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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"

19547 results found.

  1. Swift triggered on a source in Terzan 5 (trigger=637212)
  2. Fermi trigger 449861706: MASTER-SAAO possible candidate to OT of Short GRB
  3. GRB 150403A: Swift/UVOT Detection
  4. GRB 150323C: CrAO optical observations
  5. GRB 150323C: additional optical observations in Mondy
  6. GRB 150323C: Khureltogot optical observations
  7. GRB 150403A: Swift-XRT refined Analysis
  8. GRB 150403A: Fermi-LAT detection
  9. GRB 150403A: Enhanced Swift-XRT position
  10. GRB 150403A: Swift detection of a burst with an optical counterpart
  11. GRB 150402A: RATIR Optical Observations
  12. GRB 150402A: Swift ToO observations
  13. IPN Triangulation of GRB 150330A (long/very intense)
  14. GRB 150323B: Swift-XRT afterglow detection
  15. GRB 141121A: GMG observation
  16. GRB 150323C: possible host galaxy detection
  17. GRB 141212A: GMG observation limit
  18. GRB 141220A: GMG observation limit
  19. GRB 141225A: GMG observation limit
  20. GRB 150120B: GMG observation
  21. GRB 150317A: likely host galaxy detection
  22. GRB 150323B: Khureltogot optical observations
  23. GRB 150323C: Nishi-Harima NIR Observations
  24. GRB 150323A: AAO optical observations
  25. GRB 150323C: MITSuME Akeno Optical observation
  26. GRB 150220A: Optical observations at Kyiv comet station
  27. GRB 150323C; Konkoly optical observations
  28. GRB 150323B; Konkoly optical observations
  29. GRB 150323A; Konkoly optical observations
  30. GRB 150323C: Mondy optical observations
  31. GRB 150323C: Swift/UVOT Upper Limits
  32. GRB 150323C: Enhanced Swift-XRT position
  33. GRB 150323C: RATIR Optical Afterglow Observations
  34. GRB 150323C: Swift-XRT refined Analysis
  35. GRB 150323C: Xingming upper limit
  36. GRB150323C: Fermi GBM detection
  37. GRB 150323C: Nanshan optical afterglow detection
  38. GRB 150323C: Swift detection of a burst
  39. GRB 150323B: Swift ToO observations
  40. GRB 150323A: Swift-XRT refined Analysis
  41. GRB150323A: Swift-UVOT detection of the afterglow
  42. GRB 150323A: Enhanced Swift-XRT position
  43. GRB 150314A: GMG observation limit
  44. GRB 150323A: RATIR Optical Afterglow Observations
  45. GRB 150323A: P60 Optical Afterglow Candidate
  46. GRB 150323A: Swift detection of a burst
  47. GRB 150318A: Skynet PROMPT-CTIO Observations
  48. GRB 150318A: Swift/UVOT Upper Limits
  49. GRB 150318A : GROND upper limits
  50. Swift Trigger 635306 is probably not an astrophysical source
  51. GRB 150318A: Enhanced Swift-XRT position
  52. GRB 150318A: Swift detection of a burst
  53. GRB 150317A: Swift/UVOT Upper Limits
  54. GRB 150317A: Swift-XRT refined Analysis
  55. GRB 150317A: RATIR Optical Afterglow Detection
  56. GRB 150317A: Enhanced Swift-XRT position
  57. GRB 150317A: NOT optical observations
  58. GRB 150317A: Swift detection of a burst
  59. GRB 150314A: Early RAPTOR Detection
  60. GRB 150314A: NOT further optical observations
  61. GRB 150314A: NOT optical observations
  62. GRB 150314A: Swift/UVOT Detection
  63. GRB 150314A: Skynet Yerkes-41 Observations of the Optical Afterglow
  64. GRB 150314A: Enhanced Swift-XRT position
  65. GRB 150314A: Swift detection of a bright burst
  66. GRB 150309A: AAO optic upper limit
  67. GRB 150222A: CrAO optical observation
  68. GRB 150309A: CrAO optic upper limit
  69. GRB 150309A: ISON-Kislovodsk optic upper limit
  70. GRB 150309A: Swift-BAT refined analysis
  71. GRB150309A: Optical observations at Crni Vrh
  72. GRB 150309A: Swift/UVOT Upper Limits
  73. GRB 150309A: Swift-XRT refined Analysis
  74. GRB 150309A: Enhanced Swift-XRT position
  75. GRB 150309A: Swift detection of a burst
  76. Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
  77. Further UVOT Observations of Swift J0045.2+4151
  78. Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
  79. BAT trigger 633105 (GRB 150301C): NOT r-band upper limit
  80. GRB 150302A: BOOTES-2/TELMA upper limit
  81. Trigger 633105 (aka GRB150301C): Swift/UVOT Observations of XRT Counterpart
  82. GRB 150302A: Mondy optical upper limit
  83. GRB 150302A: Swift/UVOT Upper Limits
  84. GRB 150302A: MITSuME Okayama upper limits
  85. GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
  86. GRB 150302A: Enhanced Swift-XRT position
  87. GRB 150220A: further Swift-XRT observations
  88. GRB 150301B: Swift/UVOT Observations
  89. GRB 150302A: UVOT Observations
  90. GRB 150302A: NOT afterglow candidate
  91. GRB 150302A: Swift detection of a burst
  92. GRB 150301B: GROND afterglow observations
  93. GRB 150301A: Swift/UVOT Upper Limits
  94. GRB 150301B: Enhanced Swift-XRT position
  95. GRB 150301A: Swift-BAT refined analysis
  96. GRB 150301C : (Swift trigger 633105) Swift observations
  97. GRB 150301B: Swift detection of a burst with an optical afterglow
  98. Swift Trigger 633173 is probably not an astrophysical source
  99. GRB 150301A: GROND Observations
  100. Trigger 633105 is likely not a GRB

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