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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

24359 results found.

  1. GRB 260516D: GROWTH-India Telescope optical detection
  2. GRB 260516D: SVOM/VT optical bright candidate
  3. Fermi GRB 260516C: Global MASTER-Net observations report
  4. SVOM GRB260516D: Global MASTER-Net observations report
  5. GRB 260516D: SVOM possible detection of a burst
  6. GRB 260516C: Fermi GBM Final Real-time Localization
  7. Konus-Wind detection of GRB 260515A
  8. GRB 260515A: EP-FXT follow-up observation
  9. EP260514a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  10. EP260514a: NOT optical counterpart confirmation
  11. EP260514a: TRT optical counterpart candidate
  12. EP260514a: SVOM/VT optical candidate
  13. Fermi GRB 260516B: Global MASTER-Net observations report
  14. GRB 260516B: Fermi GBM Final Real-time Localization
  15. GRB 260515A: SVOM/VT optical observations
  16. GRB 260516A: Fermi GBM Final Real-time Localization
  17. GRB 260515A: LCO optical observations
  18. SVOM GRB 260515A: Global MASTER-Net observations report
  19. SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
  20. GRB 260515A: SVOM/VT optical candidate from VHF data
  21. GRB 260515A: JinShan optical counterpart candidate
  22. GRB 260515A: SVOM detection of a burst
  23. IceCube-260504A: No Candidate Transients from the Zwicky Transient Facility
  24. EP260514a: GROWTH-India Telescope optical upper limit
  25. GRB 260511B: NOT optical observations
  26. Konus-Wind detection of GRB 260512A
  27. GRB 260510C: CALET Gamma-Ray Burst Monitor detection
  28. GRB 260511B: GMG Optical Upper Limit
  29. EP260514a: Global MASTER-Net observations report
  30. IPN triangulation of GRB 260512A
  31. GRB 260511B: Mephisto multi-band optical followup
  32. Fermi GRB 260514A: Global MASTER-Net observations report
  33. The EP-WXT trigger 01709262077 is likely a flaring star
  34. GRB 260514A: Fermi GBM Final Real-time Localization
  35. EP260512a: Global MASTER-Net observations report
  36. Fermi GRB 260513A: Global MASTER-Net observations report
  37. Fermi GRB 260512A: Global MASTER-Net observations report
  38. GRB 260513A: Fermi GBM Final Real-time Localization
  39. GRB 260509A: SVOM/VT optical observations
  40. Konus-Wind detection of GRB 260511B
  41. The EP-WXT trigger 01709262036 is likely a flaring star
  42. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  43. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  44. GRB 260512A: NuSTAR detection of prompt emission
  45. GRB 260512A: Fermi GBM Final Real-time Localization
  46. Konus-Wind detection of GRB 260511A
  47. GRB 260511A: EP-FXT follow-up observation
  48. GRB 260511B: EP-FXT follow-up observation
  49. GRB 260511B: LCO optical counterpart detection
  50. GRB 260511A: SVOM/VT optical observations
  51. GRB 260511B: LCO optical observations
  52. GRB 260511B: GOTO optical counterpart detection
  53. GRB 260511B: SVOM/VT optical observations
  54. GRB 260510B: EP-FXT follow-up observation
  55. GRB 260510C: Fermi GBM Observation
  56. GRB 260511A: REM near-infrared detection
  57. GRB 260511B: GROWTH-India Telescope optical observations
  58. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  59. GRB 260511B: NuSTAR detection of prompt emission
  60. GRB 260511A: NuSTAR detection of prompt emission
  61. GRB 260511B: Fermi GBM Detection
  62. GRB 260511C: Fermi GBM Final Real-time Localization
  63. GRB 260511B: SVOM/VT optical observation with VHF data
  64. GRB 260511B: TRT optical observation
  65. GRB 260510B: SVOM/ECLAIRs refined analysis
  66. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  67. GRB 260511A: Fermi GBM Detection
  68. GRB 260511B SVOM/C-GFT optical counterpart detection
  69. GRB 260511A: UTGO H50 optical afterglow observation
  70. GRB 260511B: SVOM detection of a burst
  71. GRB 260511B: Fermi GBM Final Real-time Localization
  72. GRB 260510C: EP-FXT follow-up observation
  73. GRB 260510C: SVOM/VT optical counterpart confirmation
  74. GRB 260511A: SVOM/VT optical observation with VHF data
  75. Fermi GRB 260511A: Global MASTER-Net observations report
  76. GRB 260511A: LCO optical afterglow detection
  77. GRB 260511A: TRT optical counterpart detection
  78. GRB 260511A: SVOM detection of a bright burst
  79. GRB 260511A: BALROG localization (Fermi Trigger 800172815 / GRB 260511259)
  80. GRB 260511A: Fermi GBM Final Real-time Localization
  81. GRB 260510B: SVOM/VT optical upper limits
  82. GRB 260510C: SVOM/VT optical upper limits
  83. GRB 260510C: MAXI/GSC detection
  84. EP260509a: Global MASTER-Net observations report
  85. Fermi GBM Sub-Threshold Detection of GRB 260510B
  86. GRB 260510D: Fermi GBM Final Real-time Localization
  87. GRB 260510B: GOTO early upper limit
  88. GRB 260510C: SVOM detection of a burst
  89. GRB 260510C: Fermi GBM Final Real-time Localization
  90. GRB 260510B: LCO optical upper limits
  91. GRB 260510B: SVOM detection of a burst
  92. GRB 260509A: LCO optical observations
  93. SVOM GRB 260509A: MASTER-OAFA optical observation
  94. Fermi GRB 260510A: Global MASTER-Net observations report
  95. GRB 260509A: KAIT optical observations
  96. GRB 260510A: Fermi GBM Final Real-time Localization
  97. GRB 260509A: SVOM/VT optical candidate with VHF data
  98. GRB 260509A: LCO optical counterpart detection
  99. GRB 260509A: GOTO optical counterpart candidate
  100. GRB 260509A: SVOM detection of a burst

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