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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"

32509 results found.

  1. GRB 061122: GETS observation
  2. GRB 061121, SMARTS optical/IR observations
  3. GRB 061121: flattening of the decay
  4. INT+WFC observations of GRB 061126
  5. GRB 061126: Possible Jet Break
  6. GRB 061121: Second Epoch ATCA Radio Observations
  7. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  8. Swift XRT on-board boresight update
  9. GRB 061121: ATCA & WSRT Radio Observations
  10. GRB061121: optical observations
  11. GRB 061126: Early Super-LOTIS Observations
  12. GRB 061126: optical observation
  13. RHESSI Spectrum of GRB061126
  14. GRB 061126: Tautenburg afterglow observations
  15. GRB061126: Optical afterglow observations from MIRO
  16. GRB061126: Optical afterglow observations from MIRO
  17. GRB 061126 : SDSS Pre-Burst Observations
  18. GRB 061126: Swift-XRT refined analysis
  19. GRB 061126: Swift/UVOT Observations
  20. GRB 061126, Swift-BAT refined analysis
  21. GRB 061126: SARA Observations
  22. GRB 061126: Early Detection of the IR Afterglow
  23. GRB 061126: Faulkes Telescope North Optical Observations
  24. GRB 061121: MDM Continued Monitoring
  25. GRB 061122: Confirmation of X-ray/Optical Afterglow
  26. GRB 061121: MDM Continuing Optical Decay
  27. GRB061121: optical observations
  28. GRB 061122: Candidate Optical Afterglow
  29. GRB 061121: Ep,i - Eiso correlation
  30. GRB 061121: MDM Optical Decay
  31. GRB061122: Swift/UVOT Optical Observations
  32. GRB 061121: ART detection in Ic
  33. GRB061121: P60 Observations
  34. Radio detection of GRB 061121
  35. GRB061122: Swift-XRT position
  36. Konus-Wind observation of GRB 061122
  37. GRB 061121: MDM Optical Observations
  38. GRB 061121 declared "Burst of Interest" by Swift team
  39. RHESSI Spectrum of GRB061121
  40. Konus-Wind and Konus-A observations of GRB 061121
  41. INTEGRAL results on GRB 061122
  42. GRB 061121: Swift/UVOT Observations
  43. GRB 061121: Swift-XRT Team Refined Analysis
  44. GRB 061121, Swift-BAT refined analysis
  45. GRB061121, optical observation
  46. GRB 061121: Optical observation at the KANATA 1.5m telescope
  47. GRB 061121: Faulkes Telescope North Optical Observation
  48. GRB061121: Spectroscopic Redshift
  49. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  50. GRB 060605: NIR Observations
  51. GRB 050915B: optical afterglow
  52. GRB 060111B: Swift UVOT Refined Magnitudes
  53. GRB061110A: Correction to GCN5817
  54. GRB 061110A: refined R-band analysis
  55. GRB 061110B: NIR Observations
  56. Swift/UVOT Upper Limits for GRB061110b
  57. Swift/UVOT Upper Limits for GRB061110a
  58. GRB 061110B: Swift XRT refined analysis
  59. GRB 061110B, Swift-BAT refined analysis
  60. GRB 061110B: VLT redshift
  61. GRB 061110B: NOT optical observations
  62. GRB 061110A: Swift XRT refined analysis
  63. GRB 061110B: Swift/XRT position
  64. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  65. GRB 061110A, Swift-BAT refined analysis
  66. GRB 061110: ROTSE-III Optical Limits
  67. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  68. GRB 061109: optical observation
  69. GRB061028: MAGIC telescope GeV observation
  70. GRB 061007: Third Epoch ATCA Radio Observations
  71. GRB061019: second epoch CrAO observations
  72. GRB 061028: Swift/XRT Astrometry Correction
  73. GRB 061102: Swift/UVOT Magnitude Upper Limits
  74. GRB 061102, XRT refined analysis
  75. GRB 061004: Further VLT/NTT observations
  76. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  77. GRB061102B: Super-LOTIS observations
  78. GRB 061028: Optical R passband observations
  79. GRB 061102, Swift-BAT refined analysis
  80. GRB 061028: VLA Observation
  81. GRB 061004: Swift/XRT Astrometry Correction
  82. GRB 060801: Swift/XRT Astrometry Correction
  83. GRB 061028: Futher P200 Observations
  84. GRB 061028: MDM Observations
  85. GRB 061028: P200 Observations
  86. GRB 061028: SARA upper limit
  87. GRB 061028: z band imaging
  88. GRB061028: XRT refined analysis
  89. GRB 061028: Swift/UVOT Observations
  90. GRB 061028, Swift-BAT refined analysis
  91. GRB 061027, Swift refined analysis of a possible burst
  92. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  93. GRB061025: Swift XRT refined analysis
  94. GRB061025: Swift/UVOT observations
  95. GRB 061019: MITSuME upper limits
  96. GRB 061025: REM observations
  97. GRB 061025: Gemini-S observations
  98. GRB061025: Swift XRT position
  99. GRB 061025: ROTSE-III Optical Limits
  100. Swift XRT boresight update

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