Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

3041 results found.

  1. GRB 230506B: Fermi GBM detection
  2. GRB 230506B: Swift detection of a burst
  3. GRB 230506B: Swift detection of a burst
  4. Fermi trigger No 704837952: Global MASTER-Net observations report
  5. Konus-Wind detection of GRB 230430A
  6. IPN triangulation of GRB 230430A (short)
  7. GRB 230430A: Fermi GBM observation
  8. GRB 230430A: AstroSat CZTI detection
  9. GRB 230430A: Fermi GBM Final Real-time Localization
  10. Fermi trigger No 704365743: Global MASTER-Net observations report
  11. GRB 230427A : OHP/T193 optical upper limit
  12. GRB 230426A: Fermi GBM Detection
  13. Fermi GRB 230409C: Global MASTER-Net observations report
  14. GRB 230405B: Prompt enhanced Swift-XRT position
  15. GRB 230328B: Fermi GBM Final Real-time Localization
  16. GRB 230325A: X-shooter optical afterglow and redshift
  17. GRB 230325A: Prompt enhanced Swift-XRT position
  18. GRB 230322B: Swift/UVOT Detection
  19. Konus-Wind detection of GRB 230308A
  20. GRB 230322B: Swift detection of a burst with optical counterpart
  21. Fermi trigger No 701058254: Global MASTER-Net observations report
  22. GRB 230314A: TURBO Optical Upper Limit
  23. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  24. Fermi trigger No 700976129: Global MASTER-Net observations report
  25. GRB 230314A: Fermi GBM Final Real-time Localization
  26. Fermi GRB 230313A: Global MASTER-Net observations report
  27. GRB 230307A: soft X-ray detection with LEIA
  28. GRB 230307A: Gemini-South Confirmation of the Optical Afterglow
  29. Fermi GRB 230308A: Global MASTER-Net observations report
  30. GRB 230304A: Fermi GBM Final Real-time Localization
  31. Fermi trigger No 699294715: Global MASTER-Net observations report
  32. IceCube-230220A: Upper limits from a search for additional neutrino events in IceCube
  33. Fermi GRB 230220B: Global MASTER-Net observations report
  34. GRB 230217A: Gemini-South Optical Observation
  35. IceCube Alert 230217.87: Global MASTER-Net observations report
  36. Fermi trigger No 697678542: Global MASTER-Net observations report
  37. Fermi GRB 230209B: Global MASTER-Net observations report
  38. Fermi GRB 230207A: Global MASTER-Net observations report
  39. GRB 230205A: BOOTES-5/JGT early optical upper limit
  40. GRB 230204B: Detection by GRBAlpha
  41. GRB 230204B: MAXI/GSC detection
  42. Fermi trigger No 697098930: Global MASTER-Net observations report
  43. GRB 230201A: Fermi GBM Final Real-time Localization
  44. GRB 230130A: Fermi GBM Final Real-time Localization
  45. GRB 230128A: Fermi GBM Final Real-time Localization
  46. GRB 230116D: KGO RC-25 optical observations
  47. GRB 230116D: Sintez-Newton/CrAO optical observations
  48. GRB 230116D: Swift-XRT refined Analysis
  49. IceCube-230112A: No Candidate Counterparts from the Zwicky Transient Facility
  50. Fermi GRB 230112A: Global MASTER-Net observations report
  51. Fermi trigger No 695057654: Global MASTER-Net observations report
  52. IceCube-221223A: No Candidate Counterparts from the Zwicky Transient Facility
  53. Swift GRB221226.95: Global MASTER-Net observations report
  54. Fermi GRB 221226A: Global MASTER-Net observations report
  55. GRB 221226A: Fermi GBM Final Real-time Localization
  56. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  57. Integral GRB221218.34: Global MASTER-Net observations report
  58. GRB 221216A: AKO Upper Limit
  59. Fermi trigger No 692713692: Global MASTER-Net observations report
  60. Fermi GRB 221211A: Global MASTER-Net observations report
  61. IceCube Alert 221210.36: Global MASTER-Net observations report
  62. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  63. GRB 221206C: Fermi GBM Final Real-time Localization
  64. GRB 221206B: Fermi GBM Final Real-time Localization
  65. Swift GRB221204.45: Global MASTER-Net observations report
  66. Konus-Wind detection of GRB 221124A
  67. Fermi Gamma-ray Burst Monitor trigger 691534074/221130867 is not a GRB
  68. IceCube Alert 221124.66: Global MASTER-Net observations report
  69. GRB 221120A: TURBO Optical Upper Limit
  70. Swift GRB221110.10: Global MASTER-Net observations report
  71. GRB 221107A: Fermi GBM Observation
  72. GRB 221028A: GRANDMA observations
  73. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  74. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  75. GRB 221027B: COATLI Upper Limits
  76. IPN triangulation of GRB 221022C (short)
  77. Konus-Wind detection of GRB 221023A
  78. GRB 221017A: Swift-XRT observations
  79. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  80. MAXI GRB221017.24: Global MASTER-Net observations report
  81. GRB 221017A: MAXI/GSC detection
  82. GRB 221009A: ATCA radio spectrum
  83. Fermi trigger No 687345829: Global MASTER-Net observations report
  84. Fermi trigger No 687340841: Global MASTER-Net observations report
  85. Fermi trigger No 687337536: Global MASTER-Net observations report
  86. Fermi trigger No 687281393: Global MASTER-Net observations report
  87. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  88. INTEGRAL shows increasing activity in SGR J1935+2154
  89. Fermi GRB 220925A: Global MASTER-Net observations report
  90. GRB 220924A: Fermi GBM Final Real-time Localization
  91. IceCube-220907A: No significant detection in HAWC
  92. Fermi trigger No 684716840: Global MASTER-Net observations report
  93. Fermi GRB 220912A: Global MASTER-Net observations report
  94. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  95. Fermi GRB 220902A: Global MASTER-Net observations report
  96. Fermi trigger No 683202084: Global MASTER-Net observations report
  97. Fermi trigger No 683183601: Global MASTER-Net observations report
  98. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  99. GRB 220813A: Swift/UVOT Detection
  100. Fermi trigger No 681890304: 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