Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

19594 results found.

  1. Swift Triggers 1192735 and 1192737 are not astrophysical events
  2. Konus-Wind detection of GRB 230919A
  3. LIGO/Virgo/KAGRA S230924an: Upper limits from Swift/BAT-GUANO
  4. LIGO/Virgo/KAGRA S230920al: Upper limits from Swift/BAT-GUANO
  5. LIGO/Virgo/KAGRA S230919bj: Upper limits from Swift/BAT-GUANO
  6. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  7. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  8. IPN triangulation of GRB 230919A (short)
  9. GRB 230919A: Fermi GBM Observation
  10. GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
  11. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  12. GRB 230915A: Fermi GBM observation
  13. Swift Triggers 1192480, 1192481, 1192482 and 1192483 are not astrophysical events
  14. GRB 230911A: Fermi GBM Observation
  15. Swift GRB230916.18: Global MASTER-Net observations report
  16. GRB 230915A: Swift/BAT-GUANO detection of a burst
  17. LIGO/Virgo/KAGRA S230914ak: Upper limits from Swift/BAT-GUANO
  18. Swift GRB230916.19: Global MASTER-Net observations report
  19. Swift GRB230916.18: Global MASTER-Net observations report
  20. Swift Triggers 1192234, 1192235 and 1192236 are not astrophysical events
  21. Swift GRB230916.13: Global MASTER-Net observations report
  22. Swift GRB230916.12: Global MASTER-Net observations report
  23. Swift GRB230916.11: Global MASTER-Net observations report
  24. Swift Trigger 1192233 is not a GRB
  25. GRB 230911A: Swift-XRT afterglow detection
  26. GRB 230913A: CALET Gamma-Ray Burst Monitor detection
  27. Swift Trigger 1192088 is not an astrophysical event
  28. GRB 230913A: Glowbug gamma-ray detection
  29. Swift Trigger 1191994 is not an astrophysical event
  30. Swift GRB230913.70: Global MASTER-Net observations report
  31. GRB 230913A: Fermi GBM Observation
  32. Swift Trigger 1191904 is not a GRB
  33. Swift GRB230913.70: Global MASTER-Net observations report
  34. Swift Trigger 1191903 is not an astrophysical event
  35. GRB 230911A: Swift ToO observations
  36. GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
  37. GRB 230908A: CALET Gamma-Ray Burst Monitor detection
  38. GRB 230911C: Swift-XRT refined Analysis
  39. GRB 230911C: Swift-BAT refined analysis
  40. GRB230911C: BOOTES-6/DPRT optical upper limit
  41. GRB 230906A: Chandra detection of the X-ray afterglow
  42. Swift GRB 230911C: Global MASTER-Net observations report
  43. IPN triangulation of GRB 230911D (long)
  44. GRB 230911D: Fermi-LAT detection
  45. GRB230911C: LCOGT Optical Upper Limits
  46. GRB 230911C: Swift/UVOT Upper Limits
  47. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  48. GRB 230911C: Enhanced Swift-XRT position
  49. GRB 230911C: Swift detection of a burst
  50. GRB 230906A: BlackGEM upper limits
  51. GRB 230903A: TESS observations of optical emission
  52. GRB 230906A: Swift/UVOT Upper Limits
  53. GRID detection of GRB 230827A
  54. GRB 230906A: Swift-XRT observations
  55. IPN triangulation of GRB 230906A (short)
  56. GRB 230906A: Swift ToO observations
  57. Swift Attitude Control Affecting Some UVOT Images
  58. GRB 230903A: Swift-XRT refined Analysis
  59. GRB 230903A: Enhanced Swift-XRT position
  60. GRB 230903A: VLT/X-shooter optical observations
  61. GRB 230903A: Swift-BAT refined analysis
  62. GRB 230903A: Fermi GBM detection
  63. GRB 230903A: LCOGT Optical Upper Limits
  64. GRB 230903A: Swift detection of a burst
  65. Swift GRB230903.72: Global MASTER-Net observations report
  66. GRB 230827A: Glowbug gamma-ray detection
  67. GRB 230826A: Glowbug gamma-ray detection
  68. GRB 230827B: Swift-XRT afterglow detection
  69. GRB 230827B: Swift ToO observations
  70. GRB 230827A: Fermi GBM Observation
  71. GRB 230826A: Swift-BAT refined analysis
  72. Swift Trigger 1188089 is not a GRB
  73. GRB 230827A: VZLUSAT-2 detection
  74. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  75. GRB 230826A: VZLUSAT-2 detection
  76. Subject: GRB230826A: Swift/UVOT upper limits
  77. Swift J1727.8-1613 (GRB 230824A): Osservatorio Astronomico "Nastro Verde" optical observations
  78. Swift J1727.8-1613 (GRB 230824A): Montarrenti Observatory photometric observations
  79. GRB 230826A: GRBAlpha detection
  80. GRB 230826A: Fermi GBM Observation
  81. Swift J1727.8-1613 (GRB 230824A): Leavitt Observatory optical observations
  82. GRB 230826A: Enhanced Swift-XRT position
  83. GRB 230826A: Swift-XRT refined Analysis
  84. GRB 230826A: Mondy optical observations
  85. Swift J1727.8-1613 (GRB 230824A): GAD Observatory La Spezia - optical observations
  86. GRB 230826A: Swift detection of a burst
  87. Swift GRB230826.81: Global MASTER-Net observations report
  88. Swift J1727.8-1613 (GRB 230824A): Bassano Bresciano Observatory optical observations
  89. GRB 230824A: AKO Photometric Follow-up Observations
  90. LIGO/Virgo/KAGRA S230825k: Upper limits from Swift/BAT-GUANO
  91. Swift GRB230825.85: Global MASTER-Net observations report
  92. Trigger 1187225: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  93. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  94. Trigger 1187207: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  95. Trigger 1187203: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  96. Swift GRB230825.75: Global MASTER-Net observations report
  97. Swift Trigger 1187199 is not an astrophysical event
  98. Fermi Gamma-ray Burst Monitor trigger 714618399/230825046 is not a GRB
  99. NICER detection of Swift J1727.8-1613 (GRB 230824A)
  100. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov