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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"

22038 results found.

  1. GRB 070402: Suzaku WAM observation of the prompt emission
  2. Konus-Wind and Konus-A observations of GRB 070402
  3. IPN triangulation of GRB070402
  4. GRB 070328: Suzaku WAM observation of the prompt emission
  5. UVOT observations of GRB070330
  6. GRB 070330: TAROT La Silla observatory optical observations
  7. GRB 070330: Swift-XRT refined analysis
  8. GRB 070330 - Watcher Observations
  9. GRB 070330: Swift detection of a burst
  10. GRB 070328: Swift/UVOT Upper Limits
  11. long burst from SGR 1806-20 detected on March 26
  12. GRB 070328 : Suzaku ToO follow up starts
  13. GRB 070328: Swift detection of a burst
  14. GRB 070311, deep optical photometry
  15. Short-Hard GRB 070209: PROMPT Observations
  16. GRB 070318: absorption-line redshift
  17. GRB070318: Swift UVOT continuing observations
  18. GRB070318: Swift-XRT refined analysis
  19. GRB 070318, Swift-BAT refined analysis
  20. GRB 070318: Swift detection of a burst with an optical afterglow
  21. VLA observation of GRB 070311
  22. GRB 070311: Optical observation.
  23. GRB 070306: possible emission-line redshift
  24. GRB 070311: SARA upper limit
  25. GRB 070311: RAPTOR Detection of Optical Emission
  26. GRB070311: FRAM early follow-up limit
  27. GRB 070311: P60 Observations
  28. GRB 070311: Swift/UVOT Upper Limits
  29. GRB 070311: MITSuME Okayama Optical Observation
  30. GRB 070311: Swift-XRT refined analysis
  31. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  32. GRB 070311: REM candidate afterglow
  33. GRB060901: Candidate optical afterglow
  34. GRB070309: Swift/XRT possible afterglow detection
  35. GRB 070125: Chandra X-ray Confirmation of Jet Break
  36. GRB 070309: Swift/UVOT Upper Limits
  37. GRB 070306, optical observation
  38. Swift UVOT Finding Charts for GRB 070309
  39. VLA observation of GRB 070306
  40. GRB 070306: NOT observations
  41. GRB 070306 Swift/UVOT refined analysis
  42. GRB 070306: ART-3 early optical and near infrared constraints
  43. GRB 070306: IR observations and candidate afterglow
  44. GRB 070306: Optical and IR observations with KANATA
  45. GRB070306 - SDSS Pre-burst Observations
  46. GRB 070306: Swift detection of a burst
  47. GRB 060605 new redshift
  48. GRB 070125, deep late-time optical observation
  49. VLA observation of GRB 070224
  50. GRB 070227: Swift/UVOT Upper Limits
  51. GRB 070227: TAROT La Silla observatory optical observations
  52. GRB 070227, Swift-BAT refined analysis
  53. GRB 070227: Swift detection of a burst in ground analysis
  54. GRB 920925C: optical afterglow candidate
  55. GRB 070224: Swift/UVOT Upper Limits
  56. VLA observation of GRB 070223
  57. VLA observation of GRB 070220
  58. GRB070224: Magellan Imaging Observations
  59. GRB 070224: WHT K-band imaging
  60. GRB 070224: MDM Observations
  61. GRB070224: Gemini Imaging Observations
  62. GRB 070224: SARA upper limit
  63. GRB070224: Swift-XRT Refined Analysis
  64. GRB 070224: optical afterglow candidate
  65. GRB 070224: MASTER-Net refind analysis
  66. GRB 070224: MASTER-VWF-Kislovodsk observations
  67. GRB 070224: Swift detection of a burst
  68. GRB 070223: Optical observations
  69. GRB070223: Swift/UVOT refined analysis
  70. GRB 070223: Optical-IR observation with KANATA
  71. GRB070223: MASTER-VWF-Kislovodsk observations
  72. GRB070223 - SDSS Pre-Burst Observations
  73. GRB070223: Swift burst
  74. GRB 070220: MITSuME Okayama Optical Observation
  75. GRB 070220: ART-3 Optical and NIR limits
  76. Swift/UVOT refined analysis of GRB070220
  77. GRB 070209: Swift XRT refined analysis
  78. GRB 070220: Observation with the KANATA 1.5m telescope
  79. GRB 070219: Gemini Observations
  80. GRB 070220: Swift detection of a burst
  81. GRB070219: MASTER-VWF-Kislovodsk observations
  82. GRB 070219: Swift/UVOT Upper limits
  83. GRB 070219: I-band observations
  84. GRB 070219: optical TNG observations
  85. GRB 070219: ROTSE-III Optical Limits
  86. GRB070219 - SDSS Pre-Burst Observations
  87. GRB 070219: Swift detection of a burst
  88. GRB 070125 observations with the GMRT
  89. GRB 060927: PROMPT Observations
  90. GRB 070129: MDM I-band Detection
  91. GRB 070209: Swift XRT analysis
  92. IPN localization of very bright long hard GRB 070207
  93. IPN localization of very intense short GRB 070201
  94. GRB 070209: Swift detection of a short hard burst
  95. GRB070208 - SDSS Pre-Burst Observations
  96. GRB 070208: Swift detection of a burst
  97. GRB 070125 detection with CARMA
  98. GRB 070129: afterglow confirmation
  99. GRB070126: Swift-XRT Observation
  100. GRB 070129: Swift/UVOT Upper limits

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