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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"

5157 results found.

  1. GRB 070612B: KAIT limits
  2. GRB 070610: TAROT Calern observatory optical observations
  3. GRB 070611: Swift-XRT refined analysis
  4. GRB 070529: Swift-XRT refined analysis
  5. GRB 070521: Swift-XRT refined analysis
  6. GRB 070520A: Subaru Observations
  7. GRB 070520B: Swift-XRT refined analysis
  8. GRB 070521: optical limit by Pi of the Sky
  9. GRB 070521: TAROT La Silla observatory optical observations
  10. GRB 070520A: Swift-XRT refined analysis
  11. GRB 070518: Swift-XRT refined analysis
  12. GRB070517: Swift-XRT Refined Analysis
  13. GRB070509: Swift-XRT Refined Analysis
  14. Swift-BAT trigger 278809 is not a GRB
  15. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  16. GRB070506: Swift XRT refined analysis
  17. GRB 070506: Swift detection of a burst with optical afterglow
  18. GRB 070429A: optical observations
  19. Swift/UVOT observations of GRB070429A
  20. GRB 070429A: Swift XRT refined analysis
  21. GRB 070429A: optical and NIR observations
  22. GRB 070429B: Swift XRT refined analysis
  23. GRB 070429: Swift detection of a burst
  24. GRB070419A, optical observation
  25. GRB 070418: Optical and IR observations with KANATA
  26. GRB 070411: Swift-XRT refined analysis
  27. GRB 070412: Gemini/GMOS afterglow candidate
  28. GRB 070412: NOT observations
  29. Suzaku ToO observation of SGR 1806-20
  30. IPN triangulation of GRB070402
  31. long burst from SGR 1806-20 detected on March 26
  32. GRB 070328: Swift/XRT Refined Analysis
  33. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  34. GRB 070311: Swift-XRT refined analysis
  35. GRB 070306, optical observation
  36. GRB 070306: ART-3 early optical and near infrared constraints
  37. GRB 070306: XRT Team Refined Analysis
  38. GRB 920925C: optical afterglow candidate
  39. VLA observation of GRB 070220
  40. GRB 070224: WHT K-band imaging
  41. GRB 070224: MASTER-Net refind analysis
  42. GRB 070224: MASTER observations
  43. GRB 070220: MITSuME Okayama Optical Observation
  44. GRB 070220: Swift-XRT Refined Analysis
  45. GRB 070219: XRT Refined Analysis
  46. GRB 070110: optical break
  47. GRB070110: Swift XRT Team refined analysis
  48. GRB 070110: Swift detection of a burst with a possible optical afterglow
  49. GRB 070107: Swift/XRT position
  50. GRB070103: Swift XRT refined analysis
  51. Retractions of previous Swift-BAT triggers
  52. GRB 050826: MDM Redshift
  53. GRB 061222B: TAROT La Silla observatory early optical observations
  54. GRB 061217: TAROT Calern observatory optical observations
  55. GRB061217 - Swift/XRT refined analysis
  56. GRB 061214(?): ROTSE-III Optical Limits
  57. GRB061121: optical observations
  58. GRB 061126: Swift-XRT refined analysis
  59. GRB 061126: Swift detection of a burst
  60. GRB 061121: MDM Continuing Optical Decay
  61. GRB 061122: Candidate Optical Afterglow
  62. GRB 061121: ART detection in Ic
  63. GRB 061121: Swift-XRT Team Refined Analysis
  64. GRB061121, optical observation
  65. GRB 061121: Swift detection of a bright burst with an optical counterpart
  66. GRB 050915B: optical afterglow
  67. GRB061025: Swift XRT refined analysis
  68. GRB061019: Swift XRT refined analysis
  69. GRB 061006: optical afterglow
  70. GRB 061006: VLT observation
  71. GRB 061006: Swift-XRT Team Refined Analysis
  72. GRB061006 (Swift 232585) might be a short-hard GRB
  73. GRB 061006: Swift detection of a burst
  74. GRB 061004: Swift-XRT Team Refined Analysis
  75. GRB 061004: Nearby 2MASS Galaxy
  76. GRB 061002: Swift-XRT Team Refined Analysis
  77. VLA observations of GRB 060926
  78. GRB 060929: Further XRT Refined Analysis
  79. GRB 060927, Swift-BAT refined analysis
  80. GRB 060923C: Gemini Observations and Afterglow Candidate
  81. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  82. GRB 060923C: VLT J-band observations
  83. Swift detection of IGR J17497-2821 (trigger 230504)
  84. GRB 060919, Swift-BAT refined analysis
  85. GRB 060912: Swift XRT Team Refined Analysis
  86. GRB 060908, Swift/XRT refined analysis
  87. GRB 060906: Swift/XRT Refined Analysis
  88. GRB 060906: observations with FRAM
  89. GRB 060904A: Subaru NIR observation
  90. GRB 060901: Swift/XRT Refined Analysis
  91. GRB 060901: SMARTS optical/IR observations
  92. GRB 060825: XRT Team Refined Analysis
  93. GRB 060814: Swift XRT refined analysis
  94. GRB 060814: VLT optical limits
  95. GRB 060813: Swift XRT refined analysis
  96. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  97. VLA Upper Limit on Outburst of SGR 1806-20
  98. GRB060806 is similar to previous activity of SGR1806-20
  99. GRB 060807: XRT Team refined analysis
  100. IPN triangulation of GRB060806 (long, exceptionally bright)

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