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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"

28096 results found.

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

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