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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"

31633 results found.

  1. GRB 070412: Swift-XRT refined position
  2. GRB 070412: further NOT observations
  3. GRB 070412: Gemini/GMOS afterglow candidate
  4. GRB 070412: IAC80 optical afterglow candidate
  5. GRB 070412: NOT observations
  6. GRB 070412: Nearby bright galaxy
  7. GRB 070411, Swift-BAT refined analysis
  8. GRB 070411 : Liverpool Telescope Observations
  9. GRB 070411: Optical observations at Crni Vrh
  10. GRB 070411: ROTSE-III Detection of Optical Counterpart
  11. GRB 070411: Tautenburg RRM Afterglow Confirmation
  12. GRB 070406: "Star" in XRT error circle S2 is an AGN?
  13. GRB 070406: Swift XRT team further analysis
  14. Suzaku ToO observation of SGR 1806-20
  15. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  16. GRB 070406, Swift-BAT refined analysis
  17. GRB 070406: Gemini South Imaging and XRT analysis
  18. GRB070406: Swift UVOT observations
  19. GRB 070406: further analysis of NOT images.
  20. Short GRB 070406 - Possible Bright Host Galaxy
  21. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  22. GRB 070406: NOT observations
  23. GRB 070406: Optical candidate
  24. GRB 070406: photo-z of a bright galaxy in BAT error circle
  25. GRB 070402: Suzaku WAM observation of the prompt emission
  26. GRB 070311, deep optical photometry
  27. Konus-Wind and Konus-A observations of GRB 070402
  28. IPN triangulation of GRB070402 - correction
  29. GRB 070328: Suzaku WAM observation of the prompt emission
  30. INTEGRAL ToO Observation of SGR1806-20
  31. UVOT observations of GRB070330
  32. GRB 070330, Swift-BAT refined analysis
  33. GRB 070330, SMARTS optical/IR observations
  34. GRB 070330: Swift-XRT refined analysis
  35. GRB 070330 - Watcher Observations
  36. Konus-Wind observation of GRB 070328
  37. GRB 070328: Swift/UVOT Upper Limits
  38. long burst from SGR 1806-20 detected on March 26
  39. GRB 070328: Swift/XRT Refined Analysis
  40. GRB 070328 : Suzaku ToO follow up starts
  41. GRB 070328, Swift-BAT refined analysis
  42. GRB070220: optical observations
  43. GRB070208: optical observations
  44. GRB070223: confirmation of nIR and optical afterglow
  45. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  46. GRB 070311, deep optical photometry
  47. Short-Hard GRB 070209: PROMPT Observations
  48. GRB 070318: Gemini + Magellan spectra
  49. GRB 070318: absorption-line redshift
  50. GRB070318: Swift UVOT continuing observations
  51. GRB070318: Swift-XRT refined analysis
  52. GRB 070318: Swift/UVOT Continued Observations
  53. GRB 070318, Swift-BAT refined analysis
  54. GRB 070311: Late Central Engine Activity Optical Flare??
  55. GRB 070311: MDM Optical Monitoring
  56. VLA observation of GRB 070311
  57. GRB 070311: Tautenburg sees afterglow fading
  58. GRB 070311: Optical observation.
  59. GRB 070311: Optical Brightening
  60. GRB 070306: possible emission-line redshift
  61. GRB 070311: SARA upper limit
  62. GRB 070309: variability of the XRT afterglow candidate
  63. GRB 070311: MDM Optical Follow-up
  64. GRB 070311: RAPTOR Detection of Optical Emission
  65. GRB070311: FRAM early follow-up limit
  66. GRB 070311: P60 Observations
  67. GRB 070311: MDM Optical Detection
  68. GRB 070311: Swift/UVOT Upper Limits
  69. GRB 070311: MITSuME Okayama Optical Observation
  70. GRB 070311: Swift-XRT refined analysis
  71. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  72. GRB 070311: REM candidate afterglow
  73. GRB060901: Candidate optical afterglow
  74. GRB070309: Swift/XRT possible afterglow detection
  75. GRB 070125: Chandra X-ray Confirmation of Jet Break
  76. GRB 070309: Swift/UVOT Upper Limits
  77. GRB 070306, optical observation
  78. Swift UVOT Finding Charts for GRB 070309
  79. GRB 070125: X-ray light curve analysis
  80. VLA observation of GRB 070306
  81. GRB 070306: NOT observations
  82. GRB 070306 Swift/UVOT refined analysis
  83. GRB070306: confirmation of near infrared afterglow
  84. GRB 070306: ART-3 early optical and near infrared constraints
  85. GRB 070306, Swift-BAT refined analysis
  86. GRB 070306: XRT Team Refined Analysis
  87. GRB 070306: Optical and IR observations with KANATA
  88. GRB 070223: NIR observations at WHT
  89. GRB070227: Swift-XRT refined analysis
  90. GRB 060605 new redshift
  91. GRB 070125, deep late-time optical observation
  92. VLA observation of GRB 070224
  93. GRB 070223: Optical Observations
  94. GRB 070227: optical observations
  95. GRB 070227: Swift/UVOT Upper Limits
  96. GRB 070227, Swift-BAT refined analysis
  97. GRB070227: possible X-ray afterglow detection
  98. GRB 070224: Optical afterglow confirmation
  99. GRB 070224: Swift/UVOT Upper Limits
  100. GRB070224: Swift-XRT Astrometrically Corrected Position

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