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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"

27028 results found.

  1. EP260903a: EP-WXT detection of a fast X-ray transient
  2. GRB 260830A: Insight-HXMT/HE detection
  3. GRB 260903A: EP-FXT follow-up observation
  4. GRB 260903A: NOT optical observations and afterglow fading
  5. NuSTAR Transient 260828: SOAR Optical Upper Limits
  6. GRB 260903A: LCO optical observations
  7. GRB 260903A: SVOM/VT optical candidate
  8. GRB 260831A: GECAM-B observation
  9. GRB 260903A: LCO optical counterpart detection
  10. GRB 260827A: Insight-HXMT/HE detection
  11. GRB 260903A: SVOM detection of a soft faint burst
  12. EP260901a: SVOM/VT optical upper limits
  13. EP260901a: EP-FXT follow-up observation
  14. GRB 260829A: SVOM/GRM observation
  15. GRB 260818A: ATCA detection of a candidate radio counterpart
  16. EP260830a: EP-FXT follow-up observation
  17. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  18. GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
  19. NuSTAR Transient 260828: LCO Optical Upper Limits
  20. EP260901a: EP-WXT detection of a fast X-ray transient
  21. GRB 260829A: AstroSat CZTI detection
  22. GRB 260831B: EP-FXT follow-up observation
  23. GRB 260830A: NuSTAR detection of prompt emission
  24. GRB 260831B: LCO optical upper limits
  25. EP260830a: EP-WXT detection of a fast X-ray transient
  26. GRB 260827A: SVOM/GRM observation
  27. NuSTAR 260828: a 1100s hard X-ray transient
  28. GRB 260831B: SVOM detection of a possible burst
  29. IPN triangulation of GRB 260829A
  30. GRB 260827A: Glowbug gamma-ray detection
  31. EP260727a: ATCA 10 GHz detection
  32. GRB 260831A: Fermi GBM Final Real-time Localization
  33. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  34. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  35. GRB 260829A: GECAM-B observation of a long burst
  36. GRB 260825A: SVOM/GRM observation of a long burst
  37. GRB 260825A: GECAM-B observation
  38. GRB 260829A: Fermi GBM Detection
  39. GRB 260825A: AstroSat CZTI detection
  40. GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
  41. GRB 260829A: Fermi GBM Final Real-time Localization
  42. Fermi GBM trigger 809666623/260829141 is not a GRB
  43. GRB 260818B: Further EP-FXT observation
  44. GRB 260818B: VLT optical and nIR observations
  45. GRB 260818B: TNG NIR observations
  46. IceCube-260827A - IceCube observation of a high-energy neutrino candidate track-like event
  47. The EP-WXT trigger 01709291839 is likely the known LMXB 4U 1745-203
  48. GRB 260827A: Fermi GBM Final Real-time Localization
  49. GRB 260818B: 6 GHz VLA observations
  50. GRB 260818B: SVOM/VT optical upper limit and continuous observations
  51. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  52. GRB 260808B: SAO RAS observations of the optical rebrightening
  53. IceCube-260825A: No transient candidates from the Zwicky Transient Facility
  54. GRB 260807A: EP-FXT follow-up observations
  55. GRB 260822A: SVOM/ECLAIRs refined analysis
  56. GRB 260809A: SVOM/ECLAIRs refined analysis
  57. GRB 260822A: SVOM/VT optical upper limits
  58. GRB 260825A: Fermi GBM Final Real-time Localization
  59. IceCube-260825A - IceCube observation of a high-energy neutrino candidate track-like event
  60. GRB 260822A: PRIME near-infrared upper limits from multiple epochs
  61. GRB 260822A: EP/FXT follow-up observations
  62. GRB 260822A: the candidate optical afterglow is an unrelated type-Ia SN
  63. GRB 260818A: further EP-FXT observations and X-ray afterglow confirmation
  64. EP260822a: EP-FXT non-detection and upper limit
  65. GRB 260822A: GOTO optical counterpart detection
  66. GRB 260822A: SVOM/VT optical detection of COLIBRÍ candidate
  67. GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  68. EP260822a: Einstein Probe detection of a fast X-ray transient
  69. GRB 260822A: LCO optical upper limits
  70. The EP-WXT trigger 01709287395 is likely a flaring star
  71. GRB260822B: Fermi GBM Final Localization
  72. GRB 260822A: GOTO optical upper limit
  73. GRB 260822A: SVOM detection of a short burst
  74. Fermi-LAT Gamma-ray Observations of IceCube-260821A
  75. Fermi-LAT Gamma-ray Observations of IceCube-260807A
  76. GRB 260818B: SVOM/C-GFT optical upper limit
  77. EP260731a: SVOM/ECLAIRs detection through offline targeted search
  78. The EP-WXT trigger 01709286204 is likely a flaring star
  79. GRB 260820A: Insight-HXMT/HE detection
  80. IceCube-260821A - IceCube observation of a high-energy neutrino candidate track-like event
  81. GRB 260818B: SVOM/GRM observation
  82. EP detected a brightening of LMXB 1ES 1735-26.9
  83. GRB260820A: Fermi GBM Final Real-Time Localization
  84. GRB 260818B: Insight-HXMT detection
  85. GRB 260818B: EP-FXT follow-up observation
  86. GRB 260818A: J-band observations with WINTER
  87. GRB 260818B: SVOM/ECLAIRs refined analysis
  88. GRB 260818A: SVOM/ECLAIRs refined analysis
  89. GRB 260818B: NOT optical upper limits
  90. GRB 260810A: SVOM/GRM observation
  91. GRB260818A: EP-FXT follow-up observation
  92. GRB 260818B: LCO optical upper limits
  93. GRB 260818B: SVOM detection of a short burst
  94. EP260806a: SAO RAS multicolor optical observations
  95. GRB 260818A: LCO optical upper limits
  96. EP260812a: AbAO optical upper limit
  97. GRB 260810A: Insight-HXMT/HE detection
  98. GRB 260818A: SVOM possible detection of a long and faint GRB
  99. EP260806a: SVOM/ECLAIRs detection through targeted search
  100. EP260806a: NUTTELA-TAO optical observations

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