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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

12172 results found.

  1. GRB 210419C: MITSuME Akeno optical upper limits
  2. GRB 210420B: Montarrenti Observatory optical afterglow detection
  3. Swift GRB 210421A: Global MASTER-Net observations report
  4. GRB 210420B: BOOTES-4/MET optical afterglow detection
  5. GRB 210420B: MASTER optical counterpart detection
  6. GRB 210420B: Swift detection of a burst
  7. GRB 210419C: Montarrenti Observatory Upper Limit
  8. GRB 210420A: Fermi GBM Final Real-time Localization
  9. Swift GRB210419.98: Global MASTER-Net observations report
  10. GRB 210419A: Swift-XRT refined Analysis
  11. GRB 210419A: Swift detection of a burst
  12. GRB 210411B: AstroSat CZTI detection
  13. GRB 210410A: AstroSat CZTI detection
  14. GRB 210415A: Fermi GBM Final Real-time Localization
  15. GRB 210411C: Swift/UVOT Detection
  16. GRB 210411C: Swift-XRT refined Analysis
  17. GRB 210411C: BOOTES-4/MET optical upper limit
  18. Fermi GRB 210411B: Global MASTER-Net observations report
  19. GRB 210406A: 10.4m GTC follow-up observation
  20. Konus-Wind detection of GRB 210410A
  21. GRB 210411C: Swift detection of a burst with an optical counterpart
  22. Fermi GRB 210411A: Global MASTER-Net observations report
  23. GRB 210410A: Swift-XRT refined Analysis
  24. GRB 210409A: GECAM detection
  25. GRB 210410A: AGILE detection of a burst
  26. GRB 210410A: Fermi-LAT detection
  27. Fermi GRB 210410A: Global MASTER-Net observations report
  28. GRB 210406A: Mondy optical afterglow candidate
  29. GRB 210406B: Fermi GBM detection
  30. Konus-Wind detection of GRB 210406A
  31. GRB 210406A: A long GRB detected by INTEGRAL
  32. Integral GRB210406.72: Global MASTER-Net observations report
  33. GRB 210404.141: DDOTI Upper Limits
  34. GRB 210402A: Swift-XRT refined Analysis
  35. GRB 210330A: AstroSat CZTI detection
  36. GRB 210328A: AstroSat CZTI detection
  37. Konus-Wind detection of GRB 210401A
  38. GRB 210402A: Swift detection of a burst
  39. Fermi GRB 210401A: Global MASTER-Net observations report
  40. GRB 210328A: GECAM detection
  41. GRB 210330A: GECAM detection
  42. GRB 210324A: AstroSat CZTI detection
  43. GRB 210324C: AstroSat CZTI detection
  44. GRB 210328A: BALROG localization (Fermi Trigger / GRB 210328865)
  45. GRB 210328A: Fermi GBM Final Real-time Localization
  46. Konus-Wind detection of GRB 210324C
  47. Fermi GRB 210324C: Global MASTER-Net observations report
  48. Fermi GRB 210324B: Global MASTER-Net observations report
  49. Konus-Wind detection of GRB 210323A (short)
  50. Fermi GBM trigger 637977270/210320996 is not a GRB
  51. Konus-Wind detection of GRB 210321A
  52. IceCube Alert 210322.11: Global MASTER-Net observations report
  53. GRB 210321A: Mondy optical observations
  54. GRB 210321A: Redshift from OSIRIS/GTC
  55. GRB 210321A: NOT optical afterglow detection and redshift limit
  56. GRB 210320A: MAXI/GSC detection
  57. GRB 210318A: Swift-XRT refined Analysis
  58. Konus-Wind detection of GRB 210318B
  59. GRB210318B: Swift detection of a burst
  60. GRB 210318A: Swift detection of a burst
  61. Fermi trigger No 637521056: Global MASTER-Net observations report
  62. GRB 210312B: MASTER OT confirmation
  63. GRB 210312B: A long GRB detected by INTEGRAL
  64. Integral GRB210312.87: Global MASTER-Net observations report
  65. INTEGRAL SPI-ACS on 2021-03-12 (04)11-08:15) are due to calibration activity
  66. Konus-Wind detection of GRB 210308A
  67. Konus-Wind detection of GRB 210306A
  68. Konus-Wind detection of GRB 210305A
  69. GRB 210306A: Swift/UVOT Detection
  70. GRB 210306A: Swift-XRT refined Analysis
  71. Swift GRB210307.36: Global MASTER-Net observations report
  72. GRB 210306A: iTelescope T24 optical observations
  73. GRB 210306A: Fermi-LAT detection
  74. GRB 210217A: 3.6m DOT optical observations
  75. Fermi trigger No 636168178: Global MASTER-Net observations report
  76. Integral GRB210227.19: Global MASTER-Net observations report
  77. GRB 210226A: Swift-XRT refined Analysis
  78. Swift GRB 210226A: Global MASTER-Net observations report
  79. GRB 210226A: Swift detection of a burst
  80. GRB 210222B: REM observations of the optical/NIR afterglow
  81. Konus-Wind detection of GRB 210222A
  82. GRB 210222B: Zeiss-1000 of Koshka observatory, optical observations
  83. GRB 210222B: Swift-BAT refined analysis
  84. GRB 210222B: Swift-XRT refined Analysis
  85. GRB 210222B: Swift/UVOT Detection
  86. GRB 210222B: FRAM-ORM afterglow detection
  87. GRB 210222B: Swift detection of a burst with an optical counterpart
  88. GRB 210222A: MAXI/GSC detection
  89. uGMRT radio detection of GRB 210204A
  90. GRB 210217A: Swift-XRT refined Analysis
  91. GRB 210218A: Swift detection of a burst
  92. Fermi/GBM observation of a burst from SGR 1830-0645
  93. GRB 210217A: Swift detection of a burst with an optical counterpart
  94. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued Assy and Mondy optical observations
  95. GRB 210210A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  96. Swift Trigger 1033144: Detection of SGR 1830-0645
  97. Konus-Wind detection of GRB 210212B / ZTF21aakruew
  98. GRB 210212B (TF21aakruew/AT2021cwd): Assy optical observations
  99. Swift Trigger 1032350: Detection of SGR 1830-0645
  100. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued CrAO and AbAO optical observations

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