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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"

23162 results found.

  1. GRB 070419B: optical afterglow confirmation
  2. GRB 070419A, Optical observations
  3. GRB070419 - SDSS Pre-Burst Observations
  4. GRB 070419A: NAYUTA Optical Observation
  5. GRB 070419A: Faulkes Telescope North Optical Observations
  6. GRB 070419B optical afterglow candidate
  7. GRB 070419A: Optical and IR observations with KANATA
  8. GRB 070419B: optical afterglow candidate
  9. GRB070419A, optical observation
  10. GRB 070419B: Swift detection of a burst
  11. GRB 070419: Swift detection of a burst
  12. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  13. GRB 070418: Optical and IR observations with KANATA
  14. Trigger 276045: Swift detection of a possible burst
  15. GRB 070412, Swift-BAT refined analysis
  16. GRB 070412 Liverpool Telescope optical limit
  17. GRB 070411: Optical photometry at Crni Vrh
  18. GRB 070411: OA redshift
  19. GRB 070412: Swift-XRT refined position
  20. GRB 070412: IAC80 optical afterglow candidate
  21. GRB 070411: Magellan/Clay photometry
  22. GRB 070411, Swift-BAT refined analysis
  23. GRB 070412: Swift detection of a burst
  24. GRB 070411: IAC80 optical observations
  25. GRB 070411 : Liverpool Telescope Observations
  26. GRB 070411: Swift detection of a burst with optical afterglow
  27. Suzaku ToO observation of SGR 1806-20
  28. GRB 070406, Swift-BAT refined analysis
  29. GRB070406: Swift UVOT observations
  30. GRB 070406: Xinglong TNT optical Upper Limit
  31. GRB 070406: Swift detection of a burst
  32. GRB 070402: Suzaku WAM observation of the prompt emission
  33. GRB 070311, deep optical photometry
  34. Konus-Wind and Konus-A observations of GRB 070402
  35. IPN triangulation of GRB070402
  36. GRB 070328: Suzaku WAM observation of the prompt emission
  37. GRB 070330, Swift-BAT refined analysis
  38. GRB 070330: TAROT La Silla observatory optical observations
  39. GRB 070330: Swift detection of a burst
  40. Konus-Wind observation of GRB 070328
  41. long burst from SGR 1806-20 detected on March 26
  42. GRB 070328 : Suzaku ToO follow up starts
  43. GRB 070328, Swift-BAT refined analysis
  44. GRB 070328: Swift detection of a burst
  45. GRB 070311, deep optical photometry
  46. Short-Hard GRB 070209: PROMPT Observations
  47. GRB070318: Swift UVOT continuing observations
  48. GRB 070318, Swift-BAT refined analysis
  49. GRB 070318: Swift detection of a burst with an optical afterglow
  50. GRB 070311: Tautenburg sees afterglow fading
  51. IBAS Alert n. 4169: not a GRB
  52. GRB 070311: MITSuME Okayama Optical Observation
  53. GRB 070311: a long GRB detected by INTEGRAL
  54. GRB 070125: Chandra X-ray Confirmation of Jet Break
  55. GRB 070306, optical observation
  56. GRB 070309: A long GRB detected by INTEGRAL
  57. GRB 070306: NOT observations
  58. GRB 070306 Swift/UVOT refined analysis
  59. GRB070306: confirmation of near infrared afterglow
  60. GRB 070306: ART-3 early optical and near infrared constraints
  61. GRB 070306: IR observations and candidate afterglow
  62. GRB 070306, Swift-BAT refined analysis
  63. GRB 070306: Optical and IR observations with KANATA
  64. GRB070306 - SDSS Pre-burst Observations
  65. GRB 070306: Swift detection of a burst
  66. GRB 070223: NIR observations at WHT
  67. GRB 070125, deep late-time optical observation
  68. GRB 070227: optical observations
  69. GRB 070223: Optical Observations
  70. GRB 070227: optical observations
  71. GRB 070227: TAROT La Silla observatory optical observations
  72. GRB 070227, Swift-BAT refined analysis
  73. GRB 070227: Swift detection of a burst in ground analysis
  74. GRB 920925C: optical afterglow candidate
  75. GRB 070224: Swift/UVOT Upper Limits
  76. GRB070224: Swift-XRT Astrometrically Corrected Position
  77. GRB 070224: WHT K-band imaging
  78. GRB070224: Gemini Imaging Observations
  79. GRB 070224: SARA upper limit
  80. GRB 070224, Swift-BAT refined analysis
  81. GRB 070224: Swift detection of a burst
  82. RHESSI Spectrum of GRB070220
  83. GRB 070223: Optical-IR observation with KANATA
  84. GRB 070223, Swift-BAT refined analysis
  85. GRB070223 - SDSS Pre-Burst Observations
  86. GRB 070223: Liverpool Telescope Possible Afterglow Candidate
  87. GRB070223: Swift burst
  88. Konus-Wind and Konus-A observations of GRB 070220
  89. GRB 070220: MITSuME Okayama Optical Observation
  90. GRB 070220: ART-3 Optical and NIR limits
  91. GRB 070220 Swift-BAT Refined Analysis
  92. Swift/UVOT refined analysis of GRB070220
  93. GRB 070209: Swift XRT refined analysis
  94. GRB 070220: Swift-XRT Refined Analysis
  95. GRB 070220: Observation with the KANATA 1.5m telescope
  96. GRB 070220 : Faulkes Telescope North optical limit
  97. GRB 070220: Swift detection of a burst
  98. GRB 070219: XRT Refined Analysis
  99. GRB 070219: I-band observations
  100. GRB 070219, Swift-BAT refined analysis

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