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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"

27766 results found.

  1. GRB 230409B: Swift detection of a burst
  2. GRB 230409A: Fermi GBM Final Real-time Localization
  3. GRB 230405B: VZLUSAT-2 detection
  4. Konus-Wind detection of GRB 230405B
  5. GRB 230405B: AGILE detection
  6. GRB 230405B: Swift-XRT refined Analysis
  7. GRB 230405B: Fermi GBM Observation
  8. GRB 230405B: MeerLICHT upper limits
  9. GRB 230307A: further analysis of the Konus-Wind detection and rest-frame energetics
  10. GRB 230405B: Swift/UVOT Upper Limits
  11. GRB 230405B: AstroSat CZTI detection
  12. GRB 230405B: Enhanced Swift-XRT position
  13. Swift GRB 230405B: Global MASTER-Net observations report
  14. GRB 230405B: Prompt enhanced Swift-XRT position
  15. GRB 230405B: Swift detection of a burst
  16. GRB 230405B: Fermi GBM Final Real-time Localization
  17. IceCube-230405A: IceCube observation of a high-energy neutrino candidate
  18. GRB 230405A: Fermi GBM Final Real-time Localization
  19. GRB 230404A: AstroSat CZTI detection
  20. GRB 230404A: Fermi GBM Final Real-time Localization
  21. GRB 230402A: CALET Gamma-Ray Burst Monitor detection
  22. GRB 230402A: AstroSat CZTI detection
  23. Fermi-LAT gamma-ray observations of IceCube-230401A and detection of Fermi J0030.2+0005
  24. GRB 230307A: Chandra late-time detection of the X-ray afterglow
  25. GRB 230228A: detection by GTC of the potential host galaxy
  26. GRB 230328B: Swift/UVOT Detection
  27. GRB 230402A: AGILE detection
  28. GRB 230402A: Fermi GBM Final Real-time Localization
  29. IceCube-230401A: IceCube observation of a high-energy neutrino candidate
  30. GRB 230328B : GRANDMA/Kilonova-Catcher optical detection
  31. GRB 230328B: CAHA 2.2m/CAFOS detection
  32. GRB 230328B: 3.6m DOT multiband optical observation
  33. GRB 230330B: Fermi GBM Final Localization
  34. Konus-Wind detection of GRB 230328B
  35. GRB 230328B: GRBAlpha detection
  36. GRB 230330A: Fermi GBM Final Real-time Localization
  37. GRB 230328B: Swift-BAT refined analysis
  38. GRB 230328B: Nanshan/NEXT 2nd optical observation
  39. GRB 230328B: Liverpool Telescope afterglow detection
  40. GRB 230328B: GIT optical follow-up
  41. GRB 230328B: OASDG optical observations
  42. GRB 230328B: Nanshan/NEXT optical upper limit
  43. GRB 230328B: Swift-XRT refined Analysis
  44. GRB 230328B: AstroSat CZTI detection
  45. GRB 230328B: Fermi GBM observation
  46. GRB 230328B: Mondy, AbAO and Kitab optical observations
  47. GRB 230328B: Enhanced Swift-XRT position
  48. GRB 230328B: Mondy optical afterglow confirmation
  49. GRB 230328B: Swift detection of a burst with an optical afterglow
  50. GRB 230328B: Fermi GBM Final Real-time Localization
  51. GRB 230328A: Fermi GBM Final Real-time Localization
  52. GRB 230325A: Swift-BAT refined analysis
  53. GRB 230325A: Swift/UVOT Upper Limits
  54. GRB 230325A: Swift-XRT refined Analysis
  55. GRB 230322B: Swift-BAT refined analysis
  56. GRB 230325A: Enhanced Swift-XRT position
  57. GRB 230325A: Prompt enhanced Swift-XRT position
  58. GRB 230325A: Swift detection of a burst
  59. GRB 230320B: Fermi GBM Observation
  60. GRB 230322B: Swift/UVOT Detection
  61. Konus-Wind detection of GRB 230309A
  62. Konus-Wind detection of GRB 230308A
  63. Konus-Wind detection of GRB 230304B
  64. GRB 230322B: Swift-XRT refined Analysis
  65. GRB 230322B: Enhanced Swift-XRT position
  66. Swift GRB 230322B: Global MASTER-Net observations report
  67. GRB 230322B: Swift detection of a burst with optical counterpart
  68. GRB 230322A: Fermi GBM Final Real-time Localization
  69. GRB 230320B: GRBAlpha detection
  70. GRB 230321A: CALET Gamma-Ray Burst Monitor detection
  71. GRB 230320B: CALET Gamma-Ray Burst Monitor detection
  72. GRB 230320B: Swift/BAT-GUANO detection outside the coded FOV
  73. INTEGRAL detection of a burst from SGR 1806-200
  74. GRB 230321B: AstroSat CZTI detection
  75. GRB 230320B: AstroSat CZTI detection
  76. GRB 230321A: Fermi GBM Final Real-time Localization
  77. GRB 230320A: Fermi GBM Final Real-time Localization
  78. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  79. IPN triangulation of GRB 230309A
  80. GRB 230304D: AstroSat CZTI detection
  81. GRB 230316A: Fermi GBM Final Real-time Localization
  82. IPN triangulation of GRB 230304B
  83. GRB 230313A: AstroSat CZTI detection
  84. GRB 230307A: Far off-axis NuSTAR detection of the GRB
  85. IPN triangulation of GRB 230308A (short/bright)
  86. GRB 230307A: ATCA radio detection
  87. GRB 230314A: Fermi GBM Final Real-time Localization
  88. VZLUSAT-2 detection of SGR 1806-20
  89. GRB 230307A: INTEGRAL upper limit on Hard X-ray afterglow
  90. GRB 230307A: Swift/UVOT detection
  91. GRB 230313A: Fermi GBM Final Real-time Localization
  92. GRB 230307A: soft X-ray detection with LEIA
  93. GRB 230307A: Swift-XRT afterglow detection
  94. GRB 230309A: AstroSat CZTI detection of a bright long GRB
  95. Swift GRB230311.85: Global MASTER-Net observations report
  96. Swift GRB230311.83: Global MASTER-Net observations report
  97. Further improved IPN localization for GRB 230307A
  98. Swift GRB230311.81: Global MASTER-Net observations report
  99. GRB 230307A: SOAR/Goodman detection of the possible host galaxy
  100. Swift GRB230311.84: Global MASTER-Net observations report

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