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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"

28100 results found.

  1. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  2. sb26021801: SVOM detection of a long faint X-ray transient
  3. EP-WXT 01709258455: NOT optical upper limits
  4. EP260214b: Mondy optical observations
  5. EP260214b: 1.3m DFOT optical upper limit
  6. EP260210a: Mondy optical upper limits
  7. GRB 260208A: AbAO and Terskol optical upper limits
  8. GRB 260208A: continued Mondy optical observations
  9. IPN triangulation of GRB 260212A
  10. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  11. EP260214b: Liverpool Telescope optical observations
  12. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  13. EP260214b: Optical upper limit with Kinder observations
  14. EP260214a: Optical upper limits with Kinder observations
  15. EP260214b: EP-FXT follow-up observation
  16. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  17. EP260214b: DDOTI Optical Detection
  18. EP260214b: GROWTH-India Telescope optical upper limit
  19. EP260214a: VLT near-infrared observation
  20. EP260214a: NOT optical upper limits
  21. EP260214a: COLIBRÍ optical upper limits
  22. EP260214b: OHP/T120 optical observations
  23. EP260214a: refined analysis of the EP-FXT observation
  24. EP260214b: LCO optical counterpart detection
  25. GRB 260211A: SVOM/VT optical counterpart
  26. EP260214b: COLIBRÍ optical observations
  27. EP260214b: NOT optical counterpart detection
  28. EP260214b: Einstein Probe detection of a fast X-ray transient
  29. EP260214a: Global MASTER-Net observations report
  30. EP260214a: Einstein Probe detection of an X-ray transient
  31. GRB 260212A: AstroSat CZTI detection
  32. GRB 260212A: Fermi GBM Observation
  33. EP260213a: Liverpool Telescope optical upper limits
  34. EP260213a: Global MASTER-Net observations report
  35. EP260213a: COLIBRÍ optical upper limits
  36. EP260213a: Optical upper limits with Kinder observations
  37. EP260213a: Mondy R-band optical upper limit
  38. EP260213a: SVOM/C-GFT upper limit
  39. EP260213a: refined analysis of the EP-FXT observation
  40. EP260213a: Einstein Probe detection of a fast X-ray transient
  41. EP/WXT 01709258378: NOT optical upper limits
  42. GRB 260212A: SVOM/GRM observation of a long burst
  43. GRB 260213B: BALROG localization (Fermi Trigger 792697214 / GRB 260213736)
  44. GRB 260211A: EP-FXT follow-up observation
  45. GRB 260211A: SVOM/VT optical observation
  46. GRB 260212A: Glowbug gamma-ray detection
  47. Fermi GRB 260212A: Global MASTER-Net observations report
  48. GRB 260211A: LAST optical upper limit
  49. GRB 260210A: SVOM/GRM observation
  50. Fermi GBM Sub-Threshold Detection of GRB 260211A
  51. GRID detection of GRB 260207B
  52. GRB 260211A: LCO optical upper limits
  53. GRB260131A/B: 3.6m DOT Optical Observations
  54. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  55. Fermi trigger No 792537871: Global MASTER-Net observations report
  56. Swift Operations Update + Community Forum (Friday, February 13 @ 10:00 AM EST)
  57. EP260209a: COLIBRÍ optical upper limit
  58. Fermi GRB 260210C: Global MASTER-Net observations report
  59. EP260209a: LCO optical upper limits
  60. EP260210a: Global MASTER-Net observations report
  61. EP260210a: refined analysis of the EP-FXT observation
  62. EP260209a: Global MASTER-Net observations report
  63. GRB 260208A: LCO detection of the optical counterpart
  64. EP260209a: Einstein Probe detection of a fast X-ray transient
  65. EP260210a: Optical upper limits with Kinder observations
  66. GRB 260210A: Glowbug gamma-ray detection
  67. GRB 260208C: AstroSat CZTI detection
  68. EP260210a: COLIBRÍ optical upper limit
  69. EP260210a: SVOM/C-GFT upper limit
  70. EP260210a: Einstein Probe detection of an X-ray transient
  71. GRB 260207B: AstroSat CZTI detection
  72. GRB 260208C: SVOM/GRM observation
  73. GRB 260204A: Swift-XRT afterglow detection
  74. GRB 260208B: AstroSat CZTI detection of a bright long burst
  75. GRB260208A: Liverpool Telescope optical follow-up observations
  76. GRB 260208A: Glowbug gamma-ray detection
  77. GRB 260208A: NuSTAR detection of prompt emission
  78. GRB 260208A: Fermi GBM Observation
  79. Fermi GRB 260209A: Global MASTER-Net observations report
  80. GRB 260208B: Swift-XRT observations
  81. GRB 260131A/B: continued Mondy optical observations
  82. GRB 260204A: Swift/UVOT Upper Limits
  83. GRB 260208B: COLIBRÍ optical observations
  84. GRB 260208A: Mondy optical observations
  85. GRB 260208A: 1.3m DFOT optical detection
  86. GRB 260208A: COLIBRÍ optical observations
  87. GRB 260208B: EP-FXT observation
  88. Fermi GRB 260208C: Global MASTER-Net observations report
  89. GRB 260208B: SVOM/VT optical candidate
  90. GRB 260208A: GECAM-B observation of a bright burst
  91. GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
  92. GRB 260208A: SVOM/VT optical observation
  93. Fermi GRB 260208D: Global MASTER-Net observations report
  94. GRB 260208A: Swift-XRT observations
  95. GRB 260208B: SVOM/GRM observation of a bright burst
  96. GRB 260208B: Fermi GBM Detection
  97. LAT GRB 260208B: Global MASTER-Net observations report
  98. GRB 260208A : MASTER bright optical transient inside retracted Fermi error-box
  99. GRB 260208B: BALROG localization (Fermi Trigger 792237169 / GRB 260208412)
  100. Fermi GRB 260208A: Global MASTER-Net observations report

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