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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"

18675 results found.

  1. INTEGRAL ToO Observation of SGR1806-20
  2. UVOT observations of GRB070330
  3. GRB 070330, Swift-BAT refined analysis
  4. GRB 070330: TAROT La Silla observatory optical observations
  5. GRB 070330: Swift-XRT refined analysis
  6. GRB 070330: Swift detection of a burst
  7. GRB 070328: pseudo-z~2.75 from spectral parameters of the prompt
  8. Konus-Wind observation of GRB 070328
  9. GRB 070328: Swift/UVOT Upper Limits
  10. GRB 070328: Swift/XRT Refined Analysis
  11. GRB 070328, Swift-BAT refined analysis
  12. GRB 070328: Swift detection of a burst
  13. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  14. GRB 070318: Gemini + Magellan spectra
  15. GRB070318: Swift UVOT continuing observations
  16. GRB070318: Swift-XRT refined analysis
  17. GRB 070318: Swift/UVOT Continued Observations
  18. GRB 070318, Swift-BAT refined analysis
  19. GRB 070318: Swift detection of a burst with an optical afterglow
  20. GRB 070311: Late Central Engine Activity Optical Flare??
  21. VLA observation of GRB 070311
  22. GRB 070309: variability of the XRT afterglow candidate
  23. GRB 070311: Swift/UVOT Upper Limits
  24. GRB 070311: Swift-XRT refined analysis
  25. GRB070309: Swift/XRT possible afterglow detection
  26. GRB 070125: Chandra X-ray Confirmation of Jet Break
  27. GRB 070309: Swift/UVOT Upper Limits
  28. Swift UVOT Finding Charts for GRB 070309
  29. GRB 070125: X-ray light curve analysis
  30. VLA observation of GRB 070306
  31. GRB 070306: NOT observations
  32. GRB 070306 Swift/UVOT refined analysis
  33. GRB 070306, Swift-BAT refined analysis
  34. GRB 070306: XRT Team Refined Analysis
  35. GRB070306 - SDSS Pre-burst Observations
  36. GRB 070306: Swift detection of a burst
  37. GRB070227: Swift-XRT refined analysis
  38. GRB 070125, deep late-time optical observation
  39. VLA observation of GRB 070224
  40. GRB 070227: optical observations
  41. GRB 070223: Optical Observations
  42. GRB 070227: optical observations
  43. GRB 070227: Swift/UVOT Upper Limits
  44. GRB 070227: TAROT La Silla observatory optical observations
  45. GRB 070227, Swift-BAT refined analysis
  46. GRB070227: possible X-ray afterglow detection
  47. GRB 070227: Swift detection of a burst in ground analysis
  48. GRB 070224: Optical afterglow confirmation
  49. GRB 070224: Swift/UVOT Upper Limits
  50. GRB070224: Swift-XRT Astrometrically Corrected Position
  51. VLA observation of GRB 070223
  52. VLA observation of GRB 070220
  53. GRB070224: Magellan Imaging Observations
  54. GRB070224: Gemini Imaging Observations
  55. GRB 070224: SARA upper limit
  56. GRB070224: Swift-XRT Refined Analysis
  57. GRB 070224, Swift-BAT refined analysis
  58. GRB 070224: MASTER-Net refind analysis
  59. GRB 070224: MASTER-VWF-Kislovodsk observations
  60. GRB 070224: Swift detection of a burst
  61. GRB070223: Swift/UVOT refined analysis
  62. GRB 070223, Swift-BAT refined analysis
  63. GRB070223: MASTER-VWF-Kislovodsk observations
  64. GRB 070223: Swift-XRT Refined Analysis
  65. GRB 070220: pseudo-z~2.15 from spectral parameters of the prompt
  66. GRB 070223: MDM Observations
  67. GRB070223: Swift burst
  68. Konus-Wind and Konus-A observations of GRB 070220
  69. GRB 070220 Swift-BAT Refined Analysis
  70. Swift/UVOT refined analysis of GRB070220
  71. GRB 070209: Swift XRT refined analysis
  72. GRB 070220: Swift-XRT Refined Analysis
  73. GRB 070220: Swift detection of a burst
  74. GRB070219: MASTER-VWF-Kislovodsk observations
  75. GRB 070219: XRT Refined Analysis
  76. GRB 070219: Swift/UVOT Upper limits
  77. GRB 070219, Swift-BAT refined analysis
  78. GRB 070219: ROTSE-III Optical Limits
  79. GRB070219 - SDSS Pre-Burst Observations
  80. GRB 070219: Swift detection of a burst
  81. Swift-BAT trigger 260304 is NOT a burst or transient
  82. GRB 070209: Swift XRT analysis
  83. GRB 070208: MARGE Optical Observations
  84. IPN localization of very bright long hard GRB 070207
  85. IPN localization of very intense short GRB 070201
  86. GRB 070209, Swift-BAT refined analysis of the short hard burst
  87. GRB 070209: Swift detection of a short hard burst
  88. GRB 070208: Swift XRT refined analysis
  89. GRB 070208: RAPTOR detection of early afterglow onset
  90. GRB 070208: MDM Optical Decay
  91. GRB 070208, Swift-BAT refined analysis
  92. GRB070208: Faulkes Telescope North Afterglow Identification
  93. GRB 070208: ROTSE-III Optical Limits
  94. GRB 070208: MDM Observations
  95. GRB 070208: Swift detection of a burst
  96. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  97. GRB070124: Swift-XRT Follow-up Observation
  98. GRB070126: Swift-XRT Observation
  99. GRB 070129: Swift/UVOT Upper limits
  100. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT

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