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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"

3797 results found.

  1. MAXI GRB201021.68: Global MASTER-Net observations report
  2. GRB 201021B MAXI/GSC detection
  3. Fermi GRB 201020B: Global MASTER-Net observations report
  4. GRB 201020A: Swift detection of a burst with an optical counterpart.
  5. Konus-Wind observation of GRB 201013A
  6. SGR 1830-0645: Swift-BAT refined analysis
  7. GRB 201006A: Chandra upper limit on the X-ray afterglow
  8. Baksan Neutrino Observatory Alert 201006.88: Global MASTER-Net observations report
  9. GRB 201006A: Swift detection of a burst
  10. Fermi trigger No 623470566: Global MASTER-Net observations report
  11. Fermi trigger No 623493962: Global MASTER-Net observations report
  12. Swift-XRT observations of IceCube 200929A
  13. GRB 200928A: Fermi GBM Final Localization
  14. Fermi GRB 200925A: Global MASTER-Net observations report
  15. GRB 200923A: Fermi GBM Final Real-time Localization
  16. GRB 200922A: Swift-BAT refined analysis
  17. Fermi GRB 200914A: Global MASTER-Net observations report
  18. Fermi GRB 200909A: Global MASTER-Net observations report
  19. GRB 200907C: Fermi GBM Final Real-time Localization
  20. GRB 200906A: EMIR/GTC NIR upper limit
  21. GRB 200906A: LBT near-infrared upper limit
  22. Fermi GRB 200903C: Global MASTER-Net observations report
  23. GRB 200903D: MAXI/GSC detection
  24. GRB 200903A: Swift-BAT refined analysis
  25. Fermi GRB 200903B: Global MASTER-Net observations report
  26. Swift GRB200903.03: Global MASTER-Net observations report
  27. GRB 200901B: Swift-BAT refined analysis
  28. GRB 200829A: Kitab optical upper limit
  29. Zwicky Transient Facility discovery of ZTF20abtxwfx/AT2020sev, a fast optical transient and candidate afterglow
  30. IPN triangulation of GRB 200826B
  31. Fermi GRB 200824A: Global MASTER-Net observations report
  32. GRB 200815A: MASTER optical observations
  33. Baksan Neutrino Observatory Alert 200819.09: Global MASTER-Net observations report
  34. GRB 200818A: Fermi GBM Final Localization
  35. Fermi trigger No 619487843: Global MASTER-Net observations report
  36. GRB 200809B: Fermi GBM detection
  37. Fermi GRB 200809B: Global MASTER-Net observations report
  38. GRB 200809B: Swift-XRT afterglow detection
  39. GRB 200809B: MAXI/GSC detection
  40. GRB 200808A: Fermi GBM Final Real-time Localization
  41. GRB 200806A: Swift-BAT refined analysis
  42. GRB 200806A: MITSuME Akeno optical upper limits
  43. AX J1846.4-0258: Swift-BAT refined analysis
  44. Fermi GRB 200801A: Global MASTER-Net observations report
  45. GRB 200716C: Kitab optical observations
  46. Konus-Wind observation of GRB 200716C: correction to GCN 28147
  47. Konus-Wind observation of GRB 200716C
  48. GRB 200716C: Insight-HXMT/HE detection
  49. GRB 200716C: CALET Gamma-Ray Burst Monitor detection
  50. GRB 200716C: Swift-BAT refined analysis
  51. GRB 200716C: Fermi GBM detection
  52. GRB 200716C: AGILE/MCAL detection
  53. GRB 200716C: Fermi-LAT detection
  54. GRB 200716C: Swift detection of a burst with an optical counterpart
  55. GRB 200716C: Fermi GBM Final Real-time Localization
  56. Fermi GRB 200714D: Global MASTER-Net observations report
  57. Fermi GRB 200714A: Global MASTER-Net observations report
  58. Fermi-LAT-ANTARES 200407a Coincidence
  59. Fermi GRB 200702A: Global MASTER-Net observations report
  60. Fermi GRB 200626A: Global MASTER-Net observations report
  61. Fermi GRB 200625A: Global MASTER-Net observations report
  62. Fermi GRB 200623A: Global MASTER-Net observations report
  63. Fermi trigger No 614103490: Global MASTER-Net observations report
  64. Baksan Neutrino Observatory Alert 200617.47: Global MASTER-Net observations report
  65. GRB 200615B: CALET Gamma-Ray Burst Monitor detection
  66. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  67. GRB 200615B: MAXI/GSC detection
  68. IceCube Alert 200615.62: Global MASTER-Net observations report
  69. Fermi GRB 200615A: Global MASTER-Net observations report
  70. Baksan Neutrino Observatory Alert 200614.34: Global MASTER-Net observations report
  71. Fermi GRB 200613A: Global MASTER-Net observations report
  72. Fermi GRB 200607A: Global MASTER-Net observations report
  73. IPN triangulation of GRB 200605A (short)
  74. 1RXS J1708−4009: Swift-BAT refined analysis
  75. Fermi GRB 200604A: Global MASTER-Net observations report
  76. Fermi GRB 200601A: Global MASTER-Net observations report
  77. GRB 200528A: Swift-BAT refined analysis
  78. Swift GRB 200528A: Global MASTER-Net observations report
  79. GRB 200524A: Correction to the GCN 27800
  80. GRB 200524A: GROWTH-India confirmation of optical afterglow
  81. IceCube Alert 200523.10: Global MASTER-Net observations report
  82. Fermi GRB 200522B: Global MASTER-Net observations report
  83. GRB 200517A: Swift-XRT Confirmation of afterglow
  84. GRB 200519A: BOOTES-3/YA optical counterpart observations
  85. Fermi GBM Sub-Threshold Detection of GRB 200517A
  86. GRB 200519A: Swift detection of a burst with an optical afterglow
  87. GRB 200517A: Swift-XRT afterglow detection
  88. GRB 200514A: AstroSat CZTI detection
  89. Fermi trigger No 611434353: Global MASTER-Net observations report
  90. GRB 200517A: Tiled Swift observations
  91. GRB 200517A: MAXI/GSC detection
  92. Swift J1818.0-1607: BOOTES-3/YA optical upper limit
  93. GRB 200514A: MITSuME Akeno optical upper limits
  94. GRB 200514A: CALET Gamma-Ray Burst Monitor detection
  95. GRB 200514A: MAXI/GSC detection
  96. Baksan Neutrino Observatory Alert 200512.: Global MASTER-Net observations report
  97. SGR 1935+2154: MASTER optical observations
  98. Konus-Wind observation of a very intense bursting activity of SGR 1935+2154
  99. high bursting activity of SGR 1935+2154: CGBM observations
  100. SGR 1935+2154 the Insight-HXMT observation plan

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