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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"

19606 results found.

  1. GRB 150323C: Mondy optical observations
  2. GRB 150323B : Xinglong TNT upper limit
  3. GRB 150323C, Swift-BAT refined analysis
  4. GRB 150323C: Swift/UVOT Upper Limits
  5. GRB 150323B: Swift-XRT observations
  6. GRB 150323C: Enhanced Swift-XRT position
  7. GRB 150323C: RATIR Optical Afterglow Observations
  8. GRB 150323C : Xinglong TNT optical observation
  9. GRB 150323C: Swift-XRT refined Analysis
  10. GRB 150323C: Xingming upper limit
  11. GRB 150323A, Swift-BAT refined analysis
  12. GRB150323C: Fermi GBM detection
  13. GRB 150323A: KAIT Optical Observations
  14. GRB 150323C: Nanshan optical afterglow detection
  15. GRB 150323C: Prompt enhanced Swift-XRT position
  16. GRB 150323B: Fermi GBM observation
  17. GRB 150323C: MASTER-net optical observation
  18. GRB 150323C: Swift detection of a burst
  19. GRB 150323B: Swift ToO observations
  20. GRB 150323B detected in ground analysis of Swift-BAT data
  21. GRB 150323A: Swift-XRT refined Analysis
  22. GRB150323A: Swift-UVOT detection of the afterglow
  23. GRB 150323A: Enhanced Swift-XRT position
  24. GRB 150323A: RATIR Optical Afterglow Observations
  25. GRB 150323A: P60 Optical Afterglow Candidate
  26. GRB 150323A: Swift detection of a burst
  27. Swift Triggers 635788-635794 are probably not real.
  28. GRB 150318A: Swift-XRT refined Analysis
  29. Confirmation that Swift trigger 635306 is not an astrophysical source
  30. GRB 150318A: Skynet PROMPT-CTIO Observations
  31. GRB 150318A: Swift-BAT refined analysis
  32. GRB 150318A: Swift/UVOT Upper Limits
  33. GRB 150318A : GROND upper limits
  34. Swift Trigger 635306 is probably not an astrophysical source
  35. GRB 150318A: Enhanced Swift-XRT position
  36. GRB 150318A: Swift detection of a burst
  37. GRB 150317A: Swift/UVOT Upper Limits
  38. GRB 150317A: Swift-XRT refined Analysis
  39. GRB 150317A: Swift-BAT refined analysis
  40. GRB 150317A: RATIR Optical Afterglow Detection
  41. GRB 150317A: Enhanced Swift-XRT position
  42. GRB 150317A: NOT optical observations
  43. GRB 150317A: Swift detection of a burst
  44. GRB 150314A: Early RAPTOR Detection
  45. Konus-Wind observation of GRB 150314A
  46. GRB 150314A: Swift-XRT refined Analysis
  47. GRB 150314A: KAIT Optical Observations
  48. GRB 150314A Swift-BAT refined analysis
  49. GRB 150314A: Swift/UVOT Detection
  50. GRB 150314A: Fermi GBM observation
  51. GRB 150314A: Skynet Yerkes-41 Observations of the Optical Afterglow
  52. GRB 150314A: Fermi-LAT detection
  53. GRB 150314A: Enhanced Swift-XRT position
  54. GRB 150314A: KAIT Optical Candidate
  55. GRB 150314A: Swift detection of a bright burst
  56. GRB 150309A: AAO optic upper limit
  57. GRB 150222A: CrAO optical observation
  58. Konus-Wind observation of GRB 150309A
  59. GRB 150309A: CrAO optic upper limit
  60. GRB 150309A: ISON-Kislovodsk optic upper limit
  61. GRB 150309A: Swift-BAT refined analysis
  62. GRB 150309A: Fermi GBM detection
  63. GRB150309A: Optical observations at Crni Vrh
  64. GRB 150309A: Swift/UVOT Upper Limits
  65. GRB 150309A: MASTER prompt optical observation
  66. GRB 150309A: Swift-XRT refined Analysis
  67. GRB 150309A : Liverpool Telescope observations
  68. GRB 150309A: Enhanced Swift-XRT position
  69. GRB 150309A: BOOTES-1 and -2 upper limit
  70. GRB 150309A: Swift detection of a burst
  71. GRB 150305A: a long GRB detected by INTEGRAL
  72. GRB 150305A: Swift XRT confirms weak INTEGRAL event as a new GRB
  73. Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
  74. Swift J0045.2+4151: analysis of XMM-Newton archival data
  75. Further UVOT Observations of Swift J0045.2+4151
  76. Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
  77. GRB 150302A: BOOTES-2/TELMA upper limit
  78. Trigger 633105 (aka GRB150301C): Swift/UVOT Observations of XRT Counterpart
  79. GRB 150302A, Swift-BAT refined analysis
  80. GRB 150302A: Swift/UVOT Upper Limits
  81. GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
  82. GRB 150302A: Swift-XRT refined Analysis
  83. GRB 150302A: Enhanced Swift-XRT position
  84. GRB 150301B: Swift-XRT refined Analysis
  85. GRB 150220A: further Swift-XRT observations
  86. GRB 150301B: Swift/UVOT Observations
  87. GRB 150301B: LCOGT-Sutherland observations
  88. GRB 150302A: KAIT Optical Upper Limit
  89. GRB 150302A: UVOT Observations
  90. GRB 150302A: Swift detection of a burst
  91. GRB 150301B: Fermi GBM detection
  92. GRB 150301B: Swift-BAT refined analysis
  93. GRB 150301B: GROND afterglow observations
  94. GRB 150301A: Swift/UVOT Upper Limits
  95. GRB 150301B: Enhanced Swift-XRT position
  96. GRB 150301A: Swift-BAT refined analysis
  97. GRB 150301B: MASTER early OT detection
  98. GRB 150301A: Swift-XRT refined Analysis
  99. GRB 150301C : (Swift trigger 633105) Swift observations
  100. GRB 150301B: Swift detection of a burst with an optical afterglow

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