 050509b Milagro GeV/TeV Observations
  81. GRB050509B: Optical observations at the Very Large Telescope
  82. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  83. GRB 050509a: Swift-BAT refined analysis
  84. GRB 050509B: WSRT Radio Observations
  85. GRB 050505: SARA Observations
  86. Swift UVOT Follow-up Observations of GRB 050509B
  87. GRB 050509B, Optical Observations
  88. GRB 050509B: Swift/XRT refined analysis
  89. GRB050509a: Swift UVOT observations
  90. GRB 050509b: Optical observations
  91. GRB 050509b: Possible Optical Counterpart
  92. GRB 050509A: Optical observations
  93. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  94. GRB 050509b: optical observations
  95. GRB 050509b: Swift XRT Position
  96. GRB 050509B: ROTSE-III Optical Limits
  97. Swift Detection of GRB050509b: A short duration burst
  98. GRB 050509a: Swift XRT Position
  99. Swift Detection of the Burst GRB050509
  100. Swift-BAT detection of GRB 050507

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