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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

6805 results found.

  1. EP261010a: NOT optical upper limits
  2. EP261006a: Xinglong 2.16m/BFOSC optical follow-up observations
  3. EP261007b: NOT optical observations, variable source outside the FXT region
  4. EP261006a: Swift/XRT detection of the fading X-ray counterpart
  5. GRB 261007A/EP261007a: Optical follow-up observations with Kinder
  6. EP261006a: Optical follow-up observations with Kinder
  7. GRB 261007A: Swift-XRT afterglow detection
  8. GRB 261007A: Fermi GBM observation
  9. GRB 261005B: Swift-XRT refined Analysis
  10. GRB 261005B: Fermi GBM Observation
  11. EP#01709320865: Swift-XRT observations
  12. Konus-Wind detection of GRB 260919A / EP 260920a
  13. Fermi-LAT Gamma-ray Observations of IceCube-260930A
  14. EP260927a: Einstein Probe detection of a fast X-ray transient
  15. GRB 260925A: Swift-XRT refined Analysis
  16. EP260924a: EP-FXT follow-up observation
  17. Konus-Wind detection of GRB 260924A
  18. GRB 260924A: Optical follow-up observations with Kinder
  19. GRB 260924A: Swift-XRT refined Analysis
  20. Konus-Wind detection of GRB 260921A (correction to GCN 45722)
  21. GRB 260924A: Fermi GRB Observation
  22. Konus-Wind detection of GRB 260921A (possible merger-origin)
  23. GRB 260924A: Fermi-LAT detection of a bright burst
  24. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  25. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  26. GRB 260922A: Swift-XRT refined Analysis
  27. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  28. GRB 260921A: Fermi GBM Observation
  29. EP260920a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  30. EP260917a: refined analysis of the EP-FXT observations
  31. GRB 260915A: Swift-XRT afterglow detection
  32. GRB 260916B: Fermi GBM Detection
  33. GRB 260909A: Swift-XRT observations
  34. GRB 260914A: EP-FXT follow-up observation
  35. GRB 260909A: OSN 1.5m, CAHA 2.2m and GTC 10.4m optical upper limits
  36. GRB 260903A: Swift-XRT observations
  37. GRB 260903A: SAO RAS optical upper limit
  38. EP260903a: EP-FXT follow-up observation
  39. GRB 260903A: SAO RAS optical observations
  40. NuSTAR Transient 260828: SOAR Optical Upper Limits
  41. EP260901a: EP-FXT follow-up observation
  42. EP260830a: EP-FXT follow-up observation
  43. NuSTAR Transient 260828: LCO Optical Upper Limits
  44. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  45. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  46. GRB 260829A: Fermi GBM Detection
  47. GRB 260818B: Further EP-FXT observation
  48. GRB 260808B: SAO RAS observations of the optical rebrightening
  49. GRB 260807A: EP-FXT follow-up observations
  50. GRB 260822A: EP/FXT follow-up observations
  51. GRB 260822A: GROWTH-India Telescope Upper Limits
  52. Fermi-LAT Gamma-ray Observations of IceCube-260821A
  53. Fermi-LAT Gamma-ray Observations of IceCube-260807A
  54. GRB 260818B: EP-FXT follow-up observation
  55. GRB260818A: EP-FXT follow-up observation
  56. EP260806a: SAO RAS multicolor optical observations
  57. EP260812b: Optical upper limit with Kinder
  58. EP260812a: NOT and Liverpool Telescope upper limits:
  59. GRB 260809A: SAO RAS optical observations
  60. GRB 260808B: SAO RAS optical observations
  61. GRB260809A/EPF_J234751.2+210212: EP-FXT follow-up observation
  62. GRB 260808B / EPF_J230056.0+082842: EP-FXT follow-up observation
  63. AT 2026wki: EP/FXT follow-up observations
  64. GRB 260802A / EP J223759.5+521421: EP-FXT follow-up observation
  65. GRB 260727A: EP-FXT further follow-up observations and candidate afterglow
  66. Fermi-LAT Gamma-ray Observations of IceCube-260722A
  67. EP260727a: SAO RAS optical observations
  68. EP260728a: EP-FXT follow-up observation
  69. GRB 260726A: EP-FXT follow-up observations
  70. GRB 260726A: Fermi GBM Observation
  71. Konus-Wind detection of GRB 260727A
  72. GRB 260727A: EP/FXT follow-up observations
  73. EP260723a: further EP-FXT follow-up observation
  74. EP260725a: EP-WXT detection of an X-ray transient
  75. EP260723a: EP-FXT follow-up observation
  76. GRB 260718A: EP-FXT follow-up observation
  77. GRB 260718A: Fermi GBM Observation
  78. GRB 260310A / AT2026fgk: Late-time Chandra Detection
  79. GRB 260618B: EP-FXT follow-up observation upper limit
  80. GRB 260714B: Fermi-LAT detection
  81. GRB 260714B: Fermi GBM Detection
  82. GRB 260708A: slowly decaying X-ray emission observed by EP/FXT
  83. EP260711a: EP-FXT follow-up observation
  84. Fermi-LAT Gamma-ray Observations of IceCube-260712A
  85. Fermi-LAT Gamma-ray Observations of IceCube-260708A
  86. Fermi-LAT Gamma-ray Observations of IceCube-260704A
  87. GRB 260710A: Fermi GBM Detection
  88. GRB 260708A: Fermi-GBM observation
  89. GRB 260708A: Fermi-LAT detection
  90. GRB 260706A: Further EP-FXT follow-up observation
  91. GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
  92. GRB 260706A: EP-FXT follow-up observation
  93. GRB 260706A: Fermi GBM Observation
  94. GRB 260704A: EP-FXT follow-up observation
  95. EP260703a: EP-FXT follow-up observation
  96. EP260628b: EP-WXT detection of an X-ray transient and EP-FXT follow-up observation
  97. Fermi-LAT Gamma-ray Observations of IceCube-260622A
  98. EP260628a: EP-FXT follow-up observation
  99. EP260626a: EP-FXT follow-up observation
  100. Konus-Wind detection of GRB 260623B / EP260623a

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