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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 060109: Upper Limit on Host Galaxy
  2. GRB 060105: Upper limit on Host Galaxy
  3. GRB060614: Detection of the host galaxy but no supernova emission
  4. GRB 060614: redshift confirmation
  5. GRB 060614: Redshift
  6. Swift-BAT trigger 215279 is not a GRB
  7. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  8. GRB060614: Optical observations
  9. GRB 060614: spectroscopy
  10. GRB050326: Host Galaxy Candidates
  11. GRB050124: Possible Host Galaxy
  12. GRB050223: Host Galaxy
  13. GRB060512: near IR observations
  14. GRB060526: optical observations
  15. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  16. Konus-Wind observation of GRB 060614
  17. GRB060605: optical observation
  18. The Unusually Long-Lived Afterglow of GRB 060614
  19. GRB 060614: optical observations
  20. GRB 060605, optical observations
  21. GRB 060614, SMARTS optical/IR afterglow observation
  22. GRB060614: SSO 1m observations
  23. GRB060614: Watcher observation
  24. GRB 060614: Swift-BAT refined analysis
  25. GRB 060614: Swift/UVOT Observations
  26. GRB060614: Swift-XRT refined analysis
  27. GRB 060604, optical observations
  28. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
  29. GRB 060602A: Swift/XRT analysis
  30. BAT Trigger #214277 is SGR 1900+14
  31. GRB 060610: KAIT observations
  32. GRB 060607: RTT150 optical observations
  33. GRB 070706B: Watcher upper limit
  34. GRB 060607B: Swift-BAT Refined Analysis
  35. GRB060602A: Swift/UVOT upper limits
  36. GRB 060607B: Swift detection of a burst
  37. GCN 060607: Swift-UVOT obswervations.
  38. GRB 060607: Swift-BAT Refined Analysis
  39. GRB 060607: optical limit by "Pi of the Sky"
  40. GRB 060607: Swift-XRT Team refined analysis
  41. GRB 060607: IR observations
  42. GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
  43. VLT/UVES observations of GRB 060607
  44. GRB 060607: PROMPT Observations
  45. GRB 060605: RTT150 optical observations
  46. GRB 060607: REM NIR afterglow
  47. GRB 060607: Swift detection of a burst with bright optical counterpart
  48. GRB 060522: PROMPT Optical Limits
  49. GRB 060605 BAT refined analysis
  50. GRB 060605: Xinglong TNT optical observations
  51. GRB060602B : REM infrared observations
  52. GRB060605: Swift/UVOT detections
  53. GRB 060605: Swift-XRT Team refined analysis
  54. SALT spectroscopy of GRB 060605
  55. GRB 060605: TNG optical observations
  56. GRB 060605: RTT150 optical observations
  57. GRB060605: Spectral Observations and Redshift
  58. GRB 060605: ROTSE-III Optical Counterpart
  59. GRB 060605: Swift detection of a burst with optical counterpart
  60. GRB 060605: ROTSE-III Detection of Optical Counterpart
  61. GRB060604: Swift/UVOT detections
  62. GRB 060604: redshift
  63. GRB 060512: Keck Redshift
  64. GRB 060604 optical photometry
  65. GRB 060604: Swift-XRT Team refined analysis
  66. GRB 060604: BAT refined analysis
  67. GRB 060604A: ROTSE-III Optical Limits
  68. GRB 060604: Swift detection of a burst with possible optical counterpart
  69. GRB 060602A: Swift-BAT Refined Analysis: Correction
  70. GRB 060602B: XMM-Newton Survey Source
  71. GRB 060602B: Swift-XRT Refined Analysis
  72. GRB 060602B: Swift-BAT Refined Analysis
  73. GRB 060602B: Swift/UVOT observations
  74. GRB 060602A: Swift-BAT Refined Analysis
  75. GRB 060602B: RTT150 optical observations
  76. GRB 060211A : WIDGET simultaneous optical observations
  77. GRB060602A: optical observations(/transient?)
  78. GRB 060526: Tautenburg Second Epoch Observations
  79. GRB060602A: Bootes-IR observations
  80. GRB 060602B: Swift detection of a burst
  81. GRB060602B: Watcher observations - no OT candidate
  82. GRB060602B: BOOTES-IR candidate afterglow
  83. GRB060602 - SDSS Pre-Burst Observations
  84. GRB 060602: Swift detection of a burst
  85. GRB 060502A: Optical afterglow observations
  86. GRB 060526: Break in X-ray light curve
  87. GRB 060526: RTT150 optical observations
  88. GRB060526, optical observations
  89. GRB 051227 : WIDGET simultaneous optical observations
  90. GRB 051028 : WIDGET pre-trigger limit
  91. GRB 060526: RTT150 optical observations
  92. GRB 060526: Multiple Optical Flares
  93. GRB060526: afterglow fitting and probable jet break
  94. GRB 060526: RTT150 optical observations
  95. GRB060526: Optical counterpart from MIRO
  96. GRB060502b: optical observations
  97. GRB 060526: RTT150 optical observations
  98. GRB 060526: Tautenburg OT observation and light curve fitting
  99. GRB060526: optical observations
  100. GRB 060526: SMARTS optical/IR afterglow observations

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