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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"

21456 results found.

  1. GRB 070419 optical afterglow candidate
  2. GRB 070419A: ROTSE-III Optical Limits
  3. GRB 070419: Swift detection of a burst
  4. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  5. Trigger 276045: Swift detection of a possible burst
  6. GRB 070406: Swift XRT refined analysis
  7. GRB 070411: TLS data shows plateau, flares
  8. GRB070412: Swift UVOT observations
  9. GRB 070411: Swift/UVOT observations
  10. GRB 070412, Swift-BAT refined analysis
  11. GRB 070412 Liverpool Telescope optical limit
  12. GRB 070412: Swift-XRT refined analysis
  13. GRB 070411: Swift-XRT refined analysis
  14. GRB 070412: further reanalysis of NOT images
  15. GRB 070412: Optical observations at Crni Vrh
  16. GRB 070412: Swift-XRT refined position
  17. GRB 070412: further NOT observations
  18. GRB 070412: Gemini/GMOS afterglow candidate
  19. GRB 070412: NOT observations
  20. GRB 070412: Nearby bright galaxy
  21. GRB 070411, Swift-BAT refined analysis
  22. GRB 070412: Swift detection of a burst
  23. GRB 070411: ROTSE-III Detection of Optical Counterpart
  24. GRB 070411: Tautenburg RRM Afterglow Confirmation
  25. GRB 070411: Swift detection of a burst with optical afterglow
  26. GRB 070406: "Star" in XRT error circle S2 is an AGN?
  27. GRB 070406: Swift XRT team further analysis
  28. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  29. GRB 070406: Bright galaxy in XRT error circle is a quasar
  30. GRB 070406, Swift-BAT refined analysis
  31. GRB 070406: Gemini South Imaging and XRT analysis
  32. GRB070406: Swift UVOT observations
  33. GRB 070406: further analysis of NOT images.
  34. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  35. GRB 070406: SARA upper limit
  36. GRB 070406: Xinglong TNT optical Upper Limit
  37. GRB 070406: Swift detection of a burst
  38. INTEGRAL ToO Observation of SGR1806-20
  39. UVOT observations of GRB070330
  40. GRB 070330, Swift-BAT refined analysis
  41. GRB 070330: TAROT La Silla observatory optical observations
  42. GRB 070330: Swift-XRT refined analysis
  43. GRB 070330: Swift detection of a burst
  44. GRB 070328: pseudo-z~2.75 from spectral parameters of the prompt
  45. Konus-Wind observation of GRB 070328
  46. GRB 070328: Swift/UVOT Upper Limits
  47. GRB 070328: Swift/XRT Refined Analysis
  48. GRB 070328, Swift-BAT refined analysis
  49. GRB 070328: Swift detection of a burst
  50. GRB070220: optical observations
  51. GRB070223: confirmation of nIR and optical afterglow
  52. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  53. GRB 070318: Gemini + Magellan spectra
  54. GRB070318: Swift UVOT continuing observations
  55. GRB070318: Swift-XRT refined analysis
  56. GRB 070318: Swift/UVOT Continued Observations
  57. GRB 070318, Swift-BAT refined analysis
  58. GRB 070318: Swift detection of a burst with an optical afterglow
  59. GRB 070311: Late Central Engine Activity Optical Flare??
  60. VLA observation of GRB 070311
  61. GRB 070309: variability of the XRT afterglow candidate
  62. GRB 070311: Swift/UVOT Upper Limits
  63. GRB 070311: MITSuME Okayama Optical Observation
  64. GRB 070311: Swift-XRT refined analysis
  65. GRB060901: Candidate optical afterglow
  66. GRB070309: Swift/XRT possible afterglow detection
  67. GRB 070125: Chandra X-ray Confirmation of Jet Break
  68. GRB 070309: Swift/UVOT Upper Limits
  69. GRB 070306, optical observation
  70. Swift UVOT Finding Charts for GRB 070309
  71. GRB 070125: X-ray light curve analysis
  72. VLA observation of GRB 070306
  73. GRB 070306: NOT observations
  74. GRB 070306 Swift/UVOT refined analysis
  75. GRB 070306: ART-3 early optical and near infrared constraints
  76. GRB 070306, Swift-BAT refined analysis
  77. GRB 070306: XRT Team Refined Analysis
  78. GRB 070306: Optical and IR observations with KANATA
  79. GRB070306 - SDSS Pre-burst Observations
  80. GRB 070306: Swift detection of a burst
  81. GRB 070223: NIR observations at WHT
  82. GRB070227: Swift-XRT refined analysis
  83. GRB 070125, deep late-time optical observation
  84. VLA observation of GRB 070224
  85. GRB 070227: optical observations
  86. GRB 070223: Optical Observations
  87. GRB 070227: optical observations
  88. GRB 070227: Swift/UVOT Upper Limits
  89. GRB 070227: TAROT La Silla observatory optical observations
  90. GRB 070227, Swift-BAT refined analysis
  91. GRB070227: possible X-ray afterglow detection
  92. GRB 070227: Swift detection of a burst in ground analysis
  93. GRB 070224: Optical afterglow confirmation
  94. GRB 070224: Swift/UVOT Upper Limits
  95. GRB070224: Swift-XRT Astrometrically Corrected Position
  96. VLA observation of GRB 070223
  97. VLA observation of GRB 070220
  98. GRB070224: Magellan Imaging Observations
  99. GRB 070224: WHT K-band imaging
  100. GRB070224: Gemini Imaging Observations

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