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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').
  1. GRB Testing for Kafka
  2. GRB Testing
  3. GRB foobar
  4. GRB foobar test
  5. GRB testing 3
  6. GRB testing 2
  7. GRB testing
  8. GRB test 4
  9. GRB test 3
  10. GRB test 2
  11. GRB test
  12. GRB foobar
  13. GRB foobar
  14. LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
  15. LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
  16. GRB foobar
  17. GRB foobar
  18. PKS2326-505, millimeter wavelength flare, transient
  19. GRB foo 3
  20. GRB foo 2
  21. GRB foo
  22. GRB foo
  23. GRB foo
  24. GRB foo
  25. GRB test
  26. GRB foo
  27. GRB foobar
  28. GRB foobar
  29. GRB foobar
  30. GRB foobar
  31. GRB foobar
  32. GRB test
  33. MAGIC test
  34. GRB test
  35. GRB foo
  36. Test GCN GW submission
  37. GRB test 2
  38. GRB test
  39. GRB test
  40. Test GW GCN hermes submission 2
  41. Test GW GCN hermes submission
  42. Test GW GCN hermes submission
  43. A GRB test
  44. TEST GW GCN hermes submission
  45. GRB 170817A: an awesome GCN Circular
  46. VIRT optical transient detection
  47. GRB 230414B: 3.6m DOT Optical observations, slow decay at early epochs
  48. GRB 230307A: iTelescope optical upper limit (likely)
  49. GRB 230414B: Montarrenti Observatory late time optical afterglow detection
  50. IceCube-230416A: IceCube observation of a high-energy neutrino candidate
  51. Fermi trigger No 703284533: Global MASTER-Net observations report
  52. GRB 230414B: Lulin 40cm-SLT optical limit
  53. GRB 230414B: Bassano Bresciano Observatory optical observations
  54. GRB 230414B: Redshift from OSIRIS/GTC
  55. GRB 230414B: AbAO optical observations
  56. GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
  57. GRB 230414B: Swift-XRT refined Analysis
  58. GRB 230414B: Dabancheng/GHOST optical observations
  59. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230414A
  60. GRB 230414B: slow optical light curve decay
  61. GRB 230414B: SAO RAS optical observations
  62. GRB 230414B: Enhanced Swift-XRT position
  63. GRB 230414B: 1.3m DFOT Optical observations
  64. Fermi GRB 230414A: Global MASTER-Net observations report
  65. GRB 230414B: GROWTH India Telescope afterglow confirmation
  66. GRB 230414B (correction GRB name in the GCN 33615): Mondy optical afterglow candidate
  67. GRB 230414B: Nanshan/HMT optical afterglow detection
  68. GRB 230414A: Mondy optical afterglow candidate
  69. Swift GRB 230414B: Global MASTER-Net observations report
  70. GRB 230414B: Prompt enhanced Swift-XRT position
  71. GRB 230414B: Swift detection of a burst
  72. IceCube-230405A: BOOTES-4/MET Optical Upper Limits
  73. GRB 230414A: Fermi GBM Final Real-time Localization
  74. GRB 230328B: redshift lower limit estimating
  75. GRB 230409B: Mondy optical upper limit
  76. GRB 230409B: OHP/T193 optical upper limit
  77. GRB 230410B: VZLUSAT-2 detection
  78. GRB 230409D: VZLUSAT-2 detection
  79. GRB 230410B: AGILE detection of a burst
  80. GRB 230410A: Fermi GBM Final Real-time Localization
  81. Fermi GRB 230409C: Global MASTER-Net observations report
  82. Fermi GRB 230409A: Global MASTER-Net observations report
  83. GRB 230409C: Fermi GBM Final Real-time Localization
  84. GRB 230409B: Swift-XRT refined Analysis
  85. GRB 230409B: Swift-BAT refined analysis
  86. Fermi trigger No 702745263: Global MASTER-Net observations report
  87. Swift GRB 230409B: Global MASTER-Net observations report
  88. GRB 230409B: Swift/UVOT Detection
  89. GRB 230409B: Enhanced Swift-XRT position
  90. MAXI GRB230408.82: Global MASTER-Net observations report
  91. GRB 230409B: Swift detection of a burst
  92. GRB 230409A: Fermi GBM Final Real-time Localization
  93. GRB 230405B: VZLUSAT-2 detection
  94. IceCube-230405A: Upper limits from a search for additional neutrino events in IceCube
  95. Fermi-LAT gamma-ray observations of IceCube-230405A
  96. Konus-Wind detection of GRB 230405B
  97. GRB 230405B: AGILE detection
  98. GRB 230405B: Swift-XRT refined Analysis
  99. GRB 230405B: Fermi GBM Observation
  100. GRB 230405B: MeerLICHT upper limits

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