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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"

16155 results found.

  1. GRB 061201: Magellan redshift of nearby galaxy
  2. GRB 061217, Candidate host galaxy
  3. GRB 061218: TAROT La Silla observatory optical observations
  4. GRB 061217: TAROT Calern observatory optical observations
  5. GRB 061218: TORTOREM optical upper limits
  6. GRB 061218, SMARTS optical/IR observations
  7. GRB 061218: REM prompt observations
  8. GRB 061217, SMARTS optical observations
  9. GRB061217: Swift/UVOT refined analysis.
  10. GRB 061217: optical observations at Calar Alto
  11. GRB 061217: REM prompt observations
  12. GRB 061217: ROTSE-III Optical Limits
  13. GRB 061210: MDM Follow-up Observation
  14. GRB061210: Swift/UVOT observations
  15. GRB 061210: Optical sources near XRT positions
  16. GRB 061210 : Faulkes North Telescope optical limit
  17. GRB 061214(?): ROTSE-III Optical Limits
  18. GRB 061213: MASTER-VWF-Kislovodsk optical candidate
  19. GRB061201, VLT optical decay: correction
  20. Optical Afterglow observations of GRB 061126
  21. GRB061126: optical observations
  22. GRB 060926: MASTER: discovery of the optical flare
  23. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  24. GRB 061202: TORTOREM optical upper limits
  25. GRB 061201: VLT optical decay
  26. GRB061126 : NMSU 1.0m observations
  27. GRB061202 optical limit by "Pi of the Sky"
  28. GRB061202: optical/NIR observations with REM
  29. GRB 061201: Swift XRT Team refined analysis
  30. GRB 061201: VLT optical observations
  31. GRB 061201: Initial UVOT Observations
  32. GRB 061122: GETS observation
  33. GRB 061121, SMARTS optical/IR observations
  34. INT+WFC observations of GRB 061126
  35. GRB 061121: Second Epoch ATCA Radio Observations
  36. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  37. GRB 061121: ATCA & WSRT Radio Observations
  38. GRB061121: optical observations
  39. GRB 061126: Early Super-LOTIS Observations
  40. GRB 061126: optical observation
  41. GRB061126: Optical afterglow observations from MIRO
  42. GRB061126: Optical afterglow observations from MIRO
  43. GRB 061126: Swift/UVOT Observations
  44. GRB 061126: Early Detection of the IR Afterglow
  45. GRB 061126: Faulkes Telescope North Optical Observations
  46. GRB 061121: MDM Continued Monitoring
  47. GRB 061122: Confirmation of X-ray/Optical Afterglow
  48. GRB 061121: MDM Continuing Optical Decay
  49. GRB061121: optical observations
  50. GRB 061122: Candidate Optical Afterglow
  51. GRB 061121: MDM Optical Decay
  52. GRB061122: Swift/UVOT Optical Observations
  53. GRB 061121: ART detection in Ic
  54. GRB 061121: MDM Optical Observations
  55. GRB 061121 declared "Burst of Interest" by Swift team
  56. GRB 061121: Swift/UVOT Observations
  57. GRB061121, optical observation
  58. GRB 061121: Optical observation at the KANATA 1.5m telescope
  59. GRB 061121: Faulkes Telescope North Optical Observation
  60. GRB061121: Spectroscopic Redshift
  61. GRB061121: Keck spectroscopic observations
  62. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  63. GRB 061121: Swift detection of a bright burst with an optical counterpart
  64. GRB 060605: NIR Observations
  65. GRB 050915B: optical afterglow
  66. GRB 061110B: Swift XRT refined analysis
  67. GRB061110B: Optical observations at Crni Vrh
  68. GRB 061110B: NOT optical observations
  69. GRB 061110A: Swift XRT refined analysis
  70. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  71. GRB 061110B: TAROT Calern observatory optical observations
  72. GRB 061110: NOT observations
  73. GRB 061110 : Optical afterglow candidate
  74. GRB 061110: ROTSE-III Optical Limits
  75. GRB061110A - Optical Non-detection
  76. GRB 061109: optical observation
  77. GRB 061109: TAROT Calern observatory optical observations
  78. GRB061028: MAGIC telescope GeV observation
  79. GRB 061027: TAROT La Silla observatory optical observations
  80. GRB 061007: Third Epoch ATCA Radio Observations
  81. GRB061019: second epoch CrAO observations
  82. GRB 061028: Swift/XRT Astrometry Correction
  83. GRB 061102: Swift/UVOT Magnitude Upper Limits
  84. GRB 061004: Further VLT/NTT observations
  85. GRB 061028: Optical R passband observations
  86. GRB 061004: Swift/XRT Astrometry Correction
  87. GRB 060801: Swift/XRT Astrometry Correction
  88. GRB 061028: SARA upper limit
  89. GRB 061028: TAROT Calern observatory late optical observations
  90. GRB 061028: TAROT Calern observatory optical observations
  91. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  92. GRB 061025: REM observations
  93. GRB 061025: ROTSE-III Optical Limits
  94. GRB 061021: Swift/UVOT Observation
  95. GRB060904b: optical observations
  96. GRB061019: optical observations
  97. GRB061019: optical observations
  98. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  99. GRB 060930: MARGE Optical Limits
  100. GRB 061019: Swift/UVOT upper limit

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