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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"

12388 results found.

  1. GRB 251221A: COLIBRÍ detection of the optical counterpart
  2. GRB 251221A: Fermi GBM Final Real-time Localization
  3. GRB 251220B: Fermi GBM Final Real-time Localization
  4. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  5. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  6. IceCube-251218A - IceCube observation of a high-energy neutrino candidate track-like event
  7. GRB 251214B: VIRT Optical Upper Limit
  8. Fermi trigger No 787736968: Global MASTER-Net observations report
  9. Fermi GRB 251217A: Global MASTER-Net observations report
  10. GRB 251217A: Fermi GBM Final Real-time Localization
  11. GRB 251215A: Swift/UVOT Upper LImits
  12. GRB 251215A: Fermi GBM Observation
  13. Fermi GRB 251216A: Global MASTER-Net observations report
  14. GRB 251202A/EP251202a: Koshka optical upper limit
  15. GRB 251214B: Mondy optical upper limit
  16. GRB 251215A: COLIBRÍ optical upper limit
  17. GRB 251216A: Fermi GBM Final Real-time Localization
  18. Fermi GRB 251215A: Global MASTER-Net observations report
  19. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  20. GRB 251215A: Glowbug gamma-ray detection
  21. GRB 251214B: UAFO optical upper limit
  22. GRB 251214B: VLT/X-shooter observations
  23. GRB 251202A: radio detection with the VLA
  24. GRB 251214B: AbAO optical observations
  25. GRB 251214B: LCO detection of the optical counterpart
  26. GRB 251209A: GECAM-B observation of a long burst
  27. GRB 251214B: Fermi GBM Observation
  28. GRB 251209A: Insight-HXMT/HE detection
  29. GRB 251215A: Swift/BAT-GUANO arcminute localization of a burst
  30. GRB 251214B: GECAM-B observation of a long burst
  31. GRB 251214A: AstroSat CZTI detection
  32. GRB 251213A: GECAM-B detection
  33. GRB 251215A: Fermi GBM Final Real-time Localization
  34. GRB 251214B: COLIBRÍ observations of the afterglow
  35. GRB 251214A: GECAM-B observation of a likely long burst
  36. GRB 251214B: 1.3m DFOT optical detection
  37. GRB 251214C: Fermi GBM Final Localization
  38. GRB 251214B : MASTER optical afterglow detection
  39. Fermi trigger No 787396657: Global MASTER-Net observations report
  40. GRB 251214B: SVOM/C-GFT optical observations
  41. EP251214a: COLIBRÍ optical upper limit
  42. GRB 251214B: Fermi GBM Final Real-time Localization
  43. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  44. Fermi GRB 251214A: Global MASTER-Net observations report
  45. GRB 251214A: Fermi GBM Final Real-time Localization
  46. GRB 251211B: AstroSat CZTI detection
  47. IceCube-251210A: No Candidate Transients from the Zwicky Transient Facility
  48. GRB 251209A: NuSTAR detection of prompt emission
  49. Fermi-LAT Gamma-ray Observations of IceCube-251210A
  50. IceCube-251210A: Upper limits from a search for additional neutrino events in IceCube
  51. Fermi GRB 251211B: Global MASTER-Net observations report
  52. GRB 251211B: Fermi GBM Final Real-time Localization
  53. GRB 251211A: Fermi GBM Final Real-time Localization
  54. GRB 251209A: Fermi GBM observation
  55. GRB 251209A: AstroSat CZTI detection
  56. IceCube-251210A - IceCube observation of a high-energy neutrino candidate track-like event
  57. GRB 251208A: AstroSat CZTI detection
  58. Fermi GBM Sub-Threshold Detection of GRB 251205A
  59. GRB 251208A: Glowbug gamma-ray detection
  60. GRB 251208B: COLIBRÍ optical upper limits
  61. GRB 251208C: GECAM-B observation of a short burst
  62. GRB 251208A: GECAM-B observation of a short burst
  63. Fermi GRB 251209A: Global MASTER-Net observations report
  64. Fermi GRB 251208C: Global MASTER-Net observations report
  65. GRB 251208B: Swift-XRT afterglow detection
  66. GRB 251209A: Fermi GBM Final Real-time Localization
  67. GRB 251208B: Fermi GBM Observation
  68. GRB 251208B: GROWTH-India Telescope optical upper limits
  69. GRB 251208A: SVOM/GRM observation of a short burst
  70. GRB 251208C: SVOM/GRM observation of a short burst
  71. GRB 251208B: Swift ToO observations
  72. GRB 251208B: Fermi-LAT detection
  73. GRB 251208B: Swift/BAT-GUANO arcminute localization of a burst
  74. GRB 251208C: Fermi GBM Final Real-time Localization
  75. GRB 251208B: Fermi GBM Final Real-time Localization
  76. GRB 251208A: Fermi GBM Final Real-time Localization
  77. Konus-Wind detection of GRB 251118A
  78. GRB 251126B: Fermi GBM Final Localization
  79. GRB 251203A: Insight-HXMT/HE detection
  80. GRB 251202A / EP251202a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm and 1-m telescopes at McDonald Observatory
  81. GRB 251202A: SVOM/GRM observation
  82. GRB 251203A: GECAM-B observation of a burst
  83. GRB 251203A: SVOM/GRM observation
  84. GRB 251201B: SALT spectroscopic redshift z = 1.599
  85. GRB 251203A: AstroSat CZTI detection
  86. Fermi Gamma-ray Burst Monitor trigger 786496343/251203967 is not a GRB
  87. GRB 251202A / EP251202a: Liverpool Telescope optical follow-up observations
  88. GRB 251201B: Insight-HXMT/HE detection
  89. EP251202a / GRB 251202A: Insight-HXMT/HE detection
  90. GRB 251203A: Fermi GBM Final Real-time Localization
  91. EP251202a / GRB251202A: AstroSat CZTI detection
  92. GRB 251202A / EP251202a: SVOM/VT optical observation
  93. GRB 251201B: Fermi GBM Observation
  94. EP251202a/GRB 251202A: KAIT optical observations
  95. Fermi GRB 251202B: Global MASTER-Net observations report
  96. GRB 251202B: Fermi GBM Final Real-time Localization
  97. GRB 251202A: Fermi GBM Observation
  98. GRB 251201B: Kilonova-Catcher optical afterglow detection
  99. GRB 251130B: Glowbug gamma-ray detection
  100. GRB 251201B: GECAM-B observation of a long burst

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