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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"

16159 results found.

  1. GRB 061222B: TAROT La Silla observatory optical observations
  2. GRB 061222b: optical afterglow
  3. GRB 061222A: Prompt ROTSE-III Optical Limits
  4. GRB 061217: Astrometry-Corrected XRT Position
  5. GRB 061201: Magellan redshift of nearby galaxy
  6. GRB 061217, Candidate host galaxy
  7. GRB 061218: TAROT La Silla observatory optical observations
  8. GRB 061217: TAROT Calern observatory optical observations
  9. GRB 061218: TORTOREM optical upper limits
  10. GRB 061218, SMARTS optical/IR observations
  11. GRB 061218: REM prompt observations
  12. GRB 061217, SMARTS optical observations
  13. GRB061217: Swift/UVOT refined analysis.
  14. GRB 061217: optical observations at Calar Alto
  15. GRB 061217: REM prompt observations
  16. GRB 061217: ROTSE-III Optical Limits
  17. GRB 061210: MDM Follow-up Observation
  18. GRB061210: Swift/UVOT observations
  19. GRB 061210: Optical sources near XRT positions
  20. GRB 061210 : Faulkes North Telescope optical limit
  21. GRB 061214(?): ROTSE-III Optical Limits
  22. GRB 061213: MASTER-VWF-Kislovodsk optical candidate
  23. GRB061201, VLT optical decay: correction
  24. Optical Afterglow observations of GRB 061126
  25. GRB061126: optical observations
  26. GRB 060926: MASTER: discovery of the optical flare
  27. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  28. GRB 061202: TORTOREM optical upper limits
  29. GRB 061201: VLT optical decay
  30. GRB061126 : NMSU 1.0m observations
  31. GRB061202 optical limit by "Pi of the Sky"
  32. GRB061202: optical/NIR observations with REM
  33. GRB 061201: Swift XRT Team refined analysis
  34. GRB 061201: VLT optical observations
  35. GRB 061201: Initial UVOT Observations
  36. GRB 061122: GETS observation
  37. GRB 061121, SMARTS optical/IR observations
  38. INT+WFC observations of GRB 061126
  39. GRB 061121: Second Epoch ATCA Radio Observations
  40. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  41. GRB 061121: ATCA & WSRT Radio Observations
  42. GRB061121: optical observations
  43. GRB 061126: Early Super-LOTIS Observations
  44. GRB 061126: optical observation
  45. GRB061126: Optical afterglow observations from MIRO
  46. GRB061126: Optical afterglow observations from MIRO
  47. GRB 061126: Swift/UVOT Observations
  48. GRB 061126: Early Detection of the IR Afterglow
  49. GRB 061126: Faulkes Telescope North Optical Observations
  50. GRB 061121: MDM Continued Monitoring
  51. GRB 061122: Confirmation of X-ray/Optical Afterglow
  52. GRB 061121: MDM Continuing Optical Decay
  53. GRB061121: optical observations
  54. GRB 061122: Candidate Optical Afterglow
  55. GRB 061121: MDM Optical Decay
  56. GRB061122: Swift/UVOT Optical Observations
  57. GRB 061121: ART detection in Ic
  58. GRB 061121: MDM Optical Observations
  59. GRB 061121 declared "Burst of Interest" by Swift team
  60. GRB 061121: Swift/UVOT Observations
  61. GRB061121, optical observation
  62. GRB 061121: Optical observation at the KANATA 1.5m telescope
  63. GRB 061121: Faulkes Telescope North Optical Observation
  64. GRB061121: Spectroscopic Redshift
  65. GRB061121: Keck spectroscopic observations
  66. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  67. GRB 061121: Swift detection of a bright burst with an optical counterpart
  68. GRB 060605: NIR Observations
  69. GRB 050915B: optical afterglow
  70. GRB 061110B: Swift XRT refined analysis
  71. GRB061110B: Optical observations at Crni Vrh
  72. GRB 061110B: NOT optical observations
  73. GRB 061110A: Swift XRT refined analysis
  74. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  75. GRB 061110B: TAROT Calern observatory optical observations
  76. GRB 061110: NOT observations
  77. GRB 061110 : Optical afterglow candidate
  78. GRB 061110: ROTSE-III Optical Limits
  79. GRB061110A - Optical Non-detection
  80. GRB 061109: optical observation
  81. GRB 061109: TAROT Calern observatory optical observations
  82. GRB061028: MAGIC telescope GeV observation
  83. GRB 061027: TAROT La Silla observatory optical observations
  84. GRB 061007: Third Epoch ATCA Radio Observations
  85. GRB061019: second epoch CrAO observations
  86. GRB 061028: Swift/XRT Astrometry Correction
  87. GRB 061102: Swift/UVOT Magnitude Upper Limits
  88. GRB 061004: Further VLT/NTT observations
  89. GRB 061028: Optical R passband observations
  90. GRB 061004: Swift/XRT Astrometry Correction
  91. GRB 060801: Swift/XRT Astrometry Correction
  92. GRB 061028: SARA upper limit
  93. GRB 061028: TAROT Calern observatory late optical observations
  94. GRB 061028: TAROT Calern observatory optical observations
  95. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  96. GRB 061025: REM observations
  97. GRB 061025: ROTSE-III Optical Limits
  98. GRB 061021: Swift/UVOT Observation
  99. GRB060904b: optical observations
  100. GRB061019: optical observations

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