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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"

19357 results found.

  1. Swift/BAT Detection of GRB050603
  2. GRB 050408: jet break in the XRT light curve
  3. GRB050528, XRT observations
  4. Correction to GCN Circ 3502 on GRB 050528
  5. Swift-BAT GRB 050528: a soft burst
  6. Update on Swift-BAT GRB 050528 (Trigger 130679)
  7. Possible GRB050528: no candidate from Liverpool Telescope
  8. Swift-BAT detection of possible GRB 050528
  9. GRB 050509b: refined XRT/Chandra afterglow position analysis
  10. GRB050525a: optical upper limits
  11. GRB 050525B: Swift-BAT observations
  12. GRB050525A,optical observation
  13. GRB050525: Super-LOTIS observations
  14. GRB 050525, spectral lag pseudo-redshift
  15. GRB050306: optical afterglow not confirmed
  16. GRB 050525A: BOOTES simultaneous optical observations
  17. GRB 050525A: Swift-BAT refined analysis
  18. Swift/UVOT UV and optical detections of GRB 050525
  19. Konus-Wind observation of GRB 050525
  20. GRB 050525: TAROT observations of the early afterglow
  21. INTEGRAL detection of GRB 050525
  22. GRB 050525: Optical observation
  23. GRB050525: ROTSE-III Refined Analysis
  24. GRB 050525 - Very Bright, Not Short
  25. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  26. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  27. XRF 050522: Swift XRT refined analysis
  28. Swift/UVOT observation of XRF 050522
  29. GRB 050509A: Further I-band imaging
  30. RBO Observations of GRB050522
  31. XRF 050522: Swift XRT observation
  32. GRB 050520: VLT/ULTRACAM observations
  33. Swift UVOT Observations of GRB 050520
  34. GRB 050520: Swift XRT refined analysis
  35. XRF050509C: Chandra Afterglow Detection
  36. XRF 050509c: Swift XRT Upper Limit
  37. RBO Observations of GRB050520
  38. GRB 050520: TAROT optical limit
  39. GRB 050520: Swift XRT position
  40. No Swift-BAT Lightcurves in real-time for next 3 weeks
  41. Swift-BAT trigger 122203 is not a real GRB
  42. GRB 050504: Swift XRT afterglow candidate has faded
  43. GRB 050509B: Subaru Optical Observations
  44. GRB050502b: Early Observation
  45. Refined Chandra analysis of GRB 050509b
  46. GRB050509b, SDSS pre-burst observations
  47. Chandra observation of GRB 050509b
  48. GRB 050509b: RAPTOR deep, early limits.
  49. GRB050509B: Optical/Infared observations
  50. GRB 050509b: Swift/UVOT follow-up measurements
  51. GRB 050509b Milagro GeV/TeV Observations
  52. GRB050509B: Optical observations at the Very Large Telescope
  53. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  54. GRB 050509a: Swift-BAT refined analysis
  55. GRB 050509B: WSRT Radio Observations
  56. GRB 050505: SARA Observations
  57. Swift UVOT Follow-up Observations of GRB 050509B
  58. GRB 050509B, Optical Observations
  59. GRB 050509B: Swift/XRT refined analysis
  60. GRB050509a: Swift UVOT observations
  61. GRB 050509b: Optical observations
  62. GRB 050509b: Possible Optical Counterpart
  63. GRB 050509A: Optical observations
  64. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  65. GRB 050509b: optical observations
  66. GRB 050509b: Swift XRT Position
  67. GRB 050509B: ROTSE-III Optical Limits
  68. Swift Detection of GRB050509b: A short duration burst
  69. GRB 050509a: Swift XRT Position
  70. Swift Detection of the Burst GRB050509
  71. Swift-BAT detection of GRB 050507
  72. GRB 050505: early time observations
  73. GRB 050505 - Faulkes Telescope North observations
  74. GRB 050502a: Swift XRT Upper Limit
  75. GRB 050505, simultaneous optical observation
  76. GRB 050505: Further Swift UVOT observations.
  77. GRB050416A : 1 GHz limit from GMRT
  78. GRB 050505 UVOT
  79. GRB 050505: Swift XRT Position
  80. GRB050505 Swift-BAT refined analysis
  81. GRB 050416b:Swift XRT afterglow upper limits
  82. GRB 050416b:Swift XRT afterglow upper limits
  83. Swift-BAT detection of GRB050505
  84. GRB 050504: Swift XRT position
  85. Swift UVOT observation of GRB 050504
  86. GRB 050502b, V band Observations
  87. GRB050502B Swift-BAT refined analysis
  88. GRB050502B: I band source in XRT error circle
  89. Swift UVOT refined analysis
  90. Retraction of Swift-BAT trigger 116145
  91. GRB 050502b : optical observation at Lulin observatory
  92. GRB 050502b: Swift XRT Position
  93. GRB050502B: Optical Limits from ANU 1m
  94. Swift Detection of the Bright Burst GRB050502b
  95. GRB050502: ANU 1m optical Observations
  96. Swift-BAT Trigger 115881 is not a real GRB
  97. Swift/BAT possible detection of a weak burst GRB050430
  98. GRB 050401: Rc observation
  99. GRB050416a: Radio Detection
  100. GRB 050422: Swift-UVOT observation

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