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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"

19193 results found.

  1. GRB050709: Candidate X-ray Afterglow from Chandra
  2. GRB 050713, R-band observations at NOT
  3. GRB 050713: Swift detection of Bright Burst
  4. GRB 050713A: ROTSE-III Optical Limits
  5. GRB050712: XRT refined analysis
  6. GRB 050709: Swift UVOT and XRT observations
  7. GRB 050712: Swift-BAT Refined Analysis
  8. GRB050712: UVOT candidate optical counterpart
  9. GRB 050712: Swift XRT afterglow position
  10. GRB 050712: Swift detection of a weak burst
  11. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  12. GRB 050626: Swift XRT observations
  13. GRB 050701
  14. GRB 050701, optical observations
  15. GRB 050701: Refined XRT analysis
  16. Swift UVOT observations of GRB 050701
  17. GRB050701: Swift-BAT Refined analysis
  18. GRB 050701: Swift XRT afterglow position
  19. Swift trigger 143708 is really GRB 050701
  20. GRB 050525A: Swift Late-Time Decay Rate
  21. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  22. GRB 050416(a): Host Galaxy Redshift Determination
  23. Swift/UVOT observations of GRB050607
  24. GRB 050607: RAPTOR-S Early Optical Limits
  25. GRB050607: KAIT optical limits
  26. GRB 050607: MDM Observations
  27. GRB050607,optical observation
  28. GRB 050607 - XRT refined data analysis
  29. GRB050607 optical limit by "Pi of the Sky"
  30. GRB050607: Swift Detection of a long GRB
  31. GRB 050603 - XRT data analysis of the first day
  32. Konus-Wind observation of GRB 050603
  33. GRB 050603: Analysis of UVOT data
  34. GRB050603: Fading Afterglow observed by Swift UVOT
  35. GRB 050603: Swift XRT Position
  36. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  37. Swift/BAT Detection of GRB050603
  38. GRB 050408: jet break in the XRT light curve
  39. GRB050528, XRT observations
  40. Correction to GCN Circ 3502 on GRB 050528
  41. Swift-BAT GRB 050528: a soft burst
  42. Update on Swift-BAT GRB 050528 (Trigger 130679)
  43. Possible GRB050528: no candidate from Liverpool Telescope
  44. Swift-BAT detection of possible GRB 050528
  45. GRB 050509b: refined XRT/Chandra afterglow position analysis
  46. GRB050525a: optical upper limits
  47. GRB 050525B: Swift-BAT observations
  48. GRB050525A,optical observation
  49. GRB050525: Super-LOTIS observations
  50. GRB 050525, spectral lag pseudo-redshift
  51. GRB050306: optical afterglow not confirmed
  52. GRB 050525A: BOOTES simultaneous optical observations
  53. GRB 050525A: Swift-BAT refined analysis
  54. Swift/UVOT UV and optical detections of GRB 050525
  55. Konus-Wind observation of GRB 050525
  56. GRB 050525: TAROT observations of the early afterglow
  57. INTEGRAL detection of GRB 050525
  58. GRB 050525: Optical observation
  59. GRB050525: ROTSE-III Refined Analysis
  60. GRB 050525 - Very Bright, Not Short
  61. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  62. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  63. XRF 050522: Swift XRT refined analysis
  64. Swift/UVOT observation of XRF 050522
  65. GRB 050509A: Further I-band imaging
  66. RBO Observations of GRB050522
  67. XRF 050522: Swift XRT observation
  68. GRB 050520: VLT/ULTRACAM observations
  69. Swift UVOT Observations of GRB 050520
  70. GRB 050520: Swift XRT refined analysis
  71. XRF050509C: Chandra Afterglow Detection
  72. XRF 050509c: Swift XRT Upper Limit
  73. RBO Observations of GRB050520
  74. GRB 050520: TAROT optical limit
  75. GRB 050520: Swift XRT position
  76. No Swift-BAT Lightcurves in real-time for next 3 weeks
  77. Swift-BAT trigger 122203 is not a real GRB
  78. GRB 050504: Swift XRT afterglow candidate has faded
  79. GRB 050509B: Subaru Optical Observations
  80. GRB050502b: Early Observation
  81. Refined Chandra analysis of GRB 050509b
  82. GRB050509b, SDSS pre-burst observations
  83. Chandra observation of GRB 050509b
  84. GRB 050509b: RAPTOR deep, early limits.
  85. GRB050509B: Optical/Infared observations
  86. GRB 050509b: Swift/UVOT follow-up measurements
  87. GRB 050509b Milagro GeV/TeV Observations
  88. GRB050509B: Optical observations at the Very Large Telescope
  89. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  90. GRB 050509a: Swift-BAT refined analysis
  91. GRB 050509B: WSRT Radio Observations
  92. GRB 050505: SARA Observations
  93. Swift UVOT Follow-up Observations of GRB 050509B
  94. GRB 050509B, Optical Observations
  95. GRB 050509B: Swift/XRT refined analysis
  96. GRB050509a: Swift UVOT observations
  97. GRB 050509b: Optical observations
  98. GRB 050509b: Possible Optical Counterpart
  99. GRB 050509A: Optical observations
  100. GRB 050509b: Swift-BAT refined analysis of the short hard burst

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