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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"
  1. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  2. Konus-Wind observation of GRB 060614
  3. GRB060605: optical observation
  4. The Unusually Long-Lived Afterglow of GRB 060614
  5. GRB 060614: optical observations
  6. GRB 060605, optical observations
  7. GRB 060614, SMARTS optical/IR afterglow observation
  8. GRB060614: SSO 1m observations
  9. GRB060614: Watcher observation
  10. GRB 060614: Swift-BAT refined analysis
  11. GRB 060614: Swift/UVOT Observations
  12. GRB060614: Swift-XRT refined analysis
  13. GRB 060604, optical observations
  14. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
  15. GRB 060602A: Swift/XRT analysis
  16. BAT Trigger #214277 is SGR 1900+14
  17. GRB 060610: KAIT observations
  18. GRB 060607: RTT150 optical observations
  19. GRB 070706B: Watcher upper limit
  20. GRB 060607B: Swift-BAT Refined Analysis
  21. GRB060602A: Swift/UVOT upper limits
  22. GRB 060607B: Swift detection of a burst
  23. GCN 060607: Swift-UVOT obswervations.
  24. GRB 060607: Swift-BAT Refined Analysis
  25. GRB 060607: optical limit by "Pi of the Sky"
  26. GRB 060607: Swift-XRT Team refined analysis
  27. GRB 060607: IR observations
  28. GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
  29. VLT/UVES observations of GRB 060607
  30. GRB 060607: PROMPT Observations
  31. GRB 060605: RTT150 optical observations
  32. GRB 060607: REM NIR afterglow
  33. GRB 060607: Swift detection of a burst with bright optical counterpart
  34. GRB 060522: PROMPT Optical Limits
  35. GRB 060605 BAT refined analysis
  36. GRB 060605: Xinglong TNT optical observations
  37. GRB060602B : REM infrared observations
  38. GRB060605: Swift/UVOT detections
  39. GRB 060605: Swift-XRT Team refined analysis
  40. SALT spectroscopy of GRB 060605
  41. GRB 060605: TNG optical observations
  42. GRB 060605: RTT150 optical observations
  43. GRB060605: Spectral Observations and Redshift
  44. GRB 060605: ROTSE-III Optical Counterpart
  45. GRB 060605: Swift detection of a burst with optical counterpart
  46. GRB 060605: ROTSE-III Detection of Optical Counterpart
  47. GRB060604: Swift/UVOT detections
  48. GRB 060604: redshift
  49. GRB 060512: Keck Redshift
  50. GRB 060604 optical photometry
  51. GRB 060604: Swift-XRT Team refined analysis
  52. GRB 060604: BAT refined analysis
  53. GRB 060604A: ROTSE-III Optical Limits
  54. GRB 060604: Swift detection of a burst with possible optical counterpart
  55. GRB 060602A: Swift-BAT Refined Analysis: Correction
  56. GRB 060602B: XMM-Newton Survey Source
  57. GRB 060602B: Swift-XRT Refined Analysis
  58. GRB 060602B: Swift-BAT Refined Analysis
  59. GRB 060602B: Swift/UVOT observations
  60. GRB 060602A: Swift-BAT Refined Analysis
  61. GRB 060602B: RTT150 optical observations
  62. GRB 060211A : WIDGET simultaneous optical observations
  63. GRB060602A: optical observations(/transient?)
  64. GRB 060526: Tautenburg Second Epoch Observations
  65. GRB060602A: Bootes-IR observations
  66. GRB 060602B: Swift detection of a burst
  67. GRB060602B: Watcher observations - no OT candidate
  68. GRB060602B: BOOTES-IR candidate afterglow
  69. GRB060602 - SDSS Pre-Burst Observations
  70. GRB 060602: Swift detection of a burst
  71. GRB 060502A: Optical afterglow observations
  72. GRB 060526: Break in X-ray light curve
  73. GRB 060526: RTT150 optical observations
  74. GRB060526, optical observations
  75. GRB 051227 : WIDGET simultaneous optical observations
  76. GRB 051028 : WIDGET pre-trigger limit
  77. GRB 060526: RTT150 optical observations
  78. GRB 060526: Multiple Optical Flares
  79. GRB060526: afterglow fitting and probable jet break
  80. GRB 060526: RTT150 optical observations
  81. GRB060526: Optical counterpart from MIRO
  82. GRB060502b: optical observations
  83. GRB 060526: RTT150 optical observations
  84. GRB 060526: Tautenburg OT observation and light curve fitting
  85. GRB060526: optical observations
  86. GRB 060526: SMARTS optical/IR afterglow observations
  87. GRB060526: possible break in the optical light curve
  88. GRB 060526: REM observations
  89. GRB 060526: RTT150 optical observations, afterglow flattening
  90. GRB 060526: Optical Flare
  91. GRB 060526: MDM-2.4m Observations
  92. GRB 060526: Refined analysis of the Swift-BAT burst
  93. GRB 060526: RTT150 optical observations
  94. GRB060526: Further Swift-UVOT Observations
  95. GRB060526, optical observations
  96. GRB 060526: Magellan Redshift
  97. GRB 060526 Lulin optical observation
  98. GRB 060526: Swift/XRT Team refined analysis
  99. GRB 060526: TNG optical observations
  100. GRB 060526: ROTSE-III Observations of Optical Counterpart

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