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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"

3757 results found.

  1. GRB 201227A: Swift-XRT observations
  2. Konus-Wind observation of GRB 201227A
  3. Baksan Neutrino Observatory Alert 201228.36: Global MASTER-Net observations report
  4. Fermi GRB 201228B: Global MASTER-Net observations report
  5. GRB 201228B: Fermi GBM Final Real-time Localization
  6. GRB 201228A: Fermi GBM Final Real-time Localization
  7. Fermi trigger No 630389391: Global MASTER-Net observations report
  8. Fermi GRB 201222B: Global MASTER-Net observations report
  9. GRB 201221D: Lowell Discovery Telescope afterglow observations
  10. GRB 201221E: Fermi GBM Final Real-time Localization
  11. Fermi GBM Sub-Threshold Detection of GRB 201221A
  12. Konus-Wind detection of GRB 201216C
  13. Baksan Neutrino Observatory Alert 201216.94: Global MASTER-Net observations report
  14. Fermi GRB 201216A: Global MASTER-Net observations report
  15. GRB 201215A: BALROG localization (Fermi Trigger 629706213 / GRB 201215266)
  16. GRB 201215A: Fermi GBM Final Real-time Localization
  17. Integral GRB201214.26: Global MASTER-Net observations report
  18. GRB 201208A: LCO observations
  19. GRB201130A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 628407054)
  20. GRB 201128B: Swift/BAT-GUANO detection and arcminute localization
  21. IceCube Alert 201130.85: Global MASTER-Net observations report
  22. GRB 201130A: DDOTI Observations
  23. Fermi trigger No 628278856: Global MASTER-Net observations report
  24. GRB 201128A: DDOTI Observations
  25. GRB 200826A: TNG and LBT constraints on a supernova bump
  26. Fermi GRB 201121A: Global MASTER-Net observations report
  27. Fermi GRB 201120B: Global MASTER-Net observations report
  28. INTEGRAL Weak#8825: AROMA-N Optical Observation
  29. Konus-Wind detection of GRB 201116A
  30. Fermi trigger No 627198169: Global MASTER-Net observations report
  31. GRB 201114A: AstroSat CZTI detection
  32. GRB 201108A: Fermi GBM Final Real-time Localization
  33. ZTF20acozryr/AT2020yxz (GRB 201103B): Assy optical observations
  34. GRB 201104B: Kitab optical observations
  35. GRB 201103B (ZTF20acozryr/AT2020yxz): Nanshan/NEXT-0.6m optical observations
  36. ZTF20acozryr/AT2020yxz: Zwicky Transient Facility discovery of a fast optical transient with no associated GRB
  37. GRB 201029A: Swift-BAT refined analysis
  38. GRB 201024A: Redshift from GTC/OSIRIS
  39. Swift GRB201024.12: Global MASTER-Net observations report
  40. GRB 201020B: Nanshan/NEXT optical afterglow confirmation
  41. GRB 201020A: DOAO optical afterglow observations
  42. GRB 201020A: MITSuME Akeno optical observation
  43. IceCube-201014A: No significant detection in HAWC
  44. Fermi GRB 201016B: Global MASTER-Net observations report
  45. Fermi GRB 201007A: Global MASTER-Net observations report
  46. Baksan Neutrino Observatory Alert 201006.88: Global MASTER-Net observations report
  47. Fermi trigger No 623470566: Global MASTER-Net observations report
  48. Fermi trigger No 623493962: Global MASTER-Net observations report
  49. IceCube-200926A: JCMT/SCUBA2 observations
  50. IceCube-200929A: Upper limits from a search for additional neutrino events in IceCube
  51. GRB 200928B: AstroSat CZTI detection
  52. GRB 200928B: BALROG localization (Fermi Trigger 622991684 / GRB 200928552)
  53. GRB 200928B: Fermi GBM Final Real-time Localization
  54. GRB 200928A: Fermi GBM Final Localization
  55. Fermi GRB 200925A: Global MASTER-Net observations report
  56. Fermi GRB 200924A: Global MASTER-Net observations report
  57. GRB 200924B: Fermi GBM Final Localization
  58. Fermi trigger No 622618714: Global MASTER-Net observations report
  59. Fermi GRB 200923A: Global MASTER-Net observations report
  60. Fermi GRB 200922B: Global MASTER-Net observations report
  61. Fermi-GBM Sub-Threshold Detection of GRB 200917A
  62. GRB 200917A: Swift detection of a burst
  63. GRB 200916A: Fermi GBM Final Real-time Localization
  64. Fermi GRB 200914A: Global MASTER-Net observations report
  65. IceCube Alert 200914.00: Global MASTER-Net observations report
  66. Swift GRB200909.97: Global MASTER-Net observations report
  67. Fermi GRB 200907C: Global MASTER-Net observations report
  68. GRB 200907C: Fermi GBM Final Real-time Localization
  69. Fermi GRB 200906A: Global MASTER-Net observations report
  70. IPN triangulation of GRB 200903E
  71. Fermi GRB 200903B: Global MASTER-Net observations report
  72. GRB 200829A: Continued Nanshan/NEXT optical observations
  73. GRB 200826A
  74. Fermi trigger No 620402299: Global MASTER-Net observations report
  75. IPN triangulation of GRB 200826B
  76. Swift Trigger 992444: a possible GRB 200821A
  77. Fermi trigger No 619270776: Global MASTER-Net observations report
  78. IceCube200806A: No significant detection in HAWC
  79. GRB 200809B: MAXI/GSC detection
  80. GRB 200806A: CALET Gamma-Ray Burst Monitor detection
  81. IPN triangulation of GRB 200805A (short)
  82. Swift GRB 200806A: Global MASTER-Net observations report
  83. GRB 200806A: Swift detection of a burst
  84. Fermi GRB 200802A: Global MASTER-Net observations report
  85. GRB 200729A: IceCube neutrino search
  86. GRB 200729A: TNG NIR upper limits
  87. IceCube GCN Notice 134327_10548129 retraction
  88. Baksan Neutrino Observatory Alert 200726.66: Global MASTER-Net observations report
  89. GRB 200723A: GOTO candidate afterglow and host galaxy
  90. IPN triangulation of GRB 200716A
  91. GRB 200716B: BALROG localization (Fermi Trigger 616577673 / GRB 200716316)
  92. GRB 200716B: Fermi GBM Final Real-time Localization
  93. GRB 200714E: Fermi GBM observation
  94. Fermi GRB 200714D: Global MASTER-Net observations report
  95. Fermi GRB 200714A: Global MASTER-Net observations report
  96. GRB 200714C: Fermi GBM Final Real-time Localization
  97. Fermi-LAT-ANTARES 200407a Coincidence
  98. Trigger 980513: Swift detection of SGR Swift J1818.0-1607
  99. GRB 200629A: AstroSat CZTI detection
  100. GRB 200623A: Further MMTCam Observations of XRT Source #3

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