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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"

5051 results found.

  1. GRB 070520B: Swift-XRT refined analysis
  2. GRB 070521: optical limit by Pi of the Sky
  3. GRB 070521: TAROT La Silla observatory optical observations
  4. GRB 070520A: Swift-XRT refined analysis
  5. GRB 070518: Swift-XRT refined analysis
  6. GRB070517: Swift-XRT Refined Analysis
  7. GRB070509: Swift-XRT Refined Analysis
  8. Swift-BAT trigger 278809 is not a GRB
  9. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  10. GRB070506: Swift XRT refined analysis
  11. GRB 070506: Swift detection of a burst with optical afterglow
  12. GRB 070429A: optical observations
  13. Swift/UVOT observations of GRB070429A
  14. GRB 070429A: Swift XRT refined analysis
  15. GRB 070429A: optical and NIR observations
  16. GRB 070429B: Swift XRT refined analysis
  17. GRB 070429: Swift detection of a burst
  18. GRB070419A, optical observation
  19. GRB 070418: Optical and IR observations with KANATA
  20. GRB 070411: Swift-XRT refined analysis
  21. GRB 070412: Gemini/GMOS afterglow candidate
  22. GRB 070412: NOT observations
  23. Suzaku ToO observation of SGR 1806-20
  24. IPN triangulation of GRB070402
  25. long burst from SGR 1806-20 detected on March 26
  26. GRB 070328: Swift/XRT Refined Analysis
  27. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  28. GRB 070311: Swift-XRT refined analysis
  29. GRB 070306, optical observation
  30. GRB 070306: ART-3 early optical and near infrared constraints
  31. GRB 070306: XRT Team Refined Analysis
  32. GRB 920925C: optical afterglow candidate
  33. VLA observation of GRB 070220
  34. GRB 070224: WHT K-band imaging
  35. GRB 070224: MASTER-Net refind analysis
  36. GRB 070224: MASTER observations
  37. GRB 070220: MITSuME Okayama Optical Observation
  38. GRB 070220: Swift-XRT Refined Analysis
  39. GRB 070219: XRT Refined Analysis
  40. GRB 070110: optical break
  41. GRB070110: Swift XRT Team refined analysis
  42. GRB 070110: Swift detection of a burst with a possible optical afterglow
  43. GRB 070107: Swift/XRT position
  44. GRB070103: Swift XRT refined analysis
  45. Retractions of previous Swift-BAT triggers
  46. GRB 050826: MDM Redshift
  47. GRB 061222B: TAROT La Silla observatory early optical observations
  48. GRB 061217: TAROT Calern observatory optical observations
  49. GRB061217 - Swift/XRT refined analysis
  50. GRB 061214(?): ROTSE-III Optical Limits
  51. GRB061121: optical observations
  52. GRB 061126: Swift-XRT refined analysis
  53. GRB 061126: Swift detection of a burst
  54. GRB 061121: MDM Continuing Optical Decay
  55. GRB 061122: Candidate Optical Afterglow
  56. GRB 061121: ART detection in Ic
  57. GRB 061121: Swift-XRT Team Refined Analysis
  58. GRB061121, optical observation
  59. GRB 061121: Swift detection of a bright burst with an optical counterpart
  60. GRB 050915B: optical afterglow
  61. GRB061025: Swift XRT refined analysis
  62. GRB061019: Swift XRT refined analysis
  63. GRB 061006: optical afterglow
  64. GRB 061006: VLT observation
  65. GRB 061006: Swift-XRT Team Refined Analysis
  66. GRB061006 (Swift 232585) might be a short-hard GRB
  67. GRB 061006: Swift detection of a burst
  68. GRB 061004: Swift-XRT Team Refined Analysis
  69. GRB 061004: Nearby 2MASS Galaxy
  70. GRB 061002: Swift-XRT Team Refined Analysis
  71. VLA observations of GRB 060926
  72. GRB 060929: Further XRT Refined Analysis
  73. GRB 060927, Swift-BAT refined analysis
  74. GRB 060923C: Gemini Observations and Afterglow Candidate
  75. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  76. GRB 060923C: VLT J-band observations
  77. Swift detection of IGR J17497-2821 (trigger 230504)
  78. GRB 060919, Swift-BAT refined analysis
  79. GRB 060912: Swift XRT Team Refined Analysis
  80. GRB 060908, Swift/XRT refined analysis
  81. GRB 060906: Swift/XRT Refined Analysis
  82. GRB 060906: observations with FRAM
  83. GRB 060904A: Subaru NIR observation
  84. GRB 060901: Swift/XRT Refined Analysis
  85. GRB 060901: SMARTS optical/IR observations
  86. GRB 060825: XRT Team Refined Analysis
  87. GRB 060814: Swift XRT refined analysis
  88. GRB 060814: VLT optical limits
  89. GRB 060813: Swift XRT refined analysis
  90. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  91. VLA Upper Limit on Outburst of SGR 1806-20
  92. GRB060806 is similar to previous activity of SGR1806-20
  93. GRB 060807: XRT Team refined analysis
  94. IPN triangulation of GRB060806 (long, exceptionally bright)
  95. GRB 060805: XRT Team Refined Analysis
  96. GRB 060804: Swift-XRT Team Refined Analysis
  97. GRB 060801: WSRT Radio Observations
  98. GRB060801: optical upper limit in R
  99. GRB 060728: Swift detection of a burst
  100. GRB060614 ATCA Radio Limits

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