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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"

32413 results found.

  1. GRB 070419: Swift detection of a burst
  2. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  3. GRB 070418: Optical and IR observations with KANATA
  4. Trigger 276045: Swift detection of a possible burst
  5. GRB 070406: Swift XRT refined analysis
  6. IBAS Alert n.4202: not a real GRB
  7. GRB 070318, SMARTS optical/IR afterglow observations
  8. GRB 070411: TLS data shows plateau, flares
  9. GRB070412: UKIRT-WFCAM JHK upper limits
  10. GRB070412: Swift UVOT observations
  11. IBAS Alert n.4199: Not a GRB
  12. GRB 070411: Swift/UVOT observations
  13. GRB 070412, Swift-BAT refined analysis
  14. GRB 070412 Liverpool Telescope optical limit
  15. GRB 070411: Optical photometry at Crni Vrh
  16. GRB 070412: Swift-XRT refined analysis
  17. GRB 070411: Swift-XRT refined analysis
  18. GRB 070412: further reanalysis of NOT images
  19. GRB 070412: Optical observations at Crni Vrh
  20. GRB 070411: OA redshift
  21. GRB 070412: Swift-XRT refined position
  22. GRB 070412: further NOT observations
  23. GRB 070412: Gemini/GMOS afterglow candidate
  24. GRB 070412: IAC80 optical afterglow candidate
  25. GRB 070411: Magellan/Clay photometry
  26. GRB 070411: Magellan/IMACS photometry
  27. GRB 070412: NOT observations
  28. GRB 070412: Nearby bright galaxy
  29. GRB 070411, Swift-BAT refined analysis
  30. GRB 070412: Swift detection of a burst
  31. GRB 070411: IAC80 optical observations
  32. GRB 070411 : Liverpool Telescope Observations
  33. GRB 070411: Optical observations at Crni Vrh
  34. GRB 070411: ROTSE-III Detection of Optical Counterpart
  35. GRB 070411: Tautenburg RRM Afterglow Confirmation
  36. GRB 070411: Swift detection of a burst with optical afterglow
  37. GRB 070406: "Star" in XRT error circle S2 is an AGN?
  38. GRB 070406: Swift XRT team further analysis
  39. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  40. GRB 070406: Bright galaxy in XRT error circle is a quasar
  41. GRB 070406, Swift-BAT refined analysis
  42. GRB 070406: Correction to the optical candidate in GCN6253
  43. GRB 070406: Gemini South Imaging and XRT analysis
  44. GRB070406: Swift UVOT observations
  45. GRB 070406: further analysis of NOT images.
  46. Short GRB 070406 - Possible Bright Host Galaxy
  47. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  48. GRB 070406: NOT observations
  49. GRB 070406: Optical candidate
  50. GRB 070406: The exprosure time of Xinglong TNT optical Upper Limit
  51. GRB 070406: SARA upper limit
  52. GRB 070406: Xinglong TNT optical Upper Limit
  53. GRB 070406: photo-z of a bright galaxy in BAT error circle
  54. GRB 070406: Swift detection of a burst
  55. GRB 070402: Suzaku WAM observation of the prompt emission
  56. GRB 070311, deep optical photometry
  57. GRB 070402: pseudo-z~3.36 from spectral parameters of the prompt
  58. Konus-Wind and Konus-A observations of GRB 070402
  59. IPN triangulation of GRB070402
  60. GRB 070328: Suzaku WAM observation of the prompt emission
  61. GRB 070330, Swift-BAT refined analysis
  62. GRB 070330, SMARTS optical/IR observations
  63. GRB 070330: TAROT La Silla observatory optical observations
  64. GRB 070330: Swift-XRT refined analysis
  65. GRB 070330 - Watcher Observations
  66. GRB 070330: Swift detection of a burst
  67. GRB 070328: pseudo-z~2.75 from spectral parameters of the prompt
  68. Konus-Wind observation of GRB 070328
  69. GRB 070328: Swift/UVOT Upper Limits
  70. long burst from SGR 1806-20 detected on March 26
  71. GRB 070328: Swift/XRT Refined Analysis
  72. GRB 070328 : Suzaku ToO follow up starts
  73. GRB 070328, Swift-BAT refined analysis
  74. GRB 070328: Swift detection of a burst
  75. GRB070220: optical observations
  76. GRB070208: optical observations
  77. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  78. GRB 070311, deep optical photometry
  79. Short-Hard GRB 070209: PROMPT Observations
  80. GRB 070318: Gemini + Magellan spectra
  81. GRB 070318: absorption-line redshift
  82. GRB070318: Swift-XRT refined analysis
  83. GRB 070318: Swift/UVOT Continued Observations
  84. GRB 070318, Swift-BAT refined analysis
  85. IBAS Alert n. 4176: not a GRB
  86. GRB 070318: Swift detection of a burst with an optical afterglow
  87. GRB 070311: Late Central Engine Activity Optical Flare??
  88. GRB 070311: MDM Optical Monitoring
  89. VLA observation of GRB 070311
  90. GRB 070311: Tautenburg sees afterglow fading
  91. IBAS Alert n. 4169: not a GRB
  92. GRB 070311: Optical observation.
  93. GRB 070311: Optical Brightening
  94. GRB 070306: possible emission-line redshift
  95. GRB 070311: SARA upper limit
  96. GRB 070309: variability of the XRT afterglow candidate
  97. GRB 070311: MDM Optical Follow-up
  98. GRB 070311: RAPTOR Detection of Optical Emission
  99. GRB070311: FRAM early follow-up limit
  100. GRB 070311: P60 Observations

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