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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. GRB050326: Host Galaxy Candidates
  2. GRB050124: Possible Host Galaxy
  3. GRB050223: Host Galaxy
  4. GRB060512: near IR observations
  5. GRB060526: optical observations
  6. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  7. Konus-Wind observation of GRB 060614
  8. GRB060605: optical observation
  9. The Unusually Long-Lived Afterglow of GRB 060614
  10. GRB 060614: optical observations
  11. GRB 060605, optical observations
  12. GRB 060614, SMARTS optical/IR afterglow observation
  13. GRB060614: SSO 1m observations
  14. GRB060614: Watcher observation
  15. GRB 060614: Swift-BAT refined analysis
  16. GRB 060614: Swift/UVOT Observations
  17. GRB060614: Swift-XRT refined analysis
  18. GRB 060604, optical observations
  19. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
  20. GRB 060602A: Swift/XRT analysis
  21. BAT Trigger #214277 is SGR 1900+14
  22. GRB 060610: KAIT observations
  23. GRB 060607: RTT150 optical observations
  24. GRB 070706B: Watcher upper limit
  25. GRB 060607B: Swift-BAT Refined Analysis
  26. GRB060602A: Swift/UVOT upper limits
  27. GRB 060607B: Swift detection of a burst
  28. GCN 060607: Swift-UVOT obswervations.
  29. GRB 060607: Swift-BAT Refined Analysis
  30. GRB 060607: optical limit by "Pi of the Sky"
  31. GRB 060607: Swift-XRT Team refined analysis
  32. GRB 060607: IR observations
  33. GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
  34. VLT/UVES observations of GRB 060607
  35. GRB 060607: PROMPT Observations
  36. GRB 060605: RTT150 optical observations
  37. GRB 060607: REM NIR afterglow
  38. GRB 060607: Swift detection of a burst with bright optical counterpart
  39. GRB 060522: PROMPT Optical Limits
  40. GRB 060605 BAT refined analysis
  41. GRB 060605: Xinglong TNT optical observations
  42. GRB060602B : REM infrared observations
  43. GRB060605: Swift/UVOT detections
  44. GRB 060605: Swift-XRT Team refined analysis
  45. SALT spectroscopy of GRB 060605
  46. GRB 060605: TNG optical observations
  47. GRB 060605: RTT150 optical observations
  48. GRB060605: Spectral Observations and Redshift
  49. GRB 060605: ROTSE-III Optical Counterpart
  50. GRB 060605: Swift detection of a burst with optical counterpart
  51. GRB 060605: ROTSE-III Detection of Optical Counterpart
  52. GRB060604: Swift/UVOT detections
  53. GRB 060604: redshift
  54. GRB 060512: Keck Redshift
  55. GRB 060604 optical photometry
  56. GRB 060604: Swift-XRT Team refined analysis
  57. GRB 060604: BAT refined analysis
  58. GRB 060604A: ROTSE-III Optical Limits
  59. GRB 060604: Swift detection of a burst with possible optical counterpart
  60. GRB 060602A: Swift-BAT Refined Analysis: Correction
  61. GRB 060602B: XMM-Newton Survey Source
  62. GRB 060602B: Swift-XRT Refined Analysis
  63. GRB 060602B: Swift-BAT Refined Analysis
  64. GRB 060602B: Swift/UVOT observations
  65. GRB 060602A: Swift-BAT Refined Analysis
  66. GRB 060602B: RTT150 optical observations
  67. GRB 060211A : WIDGET simultaneous optical observations
  68. GRB060602A: optical observations(/transient?)
  69. GRB 060526: Tautenburg Second Epoch Observations
  70. GRB060602A: Bootes-IR observations
  71. GRB 060602B: Swift detection of a burst
  72. GRB060602B: Watcher observations - no OT candidate
  73. GRB060602B: BOOTES-IR candidate afterglow
  74. GRB060602 - SDSS Pre-Burst Observations
  75. GRB 060602: Swift detection of a burst
  76. GRB 060502A: Optical afterglow observations
  77. GRB 060526: Break in X-ray light curve
  78. GRB 060526: RTT150 optical observations
  79. GRB060526, optical observations
  80. GRB 051227 : WIDGET simultaneous optical observations
  81. GRB 051028 : WIDGET pre-trigger limit
  82. GRB 060526: RTT150 optical observations
  83. GRB 060526: Multiple Optical Flares
  84. GRB060526: afterglow fitting and probable jet break
  85. GRB 060526: RTT150 optical observations
  86. GRB060526: Optical counterpart from MIRO
  87. GRB060502b: optical observations
  88. GRB 060526: RTT150 optical observations
  89. GRB 060526: Tautenburg OT observation and light curve fitting
  90. GRB060526: optical observations
  91. GRB 060526: SMARTS optical/IR afterglow observations
  92. GRB060526: possible break in the optical light curve
  93. GRB 060526: REM observations
  94. GRB 060526: RTT150 optical observations, afterglow flattening
  95. GRB 060526: Optical Flare
  96. GRB 060526: MDM-2.4m Observations
  97. GRB 060526: Refined analysis of the Swift-BAT burst
  98. GRB 060526: RTT150 optical observations
  99. GRB060526: Further Swift-UVOT Observations
  100. GRB060526, optical observations

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