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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"

36789 results found.

  1. GRB061121: optical observations
  2. GRB 061122: Candidate Optical Afterglow
  3. GRB 061121: Ep,i - Eiso correlation
  4. GRB 061121: MDM Optical Decay
  5. GRB061122: Swift/UVOT Optical Observations
  6. GRB 061121: ART detection in Ic
  7. GRB061121: P60 Observations
  8. Radio detection of GRB 061121
  9. GRB061122: Swift-XRT position
  10. Konus-Wind observation of GRB 061122
  11. GRB 061121: MDM Optical Observations
  12. GRB 061121 declared "Burst of Interest" by Swift team
  13. Konus-Wind and Konus-A observations of GRB 061121
  14. INTEGRAL results on GRB 061122
  15. Swift-BAT trigger 239987 is not a GRB
  16. GRB 061122A: a long GRB detected by INTEGRAL
  17. GRB 061121: Swift/UVOT Observations
  18. GRB 061121: Swift-XRT Team Refined Analysis
  19. GRB 061121, Swift-BAT refined analysis
  20. GRB 061121 : Planned XMM-Newton observation
  21. GRB 061121: Optical observation at the KANATA 1.5m telescope
  22. GRB 061121: Faulkes Telescope North Optical Observation
  23. GRB061121: Spectroscopic Redshift
  24. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  25. GRB 061121: Swift detection of a bright burst with an optical counterpart
  26. GRB 060605: NIR Observations
  27. GRB 050915B: optical afterglow
  28. GRB 060111B: Swift UVOT Refined Magnitudes
  29. GRB061110A: Correction to GCN5817
  30. GRB 061110A: refined R-band analysis
  31. GRB 061110B: NIR Observations
  32. Swift TOO observations of GRB061110A
  33. Swift/UVOT Upper Limits for GRB061110b
  34. Swift/UVOT Upper Limits for GRB061110a
  35. GRB 061110A - VLT tentative redshift
  36. GRB 061110B: Swift XRT refined analysis
  37. GRB 061110B, Swift-BAT refined analysis
  38. GRB 061110B: VLT redshift
  39. GRB061110B: Optical observations at Crni Vrh
  40. GRB 061110B: NOT optical observations
  41. GRB 061110A: Swift XRT refined analysis
  42. GRB 061110B: Swift/XRT position
  43. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  44. GRB 061110B: Swift-UVOT Initial Observation
  45. GRB 061110A, Swift-BAT refined analysis
  46. GRB 061110B: TAROT Calern observatory optical observations
  47. GRB 061110B: Swift detection of a burst
  48. GRB 061110: NOT observations
  49. GRB 061110: Candidate confirmed
  50. GRB 061110 : Optical afterglow candidate
  51. GRB 061110: ROTSE-III Optical Limits
  52. GRB 061110: Swift detection of a burst
  53. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  54. GRB 061109: optical observation
  55. GRB 061109: TAROT Calern observatory optical observations
  56. GRB 061109: Swift detection of a possible burst
  57. GRB061028: MAGIC telescope GeV observation
  58. GRB 061027: TAROT La Silla observatory optical observations
  59. GRB 061007: Third Epoch ATCA Radio Observations
  60. GRB061019: second epoch CrAO observations
  61. GRB 061028: Swift/XRT Astrometry Correction
  62. GRB 061102: Swift/UVOT Magnitude Upper Limits
  63. GRB 061102, XRT refined analysis
  64. GRB 061004: Further VLT/NTT observations
  65. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  66. GRB061102B: Super-LOTIS observations
  67. GRB 061028: Optical R passband observations
  68. GRB 061102B: Swift detection of a possible burst
  69. GRB 061102, Swift-BAT refined analysis
  70. GRB 061102: Swift detection of a burst
  71. GRB 061028: VLA Observation
  72. GRB 061004: Swift/XRT Astrometry Correction
  73. GRB 060801: Swift/XRT Astrometry Correction
  74. GRB 061028: Futher P200 Observations
  75. GRB 061028: MDM Observations
  76. GRB 061028: P200 Observations
  77. GRB 061028: SARA upper limit
  78. GRB 061028: z band imaging
  79. GRB061028: XRT refined analysis
  80. GRB 061028: Swift/UVOT Observations
  81. GRB 061028, Swift-BAT refined analysis
  82. GRB 061028: TAROT Calern observatory late optical observations
  83. GRB 061028: TAROT Calern observatory optical observations
  84. GRB 061028: Swift detection of a burst
  85. GRB 061027, Swift refined analysis of a possible burst
  86. GRB 061027: Swift detection of a possible burst
  87. GRB061025: Swift/UVOT observations
  88. GRB 061019: MITSuME upper limits
  89. GRB 061025: REM observations
  90. GRB 061025: Gemini-S observations
  91. GRB061025: Swift XRT position
  92. GRB 061025: ROTSE-III Optical Limits
  93. GRB 061025: a long GRB detected by INTEGRAL
  94. GRB 061021, Swift-BAT Lag analysis
  95. Konus-Wind observation of GRB 061021
  96. GRB 061021 - VLT spectrum without lines
  97. GRB 061021: Swift-XRT refined analysis
  98. GRB 061021: Swift/UVOT Observation
  99. GRB 061021, Swift-BAT refined analysis
  100. GRB 061021: Swift detection of a burst

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