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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"

23436 results found.

  1. GRB061006 (Swift 232585) might be a short-hard GRB
  2. GRB 060930: near-IR afterglow candidate retraction
  3. GRB 061006: Swift detection of a burst
  4. GRB 061004: Optical afterglow candidate and redshift
  5. GRB 061004: Las Campanas Optical/NIR Observations
  6. GRB061004: Swift/UVOT optical observations
  7. GRB 061004: Swift detection of a burst
  8. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  9. GRB 060928: Swift observations
  10. IPN triangulation of GRB060928 (long, exceptionally bright)
  11. GRB061002: Swift UVOT followup observations
  12. GRB 060930: near-IR afterglow candidate
  13. GRB 061002: Swift-XRT Team Refined Analysis
  14. VLA observations of GRB 060926
  15. GRB061002 - SDSS Pre-Burst Observations
  16. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  17. GRB 061002: Swift detection of a burst
  18. GRB 060908: Detection of a possible host
  19. GRB 060807: Detection of a possible host galaxy
  20. GRB 060923A: VLA K-band Observations
  21. GRB 060930: Xinglong TNT optical observations
  22. GRB 060929: Swift/UVOT Optical Observations
  23. GRB 060930: ROTSE-III Optical Limits
  24. GRB 060929: TNG K-band observations
  25. GRB 060929, Swift-BAT refined analysis
  26. GRB060929: Optical limit
  27. Liverpool Telescope observations of GRB 060929
  28. GRB060908: optical observations
  29. GRB 060729: An update on the late-time Swift observations
  30. GRB060923C: optical limit
  31. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  32. GRB 060927: Swift/UVOT Optical Observations
  33. GRB 060927: Swift XRT Team refined analysis
  34. GRB 060927 optical limit
  35. GRB 060927: Xinglong TNT optical observations
  36. GRB 060927, optical observation
  37. GRB060927 - SDSS Pre-Burst Observations
  38. GRB 060927: Swift detection of a burst
  39. GRB 060926: Swift-UVOT Detections
  40. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  41. GRB 060926: Swift XRT refined analysis
  42. GRB 060923A: Radio Observations
  43. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  44. GRB 060926: BOOTES-IR observations
  45. GRB 060926: Swift detection of a burst
  46. GRB 060923C: VLA Observation
  47. GRB 060923C: NIR afterglow confirmed
  48. GRB060923C: AROMA optical obsevation
  49. GRB 060923C, optical observation
  50. GRB 060923C: VLT J-band observations
  51. GRB060923B: Swift/UVOT upper limits
  52. GRB 060923A: Keck and Gemini Observations
  53. GRB 060923C: Xinglong TNT optical observations
  54. GRB 060923C: optical observation
  55. GRB 060923C: Swift detection of a burst
  56. GRB 060923B: Swift detection of a burst
  57. GRB 060923: Early Super-LOTIS Observations
  58. GRB 060923: UKIRT nIR observations - candidate afterglow
  59. GRB060923 - SDSS Pre-Burst Observations
  60. GRB 060923: Swift detection of a burst
  61. Swift detection of IGR J17497-2821 (trigger 230504)
  62. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  63. GRB060919: Swift/UVOT optical observations
  64. GRB 060919 : Faulkes South Telescope Observations
  65. GRB 060919: TAROT optical observations
  66. GRB 060919: Swift detection of a burst
  67. GRB 060912A: VLA Observation
  68. GRB 060912A: Probable Host Galaxy
  69. GRB 060912: Correction to GCN 5559
  70. GRB 060912: Swift detection of a burst with an optical afterglow
  71. GRB060906: Danish/DFOSC optical observations
  72. VLA observations of GRB 060908
  73. GRB 060908, Swift-BAT refined analysis
  74. GRB 060908 - SDSS Pre-burst Observations
  75. GRB 060904A : Optical limit
  76. GRB 060908: REM optical prompt observation
  77. GRB 060908: Swift detection of a burst with a bright optical counterpart
  78. GRB060906 , optical observation
  79. GRB 060906: Early RAPTOR optical limits
  80. GRB 060906, Swift-BAT refined spectral analysis
  81. GRB 060906: Swift-UVOT observations
  82. GRB 060906: KAIT observations
  83. GRB 060906: Confirmation of P60 Optical Afterglow
  84. GRB 060906 (?): P60 Optical Afterglow Candidate
  85. GRB 060906: Swift detection of a probable burst
  86. GRB060904b, optical observations
  87. GRB060904A: Swift/UVOT optical observations
  88. GRB 060904A: Subaru NIR observation
  89. GRB060904b: Optical observations with Swift/UVOT
  90. GRB 060904B: Swift-XRT refined analysis
  91. GRB 060904A: Refined analysis of the Swift-BAT burst
  92. GRB 060904A: Suzaku-XIS and -HXD observation plan
  93. GRB 060904A: P60 Observations
  94. GRB 060904B: Optical observations at Crni Vrh
  95. GRB 060904B: TAROT optical counterpart observations
  96. GRB060904B - SDSS Pre-Burst Observations
  97. GRB 060904: TAROT optical observations
  98. GRB 060904B: Swift detection of a burst with optical counterpart
  99. GRB060904 - SDSS Pre-Burst Observations
  100. GRB 060904: Swift detection of a bright burst

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