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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"

21394 results found.

  1. GRB 070311: MITSuME Okayama Optical Observation
  2. GRB 070311: Swift-XRT refined analysis
  3. GRB060901: Candidate optical afterglow
  4. GRB070309: Swift/XRT possible afterglow detection
  5. GRB 070125: Chandra X-ray Confirmation of Jet Break
  6. GRB 070309: Swift/UVOT Upper Limits
  7. GRB 070306, optical observation
  8. Swift UVOT Finding Charts for GRB 070309
  9. GRB 070125: X-ray light curve analysis
  10. VLA observation of GRB 070306
  11. GRB 070306: NOT observations
  12. GRB 070306 Swift/UVOT refined analysis
  13. GRB 070306: ART-3 early optical and near infrared constraints
  14. GRB 070306, Swift-BAT refined analysis
  15. GRB 070306: XRT Team Refined Analysis
  16. GRB 070306: Optical and IR observations with KANATA
  17. GRB070306 - SDSS Pre-burst Observations
  18. GRB 070306: Swift detection of a burst
  19. GRB 070223: NIR observations at WHT
  20. GRB070227: Swift-XRT refined analysis
  21. GRB 070125, deep late-time optical observation
  22. VLA observation of GRB 070224
  23. GRB 070227: optical observations
  24. GRB 070223: Optical Observations
  25. GRB 070227: optical observations
  26. GRB 070227: Swift/UVOT Upper Limits
  27. GRB 070227: TAROT La Silla observatory optical observations
  28. GRB 070227, Swift-BAT refined analysis
  29. GRB070227: possible X-ray afterglow detection
  30. GRB 070227: Swift detection of a burst in ground analysis
  31. GRB 070224: Optical afterglow confirmation
  32. GRB 070224: Swift/UVOT Upper Limits
  33. GRB070224: Swift-XRT Astrometrically Corrected Position
  34. VLA observation of GRB 070223
  35. VLA observation of GRB 070220
  36. GRB070224: Magellan Imaging Observations
  37. GRB 070224: WHT K-band imaging
  38. GRB070224: Gemini Imaging Observations
  39. GRB 070224: SARA upper limit
  40. GRB070224: Swift-XRT Refined Analysis
  41. GRB 070224: optical afterglow candidate
  42. GRB 070224, Swift-BAT refined analysis
  43. GRB 070224: MASTER-Net refind analysis
  44. GRB 070224: MASTER-VWF-Kislovodsk observations
  45. GRB 070224: Swift detection of a burst
  46. GRB070223: Swift/UVOT refined analysis
  47. GRB 070223, Swift-BAT refined analysis
  48. GRB070223: MASTER-VWF-Kislovodsk observations
  49. GRB 070223: Swift-XRT Refined Analysis
  50. GRB 070220: pseudo-z~2.15 from spectral parameters of the prompt
  51. GRB 070223: Liverpool Telescope Possible Afterglow Candidate
  52. GRB 070223: MDM Observations
  53. GRB070223: Swift burst
  54. Konus-Wind and Konus-A observations of GRB 070220
  55. GRB 070220 Swift-BAT Refined Analysis
  56. Swift/UVOT refined analysis of GRB070220
  57. GRB 070209: Swift XRT refined analysis
  58. GRB 070220: Swift-XRT Refined Analysis
  59. GRB 070219: Gemini Observations
  60. GRB 070220 : Faulkes Telescope North optical limit
  61. GRB 070220: Swift detection of a burst
  62. GRB070219: MASTER-VWF-Kislovodsk observations
  63. GRB 070219: XRT Refined Analysis
  64. GRB 070219: Swift/UVOT Upper limits
  65. GRB 070219: I-band observations
  66. GRB 070219, Swift-BAT refined analysis
  67. GRB 070219: optical TNG observations
  68. GRB 070219: Liverpool Telescope Observations
  69. GRB 070219: ROTSE-III Optical Limits
  70. GRB070219 - SDSS Pre-Burst Observations
  71. GRB 070219: Swift detection of a burst
  72. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  73. Swift-BAT trigger 260304 is NOT a burst or transient
  74. GRB 070209: Swift XRT analysis
  75. GRB 070208: MARGE Optical Observations
  76. IPN localization of very bright long hard GRB 070207
  77. IPN localization of very intense short GRB 070201
  78. GRB 070209, Swift-BAT refined analysis of the short hard burst
  79. GRB 070209: Swift detection of a short hard burst
  80. GRB 070208: Swift XRT refined analysis
  81. GRB 070208: RAPTOR detection of early afterglow onset
  82. GRB 070208: MDM Optical Decay
  83. GRB 070208, Swift-BAT refined analysis
  84. GRB 070208: Early IR detection and afterglow astrometry
  85. GRB070208: Faulkes Telescope North Afterglow Identification
  86. GRB 070208: ROTSE-III Optical Limits
  87. GRB 070208: MDM Observations
  88. GRB 070208: Swift detection of a burst
  89. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  90. GRB 070129: afterglow confirmation
  91. GRB070124: Swift-XRT Follow-up Observation
  92. GRB070126: Swift-XRT Observation
  93. GRB 070129: Swift/UVOT Upper limits
  94. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  95. GRB061217: MAGIC telescope GeV observation
  96. GRB 070129, Swift-BAT refined analysis of a particularly long
  97. GRB 070129: Xinglong TNT optical Upper Limit
  98. GRB 070129: Swift-XRT Refined Analysis
  99. GRB 070129: VLT observations
  100. GRB 070125: An IR Point Source and an Apparent Host Galaxy

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