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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').
  1. GRB 050607 optical decay
  2. GRB 050607: RTT150 optical observations
  3. GRB050607: refined analysis of prompt REM observations
  4. Swift/UVOT observations of GRB050607
  5. GRB 050607 : Lulin R-band observation
  6. GRB 050607: PROMPT VRcIc Observations
  7. GRB 050607: RAPTOR-S Early Optical Limits
  8. GRB050607: KAIT optical limits
  9. GRB 050525a, Mid-Infrared Observations
  10. GRB 050607: Optical decay and spectral slope
  11. GRB 050607: MDM Observations
  12. GRB050607,optical observation
  13. GRB 050607 - XRT refined data analysis
  14. Optical Afterglow of GRB 050607
  15. GRB050607 optical limit by "Pi of the Sky"
  16. GRB050607: Swift Detection of a long GRB
  17. GRB050607: P60 Observations
  18. GRB050607: prompt REM observations
  19. GRB 050603: prediction of t_break
  20. Limits on a SN in the field of GRB 050509b
  21. GRB 050603: Redshift
  22. GRB 050603 - XRT data analysis of the first day
  23. Konus-Wind observation of GRB 050603
  24. GRB 050603: Analysis of UVOT data
  25. GRB050603: Fading Afterglow observed by Swift UVOT
  26. GRB050603, submillimetre observations
  27. GRB 050603: Swift XRT Position
  28. GRB050603: Radio Detection
  29. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  30. GRB 050603: Afterglow Identification from LCO
  31. GRB 050603: INTEGRAL shows it is not a short GRB
  32. Swift/BAT Detection of GRB050603
  33. GRB 050408: jet break in the XRT light curve
  34. GRB 050525a, infrared observations
  35. GRB 050525a, SMARTS optical/IR afterglow observations
  36. GRB050528, XRT observations
  37. Correction to GCN Circ 3502 on GRB 050528
  38. GRB050528: updated Liverpool Telescope limits
  39. Swift-BAT GRB 050528: a soft burst
  40. Update on Swift-BAT GRB 050528 (Trigger 130679)
  41. GRB050528: BOOTES optical candidate (retraction)
  42. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  43. GRB050528: BOOTES optical candidate
  44. Possible GRB050528: no candidate from Liverpool Telescope
  45. Swift-BAT detection of possible GRB 050528
  46. GRB050525a: Radio Observations
  47. GRB 050509b: refined XRT/Chandra afterglow position analysis
  48. GRB 050525: RTT150, Optical observations
  49. GRB050525a: optical upper limits
  50. GRB 050525a: SARA Observations
  51. GRB 050525B: Swift-BAT observations
  52. GRB 050525: MITSuME Optical Observation in VRI
  53. GRB 050525a: MDM Observations
  54. GRB050525A,optical observation
  55. GRB 050525 : Lulin optical afterglow observations
  56. GRB050525: Super-LOTIS observations
  57. GRB 050525, spectral lag pseudo-redshift
  58. GRB 050525a: Gemini/GMOS Spectra
  59. GRB050306: optical afterglow not confirmed
  60. GRB 050525: BART optical observation
  61. GRB 050525A: BOOTES simultaneous optical observations
  62. GRB 050525A: Swift-BAT refined analysis
  63. GRB050525: Optical observations
  64. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  65. Subject : GRB 050525: pseudo-redshift
  66. Swift/UVOT UV and optical detections of GRB 050525
  67. Konus-Wind observation of GRB 050525
  68. GRB 050525: TAROT observations of the early afterglow
  69. INTEGRAL detection of GRB 050525
  70. GRB 050525, infrared observations
  71. GRB 050525: Optical observation
  72. GRB 050525: observatons of the optical afterglow
  73. GRB050525: ROTSE-III Refined Analysis
  74. GRB 050525 - Very Bright, Not Short
  75. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  76. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  77. XRF050522: NIR observations of XRT candidate
  78. XRF 050522: Swift XRT refined analysis
  79. XRF050522: Radio Observations
  80. Swift/UVOT observation of XRF 050522
  81. GRB 050509A: Further I-band imaging
  82. GRB050522,optical observation
  83. GRB050520,optical observation
  84. XRF 050522: Continued NIR P200 Monitoring
  85. RBO Observations of GRB050522
  86. GRB050509b: optical observations
  87. Recent GRB BVRcIc field photometry
  88. GRB050520: Radio Observations
  89. XRF 050522: Swift XRT observation
  90. XRF050522, BVRcIc field photometry
  91. XRF 050522 : Lulin observations
  92. XRF050522: Optical Observations
  93. XRF050522: Near-infrared Observations
  94. XRF 050522: KAIT observations
  95. XRF 050522 detected with INTEGRAL
  96. GRB 050520: VLT/ULTRACAM observations
  97. Swift UVOT Observations of GRB 050520
  98. GRB 050520: Swift XRT refined analysis
  99. XRF050509C: Chandra Afterglow Detection
  100. XRF 050509c: Swift XRT Upper Limit

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