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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"

23578 results found.

  1. GRB 070411: break in the optical light curve
  2. GRB 070420 Swift-BAT Refined Analysis
  3. GRB070419a: Swift UVOT observations
  4. GRB 070419A: MARGE Observations
  5. GRB 070420: optical rebrightening observed at Mt. John
  6. GRB 070420: Swift XRT refined analysis
  7. GRB070420: Swift UVOT continuing observations
  8. GRB 070420: Faulkes Telescope South Observations
  9. GBR 070419A: Swift/XRT refined analysis
  10. GRB 070420: TAROT La Silla observatory optical observations
  11. GRB 070420: Swift detection of a burst with optical afterglow
  12. GRB 070419A: MITSuME Okayama Observations
  13. GRB 070419A: Early Super-LOTIS Observations
  14. GRB 070419B, Swift-BAT refined analysis
  15. GRB 070419A Swift-BAT Refined Analysis
  16. GRB 070419: Keck/LRIS Absorption Redshift
  17. GRB 070419B: optical afterglow confirmation
  18. GRB 070419A, Optical observations
  19. GRB070419 - SDSS Pre-Burst Observations
  20. GRB 070419A: NAYUTA Optical Observation
  21. GRB 070419A: Faulkes Telescope North Optical Observations
  22. GRB 070419B optical afterglow candidate
  23. GRB 070419A: Optical and IR observations with KANATA
  24. GRB 070419B: optical afterglow candidate
  25. GRB070419A, optical observation
  26. GRB 070419B: Swift detection of a burst
  27. GRB 070419: Swift detection of a burst
  28. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  29. GRB 070418: Optical and IR observations with KANATA
  30. Trigger 276045: Swift detection of a possible burst
  31. GRB 070412, Swift-BAT refined analysis
  32. GRB 070412 Liverpool Telescope optical limit
  33. GRB 070411: Optical photometry at Crni Vrh
  34. GRB 070411: OA redshift
  35. GRB 070412: Swift-XRT refined position
  36. GRB 070412: IAC80 optical afterglow candidate
  37. GRB 070411: Magellan/Clay photometry
  38. GRB 070411, Swift-BAT refined analysis
  39. GRB 070412: Swift detection of a burst
  40. GRB 070411: IAC80 optical observations
  41. GRB 070411 : Liverpool Telescope Observations
  42. GRB 070411: Swift detection of a burst with optical afterglow
  43. Suzaku ToO observation of SGR 1806-20
  44. GRB 070406, Swift-BAT refined analysis
  45. GRB070406: Swift UVOT observations
  46. GRB 070406: Xinglong TNT optical Upper Limit
  47. GRB 070406: Swift detection of a burst
  48. GRB 070402: Suzaku WAM observation of the prompt emission
  49. GRB 070311, deep optical photometry
  50. Konus-Wind and Konus-A observations of GRB 070402
  51. IPN triangulation of GRB070402
  52. GRB 070328: Suzaku WAM observation of the prompt emission
  53. GRB 070330, Swift-BAT refined analysis
  54. GRB 070330: TAROT La Silla observatory optical observations
  55. GRB 070330: Swift detection of a burst
  56. Konus-Wind observation of GRB 070328
  57. long burst from SGR 1806-20 detected on March 26
  58. GRB 070328 : Suzaku ToO follow up starts
  59. GRB 070328, Swift-BAT refined analysis
  60. GRB 070328: Swift detection of a burst
  61. GRB 070311, deep optical photometry
  62. Short-Hard GRB 070209: PROMPT Observations
  63. GRB070318: Swift UVOT continuing observations
  64. GRB 070318, Swift-BAT refined analysis
  65. GRB 070318: Swift detection of a burst with an optical afterglow
  66. GRB 070311: Tautenburg sees afterglow fading
  67. IBAS Alert n. 4169: not a GRB
  68. GRB 070311: MITSuME Okayama Optical Observation
  69. GRB 070311: a long GRB detected by INTEGRAL
  70. GRB 070125: Chandra X-ray Confirmation of Jet Break
  71. GRB 070306, optical observation
  72. GRB 070309: A long GRB detected by INTEGRAL
  73. GRB 070306: NOT observations
  74. GRB 070306 Swift/UVOT refined analysis
  75. GRB070306: confirmation of near infrared afterglow
  76. GRB 070306: ART-3 early optical and near infrared constraints
  77. GRB 070306: IR observations and candidate afterglow
  78. GRB 070306, Swift-BAT refined analysis
  79. GRB 070306: Optical and IR observations with KANATA
  80. GRB070306 - SDSS Pre-burst Observations
  81. GRB 070306: Swift detection of a burst
  82. GRB 070223: NIR observations at WHT
  83. GRB 070125, deep late-time optical observation
  84. GRB 070227: optical observations
  85. GRB 070223: Optical Observations
  86. GRB 070227: optical observations
  87. GRB 070227: TAROT La Silla observatory optical observations
  88. GRB 070227, Swift-BAT refined analysis
  89. GRB 070227: Swift detection of a burst in ground analysis
  90. GRB 920925C: optical afterglow candidate
  91. GRB 070224: Swift/UVOT Upper Limits
  92. GRB070224: Swift-XRT Astrometrically Corrected Position
  93. GRB 070224: WHT K-band imaging
  94. GRB070224: Gemini Imaging Observations
  95. GRB 070224: SARA upper limit
  96. GRB 070224, Swift-BAT refined analysis
  97. GRB 070224: Swift detection of a burst
  98. RHESSI Spectrum of GRB070220
  99. GRB 070223: Optical-IR observation with KANATA
  100. GRB 070223, Swift-BAT refined analysis

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