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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"

25780 results found.

  1. GRB 061121: Faulkes Telescope North Optical Observation
  2. GRB 061121: Swift detection of a bright burst with an optical counterpart
  3. GRB 060605: NIR Observations
  4. GRB 050915B: optical afterglow
  5. GRB 061110B: NIR Observations
  6. Swift/UVOT Upper Limits for GRB061110b
  7. Swift/UVOT Upper Limits for GRB061110a
  8. GRB 061110A - VLT tentative redshift
  9. GRB 061110B: Swift XRT refined analysis
  10. GRB061110B: Optical observations at Crni Vrh
  11. GRB 061110A: Swift XRT refined analysis
  12. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  13. GRB 061110A, Swift-BAT refined analysis
  14. GRB 061110B: TAROT Calern observatory optical observations
  15. GRB 061110B: Swift detection of a burst
  16. GRB 061110: Candidate confirmed
  17. GRB 061110: ROTSE-III Optical Limits
  18. GRB 061110: Swift detection of a burst
  19. GRB061110A - Optical Non-detection
  20. GRB 061109: TAROT Calern observatory optical observations
  21. GRB061028: MAGIC telescope GeV observation
  22. GRB 061027: TAROT La Silla observatory optical observations
  23. GRB061019: second epoch CrAO observations
  24. GRB 061028: Swift/XRT Astrometry Correction
  25. GRB 061102: Swift/UVOT Magnitude Upper Limits
  26. GRB 061102, XRT refined analysis
  27. GRB 061004: Further VLT/NTT observations
  28. GRB061102B: Super-LOTIS observations
  29. GRB 061028: Optical R passband observations
  30. GRB 061102B: Swift detection of a possible burst
  31. GRB 061102: Swift detection of a burst
  32. GRB 061028: VLA Observation
  33. GRB 061004: Swift/XRT Astrometry Correction
  34. GRB 060801: Swift/XRT Astrometry Correction
  35. GRB 061028: Futher P200 Observations
  36. GRB 061028: P200 Observations
  37. GRB 061028: SARA upper limit
  38. GRB 061028: z band imaging
  39. GRB061028: XRT refined analysis
  40. GRB 061028: Swift/UVOT Observations
  41. GRB 061028: TAROT Calern observatory optical observations
  42. GRB 061028: Swift detection of a burst
  43. GRB 061027, Swift refined analysis of a possible burst
  44. GRB 061027: Swift detection of a possible burst
  45. GRB061025: Swift XRT refined analysis
  46. GRB061025: Swift/UVOT observations
  47. GRB 061025: REM observations
  48. GRB061025: Swift XRT position
  49. GRB 061025: ROTSE-III Optical Limits
  50. GRB 061025: a long GRB detected by INTEGRAL
  51. Konus-Wind observation of GRB 061021
  52. GRB 061021: Swift-XRT refined analysis
  53. GRB 061021: Swift/UVOT Observation
  54. GRB 061021: Swift detection of a burst
  55. GRB 061019: SARA upper limit
  56. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  57. GRB 060930: MARGE Optical Limits
  58. GRB 061019: Swift/UVOT upper limit
  59. GRB061019: Swift XRT refined analysis
  60. GRB 061019: TAROT La Silla observatory optical observations
  61. GRB 061019: REM K-band candidate afterglow
  62. GRB 061019: Swift-BAT detection of a burst
  63. GRB 061007: RHESSI Spectral Fit
  64. GRB 061006: astrometry-corrected XRT position
  65. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  66. GRB061007: Swift UVOT followup observations
  67. GRB 061006: optical afterglow
  68. GRB 061006 : Suzaku/WAM observation of the prompt emission
  69. GRB 061007: OA fading and VLT redshift
  70. GRB 061007: Correction to GCN 5712
  71. GRB 061007: Swift XRT refined analysis
  72. GRB 061006: Swift/UVOT optical observations
  73. Konus-Wind observation of the short hard GRB 061006
  74. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  75. GRB 061007: Swift detection of a burst with an optical counterpart
  76. GRB 061006: VLT observation
  77. GRB 061006: Swift-XRT Team Refined Analysis
  78. GRB 060930: near-IR afterglow candidate retraction
  79. GRB 061004: Optical afterglow candidate and redshift
  80. GRB 061004: Swift-XRT Team Refined Analysis
  81. GRB 061004: Swift detection of a burst
  82. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  83. Konus-Wind observation of GRB 060928
  84. GRB 060928: Suzaku/WAM observation of the prompt emission
  85. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  86. GRB 060928: Swift observations
  87. GRB 060928: RHESSI Spectral Fit
  88. IPN triangulation of GRB060928 (long, exceptionally bright)
  89. GRB 060930: near-IR afterglow candidate
  90. GRB 061002: Swift-XRT Team Refined Analysis
  91. VLA observations of GRB 060926
  92. GRB061002 - SDSS Pre-Burst Observations
  93. GRB 060908: Detection of a possible host
  94. GRB 060923A: Probable host galaxy in the R-band
  95. GRB 060807: Detection of a possible host galaxy
  96. GRB 060923A: VLA K-band Observations
  97. GRB 060930: Xinglong TNT optical observations
  98. GRB 060929: Further XRT Refined Analysis
  99. GRB 060929: Swift/UVOT Optical Observations
  100. GRB060929: Swift-XRT refined analysis.

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