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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"

19531 results found.

  1. GRB 070427, Swift-BAT Refined Analysis
  2. GRB 070427: Swift detection of a burst
  3. GRB070419B: Suzaku WAM observation of the prompt emission
  4. GRB 070411, deep LBT photometry
  5. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  6. GRB 070420 Swift-BAT Refined Analysis
  7. GRB070419A: Kuiper Optical detection
  8. GRB070419a: Swift UVOT observations
  9. GRB 070419A: MARGE Observations
  10. GRB 070420: optical rebrightening observed at Mt. John
  11. GRB 070420: Swift XRT refined analysis
  12. GRB070420: Swift UVOT continuing observations
  13. GRB 070420: Faulkes Telescope South Observations
  14. GBR 070419A: Swift/XRT refined analysis
  15. GRB 070420: TAROT La Silla observatory optical observations
  16. GRB 070420: NIR and optical afterglow confirmed
  17. GRB 070420: Swift detection of a burst with optical afterglow
  18. GRB 070419A: Early Super-LOTIS Observations
  19. GRB 070419B, Swift-BAT refined analysis
  20. GRB 070419A Swift-BAT Refined Analysis
  21. GRB 070419A: RAPTOR Detection of Early Emission
  22. GRB 070419B: Swift XRT refined analysis
  23. GRB 070419A, Optical observations
  24. GRB070419 - SDSS Pre-Burst Observations
  25. GRB 070419A: Faulkes Telescope North Optical Observations
  26. GRB 070419B optical afterglow candidate
  27. GRB 070419B: optical afterglow candidate
  28. GRB070419A, optical observation
  29. GRB070330: Correction to UVOT position
  30. GRB 070419B: Swift detection of a burst
  31. GRB 070419A: ROTSE-III Optical Limits
  32. GRB 070419: Swift detection of a burst
  33. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  34. Trigger 276045: Swift detection of a possible burst
  35. GRB 070406: Swift XRT refined analysis
  36. GRB 070411: TLS data shows plateau, flares
  37. GRB070412: Swift UVOT observations
  38. GRB 070411: Swift/UVOT observations
  39. GRB 070412, Swift-BAT refined analysis
  40. GRB 070412: Swift-XRT refined analysis
  41. GRB 070411: Swift-XRT refined analysis
  42. GRB 070412: Optical observations at Crni Vrh
  43. GRB 070412: Swift-XRT refined position
  44. GRB 070411, Swift-BAT refined analysis
  45. GRB 070412: Swift detection of a burst
  46. GRB 070411: ROTSE-III Detection of Optical Counterpart
  47. GRB 070411: Tautenburg RRM Afterglow Confirmation
  48. GRB 070411: Swift detection of a burst with optical afterglow
  49. GRB 070406: Swift XRT team further analysis
  50. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  51. GRB 070406, Swift-BAT refined analysis
  52. GRB070406: Swift UVOT observations
  53. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  54. GRB 070406: SARA upper limit
  55. GRB 070406: Xinglong TNT optical Upper Limit
  56. GRB 070406: Swift detection of a burst
  57. INTEGRAL ToO Observation of SGR1806-20
  58. UVOT observations of GRB070330
  59. GRB 070330, Swift-BAT refined analysis
  60. GRB 070330: TAROT La Silla observatory optical observations
  61. GRB 070330: Swift-XRT refined analysis
  62. GRB 070330: Swift detection of a burst
  63. GRB 070328: pseudo-z~2.75 from spectral parameters of the prompt
  64. Konus-Wind observation of GRB 070328
  65. GRB 070328: Swift/UVOT Upper Limits
  66. GRB 070328: Swift/XRT Refined Analysis
  67. GRB 070328, Swift-BAT refined analysis
  68. GRB 070328: Swift detection of a burst
  69. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  70. GRB 070318: Gemini + Magellan spectra
  71. GRB070318: Swift UVOT continuing observations
  72. GRB070318: Swift-XRT refined analysis
  73. GRB 070318: Swift/UVOT Continued Observations
  74. GRB 070318, Swift-BAT refined analysis
  75. GRB 070318: Swift detection of a burst with an optical afterglow
  76. GRB 070311: Late Central Engine Activity Optical Flare??
  77. VLA observation of GRB 070311
  78. GRB 070309: variability of the XRT afterglow candidate
  79. GRB 070311: Swift/UVOT Upper Limits
  80. GRB 070311: Swift-XRT refined analysis
  81. GRB070309: Swift/XRT possible afterglow detection
  82. GRB 070125: Chandra X-ray Confirmation of Jet Break
  83. GRB 070309: Swift/UVOT Upper Limits
  84. Swift UVOT Finding Charts for GRB 070309
  85. GRB 070125: X-ray light curve analysis
  86. VLA observation of GRB 070306
  87. GRB 070306: NOT observations
  88. GRB 070306 Swift/UVOT refined analysis
  89. GRB 070306, Swift-BAT refined analysis
  90. GRB 070306: XRT Team Refined Analysis
  91. GRB070306 - SDSS Pre-burst Observations
  92. GRB 070306: Swift detection of a burst
  93. GRB070227: Swift-XRT refined analysis
  94. GRB 070125, deep late-time optical observation
  95. VLA observation of GRB 070224
  96. GRB 070227: optical observations
  97. GRB 070223: Optical Observations
  98. GRB 070227: optical observations
  99. GRB 070227: Swift/UVOT Upper Limits
  100. GRB 070227: TAROT La Silla observatory optical observations

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