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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"

43668 results found.

  1. GRB 150203A iTelescope observation
  2. GRB 150206A: Swift/UVOT Detection
  3. GRB 150206A: Swift-XRT refined Analysis
  4. Konus-Wind observation of GRB 150202B
  5. GRB 150206A: VLT/X-shooter redshift
  6. GRB 150206A: GROND afterglow observations
  7. GRB 150206A: Enhanced Swift-XRT position
  8. GRB 150206B: Fermi GBM detection
  9. Trigger 630047: Swift detection of 1RXS J180408.9-342058
  10. GRB 150206B: iPTF Optical Observations
  11. GRB 150206A: MAXI/GSC detection
  12. GRB 150206A: Swift detection of a burst with an optical afterglow
  13. GRB 150204A: LCOGT-Sutherland and Siding Springs observations
  14. GRB 150204A: Swift/UVOT Upper Limits
  15. GRB 150203A: Swift-BAT refined analysis
  16. GRB 150204A: Swift-XRT observations
  17. GRB 150204A: Fermi GBM detection
  18. GRB 150204A: Swift ToO observations
  19. GRB 150204A BAT refined analysis
  20. GRB 150202B: Swift XRT/UVOT observations
  21. GRB 150204A found in ground analysis of Swift-BAT data
  22. Swift Trigger 629693 was a noise event
  23. GRB 150202A, Swift-BAT refined analysis
  24. GRB 150203A: ISON-NM early optical limit
  25. IPN Triangulation of GRB 150202B
  26. GRB 150203A: Swift-XRT refined Analysis
  27. GRB 150202B: Tiled Swift observations
  28. Swift Trigger 629693: probably not real
  29. Fermi GBM trigger 150202624 is not a GRB
  30. GRB 150202A: Swift/UVOT Upper Limits
  31. GRB 150203A: REM optical and NIR observations
  32. GRB 150202A: Swift-XRT refined Analysis
  33. GRB 150203A: Fermi GBM observation
  34. GRB 150202B: Fermi GBM detection
  35. GRB 150203A: TAROT La Silla observatory optical observations
  36. GRB 150203A: GROND Upper limits
  37. GRB 150202B: Fermi-LAT detection
  38. GRB 150203A: Enhanced Swift-XRT position
  39. GRB 150203A: RATIR Optical and NIR Observations
  40. GRB 150202A: Enhanced Swift-XRT position
  41. GRB 150202A: GROND Upper limits
  42. GRB 150203A: P60 observations
  43. GRB 150203A: Prompt enhanced Swift-XRT position
  44. GRB 150203A: Swift detection of a burst
  45. GRB 150202A: Swift detection of a burst
  46. GRB 150201A, Swift-BAT refined analysis
  47. Konus-Wind observation of GRB 150201A
  48. GRB 150201A: GROND upper limits
  49. GRB 150201A: Swift-XRT refined Analysis
  50. GRB 150201A: Fermi GBM observation
  51. GRB 150201A: Enhanced Swift-XRT position
  52. GRB 150201A: Swift detection of a burst
  53. Swift Trigger 629206 is likely 1RXS J180408.9-342058
  54. GRB 150120B: Khureltogot optical observations
  55. GRB 150128A: MASTER OT detction during inspection
  56. GRB 150127B: Fermi GBM detection
  57. Konus-Wind observation of GRB 150127B
  58. GRB 150123A: MASTER inspection
  59. GRB 150120A: 9.8 GHz VLA upper limit
  60. IPN Triangulation of GRB 150127B
  61. IPN Triangulation of GRB 150127A
  62. GRB 150120A: Gemini-N imaging and host redshift
  63. Konus-Wind observation of GRB 150126A reveals its ultra-long nature
  64. GRB 150127A: Fermi-LAT detection
  65. GRB150127A: Fermi GBM Detection
  66. Swift Trigger 628458 likely not astrophysical
  67. GRB 150126A: Fermi GBM Detection
  68. GRB 150126A: MAXI/GSC afterglow candidate detection
  69. Konus-Wind observation of GRB 150123A
  70. GRB 150120A: possible AMI 15 GHz detection
  71. GRB 150123A: Swift/UVOT observations
  72. GRB 150123A: Swift-XRT observations
  73. GRB 150120B: Mondy optical observations
  74. GRB 150123A Tiled Swift observations
  75. GRB 150123A: MAXI/GSC detection
  76. Konus-Wind observation of GRB 150118B
  77. GRB 150120B: RATIR Optical and NIR Observations
  78. IPN Triangulation of GRB 150118B (long/intense)
  79. GRB 150120A: ISON-NM early optical limit
  80. GRB 150120B: FTN early optical light curve
  81. GRB150120B: Xinglong TNT optical observation
  82. GRB 150120B: GROND Afterglow Detection
  83. GRB 150120B: Additional P60 observations
  84. GRB 150120A: Swift-XRT refined Analysis
  85. GRB 150101B: Confirmation of a fading optical counterpart
  86. GRB 150120B: Swift-BAT refined analysis
  87. GRB 150120A: Swift-BAT refined analysis
  88. GRB 150118C: Fermi GBM Detection
  89. Konus-Wind observation of GRB 150118C
  90. GRB 150101B/Swift J123205.1-105602: TNG NIR follow-up
  91. GRB 150120B: Swift-XRT refined Analysis
  92. IPN triangulation of GRB 150118C (short/hard)
  93. GRB 150110B: AMI 15 GHz detection of possible radio counterpart
  94. GRB 150101B/Swift J123205.1-105602, deep VLT observations
  95. GRB 150120B: Enhanced Swift-XRT position
  96. GRB 150120A: Fermi GBM observation
  97. GRB 150101B/Swift J123205.1-105602: XMM-Newton observation
  98. GRB 150120A: Enhanced Swift-XRT position
  99. GRB 150120B: FTN optical afterglow confirmation
  100. GRB 150120B: P60 optical afterglow

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