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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"

21459 results found.

  1. Swift Triggers 12156887-1215690 are not astrophysical events.
  2. GRB 240215A: Tiled Swift observations
  3. GRB 240215A: Swift/BAT-GUANO localization of a burst
  4. GRB 240128A: Further Swift-XRT observations
  5. GRB 240214A: Tiled Swift observations
  6. GRB 240214A/1H 0451-560: MAXI/GSC detection
  7. Konus-Wind detection of GRB 240204A
  8. IPN triangulation of GRB 240205A (short)
  9. GRB 240205B: PRIME near infrared detection
  10. Swift Trigger 1213872 is not an astrophysical event
  11. GRB240204A: Swift/UVOT Upper Limits
  12. GRB 240205B: AstroSat CZTI detection
  13. GRB 240205B: Swift-BAT refined analysis
  14. Konus-Wind detection of GRB 240205B (long / very soft)
  15. GRB 240205B: VLT/X-shooter redshift
  16. GRB 240205B: CALET Gamma-Ray Burst Monitor detection
  17. GRB 240205B: BOOTES-6 optical afterglow follow-up
  18. GRB 240205B: ATCA detection of radio counterpart
  19. GRB 240205B: REM detection of the optical/NIR afterglow
  20. GRB 240205B: Fermi GBM Observation
  21. GRB 240204A: AstroSat CZTI detection
  22. GRB 240205B: GECAM detection of a long burst
  23. GRB 240204A: Swift-BAT refined analysis
  24. GRB 240205B: Skynet Optical Afterglow Observations
  25. GRB 240205B: BOOTES-7 optical afterglow follow-up
  26. GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
  27. GRB 240205B: Swift detection of a burst
  28. Swift GRB240205.93: Global MASTER-Net observations report
  29. GRB 240204A: Fermi GBM Observation
  30. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  31. GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
  32. GRB 240204A: Montarrenti Observatory optical observations
  33. GRB 240204A: Enhanced Swift-XRT position
  34. GRB 240204A: Mondy optical afterglow candidate
  35. GRB 240204A: Swift detection of a burst
  36. Swift Trigger 1212791 is not an astrophysical event.
  37. Swift-BAT triggers 1212787, 1212789 are not astrophysical.
  38. IPN triangulation of GRB 240124B
  39. GRB 240129A: Fermi GBM Observation
  40. GRB 240129A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  41. IPN triangulation of GRB 240125A (short)
  42. GRB 240128A: Swift-XRT observations
  43. GRB 240128A: Tiled Swift observations
  44. GRB 240122A: ATCA detection of radio counterpart
  45. Swift Trigger 1211211 and 1211212 are not astrophysical
  46. GRB 240123C: AstroSat CZTI detection
  47. GRB240122A: PRIME near infrared detection
  48. GRB 240123B: Fermi GBM Observation
  49. GRB 240123A: Glowbug gamma-ray detection
  50. GRB 240123B: Swift/BAT-GUANO detection of a long burst
  51. GRB 240123A: GRBAlpha detection
  52. IPN triangulation of GRB 240123C (short)
  53. Swift trigger 1210856 is not astrophysical
  54. GRB 240123A: Swift-BAT refined analysis
  55. GRB 240123A : MITSuME Akeno optical afterglow candidate detection
  56. GRB 240123A: Enhanced Swift-XRT position
  57. GRB 240122A: Swift/UVOT Upper Limits
  58. GRB 240123A: Swift-XRT refined Analysis
  59. GRB 240122A: BOOTES-2/TELMA optical upper limit and 1.5m OSN detection
  60. Fermi GBM Sub-Threshold Detection of GRB 240123A
  61. GRB 240118A: Swift/UVOT Upper Limits
  62. GRB 240123A: Swift detection of a burst with a possible optical counterpart
  63. Swift GRB240123.46: Global MASTER-Net observations report
  64. GRB 240122A: Swift-XRT afterglow detection
  65. GRB 240122A: Tiled Swift observations
  66. IPN triangulation of GRB 240119A (short)
  67. GRB 240118C: GECAM-B detection of a long burst
  68. GRB 240118A: Mondy optical observations
  69. GRB 240118A: Swift-XRT afterglow detection
  70. GRB 240118C: Fermi GBM Observation
  71. GRB 240118C: Swift/BAT-GUANO detection of a burst
  72. GRB 240118A: GRBAlpha detection
  73. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240118A: correction on the localization
  74. GRB 240115A: Fermi GBM Observation
  75. Swift triggers 1209631, 1209632, 1209635 and 1209644 are not interesting astrophysical events
  76. GRB 240118A: Swift ToO observations
  77. GRB 240118A: AbAO optical upper limit
  78. GRB 240118A: NuSTAR Offline Analysis of the GRB
  79. GRB 240118A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  80. Konus-Wind detection of GRB 240118A
  81. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240118A
  82. GRB 240118A: NuSTAR Detection of a Long GRB
  83. GRB 240118A: Fermi GBM Observation
  84. GRB 240118A: Fermi-LAT detection
  85. GRID detection of GRB 231230A
  86. GRB 240118A: Fermi GBM Final Real-time Localization
  87. GRB 240115A: Swift/BAT-GUANO detection of a short burst
  88. Swift Trigger 1209406 is not an astrophysical event
  89. Swift Triggers 1209401 and 1209403 are not astrophysical events
  90. Swift Triggers 1209371 through 1209374 are not astrophysical events
  91. Swift Triggers 1209369 and 1209370 are not astrophysical events
  92. LIGO/Virgo/KAGRA S240109a: Upper limits from Swift/BAT-GUANO
  93. GRB 240112C: Glowbug gamma-ray detection
  94. GRB 240112C: VZLUSAT-2 detection
  95. Konus-Wind detection of GRB 240112C
  96. GRB 240112C: GRBAlpha detection
  97. GRB 240112C: Swift/UVOT Detection
  98. GRB 240112C: Fermi GBM Detection
  99. GRB 240112C: Swift-XRT refined Analysis
  100. GRB 240112C: SAO RAS optical observations

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