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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"

35260 results found.

  1. GRB 060923C, optical observation
  2. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  3. GRB 060923C: VLT J-band observations
  4. GRB060923B: Swift/UVOT upper limits
  5. GRB 060923B: Swift XRT Refined Analysis
  6. GRB 060923C: Swift XRT refined analysis
  7. GRB 060923C, Swift-BAT partial refined analysis
  8. GRB 060923A: Swift XRT refined analysis
  9. GRB 060923C: Keck Observations
  10. GRB 060923A: Keck and Gemini Observations
  11. GRB 060923C: Xinglong TNT optical observations
  12. GRB 060923B, Swift-BAT refined analysis
  13. GRB060923C : Faulkes Telescope South optical limits
  14. GRB060923C: Faulkes Telescope North optical observations
  15. GRB 060923C: optical observation
  16. GRB 060923C: Swift detection of a burst
  17. GRB 060923B: Swift detection of a burst
  18. GRB 060923, Swift-BAT refined analysis
  19. GRB 060923: Early Super-LOTIS Observations
  20. GRB 060923: UKIRT nIR observations - candidate afterglow
  21. GRB060923 - SDSS Pre-Burst Observations
  22. GRB 060923: KAIT observations
  23. GRB 060923: Swift detection of a burst
  24. Swift detection of IGR J17497-2821 (trigger 230504)
  25. GRB 060919 : Faulkes South Telescope Observations
  26. GRB 060919, Swift-BAT refined analysis
  27. GRB060919: XRT refined analysis
  28. GRB 060919: TAROT optical observations
  29. GRB 060919: Swift detection of a burst
  30. GRB 060912A: VLA Observation
  31. GRB 060912A: Probable Host Galaxy
  32. IBAS Alert n.3470: not a GRB
  33. GRB060825: MAGIC telescope GeV observation
  34. Konus-Wind observation of GRB 060912
  35. IBAS Alert No.3468: not a GRB
  36. GRB 060912: Redshift of nearby 2MASS galaxy
  37. GRB060912: optical observations
  38. GRB 060912B: Watcher observations
  39. GRB060912: OPTIMA-Burst optical observations
  40. GRB 060912B: a long GRB detected with INTEGRAL
  41. GRB 060912: Swift XRT Team Refined Analysis
  42. GRB 060912, Swift-BAT refined analysis
  43. GRB 060912: Correction to GCN 5559
  44. GRB 060912: Xinglong TNT optical observations
  45. GRB 060912: Swift detection of a burst with an optical afterglow
  46. VLA observations of GRB 060908
  47. GRB 060908: redshift
  48. GRB 060908, Swift/XRT refined analysis
  49. GRB 060908: Swift/UVOT Observations
  50. GRB 060908: Danish/DFOSC optical observations
  51. GRB 060908, Swift-BAT refined analysis
  52. GRB 060908 - SDSS Pre-burst Observations
  53. GRB 060904B : CFHT/WIRCam NIR afterglow observations
  54. GRB 060904B: Kiso Optical observation
  55. GRB 060904A : Optical limit
  56. GRB 060908: REM optical prompt observation
  57. GRB 060908: PROMPT Detection of a Bright Counterpart
  58. GRB 060908: Swift detection of a burst with a bright optical counterpart
  59. GRB 060904A: Suzaku/WAM observation of the prompt emission
  60. GRB 060906: optical observation
  61. GRB 060906: Early RAPTOR optical limits
  62. GRB 060906, Swift-BAT refined spectral analysis
  63. GRB 060906: Swift/XRT Refined Analysis
  64. GRB 060906: Swift-UVOT observations
  65. VLT redshift of GRB 060906
  66. GRB 060906, Swift-BAT refined analysis
  67. GRB 060906: FRAM observations - flash determination (airplane)
  68. GRB 060906: KAIT observations
  69. GRB 060906: Confirmation of P60 Optical Afterglow
  70. GRB 060906: observations with FRAM
  71. GRB 060906 (?): P60 Optical Afterglow Candidate
  72. GRB 060906: Swift detection of a probable burst
  73. GRB 060904A Milagro GeV/TeV Observations
  74. GRB060904b, optical observations
  75. GRB 060904b: SMARTS optical/IR afterglow observations
  76. GRB 060904B: RTT150 optical observations
  77. GRB060904A: Swift/UVOT optical observations
  78. GRB 060904A: Subaru NIR observation
  79. GRB 060904A: pseudo-z from spectral parameters of the prompt emission
  80. GRB 060904B: Swift-BAT refined analysis
  81. Konus-Wind observation of GRB 060904A
  82. GRB 060904B: Swift-XRT refined analysis
  83. GRB 060904A: Refined analysis of the Swift-BAT burst
  84. GRB 060904A: Swift-XRT refined analysis
  85. GRB 060904A: Suzaku-XIS and -HXD observation plan
  86. GRB 060904B: VLT redshift
  87. GRB 060904A: P60 Observations
  88. GRB 060904B: Optical observations at Crni Vrh
  89. GRB060904B: Watcher observations
  90. GRB 060904B BOOTES-IR and 1.5m OSN observations
  91. GRB 060904B: TAROT optical counterpart observations
  92. GRB060904B - SDSS Pre-Burst Observations
  93. GRB 060904: TAROT optical observations
  94. GRB 060904B: Swift detection of a burst with optical counterpart
  95. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  96. GRB060904 - SDSS Pre-Burst Observations
  97. GRB 060904: Swift detection of a bright burst
  98. GRB 060901: pseudo-z from spectral parameters of the prompt
  99. Konus-Wind observation of GRB 060901
  100. GRB 060901: SMARTS optical/IR observations update

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