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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"

26208 results found.

  1. GRB050709: A Possible Short-Hard GRB Localized by HETE
  2. GRB 050701
  3. GRB 050701, optical observations
  4. GRB 050701: Refined XRT analysis
  5. Swift UVOT observations of GRB 050701
  6. GRB050701: Swift-BAT Refined analysis
  7. Swift trigger 143708 is really GRB 050701
  8. GRB 050525A: Swift Late-Time Decay Rate
  9. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  10. XRF 050509c: Optical monitoring
  11. Konus-Wind observation of an intermediate burst from SGR 1806-20
  12. GRB 050607 optical decay
  13. Swift/UVOT observations of GRB050607
  14. GRB 050607: RAPTOR-S Early Optical Limits
  15. GRB 050607: MDM Observations
  16. GRB050607,optical observation
  17. GRB 050607 - XRT refined data analysis
  18. GRB050607 optical limit by "Pi of the Sky"
  19. GRB050607: Swift Detection of a long GRB
  20. GRB 050603: prediction of t_break
  21. Konus-Wind observation of GRB 050603
  22. GRB050603: Fading Afterglow observed by Swift UVOT
  23. GRB 050603: Swift XRT Position
  24. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  25. Swift/BAT Detection of GRB050603
  26. GRB 050408: jet break in the XRT light curve
  27. GRB050528, XRT observations
  28. Swift-BAT GRB 050528: a soft burst
  29. Update on Swift-BAT GRB 050528 (Trigger 130679)
  30. GRB050528: BOOTES optical candidate (retraction)
  31. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  32. GRB050528: BOOTES optical candidate
  33. Possible GRB050528: no candidate from Liverpool Telescope
  34. Swift-BAT detection of possible GRB 050528
  35. GRB 050525B: Swift-BAT observations
  36. GRB050525A,optical observation
  37. GRB050525: Super-LOTIS observations
  38. GRB 050525A: Swift-BAT refined analysis
  39. Swift/UVOT UV and optical detections of GRB 050525
  40. Konus-Wind observation of GRB 050525
  41. GRB 050525 - Very Bright, Not Short
  42. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  43. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  44. GRB 050509A: Further I-band imaging
  45. GRB050522,optical observation
  46. GRB050520,optical observation
  47. GRB 050520: VLT/ULTRACAM observations
  48. GRB 050520: BART optical limit
  49. No Swift-BAT Lightcurves in real-time for next 3 weeks
  50. Swift-BAT trigger 122203 is not a real GRB
  51. XRF 050509C: REM NIR and Optical refined analysis
  52. XRF 050509c optical afterglow
  53. GRB050502b: Early Observation
  54. GRB050509b, SDSS pre-burst observations
  55. GRB 050509b: RAPTOR deep, early limits.
  56. GRB 050509b: Swift/UVOT follow-up measurements
  57. GRB050509B: Optical observations at the Very Large Telescope
  58. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  59. GRB 050509a: Swift-BAT refined analysis
  60. GRB 050509c: ROTSE-III Optical Limits
  61. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  62. GRB050509c: REM NIR and Optical observations
  63. Swift UVOT Follow-up Observations of GRB 050509B
  64. GRB 050509B: Swift/XRT refined analysis
  65. GRB050509a: Swift UVOT observations
  66. GRB 050509b: Optical observations
  67. GRB 050509A: Optical observations
  68. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  69. GRB 050509B: ROTSE-III Optical Limits
  70. Swift Detection of GRB050509b: A short duration burst
  71. Swift Detection of the Burst GRB050509
  72. Swift-BAT detection of GRB 050507
  73. GRB050505: Infrared observations
  74. GRB 050505: Further Swift UVOT observations.
  75. GRB 050505 UVOT
  76. GRB050505 Swift-BAT refined analysis
  77. GRB 050416b:Swift XRT afterglow upper limits
  78. GRB 050416b:Swift XRT afterglow upper limits
  79. Swift-BAT detection of GRB050505
  80. Swift UVOT observation of GRB 050504
  81. GRB050504: Faulkes North optical robotic limit
  82. GRB 050502b, V band Observations
  83. GRB (?) 050504: IR Observations, Intriguing Source
  84. Renewal of SGR 1806-20 activity
  85. GRB050502B Swift-BAT refined analysis
  86. Swift UVOT refined analysis
  87. Retraction of Swift-BAT trigger 116145
  88. Swift Detection of the Bright Burst GRB050502b
  89. GRB 050502: ROTSE-III Detection of Possible Counterpart
  90. Swift-BAT Trigger 115881 is not a real GRB
  91. Swift/BAT possible detection of a weak burst GRB050430
  92. GRB 050422: Swift-UVOT observation
  93. GRB 050422: Swift-BAT refined analysis
  94. Swift Detection of GRB 050422
  95. GRB 050421: SLOTIS observations
  96. GRB 050421: Swift-UVOT observation
  97. GRB 050421: Swift-BAT refined analysis
  98. GRB 050421: ROTSE-III Optical Limits
  99. GRB050421
  100. GRB 050421: early Swift XRT analysis results

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