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

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