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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"

11546 results found.

  1. Fermi GBM trigger 640353092/210417494 is not a GRB
  2. Fermi Gamma-ray Burst Monitor trigger 640303939/210416925 is not a GRB
  3. GRB 210413B: Swift/BAT detection and probable localization of a short burst
  4. GRB 210411B: AstroSat CZTI detection
  5. GRB 210410A: AstroSat CZTI detection
  6. GRB 210410A: A twin of short GRB 090510 with complementary observations
  7. Fermi GRB 210415A: Global MASTER-Net observations report
  8. GRB 210415A: Fermi GBM Final Real-time Localization
  9. GRB 210410A: MITSuME Akeno optical upper limits
  10. Fermi GRB 210411B: Global MASTER-Net observations report
  11. Konus-Wind detection of GRB 210410A
  12. GRB 210411D: BALROG localization (Fermi Trigger 639851475 / GRB 210411688)
  13. GRB 210411D: Fermi GBM Final Real-time Localization
  14. GRB 210411B: Fermi GBM Final Real-time Localization
  15. Fermi GRB 210411A: Global MASTER-Net observations report
  16. GRB 210411A: Fermi GBM Final Real-time Localization
  17. GRB 210410A: Fermi GBM detection
  18. GRB 210410A: Swift/UVOT Upper Limits
  19. GRB210410A: Joint inspection of RATIR and D50 data
  20. GRB 210410A: RATIR Optical and NIR Observations
  21. GRB 210410A: AGILE detection of a burst
  22. GRB 210410A: Fermi-LAT detection
  23. GRB210410A: Candidate optical afterglow by Ondrejov D50
  24. Fermi GRB 210410A: Global MASTER-Net observations report
  25. GRB 210410A: Swift XRT localization
  26. GRB 210410A: Fermi GBM Final Real-time Localization
  27. GRB 210406B: Fermi GBM detection
  28. Konus-Wind detection of GRB 210406A
  29. GRB 210406A: Fermi GBM detection
  30. GRB 210402A: MASTER prompt and follow up optical observation
  31. GRB 210402A: Fermi GBM detection
  32. GRB 210404.141: DDOTI Upper Limits
  33. GRB 210401A: GECAM detection
  34. Fermi trigger No 639199407: Global MASTER-Net observations report
  35. GRB 210402A: Montarrenti Observatory upper limit
  36. GRB 210328A: AstroSat CZTI detection
  37. Konus-Wind detection of GRB 210401A
  38. GRB 210402A: Swift detection of a burst
  39. Fermi trigger No 639093861: Global MASTER-Net observations report
  40. Fermi GRB 210401A: Global MASTER-Net observations report
  41. GRB 210401A: Fermi GBM Final Real-time Localization
  42. GRB 210328A: GECAM detection
  43. GRB 210324A: AstroSat CZTI detection
  44. GRB 210324C: AstroSat CZTI detection
  45. GRB 210328A: BALROG localization (Fermi Trigger / GRB 210328865)
  46. GRB 210328A: Fermi GBM Final Real-time Localization
  47. GRB 210326A: Insight-HXMT/HE detection
  48. GRB 210326A: Fermi GBM Final Localization
  49. Fermi trigger No 638414549: Global MASTER-Net observations report
  50. IPN triangulation of GRB 210324C
  51. GRB 210323A: Insight-HXMT/HE detection
  52. Fermi GRB 210324C: Global MASTER-Net observations report
  53. Fermi GRB 210324B: Global MASTER-Net observations report
  54. GRB 210323A: Gemini-North Optical Source Detection
  55. GRB 210324C: BALROG localization (Fermi Trigger 638308803 / GRB 210324833)
  56. GRB 210324C: Fermi GBM Final Real-time Localization
  57. Short GRB 210323A: GTC Observations
  58. GRB 210324B: Fermi GBM Final Real-time Localization
  59. Konus-Wind detection of GRB 210323A (short)
  60. GRB 210323A: Classification and redshift estimation
  61. GRB 210323A: Kitab optical upper limit
  62. GRB 210323A: Fermi GBM detection
  63. GRB 210324A: Fermi GBM Final Real-time Localization
  64. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  65. Fermi GBM trigger 637977270/210320996 is not a GRB
  66. GRB 200524A: Redshift from Gemini-North
  67. GRB 210318B: Fermi GBM detection
  68. Fermi trigger No 637729731: Global MASTER-Net observations report
  69. Fermi GRB 210317A: Global MASTER-Net observations report
  70. GRB 210317A: GECAM detection
  71. GRB 210317A: Fermi GBM Final Real-time Localization
  72. Fermi trigger No 637521056: Global MASTER-Net observations report
  73. Fermi GRB 210312A: Global MASTER-Net observations report
  74. GRB 210312A: Fermi GBM Final Real-time Localization
  75. Konus-Wind detection of GRB 210308A
  76. Konus-Wind detection of GRB 210306A
  77. Konus-Wind detection of GRB 210305A
  78. Fermi trigger No 637027080: Global MASTER-Net observations report
  79. GRB 210306B: Fermi GBM detection
  80. Fermi trigger No 636926765: Global MASTER-Net observations report
  81. GRB 210305A: Fermi GBM observation
  82. GRB 210308A: Fermi GBM detection
  83. GRB 210306A: Fermi GBM observation
  84. GRB 210306A: Fermi-LAT detection
  85. GRB 210228B: Insight-HXMT/HE detection
  86. Fermi trigger No 636459103: Global MASTER-Net observations report
  87. Fermi trigger No 636187116: Global MASTER-Net observations report
  88. GRB 210228A: GECAM detection
  89. Fermi trigger No 636168178: Global MASTER-Net observations report
  90. GRB 210225A: Insight-HXMT/HE detection
  91. GRB 210226A: Fermi GBM detection
  92. Fermi trigger No 635922820: Global MASTER-Net observations report
  93. Fermi GBM Sub-Threshold Detection of GRB 210217A
  94. Fermi/GBM observation of a burst from SGR 1830-0645
  95. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued Assy and Mondy optical observations
  96. GRB 210211A: ePESSTO+ NTT optical observations
  97. Fermi GRB 210213A: Global MASTER-Net observations report
  98. GRB 210213A: Fermi GBM Final Real-time Localization
  99. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued CrAO and AbAO optical observations
  100. GRB 210204A: observations with the 3.6m Devasthal Optical Telescope and possible jet break

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