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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"

19604 results found.

  1. GRB 150301B: Swift detection of a burst with an optical afterglow
  2. Swift Trigger 633173 is probably not an astrophysical source
  3. GRB 150301A: GROND Observations
  4. Trigger 633105 is likely not a GRB
  5. GRB 150301A: Fermi GBM observation
  6. GRB 150301A: Swift detection of a short burst or new SGR
  7. Swift-BAT refined analysis of magnetar 4U 0142+61 (Trigger 632888)
  8. Trigger 632888: Swift detection of the magnetar 4U 0142+61
  9. GRB 150222A: Further GROND Observations
  10. GRB 150220A: Swift-XRT observations
  11. IPN Triangulation of GRB 150220A
  12. GRB 150220A: Swift ToO observations
  13. GRB 150222A: Swift/UVOT Upper Limits
  14. GRB 150222A: Swift-XRT refined Analysis
  15. Fermi GBM Observations of SGR 1935+2154
  16. GRB 150222A: GROND optical afterglow candidate
  17. GRB 150222A: Enhanced Swift-XRT position
  18. Fermi GBM trigger 150223068 is not a GRB
  19. GRB 150222A: Swift-BAT refined analysis
  20. SGR 1935+2154: Swift-BAT refined analysis
  21. GRB 150222A: Mondy optical observations
  22. GRB 150222A: Zadko observatory - Gingin optical observations
  23. GRB 150222A: MASTER early optical observations
  24. GRB 150222A: Swift detection of a burst
  25. Swift detection of an outburst from SGR 1935+2154
  26. Trigger 631946: Swift detection of H1745-203
  27. GRB 150219A: Swift-XRT afterglow detection
  28. Trigger 631747: Swift detection of 4U 0614+09
  29. GRB 150213B: AAO photometry
  30. GRB 150219A: Swift ToO observations
  31. GRB 150213B: Enhanced Swift-XRT position
  32. GRB 150213B: P60 Observations
  33. GRB 150213B: Swift/UVOT Detection
  34. GRB 150213B: Swift-BAT refined analysis
  35. GRB 150213B: RATIR Optical and NIR Observations
  36. GRB 150213B: Swift-XRT refined Analysis
  37. GRB 150213B: AAO optical observations
  38. GRB 150212A: Swift/UVOT Observations
  39. GRB 150213B: Tautenburg Afterglow Detection
  40. GRB 150213B: Swift detection of a burst with an optical afterglow
  41. GRB 150212A: Swift-XRT refined Analysis
  42. GRB 150211A: ROTSE-III Upper Optical Limit
  43. GRB 150212A: RATIR Optical and NIR Observations
  44. GRB 150212A: Skynet DSO14/GORT observations
  45. GRB 150212A: Swift-BAT refined analysis
  46. GRB 150212A: No Swift/UVOT detection in initial observation
  47. GRB 150212A: P60 Afterglow Retraction
  48. GRB 150210A: Swift-XRT observations
  49. GRB 150212A: Swift-XRT afterglow detection
  50. GRB150212A: P60 Afterglow Candidate
  51. Konus-Wind observation of GRB 150211A
  52. GRB 150212A: Swift detection of a burst
  53. GRB 150211A iTelescope observation
  54. GRB 150211A: Swift/UVOT Upper Limits
  55. GRB 150211A: Swift-BAT refined analysis
  56. GRB 150211A: KAIT Optical Upper Limit
  57. GRB 150211A: Swift-XRT refined Analysis
  58. GRB 150210A: Tiled Swift observations
  59. GRB 150210A: Fermi-LAT detection
  60. GRB 150211A: RATIR Optical and NIR Observations
  61. GRB 150211A: No afterglow detection in the Swift/UVOT initial observation
  62. GRB 150211A: Swift-XRT observations
  63. GRB 150211A: Swift detection of a burst
  64. GRB 150211A: MASTER early optical observations
  65. GRB 150101B/ Swift J123205.1-105602: Second epoch Chandra observations
  66. GRB 150204A: GROND observations
  67. GRB 150202B: Swift/XRT afterglow confirmation
  68. GRB 150204A: Swift/XRT afterglow confirmation
  69. Konus-Wind observation of GRB 150206A
  70. GRB 150206A: Swift-BAT refined analysis
  71. GRB 150203A iTelescope observation
  72. GRB 150206A: Swift/UVOT Detection
  73. GRB 150206A: Swift-XRT refined Analysis
  74. GRB 150206A: GROND afterglow observations
  75. GRB 150206A: Enhanced Swift-XRT position
  76. Trigger 630047: Swift detection of 1RXS J180408.9-342058
  77. GRB 150206A: Swift detection of a burst with an optical afterglow
  78. GRB 150204A: LCOGT-Sutherland and Siding Springs observations
  79. GRB 150204A: Swift/UVOT Upper Limits
  80. GRB 150203A: Swift-BAT refined analysis
  81. GRB 150204A: Swift-XRT observations
  82. GRB 150204A: Fermi GBM detection
  83. GRB 150204A: Swift ToO observations
  84. GRB 150204A BAT refined analysis
  85. GRB 150202B: Swift XRT/UVOT observations
  86. GRB 150204A found in ground analysis of Swift-BAT data
  87. Swift Trigger 629693 was a noise event
  88. GRB 150203A: RAPTOR Limits Beginning at the Gamma-Ray Emitting Interval
  89. GRB 150202A, Swift-BAT refined analysis
  90. GRB 150203A: Swift/UVOT Upper Limits
  91. GRB 150203A: ISON-NM early optical limit
  92. IPN Triangulation of GRB 150202B
  93. GRB 150203A: Swift-XRT refined Analysis
  94. GRB 150202B: Tiled Swift observations
  95. Swift Trigger 629693: probably not real
  96. GRB 150202A: Swift/UVOT Upper Limits
  97. GRB 150202A: Swift-XRT refined Analysis
  98. GRB 150203A: Fermi GBM observation
  99. GRB 150203A: TAROT La Silla observatory optical observations
  100. GRB 150203A: GROND Upper limits

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