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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"

19506 results found.

  1. GRB 050717: Swift-BAT refined analysis
  2. GRB050717: Swift XRT position
  3. Swift detection of GRB 050717
  4. Swift UVOT Observations of GRB 050716
  5. GRB 050716: Lulin B and R band optical observations
  6. GRB050716, optical observation
  7. GRB050716: Faulkes North Telescope observation
  8. Konus-Wind observation of GRB 050713A
  9. GRB 050714B: refined XRT analysis
  10. GRB 050713b: RTT150 optical observations
  11. GRB 050714B: optical afterglow
  12. GRB 050714, R-band candidate
  13. GRB 050714, optical observations
  14. GRB 050714A: ROTSE-III Optical Limits
  15. GRB 050713A: RAPTOR detection of early optical emission
  16. GRB050713B :Swift/UVOT observations
  17. GRB050712: TNG R-band observations
  18. GRB 050713A: Swift/UVOT observation
  19. GRB050712: Swift UVOT Observation of Afterglow Emission
  20. GRB 050713A : Lulin R-band observation
  21. GRB 050713A XMM-Newton observation
  22. GRB050713B: Faulkes North Telescope observation
  23. RBO RI observations of GRB 050713A
  24. GRB050709 : Chandra source optical counterpart
  25. GRB 050712, optical observations
  26. GRB050709: Candidate X-ray Afterglow from Chandra
  27. GRB050713: possible I-band afterglow
  28. GRB 050713A: ROTSE-III Optical Limits
  29. GRB050709: Radio Observations
  30. GRB 050709: Swift UVOT and XRT observations
  31. GRB050712: UVOT candidate optical counterpart
  32. GRB 050712: Swift detection of a weak burst
  33. GRB 050709: LCO40 Observations
  34. PROMPT Rc Observations of GRB 050709
  35. GRB 050525a: PROMPT VRcIc Detections
  36. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  37. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  38. GRB 050408: ARC 3.5-meter NIR Observations
  39. Swift UVOT observations of GRB 050701
  40. GRB 050607, radio observations
  41. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  42. GRB050525a: HST Observations
  43. XRF 050509c: Optical monitoring
  44. XRF050509c: Radio Detection
  45. GRB 050607 optical decay
  46. GRB050607: refined analysis of prompt REM observations
  47. GRB 050607: PROMPT VRcIc Observations
  48. GRB 050607: Optical decay and spectral slope
  49. GRB050607,optical observation
  50. GRB 050607 - XRT refined data analysis
  51. Optical Afterglow of GRB 050607
  52. GRB050607: Swift Detection of a long GRB
  53. GRB050607: prompt REM observations
  54. Limits on a SN in the field of GRB 050509b
  55. GRB 050603: Redshift
  56. GRB 050603 - XRT data analysis of the first day
  57. Konus-Wind observation of GRB 050603
  58. GRB050603, submillimetre observations
  59. GRB050603: Radio Detection
  60. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  61. GRB 050603: INTEGRAL shows it is not a short GRB
  62. GRB 050525a, infrared observations
  63. GRB050528: updated Liverpool Telescope limits
  64. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  65. Possible GRB050528: no candidate from Liverpool Telescope
  66. GRB050525a: Radio Observations
  67. GRB 050509b: refined XRT/Chandra afterglow position analysis
  68. GRB 050525: RTT150, Optical observations
  69. GRB 050525a: SARA Observations
  70. GRB 050525B: Swift-BAT observations
  71. GRB 050525: MITSuME Optical Observation in VRI
  72. GRB050525A,optical observation
  73. GRB050525: Super-LOTIS observations
  74. GRB050306: optical afterglow not confirmed
  75. GRB 050525: BART optical observation
  76. GRB 050525A: BOOTES simultaneous optical observations
  77. GRB 050525A: Swift-BAT refined analysis
  78. GRB050525: Optical observations
  79. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  80. Konus-Wind observation of GRB 050525
  81. GRB 050525: TAROT observations of the early afterglow
  82. INTEGRAL detection of GRB 050525
  83. GRB 050525, infrared observations
  84. GRB 050525: observatons of the optical afterglow
  85. GRB050525: ROTSE-III Refined Analysis
  86. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  87. XRF 050522: Swift XRT refined analysis
  88. XRF050522: Radio Observations
  89. Swift/UVOT observation of XRF 050522
  90. GRB 050509A: Further I-band imaging
  91. GRB050522,optical observation
  92. GRB050520,optical observation
  93. XRF 050522: Continued NIR P200 Monitoring
  94. Recent GRB BVRcIc field photometry
  95. GRB050520: Radio Observations
  96. XRF 050522: Swift XRT observation
  97. XRF050522, BVRcIc field photometry
  98. XRF050522: Optical Observations
  99. XRF050522: Near-infrared Observations
  100. GRB 050520: VLT/ULTRACAM observations

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