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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"

37527 results found.

  1. GRB 150323C: Swift-XRT refined Analysis
  2. GRB 150323C: Xingming upper limit
  3. GRB 150323A, Swift-BAT refined analysis
  4. GRB150323C: Fermi GBM detection
  5. GRB 150323A: KAIT Optical Observations
  6. GRB 150323C: Nanshan optical afterglow detection
  7. GRB 150323C: Prompt enhanced Swift-XRT position
  8. GRB 150323B: Fermi GBM observation
  9. GRB 150323C: MASTER-net optical observation
  10. GRB 150323C: Swift detection of a burst
  11. GRB 150323B: Swift ToO observations
  12. GRB 150323B detected in ground analysis of Swift-BAT data
  13. GRB 150323A: Swift-XRT refined Analysis
  14. GRB150323A: Swift-UVOT detection of the afterglow
  15. GRB 150323A: Keck redshift
  16. GRB 150323A: Enhanced Swift-XRT position
  17. GRB 150314A: GMG observation limit
  18. GRB 150323A: RATIR Optical Afterglow Observations
  19. GRB 150323A: P60 Optical Afterglow Candidate
  20. GRB 150323A: Swift detection of a burst
  21. Fermi GBM trigger 150319666 is not a GRB
  22. GRB 150318A: Swift-XRT refined Analysis
  23. Confirmation that Swift trigger 635306 is not an astrophysical source
  24. GRB 150314A: Further VLA observations
  25. GRB 150318A: Skynet PROMPT-CTIO Observations
  26. GRB 150318A: Swift-BAT refined analysis
  27. GRB 150318A: Swift/UVOT Upper Limits
  28. GRB 150318A : GROND upper limits
  29. GRB 150318A: Enhanced Swift-XRT position
  30. GRB 150318A: Swift detection of a burst
  31. GRB 150317A: Swift/UVOT Upper Limits
  32. GRB 150317A: Swift-XRT refined Analysis
  33. GRB 150317A: Swift-BAT refined analysis
  34. GRB 150317A: RATIR Optical Afterglow Detection
  35. GRB 150317A: Enhanced Swift-XRT position
  36. GRB 150317A: NOT optical observations
  37. GRB 150317A: Swift detection of a burst
  38. GRB 150314A: VLA observations
  39. GRB 150314A: Early RAPTOR Detection
  40. GRB 150220A, the review of the sky area in plate archives
  41. GRB 150314A: NOT further optical observations
  42. Konus-Wind observation of GRB 150314A
  43. GRB 150314A: Swift-XRT refined Analysis
  44. GRB 150314A: KAIT Optical Observations
  45. GRB 150314A: P60 observations
  46. GRB 150314A: Redshift from OSIRIS/GTC
  47. GRB 150314A: NOT optical observations
  48. GRB 150314A Swift-BAT refined analysis
  49. GRB 150314A: Swift/UVOT Detection
  50. GRB 150314A: Fermi GBM observation
  51. GRB 150314A: MITSuME Akeno upper limits
  52. GRB 150314A: Skynet Yerkes-41 Observations of the Optical Afterglow
  53. GRB 150314A: Fermi-LAT detection
  54. GRB 150314A: Enhanced Swift-XRT position
  55. GRB 150314A: KAIT Optical Candidate
  56. GRB 150314A: Swift detection of a bright burst
  57. GRB 150313A: MAXI/GSC detection
  58. Fermi GBM trigger 150312827 is not a GRB
  59. GRB 150309A: AAO optic upper limit
  60. GRB 150311A: Konus-Wind trigger at 16:16:24 is not a GRB
  61. GRB 150311A: MAXI/GSC possible afterglow detection
  62. GRB 150222A: CrAO optical observation
  63. Konus-Wind observation of GRB 150309A
  64. GRB 150309A: CrAO optic upper limit
  65. GRB 150309A: ISON-Kislovodsk optic upper limit
  66. Fermi GBM trigger 150311331 is not a GRB
  67. GRB 150309A: Swift-BAT refined analysis
  68. GRB 150309A: Fermi GBM detection
  69. GRB150309A: Optical observations at Crni Vrh
  70. GRB 150309A: Swift/UVOT Upper Limits
  71. GRB 150309A: MASTER prompt optical observation
  72. GRB 150309A: Swift-XRT refined Analysis
  73. GRB 150309A : Liverpool Telescope observations
  74. GRB 150309A: Enhanced Swift-XRT position
  75. GRB 150309A: BOOTES-1 and -2 upper limit
  76. GRB 150309A: Swift detection of a burst
  77. GRB 150305A: a long GRB detected by INTEGRAL
  78. GRB 150305A: Swift XRT confirms weak INTEGRAL event as a new GRB
  79. Fermi GBM trigger 150307942 is not a GRB
  80. Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
  81. Swift J0045.2+4151: analysis of XMM-Newton archival data
  82. Further UVOT Observations of Swift J0045.2+4151
  83. Fermi GBM trigger 150305751 is not a GRB
  84. GRB 150301C: VLA Observations
  85. Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
  86. BAT trigger 633105 (GRB 150301C): NOT r-band upper limit
  87. GRB 150302A: BOOTES-2/TELMA upper limit
  88. GRB 150302A: Mondy optical upper limit
  89. GRB 150302A, Swift-BAT refined analysis
  90. GRB 150302A: Swift/UVOT Upper Limits
  91. GRB 150302A: MITSuME Okayama upper limits
  92. GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
  93. GRB 150302A: Swift-XRT refined Analysis
  94. GRB 150302A: Enhanced Swift-XRT position
  95. GRB 150301B: Swift-XRT refined Analysis
  96. GRB 150220A: further Swift-XRT observations
  97. GRB 150301B: Swift/UVOT Observations
  98. GRB 150301B: LCOGT-Sutherland observations
  99. GRB 150302A: KAIT Optical Upper Limit
  100. GRB 150302A: UVOT Observations

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