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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"

19349 results found.

  1. GRB 050509b: refined XRT/Chandra afterglow position analysis
  2. GRB050525a: optical upper limits
  3. GRB 050525B: Swift-BAT observations
  4. GRB050525A,optical observation
  5. GRB050525: Super-LOTIS observations
  6. GRB 050525, spectral lag pseudo-redshift
  7. GRB050306: optical afterglow not confirmed
  8. GRB 050525A: BOOTES simultaneous optical observations
  9. GRB 050525A: Swift-BAT refined analysis
  10. Swift/UVOT UV and optical detections of GRB 050525
  11. Konus-Wind observation of GRB 050525
  12. GRB 050525: TAROT observations of the early afterglow
  13. INTEGRAL detection of GRB 050525
  14. GRB 050525: Optical observation
  15. GRB050525: ROTSE-III Refined Analysis
  16. GRB 050525 - Very Bright, Not Short
  17. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  18. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  19. XRF 050522: Swift XRT refined analysis
  20. Swift/UVOT observation of XRF 050522
  21. GRB 050509A: Further I-band imaging
  22. RBO Observations of GRB050522
  23. XRF 050522: Swift XRT observation
  24. GRB 050520: VLT/ULTRACAM observations
  25. Swift UVOT Observations of GRB 050520
  26. GRB 050520: Swift XRT refined analysis
  27. XRF050509C: Chandra Afterglow Detection
  28. XRF 050509c: Swift XRT Upper Limit
  29. RBO Observations of GRB050520
  30. GRB 050520: TAROT optical limit
  31. GRB 050520: Swift XRT position
  32. No Swift-BAT Lightcurves in real-time for next 3 weeks
  33. Swift-BAT trigger 122203 is not a real GRB
  34. GRB 050504: Swift XRT afterglow candidate has faded
  35. GRB 050509B: Subaru Optical Observations
  36. GRB050502b: Early Observation
  37. Refined Chandra analysis of GRB 050509b
  38. GRB050509b, SDSS pre-burst observations
  39. Chandra observation of GRB 050509b
  40. GRB 050509b: RAPTOR deep, early limits.
  41. GRB050509B: Optical/Infared observations
  42. GRB 050509b: Swift/UVOT follow-up measurements
  43. GRB 050509b Milagro GeV/TeV Observations
  44. GRB050509B: Optical observations at the Very Large Telescope
  45. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  46. GRB 050509a: Swift-BAT refined analysis
  47. GRB 050509B: WSRT Radio Observations
  48. GRB 050505: SARA Observations
  49. Swift UVOT Follow-up Observations of GRB 050509B
  50. GRB 050509B, Optical Observations
  51. GRB 050509B: Swift/XRT refined analysis
  52. GRB050509a: Swift UVOT observations
  53. GRB 050509b: Optical observations
  54. GRB 050509b: Possible Optical Counterpart
  55. GRB 050509A: Optical observations
  56. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  57. GRB 050509b: optical observations
  58. GRB 050509b: Swift XRT Position
  59. GRB 050509B: ROTSE-III Optical Limits
  60. Swift Detection of GRB050509b: A short duration burst
  61. GRB 050509a: Swift XRT Position
  62. Swift Detection of the Burst GRB050509
  63. Swift-BAT detection of GRB 050507
  64. GRB 050505: early time observations
  65. GRB 050505 - Faulkes Telescope North observations
  66. GRB 050502a: Swift XRT Upper Limit
  67. GRB 050505, simultaneous optical observation
  68. GRB 050505: Further Swift UVOT observations.
  69. GRB050416A : 1 GHz limit from GMRT
  70. GRB 050505 UVOT
  71. GRB 050505: Swift XRT Position
  72. GRB050505 Swift-BAT refined analysis
  73. GRB 050416b:Swift XRT afterglow upper limits
  74. GRB 050416b:Swift XRT afterglow upper limits
  75. Swift-BAT detection of GRB050505
  76. GRB 050504: Swift XRT position
  77. Swift UVOT observation of GRB 050504
  78. GRB 050502b, V band Observations
  79. GRB050502B Swift-BAT refined analysis
  80. GRB050502B: I band source in XRT error circle
  81. Swift UVOT refined analysis
  82. Retraction of Swift-BAT trigger 116145
  83. GRB 050502b : optical observation at Lulin observatory
  84. GRB 050502b: Swift XRT Position
  85. GRB050502B: Optical Limits from ANU 1m
  86. Swift Detection of the Bright Burst GRB050502b
  87. GRB050502: ANU 1m optical Observations
  88. Swift-BAT Trigger 115881 is not a real GRB
  89. Swift/BAT possible detection of a weak burst GRB050430
  90. GRB 050401: Rc observation
  91. GRB050416a: Radio Detection
  92. GRB 050422: Swift-UVOT observation
  93. GRB 050422: Swift-BAT refined analysis
  94. GRB 050422: Swift XRT Position
  95. Swift Detection of GRB 050422
  96. GRB 050421: SLOTIS observations
  97. GRB050421: Radio Observations
  98. GRB050421: Radio Observations
  99. GRB 050421: Swift-UVOT observation
  100. GRB 050421: Swift-BAT refined analysis

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