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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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

18345 results found.

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

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