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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"

11551 results found.

  1. Fermi trigger No 810554827: Global MASTER-Net observations report
  2. GRB 260907A: Glowbug gamma-ray detection of a likely short burst
  3. Fermi GRB 260907B: Global MASTER-Net observations report
  4. GRB 260907B: Fermi GBM Final Real-time Localization
  5. Fermi GRB 260907A: Global MASTER-Net observations report
  6. GRB 260907A: Fermi GBM Final Real-time Localization
  7. GRB 260831A: GECAM-B observation
  8. GRB 260827A: Insight-HXMT/HE detection
  9. Konus-Wind detection of GRB 260829A
  10. GRB 260829A: SVOM/GRM observation
  11. GRB 260829A: AstroSat CZTI detection
  12. GRB 260827A: SVOM/GRM observation
  13. IPN triangulation of GRB 260829A
  14. GRB 260827A: Glowbug gamma-ray detection
  15. GRB 260831A: Fermi GBM Final Real-time Localization
  16. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  17. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  18. GRB 260829A: GECAM-B observation of a long burst
  19. GRB 260825A: SVOM/GRM observation of a long burst
  20. GRB 260825A: GECAM-B observation
  21. GRB 260829A: Fermi GBM Detection
  22. GRB 260825A: AstroSat CZTI detection
  23. GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
  24. GRB 260829A: Fermi GBM Final Real-time Localization
  25. Fermi GBM trigger 809666623/260829141 is not a GRB
  26. IceCube-260827A - IceCube observation of a high-energy neutrino candidate track-like event
  27. GRB 260827A: Fermi GBM Final Real-time Localization
  28. GRB 260809A: SVOM/ECLAIRs refined analysis
  29. GRB 260825A: Fermi GBM Final Real-time Localization
  30. IceCube-260825A - IceCube observation of a high-energy neutrino candidate track-like event
  31. GRB260822B: Fermi GBM Final Localization
  32. Fermi-LAT Gamma-ray Observations of IceCube-260821A
  33. Fermi-LAT Gamma-ray Observations of IceCube-260807A
  34. GRB 260820A: Insight-HXMT/HE detection
  35. IceCube-260821A - IceCube observation of a high-energy neutrino candidate track-like event
  36. GRB260820A: Fermi GBM Final Real-Time Localization
  37. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  38. GRB 260813A: BALROG localization (Fermi Trigger 808341387 / GRB 260813803)
  39. GRB 260813A: Fermi GBM Final Real-time Localization
  40. GRB 260808A: SVOM/GRM observation
  41. Fermi GBM Sub-Threshold Detection of GRB 260809A
  42. GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5
  43. GRB 260808A: GECAM-B observation
  44. GRB 250607A: SVOM/ECLAIRs detection through offline targeted search
  45. GRB 260808A: CALET Gamma-Ray Burst Monitor detection
  46. GRB 260804A: CALET Gamma-Ray Burst Monitor detection
  47. GRB 260808A: NuSTAR detection of prompt emission
  48. GRB 260808C: Fermi GBM Final Real-time Localization
  49. GRB 260808A: BALROG localization (Fermi Trigger 807850307 / GRB 260808119)
  50. Fermi GRB 260808A: Global MASTER-Net observations report
  51. GRB 260808A: Fermi GBM Final Real-time Localization
  52. IceCube-260807A - IceCube observation of a high-energy neutrino candidate track-like event
  53. GRB 260715A: cubesat Avion detection
  54. GRB 260709A: cubesat Avion detection
  55. GRB 260708A: cubesat Avion detection
  56. SN 2026stf / GRB 260708A: ATLAS forced photometry
  57. IceCube-260805A - IceCube observation of a high-energy neutrino candidate track-like event
  58. GRB 260805B: Glowbug gamma-ray detection
  59. Fermi GRB 260805A: Global MASTER-Net observations report
  60. GRB 260805B: Fermi GBM Final Localization
  61. GRB 260804A: Glowbug gamma-ray detection
  62. GRB 260805B: BALROG localization (Fermi Trigger 807622617 / GRB 260805484)
  63. GRB 260805A: Fermi GBM Final Localization
  64. GRB 260708A / SN 2026stf: Spectroscopic host redshift z = 0.055 and confirmation of an associated type Ic-BL supernova
  65. GRB 260804A: Fermi GBM Final Real-time Localization
  66. GRB 260708A: LCO further optical observations show supernova features
  67. GRB 260803A: Fermi GBM Final Real-time Localization
  68. Fermi GRB 260802B: Global MASTER-Net observations report
  69. GRB 260802B: Fermi GBM Final Localization
  70. GRB 260618B: SVOM/VT continued optical observations indicated a steeper and redder decay
  71. Fermi-LAT Gamma-ray Observations of IceCube-260722A
  72. GRB 260726A: SVOM/ECLAIRs refined analysis
  73. GRB260730A: Fermi GBM Final Localization
  74. GRB 260726A: EP-FXT follow-up observations
  75. GRB 260726A: Fermi GBM Observation
  76. GRB 260726A: Liverpool Telescope optical observations
  77. GRB 260728A: Fermi GBM Final Localization
  78. GRB 260726A: J-band upper limit with WINTER
  79. GRB 260726A: SVOM/VT optical candidate
  80. GRB 260727B: Fermi GBM Final Real-time Localization
  81. Fermi GRB 260726A: Global MASTER-Net observations report
  82. GRB 260726A: SVOM detection of a burst
  83. GRB 260726A: Fermi GBM Final Real-time Localization
  84. GRB 260616A: cubesat Avion detection
  85. GRB 260602B: cubesat Avion detection
  86. GRB 260601A: cubesat Avion detection
  87. GRB 260718A: SVOM/ECLAIRs refined analysis
  88. Fermi Gamma-ray Burst Monitor trigger 806592752 / 260724564 is not a GRB
  89. GRB 260723A: Fermi GBM Final Localization
  90. GRB 260722A: Fermi GBM Final Real-time Localization
  91. IceCube-260722A - IceCube observation of a high-energy neutrino candidate track-like event
  92. Fermi GBM trigger 806384210/260722151 is not a GRB
  93. Konus-Wind detection of GRB 260714B
  94. GRB 260714B: Insight-HXMT/HE detection
  95. GRB 260718A: EP-FXT follow-up observation
  96. Fermi trigger No 806104130: Global MASTER-Net observations report
  97. Fermi GRB 260718A: Global MASTER-Net observations report
  98. GRB 260718A: LCO optical upper limits
  99. GRB 260710A: SVOM/GRM observation
  100. GRB 260718A: Fermi GBM Observation

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