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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"

19253 results found.

  1. Swift-BAT GRB 050528: a soft burst
  2. Update on Swift-BAT GRB 050528 (Trigger 130679)
  3. Possible GRB050528: no candidate from Liverpool Telescope
  4. Swift-BAT detection of possible GRB 050528
  5. GRB 050509b: refined XRT/Chandra afterglow position analysis
  6. GRB050525a: optical upper limits
  7. GRB 050525B: Swift-BAT observations
  8. GRB050525A,optical observation
  9. GRB050525: Super-LOTIS observations
  10. GRB 050525, spectral lag pseudo-redshift
  11. GRB050306: optical afterglow not confirmed
  12. GRB 050525A: BOOTES simultaneous optical observations
  13. GRB 050525A: Swift-BAT refined analysis
  14. Swift/UVOT UV and optical detections of GRB 050525
  15. Konus-Wind observation of GRB 050525
  16. GRB 050525: TAROT observations of the early afterglow
  17. INTEGRAL detection of GRB 050525
  18. GRB 050525: Optical observation
  19. GRB050525: ROTSE-III Refined Analysis
  20. GRB 050525 - Very Bright, Not Short
  21. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  22. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  23. XRF 050522: Swift XRT refined analysis
  24. Swift/UVOT observation of XRF 050522
  25. GRB 050509A: Further I-band imaging
  26. RBO Observations of GRB050522
  27. XRF 050522: Swift XRT observation
  28. GRB 050520: VLT/ULTRACAM observations
  29. Swift UVOT Observations of GRB 050520
  30. GRB 050520: Swift XRT refined analysis
  31. XRF050509C: Chandra Afterglow Detection
  32. XRF 050509c: Swift XRT Upper Limit
  33. RBO Observations of GRB050520
  34. GRB 050520: TAROT optical limit
  35. GRB 050520: Swift XRT position
  36. No Swift-BAT Lightcurves in real-time for next 3 weeks
  37. Swift-BAT trigger 122203 is not a real GRB
  38. GRB 050504: Swift XRT afterglow candidate has faded
  39. GRB 050509B: Subaru Optical Observations
  40. GRB050502b: Early Observation
  41. Refined Chandra analysis of GRB 050509b
  42. GRB050509b, SDSS pre-burst observations
  43. Chandra observation of GRB 050509b
  44. GRB 050509b: RAPTOR deep, early limits.
  45. GRB050509B: Optical/Infared observations
  46. GRB 050509b: Swift/UVOT follow-up measurements
  47. GRB 050509b Milagro GeV/TeV Observations
  48. GRB050509B: Optical observations at the Very Large Telescope
  49. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  50. GRB 050509a: Swift-BAT refined analysis
  51. GRB 050509B: WSRT Radio Observations
  52. GRB 050505: SARA Observations
  53. Swift UVOT Follow-up Observations of GRB 050509B
  54. GRB 050509B, Optical Observations
  55. GRB 050509B: Swift/XRT refined analysis
  56. GRB050509a: Swift UVOT observations
  57. GRB 050509b: Optical observations
  58. GRB 050509b: Possible Optical Counterpart
  59. GRB 050509A: Optical observations
  60. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  61. GRB 050509b: optical observations
  62. GRB 050509b: Swift XRT Position
  63. GRB 050509B: ROTSE-III Optical Limits
  64. Swift Detection of GRB050509b: A short duration burst
  65. GRB 050509a: Swift XRT Position
  66. Swift Detection of the Burst GRB050509
  67. Swift-BAT detection of GRB 050507
  68. GRB 050505: early time observations
  69. GRB 050505 - Faulkes Telescope North observations
  70. GRB 050502a: Swift XRT Upper Limit
  71. GRB 050505, simultaneous optical observation
  72. GRB 050505: Further Swift UVOT observations.
  73. GRB050416A : 1 GHz limit from GMRT
  74. GRB 050505 UVOT
  75. GRB 050505: Swift XRT Position
  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. GRB 050504: Swift XRT position
  81. Swift UVOT observation of GRB 050504
  82. GRB 050502b, V band Observations
  83. GRB050502B Swift-BAT refined analysis
  84. GRB050502B: I band source in XRT error circle
  85. Swift UVOT refined analysis
  86. Retraction of Swift-BAT trigger 116145
  87. GRB 050502b : optical observation at Lulin observatory
  88. GRB 050502b: Swift XRT Position
  89. GRB050502B: Optical Limits from ANU 1m
  90. Swift Detection of the Bright Burst GRB050502b
  91. GRB050502: ANU 1m optical Observations
  92. Swift-BAT Trigger 115881 is not a real GRB
  93. Swift/BAT possible detection of a weak burst GRB050430
  94. GRB 050401: Rc observation
  95. GRB050416a: Radio Detection
  96. GRB 050422: Swift-UVOT observation
  97. GRB 050422: Swift-BAT refined analysis
  98. GRB 050422: Swift XRT Position
  99. Swift Detection of GRB 050422
  100. GRB 050421: SLOTIS observations

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