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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"

19609 results found.

  1. GRB 070419A, Optical observations
  2. GRB070419 - SDSS Pre-Burst Observations
  3. GRB 070419A: Faulkes Telescope North Optical Observations
  4. GRB 070419B optical afterglow candidate
  5. GRB 070419B: optical afterglow candidate
  6. GRB070419A, optical observation
  7. GRB070330: Correction to UVOT position
  8. GRB 070419B: Swift detection of a burst
  9. GRB 070419A: ROTSE-III Optical Limits
  10. GRB 070419: Swift detection of a burst
  11. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  12. Trigger 276045: Swift detection of a possible burst
  13. GRB 070406: Swift XRT refined analysis
  14. GRB 070411: TLS data shows plateau, flares
  15. GRB070412: Swift UVOT observations
  16. GRB 070411: Swift/UVOT observations
  17. GRB 070412, Swift-BAT refined analysis
  18. GRB 070412: Swift-XRT refined analysis
  19. GRB 070411: Swift-XRT refined analysis
  20. GRB 070412: Optical observations at Crni Vrh
  21. GRB 070412: Swift-XRT refined position
  22. GRB 070411, Swift-BAT refined analysis
  23. GRB 070412: Swift detection of a burst
  24. GRB 070411: ROTSE-III Detection of Optical Counterpart
  25. GRB 070411: Tautenburg RRM Afterglow Confirmation
  26. GRB 070411: Swift detection of a burst with optical afterglow
  27. GRB 070406: Swift XRT team further analysis
  28. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  29. GRB 070406, Swift-BAT refined analysis
  30. GRB070406: Swift UVOT observations
  31. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  32. GRB 070406: SARA upper limit
  33. GRB 070406: Xinglong TNT optical Upper Limit
  34. GRB 070406: Swift detection of a burst
  35. INTEGRAL ToO Observation of SGR1806-20
  36. UVOT observations of GRB070330
  37. GRB 070330, Swift-BAT refined analysis
  38. GRB 070330: TAROT La Silla observatory optical observations
  39. GRB 070330: Swift-XRT refined analysis
  40. GRB 070330: Swift detection of a burst
  41. GRB 070328: pseudo-z~2.75 from spectral parameters of the prompt
  42. Konus-Wind observation of GRB 070328
  43. GRB 070328: Swift/UVOT Upper Limits
  44. GRB 070328: Swift/XRT Refined Analysis
  45. GRB 070328, Swift-BAT refined analysis
  46. GRB 070328: Swift detection of a burst
  47. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  48. GRB 070318: Gemini + Magellan spectra
  49. GRB070318: Swift UVOT continuing observations
  50. GRB070318: Swift-XRT refined analysis
  51. GRB 070318: Swift/UVOT Continued Observations
  52. GRB 070318, Swift-BAT refined analysis
  53. GRB 070318: Swift detection of a burst with an optical afterglow
  54. GRB 070311: Late Central Engine Activity Optical Flare??
  55. VLA observation of GRB 070311
  56. GRB 070309: variability of the XRT afterglow candidate
  57. GRB 070311: Swift/UVOT Upper Limits
  58. GRB 070311: Swift-XRT refined analysis
  59. GRB070309: Swift/XRT possible afterglow detection
  60. GRB 070125: Chandra X-ray Confirmation of Jet Break
  61. GRB 070309: Swift/UVOT Upper Limits
  62. Swift UVOT Finding Charts for GRB 070309
  63. GRB 070125: X-ray light curve analysis
  64. VLA observation of GRB 070306
  65. GRB 070306: NOT observations
  66. GRB 070306 Swift/UVOT refined analysis
  67. GRB 070306, Swift-BAT refined analysis
  68. GRB 070306: XRT Team Refined Analysis
  69. GRB070306 - SDSS Pre-burst Observations
  70. GRB 070306: Swift detection of a burst
  71. GRB070227: Swift-XRT refined analysis
  72. GRB 070125, deep late-time optical observation
  73. VLA observation of GRB 070224
  74. GRB 070227: optical observations
  75. GRB 070223: Optical Observations
  76. GRB 070227: optical observations
  77. GRB 070227: Swift/UVOT Upper Limits
  78. GRB 070227: TAROT La Silla observatory optical observations
  79. GRB 070227, Swift-BAT refined analysis
  80. GRB070227: possible X-ray afterglow detection
  81. GRB 070227: Swift detection of a burst in ground analysis
  82. GRB 070224: Optical afterglow confirmation
  83. GRB 070224: Swift/UVOT Upper Limits
  84. GRB070224: Swift-XRT Astrometrically Corrected Position
  85. VLA observation of GRB 070223
  86. VLA observation of GRB 070220
  87. GRB070224: Magellan Imaging Observations
  88. GRB070224: Gemini Imaging Observations
  89. GRB 070224: SARA upper limit
  90. GRB070224: Swift-XRT Refined Analysis
  91. GRB 070224, Swift-BAT refined analysis
  92. GRB 070224: MASTER-Net refind analysis
  93. GRB 070224: MASTER-VWF-Kislovodsk observations
  94. GRB 070224: Swift detection of a burst
  95. GRB070223: Swift/UVOT refined analysis
  96. GRB 070223, Swift-BAT refined analysis
  97. GRB070223: MASTER-VWF-Kislovodsk observations
  98. GRB 070223: Swift-XRT Refined Analysis
  99. GRB 070220: pseudo-z~2.15 from spectral parameters of the prompt
  100. GRB 070223: MDM Observations

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