Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

28257 results found.

  1. GRB 230405B: AGILE detection
  2. GRB 230405B: Swift-XRT refined Analysis
  3. GRB 230405B: Fermi GBM Observation
  4. GRB 230405B: MeerLICHT upper limits
  5. GRB 230307A: JWST NIRSpec observations, possible higher redshift
  6. GRB 230307A: further analysis of the Konus-Wind detection and rest-frame energetics
  7. GRB 230405B: Swift/UVOT Upper Limits
  8. GRB 230405B: AstroSat CZTI detection
  9. GRB 230405B: Enhanced Swift-XRT position
  10. GRB 230405B: Prompt enhanced Swift-XRT position
  11. GRB 230405B: Swift detection of a burst
  12. GRB 230405B: Fermi GBM Final Real-time Localization
  13. GRB 230307A: JWST observations consistent with the presence of a kilonova
  14. IceCube-230405A: IceCube observation of a high-energy neutrino candidate
  15. GRB 230405A: Fermi GBM Final Real-time Localization
  16. GRB 230404A: AstroSat CZTI detection
  17. GRB 230404A: Fermi GBM Final Real-time Localization
  18. GRB 230402A: CALET Gamma-Ray Burst Monitor detection
  19. GRB 230402A: AstroSat CZTI detection
  20. Fermi-LAT gamma-ray observations of IceCube-230401A and detection of Fermi J0030.2+0005
  21. GRB 230328B: Multa observatory optical afterglow observation
  22. GRB 230307A: Chandra late-time detection of the X-ray afterglow
  23. GRB 230228A: detection by GTC of the potential host galaxy
  24. GRB 230328B: Swift/UVOT Detection
  25. GRB 230402A: AGILE detection
  26. GRB 230402A: Fermi GBM Final Real-time Localization
  27. IceCube-230401A: IceCube observation of a high-energy neutrino candidate
  28. GRB 230328B : GRANDMA/Kilonova-Catcher optical detection
  29. GRB 230328B: CAHA 2.2m/CAFOS detection
  30. GRB 230328B: 3.6m DOT multiband optical observation
  31. GRB 230330B: Fermi GBM Final Localization
  32. Konus-Wind detection of GRB 230328B
  33. GRB 230328B: GRBAlpha detection
  34. GRB 230330A: Fermi GBM Final Real-time Localization
  35. GRB 230328B: Swift-BAT refined analysis
  36. GRB 230328B: Nanshan/NEXT 2nd optical observation
  37. GRB 230328B NUTTelA-TAO / BSTI Early Measurements
  38. GRB 230328B: Liverpool Telescope afterglow detection
  39. GRB 230328B: GIT optical follow-up
  40. GRB 230328B: OASDG optical observations
  41. GRB 230328B: Nanshan/NEXT optical upper limit
  42. GRB 230328B: Swift-XRT refined Analysis
  43. GRB 230328B: AstroSat CZTI detection
  44. GRB 230328B: Mondy, AbAO and Kitab optical observations
  45. GRB 230328B: Enhanced Swift-XRT position
  46. GRB 230328B: Mondy optical afterglow confirmation
  47. GRB 230328B: Swift detection of a burst with an optical afterglow
  48. GRB 230328B: Fermi GBM Final Real-time Localization
  49. GRB 230328A: Fermi GBM Final Real-time Localization
  50. GRB 230325A: Swift/UVOT Upper Limits
  51. GRB 230325A: X-shooter optical afterglow and redshift
  52. GRB 230325A: Swift-XRT refined Analysis
  53. GRB 230325A: Enhanced Swift-XRT position
  54. GRB 230325A: Prompt enhanced Swift-XRT position
  55. GRB 230325A: Swift detection of a burst
  56. GRB 230322B: Swift/UVOT Detection
  57. Konus-Wind detection of GRB 230309A
  58. Konus-Wind detection of GRB 230308A
  59. Konus-Wind detection of GRB 230304B
  60. GRB 230322B: Swift-XRT refined Analysis
  61. GRB 230322B: Enhanced Swift-XRT position
  62. GRB 230322B: Swift detection of a burst with optical counterpart
  63. GRB 230322A: Fermi GBM Final Real-time Localization
  64. GRB 230320B: GRBAlpha detection
  65. GRB 230321A: CALET Gamma-Ray Burst Monitor detection
  66. GRB 230320B: CALET Gamma-Ray Burst Monitor detection
  67. GRB 230320B: Swift/BAT-GUANO detection outside the coded FOV
  68. INTEGRAL detection of a burst from SGR 1806-200
  69. GRB 230321B: AstroSat CZTI detection
  70. GRB 230320B: AstroSat CZTI detection
  71. GRB 230321A: Fermi GBM Final Real-time Localization
  72. GRB 230320A: Fermi GBM Final Real-time Localization
  73. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  74. GRB 230307A: Continued Gemini-South observations confirm rapid optical fading
  75. IPN triangulation of GRB 230309A
  76. GRB 230304D: AstroSat CZTI detection
  77. GRB 230316A: Fermi GBM Final Real-time Localization
  78. IPN triangulation of GRB 230304B
  79. GRB 230313A: AstroSat CZTI detection
  80. GRB 230307A: Far off-axis NuSTAR detection of the GRB
  81. IPN triangulation of GRB 230308A (short/bright)
  82. GRB 230307A: ATCA radio detection
  83. GRB 230314A: Fermi GBM Final Real-time Localization
  84. VZLUSAT-2 detection of SGR 1806-20
  85. GRB 230307A: INTEGRAL upper limit on Hard X-ray afterglow
  86. GRB 230307A: Swift/UVOT detection
  87. GRB 230313A: Fermi GBM Final Real-time Localization
  88. GRB 230307A: soft X-ray detection with LEIA
  89. GRB 230307A: Swift-XRT afterglow detection
  90. GRB 230309A: AstroSat CZTI detection of a bright long GRB
  91. Further improved IPN localization for GRB 230307A
  92. GRB 230307A: SOAR/Goodman detection of the possible host galaxy
  93. Triggers 1159434, 1159435 and 1159437: Swift detection of Sco X-1 due to Star Tracker loss of lock
  94. TESS Detection of the Optical Afterglow of GRB230307A
  95. GRB 230308A: CALET Gamma-Ray Burst Monitor detection
  96. Trigger 1159327: Swift detection of SGR1806-20
  97. GRB 230310A: AstroSat CZTI detection
  98. GRB 230307A: GECKO optical observations and detections of the afterglow
  99. GRB 230307A: MAXI/GSC upper limit
  100. GRB 230307A: Gemini-South Confirmation of the Optical Afterglow

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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