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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"

14820 results found.

  1. EP240816a: PRIME upper limits
  2. Trigger 1249653: Swift detection of SGR 1E 1841-045 / Kes 73
  3. GRB 240820A: Fermi GBM Final Real-time Localization
  4. GRB 240814A: SVOM/GRM observation
  5. GRB 240814C: SVOM/GRM observation
  6. EP240816a: BOOTES-6/DPRT optical upper limit
  7. GRB 240815A: SVOM/GRM observation
  8. GRB 240817A: Fermi GBM Final Real-time Localization
  9. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  10. GRB 240814B: GRBAlpha detection
  11. EP240816a: EP detection of a fast X-ray transient and follow-up observation
  12. EP240816b: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  13. GRB 240814C: Fermi GBM Final Real-time Localization
  14. GRB 240812B: SVOM/GRM observation
  15. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  16. GRB 240814B: Fermi GBM Final Real-time Localization
  17. GRB 240814A: Fermi GBM Final Real-time Localization
  18. Konus-Wind detection of GRB 240811A
  19. Konus-Wind detection of GRB 240810A
  20. GRB 240810A: SVOM/GRM observation
  21. GRB 240809A: ATA radio non-detection
  22. GRB 240812D: Fermi GBM Final Real-time Localization
  23. GRB 240812C: Fermi GBM Final Real-time Localization
  24. GRB 240809A: VLA detection
  25. GRB 240809A: ALMA detection
  26. IPN triangulation of GRB 240810A (short)
  27. EP240807a: PRIME H-band upper limits
  28. GRB 240812B: AstroSat CZTI detection of a long burst
  29. GRB 240812A: Fermi GBM Final Real-time Localization
  30. Konus-Wind detection of GRB 240809A
  31. GRB 240811A: Swift detection of a burst
  32. GRB 240810A: Fermi GBM Final Real-time Localization
  33. GRB 240809A: REM detection of the optical afterglow
  34. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  35. GRB 240809A: Conclusive redshift from VLT
  36. GRB 240808A: AstroSat CZTI detection
  37. GRB 240809A: GIT afterglow observations
  38. GRB 240809B: MAXI/GSC detection
  39. GRB 240809A: Swift/UVOT Detection
  40. IPN triangulation of GRB 240807A / EP 240807a
  41. X-ray Transient EP240807a: PRIME near-infrared upper limits
  42. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  43. GRB 240809A: SVOM/GRM observation
  44. GRB 240808A: SVOM/GRM observation
  45. GRB 240807A: SVOM/GRM observation
  46. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  47. GRB 240807B: AstroSat CZTI detection of a short burst
  48. IceCube-240808A - IceCube observation of a high-energy neutrino candidate track-like event
  49. GRB 240801A: GRBAlpha detection
  50. GRB 240807B: Fermi GBM Final Localization
  51. GRB 240710B: VZLUSAT-2 detection
  52. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  53. GRB 240720B: VZLUSAT-2 detection
  54. GRB 240710A: VZLUSAT-2 detection
  55. EP240806A: Liverpool Telescope optical follow-up observations
  56. The EP-WXT trigger 01709018832 on August 7th is likely a flaring star
  57. GRB 240807A: Fermi GBM Final Localization
  58. EP240807a: EP-WXT detection of a fast X-ray transient
  59. EP240806a: Gemini North-GMOS spectroscopic redshift of z = 2.818
  60. GRB 240805B: GIT optical upper limit
  61. EP240806a: LCOGT optical counterpart detection
  62. Konus-Wind detection of GRB 240802A (EP240802a)
  63. Konus-Wind detection of GRB 240805A
  64. GRB 240805B: JinShan optical afterglow detection
  65. Konus-Wind detection of GRB 240804B (a counterpart of EP240804a)
  66. EP240806a: EP-FXT detection of the X-ray emission
  67. GRB 240626B: VZLUSAT-2 detection
  68. GRB 240624B: VZLUSAT-2 detection
  69. GRB 240619C: VZLUSAT-2 detection
  70. EP240806a: GSP optical counterpart detection
  71. EP240806a: EP-WXT detection of a fast X-ray transient
  72. GRB 240805B: Optical detection with 1.6m Mephisto
  73. EP240804a: BOOTES-6/DPRT optical detection
  74. GRB 240805A: SVOM/GRM observation
  75. GRB 240805B: JinShan optical upper limits
  76. GRB 240805B: Swift detection of a burst
  77. GRB 240805A: Fermi-LAT detection
  78. EP240804a: LCOGT optical counterpart detection
  79. EP240804a: NOT optical counterpart detection
  80. EP240804a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  81. GRB 240805A: Swift detection of a burst
  82. GRB 240805A: Fermi GBM Final Real-time Localization
  83. GRB 240804A: Fermi GBM Final Real-time Localization
  84. IPN triangulation of GRB 240802A / EP 240802a
  85. GRB 240802A: SVOM/GRM observation
  86. EP240802a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  87. GRB 240802A: AstroSat CZTI detection of a long burst
  88. EP240801a: GRANDMA and Kilonova-Catcher optical observations
  89. EP240801a: JinShan optical observations
  90. GRB 240727C: SVOM/GRM observation
  91. EP240801a: GSP follow-up observations of the candidate counterpart
  92. EP240801a: TRT optical counterpart detection
  93. EP240801a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  94. GRB 240801B: AstroSat CZTI detection of a bright long burst
  95. GRB 240801A: Fermi GBM Final Real-time Localization
  96. GRB 240730C: AstroSat CZTI detection of a long burst
  97. GRB 240731A: Fermi GBM Final Localization
  98. GRB 240731A: AstroSat CZTI detection
  99. GRB240730A: BOOTES-5/JGT early optical upper limit
  100. GRB 240730B: Fermi GBM Final Real-time Localization

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