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

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