Skip to main content
End of INTEGRAL Operations. 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').
  1. GRB 220117A: LCO Optical Observations
  2. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  3. Fermi-LAT Gamma-ray Observations of IceCube-220115A and detection of a new gamma-ray source, Fermi J2350.2+2620
  4. GRB 220117B: Swift-XRT refined Analysis
  5. GRB 220117A: Swift-XRT refined Analysis
  6. AMON IC_HAWC NuEm-220116A: No neutrino counterpart detected with ANTARES
  7. GRB 220117B: Nanshan/NEXT optical upper limit
  8. GRB 220117B: MITSuME Akeno optical upper limits
  9. GRB 220117B: Enhanced Swift-XRT position
  10. GRB 220117A: Enhanced Swift-XRT position
  11. GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
  12. Swift GRB 220117A: Global MASTER-Net observations report
  13. Swift GRB 220117B: Global MASTER-Net observations report
  14. GRB 220117B: Swift detection of a burst
  15. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  16. GRB 220117A: Swift detection of a burst
  17. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  18. GECAM observations of a series of bursts from SGR J1935+2154
  19. Fermi trigger No 663960124: Global MASTER-Net observations report
  20. Fermi trigger No 663967527: Global MASTER-Net observations report
  21. Fermi trigger No 663923149: Global MASTER-Net observations report
  22. Fermi trigger No 663899819: Global MASTER-Net observations report
  23. Fermi trigger No 663886592: Global MASTER-Net observations report
  24. Fermi trigger No 663966693: Global MASTER-Net observations report
  25. GRB 220115B: Fermi GBM Final Real-time Localization
  26. IceCube Alert 220115.51: Global MASTER-Net observations report
  27. Fermi trigger No 663927396: Global MASTER-Net observations report
  28. Fermi trigger No 663921434: Global MASTER-Net observations report
  29. GRB 210919A: LBT spectroscopic redshift of the host galaxy candidates
  30. GRB 220115A: Fermi GBM Final Real-time Localization
  31. IceCube-220115A - IceCube observation of a high-energy neutrino candidate track-like event
  32. Fermi Gamma-ray Burst Monitor trigger 663917434/220115230 is not a GRB
  33. GRB 220114A: Fermi GBM Final Localization
  34. GECAM observations of a series of bursts from SGR J1935+2154
  35. Fermi trigger No 663763320: Global MASTER-Net observations report
  36. Fermi trigger No 663710289: Global MASTER-Net observations report
  37. Fermi-GBM Observations of Recent Bursting Activity from SGR J1935+2154
  38. AGILE observations of a burst from SGR 1935+2154
  39. GECAM observations of a series of bursts from SGR J1935+2154
  40. GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
  41. Fermi trigger No 663669570: Global MASTER-Net observations report
  42. GRB 220111A: AstroSat CZTI detection
  43. Fermi trigger No 663658976: Global MASTER-Net observations report
  44. Fermi trigger No 663618072: Global MASTER-Net observations report
  45. Fermi GRB 220111A: Global MASTER-Net observations report
  46. Konus-Wind detection of GRB 220101A (correction to GCN 31433)
  47. GRB 220111A: BALROG localization (Fermi Trigger 663621714 / GRB 220111807)
  48. GRB 220111A: Fermi GBM Final Real-time Localization
  49. Konus-Wind detection of GRB 220101A
  50. Fermi Gamma-ray Burst Monitor trigger 220111325/663580106 is not a GRB
  51. GRB 220107A: SAO RAS optical observations
  52. Konus-Wind detection of GRB 220107B
  53. Konus-Wind detection of GRB 220107A
  54. GECAM observations of a series of bursts from SGR J1935+2154
  55. Confirmation of the X-ray afterglow of GRB 220107B
  56. GRB 220107A: further SAO RAS optical observations
  57. GRB 220101A: Additional Liverpool telescope photometry
  58. Fermi trigger No 663406755: Global MASTER-Net observations report
  59. GRB 220107A: 6m BTA spectroscopic redshift
  60. GRB 220107A: SAO RAS optical observations
  61. GRB 220108A: Swift/BAT-GUANO detection outside the coded FOV
  62. GRB 220101A: SAO RAS optical observations
  63. GRB 220107A: AbAO and Terskol optical observations
  64. GRB 220107B: MITSuME Akeno optical upper limits
  65. GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
  66. GRB 220107A: Nanshan/NEXT optical observations
  67. GRB 220107A: Swift/UVOT Detection
  68. GRB 220107B: Fermi GBM observations
  69. GRB 220107A: MITSuME Akeno optical observation
  70. GRB 220107B: AstroSat CZTI detection
  71. GRB 220107B: Swift-XRT afterglow detection
  72. GRB 220107A: Swift-XRT afterglow detection
  73. GRB 220107B: Fermi-LAT detection
  74. GRB 220107A: AstroSat CZTI detection
  75. GRB 220107B: Tiled Swift observations
  76. GRB 220107A: Fermi GBM observations
  77. Fermi trigger No 663274898: Global MASTER-Net observations report
  78. GRB 220107A: Swift ToO observations
  79. Fermi GRB 220107A: Global MASTER-Net observations report
  80. GRB 220107A: Swift/BAT-GUANO arcminute localization
  81. GRB 220101A: Tautenburg observations
  82. GRB 220107A: BALROG localization (Fermi Trigger 663259536 / GRB 220107615)
  83. GRB 220107A: Fermi GBM Final Real-time Localization
  84. GRB 220101A: Continued Mondy optical observations
  85. GECAM observation of a burst from SGR J1555.2-5402
  86. GECAM detection of a short burst from SGR 1935+2154
  87. GRB 220101A: further TNG NIR observations
  88. GRB 220101A: continued 1.3m DFOT Optical Observations
  89. Fermi trigger No 663129379: Global MASTER-Net observations report
  90. GRB 220104A: Fermi GBM Observation
  91. GECAM observations of a series of bursts from SGR J1935+2154
  92. GRB 220101A: Mondy optical observations
  93. GRB 220101A: 3rd LCO Optical Observation
  94. GRB 220101A: 2.2m CAHA (+CAFOS) first day optical detection
  95. GRB 220101A: iTelescope optical observations
  96. GRB 211227A: Lijiang 2.4m Telescope Optical Observations
  97. GRB 220101A: VLA detection
  98. GRB 220101A: 1.3m DFOT observations
  99. GRB 220101A: LCO Continued Optical Observations
  100. GRB 220104A：GECAM detection

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