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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"

20385 results found.

  1. GRB 061028: Swift/UVOT Observations
  2. GRB 061028, Swift-BAT refined analysis
  3. GRB 061028: TAROT Calern observatory optical observations
  4. GRB 061028: Swift detection of a burst
  5. GRB 061027, Swift refined analysis of a possible burst
  6. GRB 061027: Swift detection of a possible burst
  7. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  8. GRB061025: Swift/UVOT observations
  9. GRB 061025: REM observations
  10. GRB 061025: ROTSE-III Optical Limits
  11. Konus-Wind observation of GRB 061021
  12. GRB 061021: Swift-XRT refined analysis
  13. GRB 061021: Swift/UVOT Observation
  14. GRB 061021: Swift detection of a burst
  15. GRB060904b: optical observations
  16. GRB 061019: SARA upper limit
  17. GRB 061019: Swift/UVOT upper limit
  18. GRB 061019, Swift-BAT refined analysis
  19. GRB 061019: TAROT La Silla observatory optical observations
  20. GRB 061019: REM K-band candidate afterglow
  21. GRB 061007: Suzaku/WAM observation of the prompt emission
  22. GRB 061006: astrometry-corrected XRT position
  23. Konus-Wind observation of GRB 061007
  24. GRB061007: Swift UVOT followup observations
  25. GRB 061006: optical afterglow
  26. GRB 061006 : Suzaku/WAM observation of the prompt emission
  27. GRB 061007: OA fading and VLT redshift
  28. GRB 061007: Swift-BAT refined analysis
  29. GRB 061007: Swift XRT refined analysis
  30. GRB 061006: Swift/UVOT optical observations
  31. Konus-Wind observation of the short hard GRB 061006
  32. GRB 061007: Swift detection of a burst with an optical counterpart
  33. GRB 061006: VLT observation
  34. GRB 060930: near-IR afterglow candidate retraction
  35. GRB 061006: Swift detection of a burst
  36. GRB 061004: Optical afterglow candidate and redshift
  37. GRB 061004: Swift detection of a burst
  38. Konus-Wind observation of GRB 060928
  39. GRB 060928: Suzaku/WAM observation of the prompt emission
  40. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  41. GRB 060928: Swift observations
  42. GRB 060928: RHESSI Spectral Fit
  43. IPN triangulation of GRB060928 (long, exceptionally bright)
  44. GRB 060930: near-IR afterglow candidate
  45. VLA observations of GRB 060926
  46. GRB061002 - SDSS Pre-Burst Observations
  47. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  48. GRB 061002: Swift detection of a burst
  49. GRB 060908: Detection of a possible host
  50. GRB 060923A: Probable host galaxy in the R-band
  51. GRB 060807: Detection of a possible host galaxy
  52. GRB 060923A: VLA K-band Observations
  53. GRB 060930: Xinglong TNT optical observations
  54. GRB 060929: Swift/UVOT Optical Observations
  55. GRB 060930: ROTSE-III Optical Limits
  56. GRB 060929: TNG K-band observations
  57. GRB 060929, Swift-BAT refined analysis
  58. GRB060929: Optical limit
  59. Liverpool Telescope observations of GRB 060929
  60. GRB060908: optical observations
  61. GRB 060927: Swift/UVOT Optical Observations
  62. GRB 060927 optical limit
  63. GRB 060927: Xinglong TNT optical observations
  64. GRB 060927, optical observation
  65. GRB 060926: MASTER: first minutes decay
  66. GRB060927 - SDSS Pre-Burst Observations
  67. GRB 060927: Swift detection of a burst
  68. GRB 060926: Swift-UVOT Detections
  69. GRB 060923A: Radio Observations
  70. GRB 060926: MASTER OT alert observation
  71. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  72. GRB 060923C: VLA Observation
  73. GRB 060923C: NIR afterglow confirmed
  74. GRB060923C: AROMA optical obsevation
  75. GRB 060923C, optical observation
  76. GRB 060923C: VLT J-band observations
  77. GRB 060923A: Keck and Gemini Observations
  78. GRB 060923C: Xinglong TNT optical observations
  79. GRB 060923C: Swift detection of a burst
  80. GRB 060923B: Swift detection of a burst
  81. GRB 060923, Swift-BAT refined analysis
  82. GRB 060923: Early Super-LOTIS Observations
  83. GRB 060923: UKIRT nIR observations - candidate afterglow
  84. GRB060923 - SDSS Pre-Burst Observations
  85. GRB 060923: Swift detection of a burst
  86. GRB 060919 : Faulkes South Telescope Observations
  87. GRB 060919, Swift-BAT refined analysis
  88. GRB 060919: TAROT optical observations
  89. GRB 060912A: VLA Observation
  90. GRB 060912A: Probable Host Galaxy
  91. GRB060912: OPTIMA-Burst optical observations
  92. GRB 060912: Correction to GCN 5559
  93. GRB060906: Danish/DFOSC optical observations
  94. VLA observations of GRB 060908
  95. GRB 060908 - SDSS Pre-burst Observations
  96. GRB 060908: REM optical prompt observation
  97. GRB 060908: Swift detection of a burst with a bright optical counterpart
  98. GRB 060904A: Suzaku/WAM observation of the prompt emission
  99. GRB060906 , optical observation
  100. GRB 060906: Early RAPTOR optical limits

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