Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

33591 results found.

  1. GRB 220131A: Fermi GBM Final Real-time Localization
  2. Fermi GRB 220129A: Global MASTER-Net observations report
  3. GRB 220129A: Fermi GBM Final Real-time Localization
  4. GRB 220127A: GECAM detection
  5. Konus-Wind detection of GRB 220124A
  6. IPN triangulation of GRB 220124A
  7. GRB 220124A: GECAM detection
  8. GRB 220117A, GROND observations
  9. GRB 220124A: AstroSat CZTI detection of a bright long GRB
  10. GRB 220117A: Terskol and AbAO optical upper limits
  11. GRB 220118A: TARGET optical upper limit
  12. GRB 220117B: TARGET optical upper limit
  13. GRB 220121B: GECAM detection
  14. IPN triangulation of a bright burst from SGR 1935+2154
  15. GRB 220117A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  16. IPN triangulation of GRB 211226A
  17. GRB 220120A: Fermi GBM Final Localization
  18. GRB 220117C: Fermi GBM Observation
  19. GRB 220118A: 2.2m CAHA/CAFOS detections
  20. GRB 220118A: Fermi GBM detection
  21. GRB 220118A: COATLI Optical Observations
  22. GRB 220101A: KAO optical-R observation
  23. GRB 211221A: No V & R detection, KAO telescope
  24. GRB 220118A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  25. GRB 220117C: Swift/BAT-GUANO arcminute localization
  26. GRB 220118A: Swift-BAT refined analysis
  27. GRB 220118A: Swift/UVOT Detection
  28. GRB 220118A: GIT optical observations
  29. GRB 220118A: Enhanced Swift-XRT position
  30. GRB 220118A: MITSuME Akeno optical observation
  31. GRB 220117B: z-band limit
  32. Swift GRB 220118A: Global MASTER-Net observations report
  33. GRB 220118A: Swift detection of a burst with an optical counterpart
  34. GRB 220118A: Fermi GBM Final Real-time Localization
  35. GRB 220117A: MITSuME Akeno optical upper limits
  36. Fermi GBM Sub-Threshold Detection of GRB 220117A
  37. GRB 220117B: Swift-BAT refined analysis
  38. GRB 220117A: Swift-BAT refined analysis
  39. GRB 220117B: Swift/UVOT Upper Limits
  40. GRB 220117A: Swift/UVOT Upper Limits
  41. GRB 220117A: LCO Optical Observations
  42. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  43. GRB 220117B: Swift-XRT refined Analysis
  44. GRB 220117A: Swift-XRT refined Analysis
  45. GRB 220117B: Nanshan/NEXT optical upper limit
  46. GRB 220117B: MITSuME Akeno optical upper limits
  47. GRB 220117B: Enhanced Swift-XRT position
  48. GRB 220117A: Enhanced Swift-XRT position
  49. GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
  50. Swift GRB 220117A: Global MASTER-Net observations report
  51. Swift GRB 220117B: Global MASTER-Net observations report
  52. GRB 220117B: Swift detection of a burst
  53. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  54. GRB 220117A: Swift detection of a burst
  55. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  56. GRB 220115B: Fermi GBM Final Real-time Localization
  57. GRB 210919A: LBT spectroscopic redshift of the host galaxy candidates
  58. GRB 220115A: Fermi GBM Final Real-time Localization
  59. Fermi Gamma-ray Burst Monitor trigger 663917434/220115230 is not a GRB
  60. GRB 220114A: Fermi GBM Final Localization
  61. Fermi-GBM Observations of Recent Bursting Activity from SGR J1935+2154
  62. GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
  63. GRB 220111A: AstroSat CZTI detection
  64. Fermi GRB 220111A: Global MASTER-Net observations report
  65. Konus-Wind detection of GRB 220101A (correction to GCN 31433)
  66. GRB 220111A: BALROG localization (Fermi Trigger 663621714 / GRB 220111807)
  67. GRB 220111A: Fermi GBM Final Real-time Localization
  68. Konus-Wind detection of GRB 220101A
  69. Fermi Gamma-ray Burst Monitor trigger 220111325/663580106 is not a GRB
  70. GRB 220107A: SAO RAS optical observations
  71. Konus-Wind detection of GRB 220107B
  72. Konus-Wind detection of GRB 220107A
  73. Confirmation of the X-ray afterglow of GRB 220107B
  74. GRB 220107A: further SAO RAS optical observations
  75. GRB 220101A: Additional Liverpool telescope photometry
  76. GRB 220107A: 6m BTA spectroscopic redshift
  77. GRB 220107A: SAO RAS optical observations
  78. GRB 220108A: Swift/BAT-GUANO detection outside the coded FOV
  79. GRB 220101A: SAO RAS optical observations
  80. GRB 220107A: AbAO and Terskol optical observations
  81. GRB 220107B: MITSuME Akeno optical upper limits
  82. GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
  83. GRB 220107A: Nanshan/NEXT optical observations
  84. GRB 220107A: Swift/UVOT Detection
  85. GRB 220107B: Fermi GBM observations
  86. GRB 220107A: MITSuME Akeno optical observation
  87. GRB 220107B: AstroSat CZTI detection
  88. GRB 220107B: Swift-XRT afterglow detection
  89. GRB 220107A: Swift-XRT afterglow detection
  90. GRB 220107B: Fermi-LAT detection
  91. GRB 220107A: AstroSat CZTI detection
  92. GRB 220107B: Tiled Swift observations
  93. GRB 220107A: Fermi GBM observations
  94. GRB 220107A: Swift ToO observations
  95. Fermi GRB 220107A: Global MASTER-Net observations report
  96. GRB 220107A: Swift/BAT-GUANO arcminute localization
  97. GRB 220101A: Tautenburg observations
  98. GRB 220107A: BALROG localization (Fermi Trigger 663259536 / GRB 220107615)
  99. GRB 220107A: Fermi GBM Final Real-time Localization
  100. GRB 220101A: Continued Mondy optical observations

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