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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"

27467 results found.

  1. GRB 260513A: Fermi GBM Final Real-time Localization
  2. GRB 260509A: SVOM/VT optical observations
  3. The EP-WXT trigger 01709262036 is likely a flaring star
  4. EP260512a: COLIBRÍ optical upper limits
  5. EP260512a: Einstein Probe detection of an X-ray transient
  6. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  7. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  8. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  9. GRB 260512A: Fermi GBM Final Real-time Localization
  10. GRB 260511B: SAO RAS optical observations
  11. GRB 260511A: EP-FXT follow-up observation
  12. GRB 260511B: EP-FXT follow-up observation
  13. GRB 260511B: LCO optical counterpart detection
  14. GRB260511B: MAO/AZT-22 optical observations
  15. GRB 260511A: SVOM/VT optical observations
  16. GRB 260511B: LCO optical observations
  17. GRB 260511B: GOTO optical counterpart detection
  18. GRB 260511B: Xinglong 2.16m/BEFOSC redshift confirmation
  19. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  20. GRB 260511B: SVOM/VT optical observations
  21. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  22. GRB 260510B: EP-FXT follow-up observation
  23. GRB 260511B: OSIRIS+/GTC redshift z=2.006
  24. GRB 260510C: Fermi GBM Observation
  25. GRB 260509A: SAO RAS optical observations
  26. GRB 260511A: REM near-infrared detection
  27. GRB 260511B: GROWTH-India Telescope optical observations
  28. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  29. GRB 260511B: Fermi GBM Detection
  30. GRB 260511C: Fermi GBM Final Real-time Localization
  31. GRB 260511B: SVOM/VT optical observation with VHF data
  32. GRB 260511B: TRT optical observation
  33. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  34. GRB 260511A: Fermi GBM Detection
  35. GRB 260511B SVOM/C-GFT optical counterpart detection
  36. GRB 260511A: UTGO H50 optical afterglow observation
  37. GRB 260511B: SVOM detection of a burst
  38. GRB 260511B: Fermi GBM Final Real-time Localization
  39. GRB 260510C: EP-FXT follow-up observation
  40. GRB 260511A: SVOM/VT optical observation with VHF data
  41. Fermi GRB 260511A: Global MASTER-Net observations report
  42. GRB 260511A: KAIT optical afterglow observations
  43. GRB 260511A: LCO optical afterglow detection
  44. GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
  45. GRB 260511A: SVOM detection of a bright burst
  46. GRB 260511A: BALROG localization (Fermi Trigger 800172815 / GRB 260511259)
  47. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  48. GRB 260511A: Fermi GBM Final Real-time Localization
  49. GRB 260510B: SVOM/VT optical upper limits
  50. GRB 260510C: SVOM/VT optical upper limits
  51. GRB 260510C: MAXI/GSC detection
  52. EP260509a: Global MASTER-Net observations report
  53. Fermi GBM Sub-Threshold Detection of GRB 260510B
  54. GRB 260510D: Fermi GBM Final Real-time Localization
  55. GRB 260510C: SVOM detection of a burst
  56. GRB 260510C: Fermi GBM Final Real-time Localization
  57. GRB 260510B: LCO optical upper limits
  58. GRB 260509A: Liverpool Telescope optical observations
  59. GRB 260510B: SVOM detection of a burst
  60. GRB 260509A: NOT spectroscopic redshift upper limit z < 1.95
  61. SVOM GRB 260509A: MASTER-OAFA optical observation
  62. Fermi GRB 260510A: Global MASTER-Net observations report
  63. GRB 260510A: Fermi GBM Final Real-time Localization
  64. GRB 260509A: SVOM/VT optical candidate with VHF data
  65. GRB 260509A: LCO optical counterpart detection
  66. GRB 260509A: GOTO optical counterpart candidate
  67. GRB 260509A: SVOM detection of a burst
  68. EP260507a: REM optical/NIR observations
  69. GRB 260507B / EP260507a: Fermi-GBM Sub-Threshold Detection
  70. EP260507a: COLIBRÍ optical observations
  71. EP260507a: SVOM/VT optical observations
  72. EP260507a: Liverpool Telescope optical upper limits
  73. GRB 260507A: Fermi GBM Final Real-time Localization
  74. EP260507a: GOTO optical counterpart detection
  75. EP260507a: TRT optical counterpart detection
  76. EP260507a: Kinder optical counterpart candidate
  77. EP260507a: LCO optical counterpart
  78. GRB 260504B: SVOM/ECLAIRs refined analysis
  79. GRB 260506B: BALROG localization (Fermi Trigger 799765648 / GRB 260506547)
  80. GRB 260506B: Fermi GBM Final Real-time Localization
  81. EP260502a is likely a flaring star
  82. Fermi GRB 260506A: Global MASTER-Net observations report
  83. GRB 260506A: Fermi GBM Final Real-time Localization
  84. IceCube Alert 260505A: Global MASTER-Net observations report
  85. GRB 260504B: SVOM/VT optical upper limits
  86. GRB 260504C: SVOM/GRM observation of short GRB
  87. GRB 260504B: SVOM/MXT refined analysis and potential detection
  88. GRB 260503A: SVOM/GRM observation of a GRB
  89. GRB 260310A / AT2026fgk: photometric monitoring and tentative maximum of a possible SN
  90. GRB 260504B: REM optical/NIR observations
  91. IPN triangulation of GRB 260429A
  92. GRB 260504B: LCO z-band upper limit
  93. SVOM GRB 260504B: MASTER-OAFA optical observations
  94. GRB 260504B: SVOM detection of a short burst
  95. Fermi GRB 260504A: Global MASTER-Net observations report
  96. GRB 260504A: Fermi GBM Final Real-time Localization
  97. GRB 260503A: Fermi GBM Final Real-time Localization
  98. GRB 260502A: Fermi GBM Final Localization
  99. The EP-WXT trigger 01709261576 is likely a flaring star
  100. GRB 260429B / EP260429a: EP-FXT follow-up observation

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