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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"

44630 results found.

  1. GRB 061121: MDM Optical Observations
  2. GRB 061121 declared "Burst of Interest" by Swift team
  3. RHESSI Spectrum of GRB061121
  4. Konus-Wind and Konus-A observations of GRB 061121
  5. INTEGRAL results on GRB 061122
  6. Swift-BAT trigger 239987 is not a GRB
  7. GRB 061122A: a long GRB detected by INTEGRAL
  8. GRB 061121: Swift/UVOT Observations
  9. GRB 061121: Swift-XRT Team Refined Analysis
  10. GRB 061121, Swift-BAT refined analysis
  11. GRB061121, optical observation
  12. GRB 061121 : Planned XMM-Newton observation
  13. GRB 061121: Optical observation at the KANATA 1.5m telescope
  14. GRB 061121: Faulkes Telescope North Optical Observation
  15. GRB061121: Spectroscopic Redshift
  16. GRB061121: Keck spectroscopic observations
  17. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  18. GRB 061121: Swift detection of a bright burst with an optical counterpart
  19. GRB 060605: NIR Observations
  20. GRB 050915B: optical afterglow
  21. GRB 060111B: Swift UVOT Refined Magnitudes
  22. Swift-BAT triggers 238544 and 238546 are not GRBs
  23. GRB061110A: Correction to GCN5817
  24. GRB 061110A: refined R-band analysis
  25. GRB 061110B: NIR Observations
  26. Swift TOO observations of GRB061110A
  27. Swift/UVOT Upper Limits for GRB061110b
  28. Swift/UVOT Upper Limits for GRB061110a
  29. GRB 061110A - VLT tentative redshift
  30. GRB 061110B: Swift XRT refined analysis
  31. GRB 061110B, Swift-BAT refined analysis
  32. GRB 061110B: VLT redshift
  33. GRB061110B: Optical observations at Crni Vrh
  34. GRB 061110B: NOT optical observations
  35. GRB 061110A: Swift XRT refined analysis
  36. GRB 061110B: Swift/XRT position
  37. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  38. GRB 061110B: Swift-UVOT Initial Observation
  39. GRB 061110A, Swift-BAT refined analysis
  40. GRB 061110B: TAROT Calern observatory optical observations
  41. GRB 061110B: Swift detection of a burst
  42. GRB 061110: NOT observations
  43. GRB 061110: Candidate confirmed
  44. GRB 061110 : Optical afterglow candidate
  45. GRB 061110: ROTSE-III Optical Limits
  46. GRB 061110: Swift detection of a burst
  47. GRB061110A - Optical Non-detection
  48. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  49. GRB 061109: optical observation
  50. GRB 061109: TAROT Calern observatory optical observations
  51. GRB 061109: Swift detection of a possible burst
  52. GRB061028: MAGIC telescope GeV observation
  53. GRB 061027: TAROT La Silla observatory optical observations
  54. GRB 061007: Third Epoch ATCA Radio Observations
  55. GRB061019: second epoch CrAO observations
  56. GRB 061028: Swift/XRT Astrometry Correction
  57. GRB 061102: Swift/UVOT Magnitude Upper Limits
  58. GRB 061102, XRT refined analysis
  59. GRB 061004: Further VLT/NTT observations
  60. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  61. GRB061102B: Super-LOTIS observations
  62. GRB 061028: Optical R passband observations
  63. GRB 061102B: Swift detection of a possible burst
  64. GRB 061102, Swift-BAT refined analysis
  65. GRB 061102: Swift detection of a burst
  66. GRB 061028: VLA Observation
  67. GRB 061004: Swift/XRT Astrometry Correction
  68. GRB 060801: Swift/XRT Astrometry Correction
  69. GRB 061028: Futher P200 Observations
  70. GRB 061028: MDM Observations
  71. GRB 061028: P200 Observations
  72. GRB 061028: SARA upper limit
  73. GRB 061028: z band imaging
  74. GRB061028: XRT refined analysis
  75. GRB 061028: Swift/UVOT Observations
  76. GRB 061028, Swift-BAT refined analysis
  77. GRB 061028: TAROT Calern observatory late optical observations
  78. GRB 061028: TAROT Calern observatory optical observations
  79. GRB 061028: Swift detection of a burst
  80. GRB 061027, Swift refined analysis of a possible burst
  81. GRB 061027: Swift detection of a possible burst
  82. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  83. GRB061025: Swift XRT refined analysis
  84. GRB061025: Swift/UVOT observations
  85. GRB 061019: MITSuME upper limits
  86. GRB 061025: REM observations
  87. GRB 061025: Gemini-S observations
  88. GRB061025: Swift XRT position
  89. GRB 061025: ROTSE-III Optical Limits
  90. GRB 061025: a long GRB detected by INTEGRAL
  91. Swift XRT boresight update
  92. GRB 061021, Swift-BAT Lag analysis
  93. Konus-Wind observation of GRB 061021
  94. GRB 061021 - VLT spectrum without lines
  95. GRB 061021: Swift-XRT refined analysis
  96. GRB 061021: Swift/UVOT Observation
  97. GRB 061021, Swift-BAT refined analysis
  98. GRB 061021: Swift detection of a burst
  99. GRB 061019: Super-LOTIS upper limit
  100. GRB060904b: optical observations

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