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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"

32107 results found.

  1. Fermi GRB 240317A: Global MASTER-Net observations report
  2. GRB 240317B: Fermi GBM Final Real-time Localization
  3. GRB 240317A: Fermi GBM Final Real-time Localization
  4. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  5. GRID detection of GRB 240306A
  6. Changes to the Fermi-GBM Triggering Thresholds
  7. GRB 240315A: Fermi GBM Final Real-time Localization
  8. Fermi GRB 240314A: Global MASTER-Net observations report
  9. GRB 240314A: Fermi GBM Final Real-time Localization
  10. GRB 240312A: Glowbug gamma-ray detection
  11. Swift Trigger 1219905 is not a GRB
  12. GRB 240312A: GECAM detection of a long burst
  13. GRB 240303C: VZLUSAT-2 detection
  14. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  15. GRB 240310B: Glowbug gamma-ray detection
  16. Fermi GRB 240310A: Global MASTER-Net observations report
  17. GRB 240310A: Fermi GBM Final Real-time Localization
  18. GRB 240309A: MAXI/GSC detection
  19. Swift Trigger 1219325 is not a GRB
  20. GRID detection of GRB 240229A (Updated Report)
  21. GRID detection of GRB 240229A
  22. GRB 240308A: Fermi GBM Final Localization
  23. GRB 231215A: further radio observations with the VLA
  24. GRB 240306A: Fermi GBM observation
  25. GRB 240229A: Glowbug gamma-ray detection
  26. GRB 240227A (short): Glowbug gamma-ray detection
  27. GRB 240229A: GRBAlpha detection
  28. Konus-Wind detection of GRB 231118A
  29. GRB 240306A: AstroSat CZTI detection
  30. Fermi GRB 240306A: Global MASTER-Net observations report
  31. Fermi GRB 240305A: Global MASTER-Net observations report
  32. GRB 240306A: Swift/BAT-GUANO detection of a burst
  33. GRB 240305A: Fermi GBM observation
  34. GRB 240305C: AstroSat CZTI detection of a short burst
  35. GRB 240306A: Fermi GBM Final Real-time Localization
  36. Fermi GRB 240305C: Global MASTER-Net observations report
  37. GRB 240305C: Fermi GBM Final Real-time Localization
  38. GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
  39. GRB 231028C: Glowbug gamma-ray confirmation of a prior burst
  40. GRB 240218A: ALMA detection
  41. GRB 240218A: Chandra Detection and Jet Break Confirmation
  42. GRB 240305B: Fermi GBM Final Localization
  43. Konus-Wind detection of GRB 240227A (short/hard)
  44. GRB 240303B: VZLUSAT-2 detection
  45. GRB 240229A: VZLUSAT-2 detection
  46. Improved IPN triangulation of GRB 240227A (short)
  47. IPN triangulation of GRB 240229A
  48. GRB 240305A: Fermi GBM Final Real-time Localization
  49. Konus-Wind detection of GRB 240303B
  50. IPN triangulation of GRB 240303B
  51. GRB 240303B: Fermi GBM Detection
  52. GRB 240225B: Swift-XRT afterglow detection
  53. Swift detection of Swift J151857.0-572147
  54. GRB 240303B: CALET Gamma-Ray Burst Monitor detection
  55. GRB 240303C: BALROG localization (Fermi Trigger 731189113 / GRB 240303837)
  56. Swift GRB 240303A: Global MASTER-Net observations report
  57. Swift J151857.0-572147: Confirmation of a new galactic transient
  58. GRB 240215A: Swift-XRT afterglow detection
  59. GRB 240303B: BALROG localization (Fermi Trigger 731161136 / GRB 240303513)
  60. GRB 240303B: Fermi GBM Final Localization
  61. GRB 240303A: Swift detection of a burst
  62. GRB 240225B: Glowbug gamma-ray detection
  63. GRB 240225C: Glowbug gamma-ray detection
  64. GRB 240225A (short): Glowbug gamma-ray detection
  65. GRB 240229A: DDOTI Upper Limits on the Afterglow
  66. GRB 240218A: NOEMA upper limit
  67. GRB 240229A: CALET Gamma-Ray Burst Monitor detection
  68. GRB 240225B: further SAO RAS optical observations
  69. Fermi GRB 240229A: Global MASTER-Net observations report
  70. GRB 240225B: Swift ToO observations
  71. Konus-Wind detection of GRB 240225B (long)
  72. GRB 240229A: BALROG localization (Fermi Trigger 730908432 / GRB 240229588)
  73. GRB 240229A: Fermi GBM Final Real-time Localization
  74. GRB 240225B: VLT/X-shooter redshift
  75. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  76. GRB 240225B: 3.6m DOT observation
  77. GRB 240225B: WINTER near-IR observations and upper limits
  78. GRB 240225B: SAO RAS optical observations
  79. GRB 240226A: GRBAlpha detection
  80. GRB 240225B: Mondy afterglow observations
  81. Fermi GRB 240227A: Global MASTER-Net observations report
  82. GRB 240225B: Liverpool Telescope afterglow observations
  83. Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
  84. Swift Trigger 1217799 is not a GRB
  85. IPN triangulation of GRB 240227A (short)
  86. GRB 240225B: Liverpool Telescope optical afterglow observations
  87. GRB 240225B: NOT optical observations
  88. GRB 240218A: CMO SAI NIR upper limit
  89. Fermi GRB 240226A: Global MASTER-Net observations report
  90. GRB 240227A: Fermi GBM Final Real-time Localization
  91. Fermi Gamma-ray Burst Monitor trigger 730618809/240226236 is not a GRB
  92. GRB 240225B: Nanshan/HMT optical afterglow detection
  93. GRB 240225B: CALET Gamma-Ray Burst Monitor detection
  94. GRB 240225B: Swift-XRT observations
  95. GRB 240226B: Fermi GBM Final Real-time Localization
  96. GRB 240225C: CALET Gamma-Ray Burst Monitor detection
  97. GRB 240225B: GOTO detection of a candidate optical afterglow
  98. GRB 240226A: Fermi GBM Final Real-time Localization
  99. GRB 240225C: GRBAlpha detection
  100. GRB 240222A: ATCA radio observations

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