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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"

3401 results found.

  1. Fermi trigger No 626247072: Global MASTER-Net observations report
  2. GRB 201104B: Swift/UVOT Detection
  3. GRB 201104A: Fermi GBM observation
  4. Fermi trigger No 625695596: Global MASTER-Net observations report
  5. MAXI GRB201021.68: Global MASTER-Net observations report
  6. GRB 201021B MAXI/GSC detection
  7. Fermi GRB 201020B: Global MASTER-Net observations report
  8. GRB 201020A: Swift detection of a burst with an optical counterpart.
  9. Konus-Wind observation of GRB 201013A
  10. SGR 1830-0645: Swift-BAT refined analysis
  11. GRB 201006A: Chandra upper limit on the X-ray afterglow
  12. Baksan Neutrino Observatory Alert 201006.88: Global MASTER-Net observations report
  13. GRB 201006A: Swift detection of a burst
  14. Fermi trigger No 623470566: Global MASTER-Net observations report
  15. Fermi trigger No 623493962: Global MASTER-Net observations report
  16. Swift-XRT observations of IceCube 200929A
  17. GRB 200928A: Fermi GBM Final Localization
  18. Fermi GRB 200925A: Global MASTER-Net observations report
  19. GRB 200923A: Fermi GBM Final Real-time Localization
  20. GRB 200922A: Swift-BAT refined analysis
  21. Fermi GRB 200914A: Global MASTER-Net observations report
  22. Fermi GRB 200909A: Global MASTER-Net observations report
  23. GRB 200907C: Fermi GBM Final Real-time Localization
  24. GRB 200906A: EMIR/GTC NIR upper limit
  25. GRB 200906A: LBT near-infrared upper limit
  26. Fermi GRB 200903C: Global MASTER-Net observations report
  27. GRB 200903D: MAXI/GSC detection
  28. GRB 200903A: Swift-BAT refined analysis
  29. Fermi GRB 200903B: Global MASTER-Net observations report
  30. Swift GRB200903.03: Global MASTER-Net observations report
  31. GRB 200901B: Swift-BAT refined analysis
  32. GRB 200829A: Kitab optical upper limit
  33. Zwicky Transient Facility discovery of ZTF20abtxwfx/AT2020sev, a fast optical transient and candidate afterglow
  34. IPN triangulation of GRB 200826B
  35. Fermi GRB 200824A: Global MASTER-Net observations report
  36. GRB 200815A: MASTER optical observations
  37. Baksan Neutrino Observatory Alert 200819.09: Global MASTER-Net observations report
  38. GRB 200818A: Fermi GBM Final Localization
  39. Fermi trigger No 619487843: Global MASTER-Net observations report
  40. GRB 200809B: Fermi GBM detection
  41. Fermi GRB 200809B: Global MASTER-Net observations report
  42. GRB 200809B: Swift-XRT afterglow detection
  43. GRB 200809B: MAXI/GSC detection
  44. GRB 200808A: Fermi GBM Final Real-time Localization
  45. GRB 200806A: Swift-BAT refined analysis
  46. GRB 200806A: MITSuME Akeno optical upper limits
  47. AX J1846.4-0258: Swift-BAT refined analysis
  48. Fermi GRB 200801A: Global MASTER-Net observations report
  49. GRB 200716C: Kitab optical observations
  50. Konus-Wind observation of GRB 200716C: correction to GCN 28147
  51. Konus-Wind observation of GRB 200716C
  52. GRB 200716C: Insight-HXMT/HE detection
  53. GRB 200716C: CALET Gamma-Ray Burst Monitor detection
  54. GRB 200716C: Swift-BAT refined analysis
  55. GRB 200716C: Fermi GBM detection
  56. GRB 200716C: AGILE/MCAL detection
  57. GRB 200716C: Fermi-LAT detection
  58. GRB 200716C: Swift detection of a burst with an optical counterpart
  59. GRB 200716C: Fermi GBM Final Real-time Localization
  60. Fermi GRB 200714D: Global MASTER-Net observations report
  61. Fermi GRB 200714A: Global MASTER-Net observations report
  62. Fermi-LAT-ANTARES 200407a Coincidence
  63. Fermi GRB 200702A: Global MASTER-Net observations report
  64. Fermi GRB 200626A: Global MASTER-Net observations report
  65. Fermi GRB 200625A: Global MASTER-Net observations report
  66. Fermi GRB 200623A: Global MASTER-Net observations report
  67. Fermi trigger No 614103490: Global MASTER-Net observations report
  68. Baksan Neutrino Observatory Alert 200617.47: Global MASTER-Net observations report
  69. GRB 200615B: CALET Gamma-Ray Burst Monitor detection
  70. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  71. GRB 200615B: MAXI/GSC detection
  72. IceCube Alert 200615.62: Global MASTER-Net observations report
  73. Fermi GRB 200615A: Global MASTER-Net observations report
  74. Baksan Neutrino Observatory Alert 200614.34: Global MASTER-Net observations report
  75. Fermi GRB 200613A: Global MASTER-Net observations report
  76. Fermi GRB 200607A: Global MASTER-Net observations report
  77. IPN triangulation of GRB 200605A (short)
  78. 1RXS J1708−4009: Swift-BAT refined analysis
  79. Fermi GRB 200604A: Global MASTER-Net observations report
  80. Fermi GRB 200601A: Global MASTER-Net observations report
  81. GRB 200528A: Swift-BAT refined analysis
  82. Swift GRB 200528A: Global MASTER-Net observations report
  83. GRB 200524A: Correction to the GCN 27800
  84. GRB 200524A: GROWTH-India confirmation of optical afterglow
  85. IceCube Alert 200523.10: Global MASTER-Net observations report
  86. Fermi GRB 200522B: Global MASTER-Net observations report
  87. GRB 200517A: Swift-XRT Confirmation of afterglow
  88. GRB 200519A: BOOTES-3/YA optical counterpart observations
  89. Fermi GBM Sub-Threshold Detection of GRB 200517A
  90. GRB 200519A: Swift detection of a burst with an optical afterglow
  91. GRB 200517A: Swift-XRT afterglow detection
  92. GRB 200514A: AstroSat CZTI detection
  93. Fermi trigger No 611434353: Global MASTER-Net observations report
  94. GRB 200517A: Tiled Swift observations
  95. GRB 200517A: MAXI/GSC detection
  96. Swift J1818.0-1607: BOOTES-3/YA optical upper limit
  97. GRB 200514A: MITSuME Akeno optical upper limits
  98. GRB 200514A: CALET Gamma-Ray Burst Monitor detection
  99. GRB 200514A: MAXI/GSC detection
  100. Baksan Neutrino Observatory Alert 200512.: Global MASTER-Net observations report

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