Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. 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').

552 results found.

  1. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  2. GRB 240419B: Swift-BAT refined analysis
  3. LIGO/Virgo/KAGRA S240422ed: NOT J-band upper limit on the Swift/XRT source S240422ed_X61
  4. LIGO/Virgo/KAGRA S240422ed: WINTER J-band upper limits on the Swift/XRT source S240422ed_X61
  5. LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61
  6. Swift GRB 240419B: Global MASTER-Net observations report
  7. GRB 240414A: Swift-BAT refined analysis
  8. LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
  9. Swift Trigger 1220736: detection of 4U 1543-62.
  10. Fermi GRB 240408A: Global MASTER-Net observations report
  11. Konus-Wind detection of LXT 240402A/GRB 240402B
  12. Konus-Wind detection of GRB 240303B
  13. GRB 240109A: Swift-BAT refined analysis
  14. GRB 231215A: radio detection with the VLA
  15. GRB 231129A: Swift-BAT refined analysis
  16. GRB 231129A: BOOTES-5/JGT optical upper limit
  17. GRB 231118A: Swift-BAT refined analysis
  18. GRB 231111A: Swift-BAT refined analysis
  19. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  20. IceCube Alert 231027.18: Global MASTER-Net observations report
  21. GRB 230911C: Swift-BAT refined analysis
  22. GRB 230826A: Swift-BAT refined analysis
  23. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  24. Fermi GRB 230827A: Global MASTER-Net observations report
  25. Swift GRB230825.75: Global MASTER-Net observations report
  26. Fermi GRB 230814A: Global MASTER-Net observations report
  27. Swift GRB230728.12: Global MASTER-Net observations report
  28. LIGO/Virgo S230622e: Global MASTER-Net observations report
  29. LIGO/Virgo S230615be: Global MASTER-Net observations report
  30. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  31. GRB 230430A: AstroSat CZTI detection
  32. IPN triangulation of GRB 230418A (short)
  33. Fermi GRB 230402A: Global MASTER-Net observations report
  34. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  35. Fermi GRB 230227A: Global MASTER-Net observations report
  36. Fermi GRB 230215A: Global MASTER-Net observations report
  37. GRB 221231A: Fermi GBM Observation
  38. GRB 230101A: AstroSat CZTI detection
  39. Fermi GRB 221223A: Global MASTER-Net observations report
  40. GRB 221216A: Swift-XRT refined Analysis
  41. Fermi trigger No 687190301: Global MASTER-Net observations report
  42. GRB 220831A: ATCA 5/9 GHz radio observations
  43. GRB 220711B: Fermi GBM Detection
  44. GRB 220624A: Fermi GBM Detection
  45. Fermi GRB 220623B: Global MASTER-Net observations report
  46. GRB 220623A: Swift-XRT observations
  47. Konus-Wind detection of an intermediate flare from SGR 1935+2154 on June 16
  48. Swift GRB220521.97: Global MASTER-Net observations report
  49. GRB 220514B: MAXI/GSC detection
  50. Fermi-LAT Gamma-ray Observations of IceCube-220509A
  51. MAXI GRB220506.27: Global MASTER-Net observations report
  52. IceCube Alert 220501.95: Global MASTER-Net observations report
  53. GRB 220319A: Mondy optical uper limit
  54. GRB 220315A: MASTER Global Robotic Net optical observations
  55. Konus-Wind detection of GRB 220310A
  56. Fermi trigger No 668410535: Global MASTER-Net observations report
  57. Swift GRB 220306B: Global MASTER-Net observations report
  58. Konus-Wind observation of GRB 220219B
  59. GRB 220210A: BOOTES-5/JGT optical afterglow candidate
  60. GRB 220130A: Fermi GBM Observation
  61. Konus-Wind detection of GRB 220107A
  62. Konus-Wind detection of GRB 210928A
  63. Swift GRB 210919A: Global MASTER-Net observations report
  64. Konus-Wind detection of GRB 210905A
  65. Integral GRB210829.17: Global MASTER-Net observations report
  66. Integral GRB210829.14: Global MASTER-Net observations report
  67. GRB 210807C: Fermi GBM detection
  68. Trigger 1062273: Swift detection of 4U 1700-377
  69. Konus-Wind detection of GRB 210702A
  70. Fermi trigger No 646194855: Global MASTER-Net observations report
  71. Swift GRB210618.07: Global MASTER-Net observations report
  72. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  73. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  74. Swift Detection of probable new Swift SGR J1555.2-5402
  75. Fermi GRB 210528A: Global MASTER-Net observations report
  76. GRB 210521A: MAXI/GSC detection
  77. GRB 210514A: update on the BAT trigger time and burst duration
  78. Swift trigger 1047857 is 4U 1700-377
  79. Swift Trigger 1045571 is not a GRB
  80. GRB 210419A: Swift-BAT refined analysis
  81. GRB 210410A: Swift-XRT refined Analysis
  82. Fermi trigger No 639199407: Global MASTER-Net observations report
  83. GRB 210403A: Swift-BAT refined analysis
  84. GRB 210318B: Swift-BAT refined analysis
  85. GRB 210204A: AstroSat CZTI Detection
  86. GECAM detection of a burst possibly from the X-ray burster 4U 0614+09 or GRB 210124A
  87. Fermi GRB 210120A: Global MASTER-Net observations report
  88. Fermi trigger No 631602681: Global MASTER-Net observations report
  89. GRB 210104A: GWAC-F60A optical afterglow observations
  90. Konus-Wind detection of GRB 201216C
  91. IceCube Alert 201014.09: Global MASTER-Net observations report
  92. GRB 201004A: Fermi GBM Final Localization
  93. Fermi trigger No 622618714: Global MASTER-Net observations report
  94. IPN triangulation of GRB 200916B (short)
  95. GRB 200903A: Fermi GBM detection
  96. Swift Trigger 992444 is due to detector noise
  97. Swift Trigger 990358 is due to detector noise
  98. Swift Trigger 989458 is due to detector noise
  99. Fermi GRB 200723A: Global MASTER-Net observations report
  100. GRB 200630A: Swift-BAT refined analysis

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov