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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"

14832 results found.

  1. GRB 150430A: Swift detection of a burst
  2. GRB 150426A: Fermi GBM detection
  3. GRB 150428C/MAXI J0400+678: MAXI/GSC detection
  4. GRB 150428B: Swift detection of a burst
  5. GRB 150428A: Swift detection of a burst
  6. Trigger 639199: Swift detection of IGRJ16418-4532
  7. GRB 150424A: 10.4m GTC spectroscopy
  8. GRB 150424A: GROND detects strong fading
  9. GRB 150423A: VLT/X-shooter spectroscopy and tentative redshift
  10. GRB 150424B: Fermi GBM detection
  11. Konus-Wind observation of GRB 150424A
  12. GRB 150424A: Swift/UVOT Observations
  13. GRB 150424B: MAXI/GSC detection
  14. GRB 150424A: Keck detection of optical afterglow
  15. GRB 150424A: Swift detection of a short burst
  16. GRB 150423A: UKIRT NIR observations
  17. GRB 150423A: VLT detection
  18. GRB 150422A: Fermi GBM detection
  19. GRB 150423A: Swift detection of a short burst
  20. Swift trigger 638589 is probably not an astrophysical source
  21. GRB 150418A: MAXI/GSC detection
  22. GRB 150416A: Fermi GBM detection
  23. Swift Trigger 638217 is probably not an astrophysical source
  24. GRB 150416A: Fermi-LAT detection
  25. GRB 150413A: Refined redshift
  26. GRB 150413A: AMI 15 GHz detection of possible radio counterpart
  27. GRB 150413A: redshift determination with the 2.2m CAHA
  28. GRB 150413A: MAXI/GSC detection
  29. GRB 150413A: MASTER very bright unusual OT observations
  30. GRB 150413A: MASTER bright OT detection
  31. GRB 150413A: Swift detection of a burst
  32. Swift detection of SAX J1808.4-3658
  33. GRB 150407A: Swift detection of a possible burst
  34. GRB 150404A: Fermi GBM detection
  35. Konus-Wind observation of GRB 150403A
  36. GRB 150403A: Fermi GBM Detection
  37. GRB 150403A: Swift/UVOT Detection
  38. GRB 150403A: Fermi-LAT detection
  39. GRB 150403A: Swift detection of a burst with an optical counterpart
  40. Konus-Wind observation of GRB 150330A
  41. GRB 150330A: Fermi GBM detection
  42. GRB 150323B: Swift-XRT afterglow detection
  43. GRB 150323C: possible host galaxy detection
  44. GRB 150317A: likely host galaxy detection
  45. GRB 150323B: Khureltogot optical observations
  46. GRB150323C: Fermi GBM detection
  47. GRB 150323C: Nanshan optical afterglow detection
  48. GRB 150323C: Swift detection of a burst
  49. GRB150323A: Swift-UVOT detection of the afterglow
  50. GRB 150323A: Swift detection of a burst
  51. GRB 150318A: Swift detection of a burst
  52. GRB 150317A: Swift/UVOT Upper Limits
  53. GRB 150317A: RATIR Optical Afterglow Detection
  54. GRB 150317A: Swift detection of a burst
  55. GRB 150314A: Early RAPTOR Detection
  56. Konus-Wind observation of GRB 150314A
  57. GRB 150314A: Swift/UVOT Detection
  58. GRB 150314A: Fermi-LAT detection
  59. GRB 150314A: Swift detection of a bright burst
  60. GRB 150313A: MAXI/GSC detection
  61. GRB 150311A: MAXI/GSC possible afterglow detection
  62. GRB 150309A: Fermi GBM detection
  63. GRB 150309A: Swift detection of a burst
  64. GRB 150305A: a long GRB detected by INTEGRAL
  65. Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
  66. GRB 150302A: BOOTES-2/TELMA upper limit
  67. GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
  68. GRB 150220A: further Swift-XRT observations
  69. GRB 150302A: Swift detection of a burst
  70. GRB 150301B: Fermi GBM detection
  71. GRB 150301B: MASTER early OT detection
  72. GRB 150301B: Swift detection of a burst with an optical afterglow
  73. Swift Trigger 633173 is probably not an astrophysical source
  74. GRB 150301A: Swift detection of a short burst or new SGR
  75. Trigger 632888: Swift detection of the magnetar 4U 0142+61
  76. GRB 150222B: MAXI/GSC detection
  77. SGR 1935+2154: Swift-BAT refined analysis
  78. GRB 150222A: Swift detection of a burst
  79. Swift detection of an outburst from SGR 1935+2154
  80. Trigger 631946: Swift detection of H1745-203
  81. GRB 150219A: Swift-XRT afterglow detection
  82. Trigger 631747: Swift detection of 4U 0614+09
  83. GRB 150213B: Swift/UVOT Detection
  84. GRB 150213B: optical detection from the NOT
  85. GRB 150213B: Tautenburg Afterglow Detection
  86. GRB 150213B: Swift detection of a burst with an optical afterglow
  87. GRB 150213A: Fermi GBM detection
  88. GRB 150212A: No Swift/UVOT detection in initial observation
  89. GRB 150212A: Swift-XRT afterglow detection
  90. GRB 150212A: Swift detection of a burst
  91. GRB 150210A: MASTER SN detection during LAT error box inspection
  92. Konus-Wind observation of GRB 150210A
  93. GRB 150210A: Fermi-LAT detection
  94. GRB 150211A: No afterglow detection in the Swift/UVOT initial observation
  95. GRB 150211A: Swift detection of a burst
  96. GRB 150210A: Fermi GBM detection
  97. GRB 150202B: Swift/XRT afterglow confirmation
  98. GRB 150204A: Swift/XRT afterglow confirmation
  99. Konus-Wind observation of GRB 150206A
  100. GRB 150206A: Swift/UVOT Detection

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Download all Circulars as a .tar.gz archive (updated once a day):
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