Skip to main content
Circulars over Kafka event name backfill. 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"

333 results found.

  1. Fermi GRB 250214A: Global MASTER-Net observations report
  2. Fermi GRB 241206A: Global MASTER-Net observations report
  3. Fermi GRB 241104A: Global MASTER-Net observations report
  4. EP240918a: EP observation update
  5. Fermi GRB 240828A: Global MASTER-Net observations report
  6. Fermi trigger No 746438824: Global MASTER-Net observations report
  7. Fermi GRB 240814C: Global MASTER-Net observations report
  8. Fermi trigger No 745306088: Global MASTER-Net observations report
  9. Fermi trigger No 740949590: Global MASTER-Net observations report
  10. Fermi GRB 240610A: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
  12. LIGO/Virgo/KAGRA S240422ed: ENGRAVE VLT/XShooter spectroscopy of the host galaxy of J-GEM24a
  13. GRB 240418A: Swift detection of a burst
  14. GRB 240329A: AstroSat CZTI detection
  15. IceCube Alert 240229.66: Global MASTER-Net observations report
  16. Fermi GRB 240213A: Global MASTER-Net observations report
  17. GRB 240102C: AstroSat CZTI detection
  18. Fermi trigger No 725806648: Global MASTER-Net observations report
  19. Fermi trigger No 724781422: Global MASTER-Net observations report
  20. Swift GRB231215.41: Global MASTER-Net observations report
  21. Fermi trigger No 723581802: Global MASTER-Net observations report
  22. IceCube Alert 231103.39: Global MASTER-Net observations report
  23. Fermi GRB 231030B: Global MASTER-Net observations report
  24. Fermi GRB 230827A: Global MASTER-Net observations report
  25. GRB 230824B: AstroSat CZTI detection
  26. Fermi GRB 230818A: Global MASTER-Net observations report
  27. Fermi trigger No 712713532: Global MASTER-Net observations report
  28. IceCube Alert 230724.08: Global MASTER-Net observations report
  29. Fermi GRB 230723A: Global MASTER-Net observations report
  30. Fermi GRB 230707A: Global MASTER-Net observations report
  31. Swift GRB 230622A: Global MASTER-Net observations report
  32. LIGO/Virgo S230601bf: Global MASTER-Net observations report
  33. GRB 230217A: ATCA rapid-response radio detection
  34. Fermi GRB 221215B: Global MASTER-Net observations report
  35. IceCube Alert 221124.66: Global MASTER-Net observations report
  36. Integral GRB221010.89: Global MASTER-Net observations report
  37. Konus-Wind detection of GRB 221009A
  38. GRB 220907A: Fermi GBM observation
  39. Konus-Wind detection of GRB 220609B
  40. Fermi trigger No 675411172: Global MASTER-Net observations report
  41. IceCube Alert 220513.97: Global MASTER-Net observations report
  42. GRB 220426A: Swift-XRT and UVOT observations
  43. Fermi GRB 220411A: Global MASTER-Net observations report
  44. GRB 220315A: MASTER Global Robotic Net optical observations
  45. Fermi GRB 220310B: Global MASTER-Net observations report
  46. Fermi GRB 220211A: Global MASTER-Net observations report
  47. GRB 220101A: Swift-BAT refined analysis
  48. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  49. GRB 211221A: Swift detection of a burst
  50. Fermi GRB 211204C: Global MASTER-Net observations report
  51. Fermi trigger No 658971499: Global MASTER-Net observations report
  52. GRB 211110A: AstroSat CZTI detection
  53. Fermi trigger No 652927551: Global MASTER-Net observations report
  54. GRB 210807C: Fermi GBM detection
  55. Swift GRB210807.79: Global MASTER-Net observations report
  56. Fermi trigger No 649390368: Global MASTER-Net observations report
  57. GRB 210730A: Fermi GBM observation
  58. Fermi trigger No 647942198: Global MASTER-Net observations report
  59. Fermi GRB 210709A: Global MASTER-Net observations report
  60. Integral GRB210707.02: Global MASTER-Net observations report
  61. Fermi GRB 210627B: Global MASTER-Net observations report
  62. Fermi trigger No 645047470: Global MASTER-Net observations report
  63. Swift GRB 210610B: Global MASTER-Net observations report
  64. GRB 210528B: MAXI/GSC detection
  65. Fermi GRB 210503A: Global MASTER-Net observations report
  66. GRB 210226A: Fermi GBM detection
  67. GRB 210218A: Swift/UVOT observations
  68. GRB 210218A: Swift-XRT observations
  69. Konus-Wind detection of GRB 210124B
  70. Swift GRB 201221A: Global MASTER-Net observations report
  71. Fermi GRB 201121A: Global MASTER-Net observations report
  72. GRB 201026A: Swift-BAT refined analysis
  73. Konus-Wind observation of GRB 200914A
  74. LAT GRB200803.15: Global MASTER-Net observations report
  75. Fermi GRB 200803A: Global MASTER-Net observations report
  76. GRB 200711A: Swift/UVOT Upper Limits
  77. Fermi GRB 200616A: Global MASTER-Net observations report
  78. Fermi GRB 200605A: Global MASTER-Net observations report
  79. Konus-Wind detection of short/hard GRB 200521A
  80. GRB 200514B: BALROG localization (Fermi Trigger 611140062 / GRB 200514380)
  81. bright SGR burst detected by CALET Gamma-Ray Burst Monitor
  82. IceCube Alert 200410.97: Global MASTER-Net observations report
  83. Fermi trigger No 606263732: Global MASTER-Net observations report
  84. LIGO/Virgo S200302c: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  85. Swift GRB200205.81: Global MASTER-Net observations report
  86. Fermi trigger No 601841483: Global MASTER-Net observations report
  87. GRB 200125A: Swift-BAT refined analysis
  88. Fermi trigger No 601677816: Global MASTER-Net observations report
  89. Baksan Neutrino Observatory Alert 200116.22: Global MASTER-Net observations report
  90. LIGO/Virgo S200105ae: Global MASTER-Net observations report
  91. LIGO/Virgo S191215w: Global MASTER-Net observations report
  92. Baksan Neutrino Observatory Alert 191102.06: Global MASTER-Net observations report
  93. Swift GRB191031.89: Global MASTER-Net observations report
  94. FACT follow-up of ANTARES-Fermi 191011A
  95. Swift GRB191019.63: Global MASTER-Net observations report
  96. Swift GRB191011.19: Global MASTER-Net observations report
  97. Update to the Fermi GBM Localizations
  98. Fermi trigger No 585007213 Global MASTER-Net observations report
  99. Swift GRB190624.86 Global MASTER-Net observations report
  100. Fermi trigger No 581882394 Global MASTER-Net observations report

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