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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"

3323 results found.

  1. The EP-WXT trigger 01709258631 is likely a flaring star
  2. EP260213a: Mephisto optical upper limits
  3. EP260223a: EP-FXT follow-up observation
  4. EP260223a: Einstein Probe detection of an X-ray transient
  5. EP260221a: Optical upper limit with Kinder observations
  6. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  7. EP260221a: COLIBRÍ optical counterpart candidate
  8. EP260221a: Gemini South z-band upper limit
  9. EP260221a: Global MASTER-Net observations report
  10. EP260221a: EP-FXT follow-up observation
  11. EP-WXT01709258519: Xinglong optical upper limit
  12. EP260221a: Xinglong optical upper limit
  13. EP260221a: GOTO optical upper limit
  14. EP260221a: COLIBRÍ optical upper limit
  15. EP260221a: Einstein Probe detection of an X-ray transient
  16. The EP-WXT trigger 01709258519 is likely caused by Mrk 421
  17. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  18. The EP-WXT trigger 01709258455 is likely a flaring star
  19. EP-WXT 01709258455: NOT optical upper limits
  20. EP260214b: 1.3m DFOT optical upper limit
  21. EP260210a: Mondy optical upper limits
  22. Konus-Wind detection of GRB 260212A
  23. EP260214b: Liverpool Telescope optical observations
  24. EP260214b: Optical upper limit with Kinder observations
  25. EP260214a: Optical upper limits with Kinder observations
  26. EP260214b: EP-FXT follow-up observation
  27. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  28. EP260214b: GROWTH-India Telescope optical upper limit
  29. EP260214a: VLT near-infrared observation
  30. EP260214a: NOT optical upper limits
  31. EP260214a: COLIBRÍ optical upper limits
  32. EP260214a: refined analysis of the EP-FXT observation
  33. EP260214b: LCO optical counterpart detection
  34. GRB 260211A: SVOM/VT optical counterpart
  35. EP260214a: SVOM/VT optical upper limits
  36. EP260214b: NOT optical counterpart detection
  37. EP260214b: Einstein Probe detection of a fast X-ray transient
  38. EP260214a: Global MASTER-Net observations report
  39. EP260214a: Einstein Probe detection of an X-ray transient
  40. EP260213a: Liverpool Telescope optical upper limits
  41. EP260213a: Global MASTER-Net observations report
  42. EP260213a: COLIBRÍ optical upper limits
  43. EP260213a: Optical upper limits with Kinder observations
  44. EP260213a: SVOM/VT optical upper limit
  45. EP260213a: NUTTelA-TAO Early Optical Limits
  46. EP260213a: SVOM/C-GFT upper limit
  47. EP260213a: refined analysis of the EP-FXT observation
  48. EP260213a: Einstein Probe detection of a fast X-ray transient
  49. EP/WXT 01709258378: NOT optical upper limits
  50. GRB 260211A: EP-FXT follow-up observation
  51. GRB 260211A: SVOM/VT optical observation
  52. Konus-Wind detection of GRB 260207B
  53. Konus-Wind detection of GRB 260209B
  54. Konus-Wind detection of GRB 260127B
  55. EP260209a: COLIBRÍ optical upper limit
  56. EP260209a: LCO optical upper limits
  57. EP260210a: Global MASTER-Net observations report
  58. EP260210a: refined analysis of the EP-FXT observation
  59. EP260209a: Global MASTER-Net observations report
  60. EP260209a: Einstein Probe detection of a fast X-ray transient
  61. EP260210a: Optical upper limits with Kinder observations
  62. EP260210a: SVOM/VT optical upper limit
  63. EP260210a: COLIBRÍ optical upper limit
  64. EP260210a: SVOM/C-GFT upper limit
  65. GRB 260208B: refined analysis of the EP-FXT observation
  66. EP260210a: Einstein Probe detection of an X-ray transient
  67. GRB 260208B: Swift-XRT observations
  68. GRB 260208B: EP-FXT observation
  69. EP260110a: Late GTC/EMIR near-infrared observations
  70. Konus-Wind detection of GRB 260121A
  71. GRB 260131A/B: EP/FXT X-ray afterglow detection
  72. EP260131a: Liverpool Telescope optical upper limits
  73. Konus-Wind detection of GRB 260128A / EP260128a
  74. Konus-Wind detection of GRB 260131A/B
  75. EP260131a: SVOM/VT optical observation
  76. EP260131a: Xinglong optical upper limit
  77. EP260131a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  78. EP260131a: Las Cumbres detection of an optical counterpart
  79. EP260131a: Einstein Probe detection of an X-ray transient
  80. EP260128a / GRB 260128A: NOT and TNG optical and NIR upper limits
  81. EP260128a: J band upper limit by SYSU 80cm infrared telescope
  82. GRB 260128A / EP260128a: Fermi-GBM Sub-Threshold Detection
  83. EP260128a: NOT optical counterpart candidate
  84. EP260128a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  85. EP260128a: Liverpool Telescope optical observations and possible counterpart
  86. EP260128a: LCO optical upper limits
  87. EP260126a: SVOM/VT optical upperlimit
  88. EP260128a: Global MASTER-Net observations report
  89. EP260128a: Einstein Probe detection of an X-ray transient
  90. EP260126a: Seimei/TriCCS optical upper limit
  91. The EP-WXT trigger 01709253145 is likely a flaring star
  92. EP260126a: EP-FXT follow-up observation
  93. EP260126a: Optical upper limit with Kinder observations
  94. EP260126a: Liverpool Telescope optical upper limits
  95. EP260126a: Further NOT optical upper limits
  96. EP260126a: COLIBRÍ optical upper limits
  97. EP260126a: NOT optical observations
  98. EP260126a: Einstein Probe detection of a fast X-ray transient
  99. Konus-Wind detection of GRB 260120B
  100. EP260119a: Xinglong optical upper limit

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