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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"

22917 results found.

  1. GRB050713B: Faulkes North Telescope observation
  2. GRB 050713B
  3. GRB050709 : Chandra source optical counterpart
  4. GRB050713: Liverpool Telescope prompt observations
  5. GRB 050712, optical observations
  6. GRB050709: Candidate X-ray Afterglow from Chandra
  7. GRB050713: possible I-band afterglow
  8. GRB 050713: Swift detection of Bright Burst
  9. GRB 050713A: ROTSE-III Optical Limits
  10. GRB050709: Radio Observations
  11. GRB 050709: Swift UVOT and XRT observations
  12. GRB 050712: Swift-BAT Refined Analysis
  13. GRB050712: UVOT candidate optical counterpart
  14. GRB 050712: Swift detection of a weak burst
  15. GRB 050709: LCO40 Observations
  16. PROMPT Rc Observations of GRB 050709
  17. GRB 050525a: PROMPT VRcIc Detections
  18. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  19. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  20. GRB 050626: Swift XRT observations
  21. GRB 050408: ARC 3.5-meter NIR Observations
  22. Swift UVOT observations of GRB 050701
  23. Swift trigger 143708 is really GRB 050701
  24. GRB 050607, radio observations
  25. GRB050525a: HST Observations
  26. XRF 050509c: Optical monitoring
  27. XRF050509c: Radio Detection
  28. GRB 050607 optical decay
  29. GRB050607: refined analysis of prompt REM observations
  30. Swift/UVOT observations of GRB050607
  31. GRB 050607: PROMPT VRcIc Observations
  32. GRB 050607: Optical decay and spectral slope
  33. GRB050607,optical observation
  34. GRB 050607 - XRT refined data analysis
  35. Optical Afterglow of GRB 050607
  36. GRB050607: Swift Detection of a long GRB
  37. GRB050607: prompt REM observations
  38. GRB 050603: prediction of t_break
  39. Limits on a SN in the field of GRB 050509b
  40. Konus-Wind observation of GRB 050603
  41. GRB050603: Fading Afterglow observed by Swift UVOT
  42. GRB050603, submillimetre observations
  43. GRB050603: Radio Detection
  44. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  45. GRB 050603: INTEGRAL shows it is not a short GRB
  46. Swift/BAT Detection of GRB050603
  47. GRB 050525a, infrared observations
  48. GRB050528, XRT observations
  49. GRB050528: updated Liverpool Telescope limits
  50. Swift-BAT GRB 050528: a soft burst
  51. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  52. Possible GRB050528: no candidate from Liverpool Telescope
  53. Swift-BAT detection of possible GRB 050528
  54. GRB050525a: Radio Observations
  55. GRB 050509b: refined XRT/Chandra afterglow position analysis
  56. GRB 050525: RTT150, Optical observations
  57. GRB 050525a: SARA Observations
  58. GRB 050525B: Swift-BAT observations
  59. GRB 050525: MITSuME Optical Observation in VRI
  60. GRB050525A,optical observation
  61. GRB050525: Super-LOTIS observations
  62. GRB050306: optical afterglow not confirmed
  63. GRB 050525: BART optical observation
  64. GRB 050525A: BOOTES simultaneous optical observations
  65. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  66. Konus-Wind observation of GRB 050525
  67. GRB 050525: TAROT observations of the early afterglow
  68. INTEGRAL detection of GRB 050525
  69. GRB 050525, infrared observations
  70. GRB 050525: observatons of the optical afterglow
  71. GRB050525: ROTSE-III Refined Analysis
  72. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  73. XRF050522: Radio Observations
  74. Swift/UVOT observation of XRF 050522
  75. GRB 050509A: Further I-band imaging
  76. GRB050522,optical observation
  77. GRB050520,optical observation
  78. XRF 050522: Continued NIR P200 Monitoring
  79. Recent GRB BVRcIc field photometry
  80. GRB050520: Radio Observations
  81. XRF 050522: Swift XRT observation
  82. XRF050522, BVRcIc field photometry
  83. XRF050522: Optical Observations
  84. XRF050522: Near-infrared Observations
  85. GRB 050520: VLT/ULTRACAM observations
  86. Swift UVOT Observations of GRB 050520
  87. GRB 050520: Swift XRT refined analysis
  88. XRF 050509c: Swift XRT Upper Limit
  89. XRF050509c: Radio Observations
  90. RBO Observations of GRB050520
  91. GRB 050520: P200 Observations
  92. GRB050520: Liverpool Telescope follow-up
  93. GRB 050520: TAROT optical limit
  94. GRB 050520: VLT/ULTRACAM observations
  95. GRB 050520: OSN optical observations
  96. No Swift-BAT Lightcurves in real-time for next 3 weeks
  97. XRF 050509C: REM NIR and Optical refined analysis
  98. GRB 050504: Swift XRT afterglow candidate has faded
  99. GRB 050509B and short GRB-SN association? (corrected)
  100. GRB 050509B and short GRB-SN association?

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