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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"

27776 results found.

  1. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  2. GRB 240820A: Fermi GBM Final Real-time Localization
  3. GRB 240819A: Swift ToO observations
  4. EP240816a: BOOTES-6/DPRT optical upper limit
  5. GRB 240817A: Fermi GBM Final Real-time Localization
  6. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  7. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  8. GRB 240814B: GRBAlpha detection
  9. EP240816a: EP detection of a fast X-ray transient and follow-up observation
  10. EP240816b: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  11. GRB 240814C: Fermi GBM Final Real-time Localization
  12. GRB 240812B: SVOM/GRM observation
  13. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  14. GRB 240814B: Fermi GBM Final Real-time Localization
  15. GRB 240814A: Fermi GBM Final Real-time Localization
  16. Konus-Wind detection of GRB 240811A
  17. Konus-Wind detection of GRB 240810A
  18. GRB 240809A: ATA radio non-detection
  19. GRB 240812D: Fermi GBM Final Real-time Localization
  20. GRB 240812C: Fermi GBM Final Real-time Localization
  21. GRB 240809A: VLA detection
  22. GRB 240809A: ALMA detection
  23. IPN triangulation of GRB 240810A (short)
  24. GRB 240811A: Swift-BAT refined analysis
  25. GRB 240809A: Swift-BAT refined analysis
  26. EP240807a: PRIME H-band upper limits
  27. GRB 240812B: AstroSat CZTI detection of a long burst
  28. GRB 240811A: Bassano Bresciano Observatory upper limit
  29. GRB 240811A: Swift-XRT refined Analysis
  30. GRB 240811A: Swift/UVOT Upper Limits
  31. GRB 240812A: Fermi GBM Final Real-time Localization
  32. GRB 240811A: LCOGT Optical Upper Limit
  33. GRB 240811A: Enhanced Swift-XRT position
  34. GRB 240811A: Upper limits with Mephisto
  35. Konus-Wind detection of GRB 240809A
  36. Swift GRB 240811A: Global MASTER-Net observations report
  37. GRB 240811A: Swift detection of a burst
  38. GRB 240810A: Fermi GBM Final Real-time Localization
  39. GRB 240809A: REM detection of the optical afterglow
  40. GRB 240809A: Bassano Bresciano Observatory optical observations
  41. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  42. GRB 240809A: Conclusive redshift from VLT
  43. GRB 240809A: KAIT optical observations
  44. GRB 240808A: AstroSat CZTI detection
  45. GRB 240809A: GIT afterglow observations
  46. GRB 240809B: MAXI/GSC detection
  47. GRB 240809A: Swift/UVOT Detection
  48. GRB 240809A: Swift-XRT refined Analysis
  49. IPN triangulation of GRB 240807A / EP 240807a
  50. X-ray Transient EP240807a: PRIME near-infrared upper limits
  51. Swift GRB 240809A: Global MASTER-Net observations report
  52. GRB 240809A: JinShan optical observations
  53. GRB 240809A: Enhanced Swift-XRT position
  54. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  55. GRB 240809A: SVOM/GRM observation
  56. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  57. GRB 240807B: AstroSat CZTI detection of a short burst
  58. IceCube-240808A - IceCube observation of a high-energy neutrino candidate track-like event
  59. GRB 240801A: GRBAlpha detection
  60. GRB 240807B: Fermi GBM Final Localization
  61. GRB 240710B: VZLUSAT-2 detection
  62. GRB 240805A: ATCA Radio Upper Limits
  63. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  64. GRB 240720B: VZLUSAT-2 detection
  65. GRB 240710A: VZLUSAT-2 detection
  66. EP240806A: Liverpool Telescope optical follow-up observations
  67. The EP-WXT trigger 01709018832 on August 7th is likely a flaring star
  68. GRB 240807A: Fermi GBM Final Localization
  69. EP240807a: EP-WXT detection of a fast X-ray transient
  70. EP240806a: Gemini North-GMOS spectroscopic redshift of z = 2.818
  71. GRB 240805B: GIT optical upper limit
  72. GRB 240805B: Swift-BAT refined analysis
  73. GRB 240805A: Swift-BAT refined analysis
  74. EP240806a: LCOGT optical counterpart detection
  75. Konus-Wind detection of GRB 240802A (EP240802a)
  76. Konus-Wind detection of GRB 240805A
  77. GRB 240805B Bassano Bresciano Observatory upper limit
  78. GRB240805A: Fermi GBM Observation
  79. GRB 240805B: JinShan optical afterglow detection
  80. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  81. Konus-Wind detection of GRB 240804B (a counterpart of EP240804a)
  82. EP240806a: EP-FXT detection of the X-ray emission
  83. GRB 240626B: VZLUSAT-2 detection
  84. GRB 240624B: VZLUSAT-2 detection
  85. GRB 240619C: VZLUSAT-2 detection
  86. EP240806a: GSP optical counterpart detection
  87. EP240806a: EP-WXT detection of a fast X-ray transient
  88. GRB 240805B: Optical detection with 1.6m Mephisto
  89. EP240804a: BOOTES-6/DPRT optical detection
  90. GRB 240805B: Swift-XRT refined Analysis
  91. GRB 240805B: Swift/UVOT Upper Limits
  92. GRB 240805A: Swift/UVOT Upper Limits
  93. GRB 240805A: SVOM/GRM observation
  94. GRB 240805B: Enhanced Swift-XRT position
  95. GRB 240805B: LCOGT Optical Upper Limits
  96. Swift GRB 240805B: Global MASTER-Net observations report
  97. GRB 240805B: JinShan optical upper limits
  98. Swift GRB 240805A: Global MASTER-Net observations report
  99. GRB 240805A: Swift-XRT refined Analysis
  100. GRB 240805B: Swift detection of a burst

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