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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"

2857 results found.

  1. GRB 200917A: Swift detection of a burst
  2. Fermi GRB 200916A: Global MASTER-Net observations report
  3. GRB 200916A: Fermi GBM Final Real-time Localization
  4. IceCube Alert 200914.00: Global MASTER-Net observations report
  5. Fermi GRB 200907C: Global MASTER-Net observations report
  6. Fermi GRB 200903C: Global MASTER-Net observations report
  7. GRB 200903B: Insight-HXMT/HE detection
  8. AGILE detection of a burst (AGILE trigger no. 526185273)
  9. Fermi GRB 200903B: Global MASTER-Net observations report
  10. GRB 200903B: Fermi GBM Final Real-time Localization
  11. GRB 200901B: Swift-BAT refined analysis
  12. GRB 200901B: Enhanced Swift-XRT position
  13. GRB 200901B: Swift detection of a burst
  14. GRB 200829A: Liverpool Telescope observations
  15. GRB 200826B: Fermi GBM Final Real-time Localization
  16. GRB 200826A: AstroSat CZTI detection
  17. Fermi GRB 200826A: Global MASTER-Net observations report
  18. Fermi trigger No 619270776: Global MASTER-Net observations report
  19. HAWC alert 200815.26: MASTER optical observations
  20. GRB 200811A: Fermi GBM Final Real-time Localization
  21. GRB 200811A: BALROG localization (Fermi Trigger 618851447 / GRB 200811632)
  22. Fermi GRB 200809B: Global MASTER-Net observations report
  23. Fermi trigger No 618642276: Global MASTER-Net observations report
  24. GRB 200806A: Nanshan/NEXT optical upper limit
  25. GRB 200806A: AbAO optical upper limit
  26. GRB 200803A: AstroSat CZTI detection
  27. LAT GRB200803.15: Global MASTER-Net observations report
  28. Fermi GRB 200803A: Global MASTER-Net observations report
  29. Fermi GRB 200801B: Global MASTER-Net observations report
  30. Fermi GRB 200802A: Global MASTER-Net observations report
  31. Fermi GRB 200801A: Global MASTER-Net observations report
  32. GRB 200723A: GOTO candidate afterglow and host galaxy
  33. Fermi GRB 200723A: Global MASTER-Net observations report
  34. Konus-Wind observation of GRB 200716C: correction to GCN 28147
  35. Konus-Wind observation of GRB 200716C
  36. Fermi GRB 200714D: Global MASTER-Net observations report
  37. Fermi GRB 200714A: Global MASTER-Net observations report
  38. GRB 200714E: Fermi GBM Final Real-time Localization
  39. GRB 200713A: Swift detection of a burst
  40. HAWC-200907A: No Neutrino Counterpart detected with ANTARES
  41. GRB 200703B: AstroSat CZTI detection
  42. GRB 200702A: Fermi GBM Final Real-time Localization
  43. GRB 200630A: Fermi GBM detection
  44. GRB 200629A: AstroSat CZTI detection
  45. Fermi trigger No 614103490: Global MASTER-Net observations report
  46. Baksan Neutrino Observatory Alert 200617.47: Global MASTER-Net observations report
  47. Fermi GRB 200615A: Global MASTER-Net observations report
  48. Baksan Neutrino Observatory Alert 200614.34: Global MASTER-Net observations report
  49. Fermi GRB 200613A: Global MASTER-Net observations report
  50. Fermi GRB 200607A: Global MASTER-Net observations report
  51. IPN triangulation of GRB 200605A (short)
  52. GRB 200605A: Fermi GBM Final Real-time Localization
  53. Baksan Neutrino Observatory Alert 200603.12: Global MASTER-Net observations report
  54. Fermi GRB 200531A: Global MASTER-Net observations report
  55. GRB 200528A: 1.3m DFOT Optical Upper Limits
  56. IceCube Alert 200523.10: Global MASTER-Net observations report
  57. Fermi GRB 200522B: Global MASTER-Net observations report
  58. GRB 200522A: Swift detection of a short burst
  59. Fermi trigger No 611676654: Global MASTER-Net observations report
  60. GRB 200519A: Swift-XRT refined Analysis
  61. Fermi trigger No 611605955: Global MASTER-Net observations report
  62. Fermi trigger No 611434353: Global MASTER-Net observations report
  63. GRB 200514A: MITSuME Akeno optical upper limits
  64. GRB 200514A: MAXI/GSC detection
  65. GRB 200509C: Fermi GBM Final Real-time Localization
  66. GRB 200506B: Fermi GBM Final Real-time Localization
  67. GRB 200424A: Swift-XRT afterglow detection
  68. SGR 1935+2154: MASTER optical observations
  69. SGR 1935+2154 the Insight-HXMT observation plan
  70. GRB 200424A: Swift-XRT observations
  71. Konus-Wind observation of GRB 200422A
  72. Fermi GRB 200423A: Global MASTER-Net observations report
  73. Fermi GRB 200421A: Global MASTER-Net observations report
  74. Fermi GRB 200420A: Global MASTER-Net observations report
  75. GRB 200412B: AbAO optical observations
  76. IceCube Alert 200410.97: Global MASTER-Net observations report
  77. Baksan Neutrino Observatory Alert 200409.81: Global MASTER-Net observations report
  78. LIGO/Virgo S200224ca: Swift XRT observations, 8 X-ray sources
  79. Baksan Neutrino Observatory Alert 200409.23: Global MASTER-Net observations report
  80. Fermi GRB 200407A: Global MASTER-Net observations report
  81. Fermi GRB 200407B: Global MASTER-Net observations report
  82. IPN triangulation of GRB 200407A (short)
  83. Fermi GRB 200403B: Global MASTER-Net observations report
  84. Fermi GRB 200402C: Global MASTER-Net observations report
  85. Fermi GRB 200401A: Global MASTER-Net observations report
  86. Fermi trigger No 606799116: Global MASTER-Net observations report
  87. GRB 200324A: AROMA-N Optical Observation
  88. GRB 200324A:MITSuME Akeno optical upper limits
  89. GRB 200324A: Swift detection of a burst
  90. Fermi trigger No 606681997: Global MASTER-Net observations report
  91. GRB 200320A: Fermi GBM Final Localization
  92. Fermi trigger No 606263732: Global MASTER-Net observations report
  93. LIGO/Virgo S200316bj : No significant candidates in TAROT - FRAM - GRANDMA observations.
  94. Fermi trigger No 606098435: Global MASTER-Net observations report
  95. IPN triangulation of GRB 200311A
  96. Fermi trigger No 605756501: Global MASTER-Net observations report
  97. Fermi trigger No 605632577: Global MASTER-Net observations report
  98. GRB 200311A: Fermi GBM Final Real-time Localization
  99. GRB 200306C: Swift-BAT refined analysis
  100. Swift GRB200306.95: Global MASTER-Net observations report

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