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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"

15986 results found.

  1. GRB 061202: TORTOREM optical upper limits
  2. GRB 061201: VLT optical decay
  3. GRB061126 : NMSU 1.0m observations
  4. GRB061202 optical limit by "Pi of the Sky"
  5. GRB061202: optical/NIR observations with REM
  6. GRB 061201: Swift XRT Team refined analysis
  7. GRB 061201: VLT optical observations
  8. GRB 061201: Initial UVOT Observations
  9. GRB 061122: GETS observation
  10. GRB 061121, SMARTS optical/IR observations
  11. INT+WFC observations of GRB 061126
  12. GRB 061121: Second Epoch ATCA Radio Observations
  13. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  14. GRB 061121: ATCA & WSRT Radio Observations
  15. GRB061121: optical observations
  16. GRB 061126: Early Super-LOTIS Observations
  17. GRB 061126: optical observation
  18. GRB061126: Optical afterglow observations from MIRO
  19. GRB061126: Optical afterglow observations from MIRO
  20. GRB 061126: Swift/UVOT Observations
  21. GRB 061126: Early Detection of the IR Afterglow
  22. GRB 061126: Faulkes Telescope North Optical Observations
  23. GRB 061122: Confirmation of X-ray/Optical Afterglow
  24. GRB 061121: MDM Continuing Optical Decay
  25. GRB061121: optical observations
  26. GRB 061122: Candidate Optical Afterglow
  27. GRB 061121: MDM Optical Decay
  28. GRB061122: Swift/UVOT Optical Observations
  29. GRB 061121: ART detection in Ic
  30. GRB 061121: MDM Optical Observations
  31. GRB 061121 declared "Burst of Interest" by Swift team
  32. GRB 061121: Swift/UVOT Observations
  33. GRB061121, optical observation
  34. GRB 061121: Optical observation at the KANATA 1.5m telescope
  35. GRB 061121: Faulkes Telescope North Optical Observation
  36. GRB061121: Spectroscopic Redshift
  37. GRB061121: Keck spectroscopic observations
  38. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  39. GRB 061121: Swift detection of a bright burst with an optical counterpart
  40. GRB 060605: NIR Observations
  41. GRB 050915B: optical afterglow
  42. GRB 061110B: Swift XRT refined analysis
  43. GRB061110B: Optical observations at Crni Vrh
  44. GRB 061110B: NOT optical observations
  45. GRB 061110A: Swift XRT refined analysis
  46. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  47. GRB 061110B: TAROT Calern observatory optical observations
  48. GRB 061110: NOT observations
  49. GRB 061110 : Optical afterglow candidate
  50. GRB 061110: ROTSE-III Optical Limits
  51. GRB061110A - Optical Non-detection
  52. GRB 061109: optical observation
  53. GRB 061109: TAROT Calern observatory optical observations
  54. GRB 061027: TAROT La Silla observatory optical observations
  55. GRB 061007: Third Epoch ATCA Radio Observations
  56. GRB061019: second epoch CrAO observations
  57. GRB 061028: Swift/XRT Astrometry Correction
  58. GRB 061102: Swift/UVOT Magnitude Upper Limits
  59. GRB 061004: Further VLT/NTT observations
  60. GRB 061028: Optical R passband observations
  61. GRB 061004: Swift/XRT Astrometry Correction
  62. GRB 060801: Swift/XRT Astrometry Correction
  63. GRB 061028: TAROT Calern observatory late optical observations
  64. GRB 061028: TAROT Calern observatory optical observations
  65. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  66. GRB 061025: REM observations
  67. GRB 061025: ROTSE-III Optical Limits
  68. GRB 061021: Swift/UVOT Observation
  69. GRB060904b: optical observations
  70. GRB061019: optical observations
  71. GRB061019: optical observations
  72. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  73. GRB 060930: MARGE Optical Limits
  74. GRB 061019: Swift/UVOT upper limit
  75. GRB 061019: SMARTS afterglow confirmation
  76. GRB 061019: TAROT La Silla observatory optical observations
  77. GRB 061019: REM K-band candidate afterglow
  78. GRB 060825: GORT Observations
  79. GRB 061007: Second Epoch ATCA Radio Observations
  80. GRB 061006: astrometry-corrected XRT position
  81. GRB 061007: ATCA Radio Observations
  82. GRB 061006: optical afterglow
  83. GRB 061007: OA fading and VLT redshift
  84. GRB 061006: Swift/UVOT optical observations
  85. GRB 061007 - FTS early brightening and power law decay
  86. GRB 061007: Swift detection of a burst with an optical counterpart
  87. GRB 061007: ROTSE-III Detection of Optical Counterpart
  88. GRB 061004: Optical afterglow candidate and redshift
  89. GRB 061004: Las Campanas Optical/NIR Observations
  90. GRB061004: Swift/UVOT optical observations
  91. GRB 060930: Xinglong TNT optical observations
  92. GRB 060929: Swift/UVOT Optical Observations
  93. GRB 060930: ROTSE-III Optical Limits
  94. GRB 060927 : GAO 150cm telescope optical observation
  95. GRB060929: Optical limit
  96. GRB 060929: BOOTES-IR & OSN observations
  97. GRB060908: optical observations
  98. GRB 060729: An update on the late-time Swift observations
  99. GRB060923C: optical limit
  100. GRB060927: optical observations

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