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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"

27400 results found.

  1. GRB 150212A: MASTER optical observations
  2. GRB 150212A: No Swift/UVOT detection in initial observation
  3. GRB 150212A: Swift-XRT afterglow detection
  4. GRB150212A: P60 Afterglow Candidate
  5. Konus-Wind observation of GRB 150211A
  6. GRB 150212A: Swift detection of a burst
  7. GRB 150211A iTelescope observation
  8. GRB 150211A: Swift/UVOT Upper Limits
  9. GRB 150210A: MASTER SN detection during LAT error box inspection
  10. GRB 150211A: Swift-BAT refined analysis
  11. GRB 150211A: Swift-XRT refined Analysis
  12. GRB 150210A: Fermi-LAT detection
  13. GRB 150211A: RATIR Optical and NIR Observations
  14. GRB 150211A: No afterglow detection in the Swift/UVOT initial observation
  15. GRB 150211A: Swift-XRT observations
  16. GRB 150211A: Swift detection of a burst
  17. GRB 150211A: MASTER early optical observations
  18. GRB 150210A: Fermi GBM detection
  19. GRB 150204A: GROND observations
  20. Konus-Wind observation of GRB 150206A
  21. GRB 150206A: Swift-BAT refined analysis
  22. GRB 150203A iTelescope observation
  23. GRB 150206A: Swift/UVOT Detection
  24. GRB 150206A: Swift-XRT refined Analysis
  25. GRB 150206A: GROND afterglow observations
  26. GRB 150206B: Fermi GBM detection
  27. Trigger 630047: Swift detection of 1RXS J180408.9-342058
  28. GRB 150206B: iPTF Optical Observations
  29. GRB 150206A: MAXI/GSC detection
  30. GRB 150206A: Swift detection of a burst with an optical afterglow
  31. GRB 150204A: LCOGT-Sutherland and Siding Springs observations
  32. GRB 150204A: Swift/UVOT Upper Limits
  33. GRB 150203A: Swift-BAT refined analysis
  34. GRB 150204A: Swift-XRT observations
  35. GRB 150204A: Fermi GBM detection
  36. GRB 150204A: Swift ToO observations
  37. GRB 150204A BAT refined analysis
  38. GRB 150204A found in ground analysis of Swift-BAT data
  39. Swift Trigger 629693 was a noise event
  40. GRB 150203A: RAPTOR Limits Beginning at the Gamma-Ray Emitting Interval
  41. GRB 150202A, Swift-BAT refined analysis
  42. GRB 150203A: Swift/UVOT Upper Limits
  43. GRB 150203A: ISON-NM early optical limit
  44. IPN Triangulation of GRB 150202B
  45. GRB 150203A: Swift-XRT refined Analysis
  46. Swift Trigger 629693: probably not real
  47. Fermi GBM trigger 150202624 is not a GRB
  48. GRB 150202A: Swift/UVOT Upper Limits
  49. GRB 150202A: Swift-XRT refined Analysis
  50. GRB 150203A: Fermi GBM observation
  51. GRB 150202B: Fermi GBM detection
  52. GRB 150203A: TAROT La Silla observatory optical observations
  53. GRB 150203A: GROND Upper limits
  54. GRB 150202B: Fermi-LAT detection
  55. GRB 150203A: RATIR Optical and NIR Observations
  56. GRB 150202A: GROND Upper limits
  57. GRB 150203A: P60 observations
  58. GRB 150203A: Swift detection of a burst
  59. GRB 150202A: Swift detection of a burst
  60. GRB 150201A: Swift/UVOT Upper Limits
  61. GRB 150201A, Swift-BAT refined analysis
  62. Konus-Wind observation of GRB 150201A
  63. GRB 150201A: GROND upper limits
  64. GRB 150201A: Swift-XRT refined Analysis
  65. GRB 150201A: Fermi GBM observation
  66. GRB 150201A: Swift detection of a burst
  67. Swift Trigger 629206 is likely 1RXS J180408.9-342058
  68. GRB 150128A: MASTER OT detction during inspection
  69. GRB 150127B: Fermi GBM detection
  70. GRB 150123A: MASTER inspection
  71. IPN Triangulation of GRB 150127B
  72. GRB 150127A: Fermi-LAT detection
  73. GRB150127A: Fermi GBM Detection
  74. Swift Trigger 628458 likely not astrophysical
  75. GRB 150126A: Fermi GBM Detection
  76. GRB 150126A: MAXI/GSC afterglow candidate detection
  77. GRB 150123A: Swift/UVOT observations
  78. GRB 150123A: Swift-XRT observations
  79. GRB 150120B: RATIR Optical and NIR Observations
  80. IPN Triangulation of GRB 150118B (long/intense)
  81. GRB 150120A: ISON-NM early optical limit
  82. GRB 150120B: FTN early optical light curve
  83. GRB 150120B: Swift/UVOT Upper Limits
  84. GRB 150120B: GROND Afterglow Detection
  85. GRB 150120A: Swift-XRT refined Analysis
  86. GRB 150101B: Confirmation of a fading optical counterpart
  87. GRB 150120B: Swift-BAT refined analysis
  88. GRB 150120A: Swift-BAT refined analysis
  89. GRB 150118C: Fermi GBM Detection
  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 150120A: Swift/UVOT Upper Limits
  94. GRB 150101B/Swift J123205.1-105602, deep VLT observations
  95. GRB 150120A: Fermi GBM observation
  96. GRB 150120B: FTN optical afterglow confirmation
  97. GRB 150120B: Swift detection of a burst
  98. GRB 150120A: Gemini-North optical imaging
  99. GRB 150120A: P60 optical observations
  100. GRB 150120A: Swift detection of a possibly-short burst

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