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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"

35343 results found.

  1. GRB061202: optical/NIR observations with REM
  2. GRB061202: Swift/UVOT Upper Limits
  3. GRB 061202, Swift-BAT refined analysis
  4. GRB 061202: Swift detection of a burst
  5. GRB 061201: Swift XRT Team refined analysis
  6. GRB 061201: VLT optical observations
  7. GRB 061201: Initial UVOT Observations
  8. GRB 061201, Swift-BAT refined analysis of the SHB
  9. GRB 061201: Swift detection of a short hard burst
  10. GRB 061201: Coincidence with a Galaxy Cluster
  11. GRB 061122: GETS observation
  12. GRB 061121, SMARTS optical/IR observations
  13. GRB 061121: flattening of the decay
  14. INT+WFC observations of GRB 061126
  15. GRB 061126: Possible Jet Break
  16. GRB 061121: Second Epoch ATCA Radio Observations
  17. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  18. GRB 061121: ATCA & WSRT Radio Observations
  19. GRB061121: optical observations
  20. GRB 061126: Early Super-LOTIS Observations
  21. GRB 061126: optical observation
  22. GRB 061126: Tautenburg afterglow observations
  23. GRB 061126 : SDSS Pre-Burst Observations
  24. GRB 061126: Swift-XRT refined analysis
  25. GRB 061126: Swift/UVOT Observations
  26. GRB 061126, Swift-BAT refined analysis
  27. GRB 061126: SARA Observations
  28. GRB 061126: Early Detection of the IR Afterglow
  29. GRB 061126: Faulkes Telescope North Optical Observations
  30. GRB 061126: Swift/UVOT Afterglow Detection
  31. GRB 061126: XRT position
  32. GRB 061126: Swift detection of a burst
  33. GRB 061121: MDM Continued Monitoring
  34. GRB 061122: Confirmation of X-ray/Optical Afterglow
  35. GRB 061121: MDM Continuing Optical Decay
  36. GRB061121: optical observations
  37. GRB 061122: Candidate Optical Afterglow
  38. GRB 061121: Ep,i - Eiso correlation
  39. GRB 061121: MDM Optical Decay
  40. GRB061122: Swift/UVOT Optical Observations
  41. GRB 061121: ART detection in Ic
  42. GRB061121: P60 Observations
  43. Radio detection of GRB 061121
  44. GRB061122: Swift-XRT position
  45. Konus-Wind observation of GRB 061122
  46. GRB 061121: MDM Optical Observations
  47. GRB 061121 declared "Burst of Interest" by Swift team
  48. Konus-Wind and Konus-A observations of GRB 061121
  49. INTEGRAL results on GRB 061122
  50. Swift-BAT trigger 239987 is not a GRB
  51. GRB 061122A: a long GRB detected by INTEGRAL
  52. GRB 061121: Swift/UVOT Observations
  53. GRB 061121: Swift-XRT Team Refined Analysis
  54. GRB 061121, Swift-BAT refined analysis
  55. GRB 061121 : Planned XMM-Newton observation
  56. GRB 061121: Optical observation at the KANATA 1.5m telescope
  57. GRB 061121: Faulkes Telescope North Optical Observation
  58. GRB061121: Spectroscopic Redshift
  59. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  60. GRB 061121: Swift detection of a bright burst with an optical counterpart
  61. GRB 060605: NIR Observations
  62. GRB 050915B: optical afterglow
  63. GRB 060111B: Swift UVOT Refined Magnitudes
  64. GRB061110A: Correction to GCN5817
  65. GRB 061110A: refined R-band analysis
  66. GRB 061110B: NIR Observations
  67. Swift TOO observations of GRB061110A
  68. Swift/UVOT Upper Limits for GRB061110b
  69. Swift/UVOT Upper Limits for GRB061110a
  70. GRB 061110A - VLT tentative redshift
  71. GRB 061110B: Swift XRT refined analysis
  72. GRB 061110B, Swift-BAT refined analysis
  73. GRB 061110B: VLT redshift
  74. GRB061110B: Optical observations at Crni Vrh
  75. GRB 061110B: NOT optical observations
  76. GRB 061110A: Swift XRT refined analysis
  77. GRB 061110B: Swift/XRT position
  78. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  79. GRB 061110B: Swift-UVOT Initial Observation
  80. GRB 061110A, Swift-BAT refined analysis
  81. GRB 061110B: TAROT Calern observatory optical observations
  82. GRB 061110B: Swift detection of a burst
  83. GRB 061110: NOT observations
  84. GRB 061110: Candidate confirmed
  85. GRB 061110 : Optical afterglow candidate
  86. GRB 061110: ROTSE-III Optical Limits
  87. GRB 061110: Swift detection of a burst
  88. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  89. GRB 061109: optical observation
  90. GRB 061109: TAROT Calern observatory optical observations
  91. GRB 061109: Swift detection of a possible burst
  92. GRB061028: MAGIC telescope GeV observation
  93. GRB 061027: TAROT La Silla observatory optical observations
  94. GRB 061007: Third Epoch ATCA Radio Observations
  95. GRB061019: second epoch CrAO observations
  96. GRB 061028: Swift/XRT Astrometry Correction
  97. GRB 061102: Swift/UVOT Magnitude Upper Limits
  98. GRB 061102, XRT refined analysis
  99. GRB 061004: Further VLT/NTT observations
  100. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event

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