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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"

36398 results found.

  1. GRB 230415A: Swift/BAT-GUANO detection
  2. New GCN Circulars Portal for Rapid Communications on Astronomical Transients is Online
  3. GRB 230414B: 3.6m DOT Optical observations, slow decay at early epochs
  4. GRB 230307A: iTelescope optical upper limit (likely)
  5. GRB 230414B: Montarrenti Observatory late time optical afterglow detection
  6. GRB 230414B: Lulin 40cm-SLT optical limit
  7. GRB 230414B: Bassano Bresciano Observatory optical observations
  8. GRB 230414B: Redshift from OSIRIS/GTC
  9. GRB 230414B: AbAO optical observations
  10. GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
  11. GRB 230414B: Swift-XRT refined Analysis
  12. GRB 230414B: Dabancheng/GHOST optical observations
  13. GRB 230414B: slow optical light curve decay
  14. GRB 230414B: SAO RAS optical observations
  15. GRB 230414B: Enhanced Swift-XRT position
  16. GRB 230414B: 1.3m DFOT Optical observations
  17. Fermi GRB 230414A: Global MASTER-Net observations report
  18. GRB 230414B: GROWTH India Telescope afterglow confirmation
  19. GRB 230414B (correction GRB name in the GCN 33615): Mondy optical afterglow candidate
  20. GRB 230414B: Nanshan/HMT optical afterglow detection
  21. GRB 230414A: Mondy optical afterglow candidate
  22. Swift GRB 230414B: Global MASTER-Net observations report
  23. GRB 230414B: Prompt enhanced Swift-XRT position
  24. GRB 230414B: Swift detection of a burst
  25. GRB 230414A: Fermi GBM Final Real-time Localization
  26. GRB 230328B: redshift lower limit estimating
  27. GRB 230409B: Mondy optical upper limit
  28. GRB 230409B: OHP/T193 optical upper limit
  29. GRB 230410B: VZLUSAT-2 detection
  30. GRB 230409D: VZLUSAT-2 detection
  31. GRB 230410B: AGILE detection of a burst
  32. GRB 230410A: Fermi GBM Final Real-time Localization
  33. Fermi GRB 230409C: Global MASTER-Net observations report
  34. Fermi GRB 230409A: Global MASTER-Net observations report
  35. GRB 230409C: Fermi GBM Final Real-time Localization
  36. GRB 230409B: Swift-XRT refined Analysis
  37. GRB 230409B: Swift-BAT refined analysis
  38. Swift GRB 230409B: Global MASTER-Net observations report
  39. GRB 230409B: Swift/UVOT Detection
  40. GRB 230409B: Enhanced Swift-XRT position
  41. GRB 230409B: Swift detection of a burst
  42. GRB 230409A: Fermi GBM Final Real-time Localization
  43. GRB 230405B: VZLUSAT-2 detection
  44. Konus-Wind detection of GRB 230405B
  45. GRB 230405B: AGILE detection
  46. GRB 230405B: Swift-XRT refined Analysis
  47. GRB 230405B: Fermi GBM Observation
  48. GRB 230405B: MeerLICHT upper limits
  49. GRB 230307A: JWST NIRSpec observations, possible higher redshift
  50. GRB 230307A: further analysis of the Konus-Wind detection and rest-frame energetics
  51. GRB 230307A: good match with kilonova models
  52. GRB 230307A: short mininum variability timescale compatible with a merger origin
  53. GRB 230405B: Swift/UVOT Upper Limits
  54. GRB 230405B: AstroSat CZTI detection
  55. GRB 230405B: Enhanced Swift-XRT position
  56. Swift GRB 230405B: Global MASTER-Net observations report
  57. GRB 230405B: Prompt enhanced Swift-XRT position
  58. GRB 230405B: Swift detection of a burst
  59. GRB 230405B: Fermi GBM Final Real-time Localization
  60. GRB 230307A: JWST observations consistent with the presence of a kilonova
  61. Fermi GRB 230405A: Global MASTER-Net observations report
  62. GRB 230405A: Fermi GBM Final Real-time Localization
  63. GRB 230404A: AstroSat CZTI detection
  64. GRB 230404A: Fermi GBM Final Real-time Localization
  65. GRB 230402A: CALET Gamma-Ray Burst Monitor detection
  66. GRB 230402A: AstroSat CZTI detection
  67. GRB 230328B: Multa observatory optical afterglow observation
  68. GRB 230307A: Chandra late-time detection of the X-ray afterglow
  69. GRB 230228A: detection by GTC of the potential host galaxy
  70. GRB 230328B: Swift/UVOT Detection
  71. GRB 230402A: AGILE detection
  72. Fermi GRB 230402A: Global MASTER-Net observations report
  73. GRB 230402A: Fermi GBM Final Real-time Localization
  74. GRB 230307A: Bad Time Intervals for Fermi GBM data
  75. GRB 230328B : GRANDMA/Kilonova-Catcher optical detection
  76. GRB 230328B: CAHA 2.2m/CAFOS detection
  77. GRB 230328B: 3.6m DOT multiband optical observation
  78. GRB 230330B: Fermi GBM Final Localization
  79. Konus-Wind detection of GRB 230328B
  80. GRB 230328B: GRBAlpha detection
  81. GRB 230330A: Fermi GBM Final Real-time Localization
  82. GRB 230328B: Swift-BAT refined analysis
  83. GRB 230328B: Nanshan/NEXT 2nd optical observation
  84. GRB 230328B NUTTelA-TAO / BSTI Early Measurements
  85. GRB 230328B: Liverpool Telescope afterglow detection
  86. GRB 230328B: OHP/T120 optical observations
  87. GRB 230328B: GIT optical follow-up
  88. GRB 230328B: OASDG optical observations
  89. GRB 230328B: Nanshan/NEXT optical upper limit
  90. GRB 230328B: Swift-XRT refined Analysis
  91. GRB 230328B: AstroSat CZTI detection
  92. GRB 230328B: Fermi GBM observation
  93. GRB 230328B: Mondy, AbAO and Kitab optical observations
  94. GRB 230328B: Enhanced Swift-XRT position
  95. GRB 230328B: Mondy optical afterglow confirmation
  96. GRB 230328B: Swift detection of a burst with an optical afterglow
  97. GRB 230328B: Fermi GBM Final Real-time Localization
  98. Fermi GRB 230328A: Global MASTER-Net observations report
  99. GRB 230328A: Fermi GBM Final Real-time Localization
  100. GRB 230325A: Swift-BAT refined analysis

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