Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

3757 results found.

  1. Fermi GRB 220111A: Global MASTER-Net observations report
  2. Konus-Wind detection of GRB 220101A
  3. Fermi trigger No 663406755: Global MASTER-Net observations report
  4. GRB 220107A: AbAO and Terskol optical observations
  5. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  6. Fermi GRB 211229A: Global MASTER-Net observations report
  7. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  8. GRB 211227A: Liverpool Telescope upper limits
  9. GRB 211227A: LCO Optical Observations
  10. GRB 211227A: MAXI/GSC detection
  11. GRB 211225A: MITSuME Akeno optical upper limits
  12. Swift GRB 211225B: Global MASTER-Net observations report
  13. Fermi GRB 211225C: Global MASTER-Net observations report
  14. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  15. GRB 211218A: MITSuME Akeno optical upper limits
  16. GRB 211218A, MAXI J0909-041: MAXI/GSC detection
  17. MAXI GRB211218.04: Global MASTER-Net observations report
  18. GRB 211212A: Fermi GBM Final Real-time Localization
  19. Fermi GRB 211211B: Global MASTER-Net observations report
  20. Fermi trigger No 660736561: Global MASTER-Net observations report
  21. Fermi GRB 211204A: Global MASTER-Net observations report
  22. Fermi GRB 211130A: Global MASTER-Net observations report
  23. GRB 211129A: Swift/UVOT Upper Limits
  24. IceCube-Cascade 211128A: Upper limits from a search for additional neutrino events in IceCube
  25. IPN triangulation of GRB 211120A
  26. Fermi trigger No 658971499: Global MASTER-Net observations report
  27. Fermi trigger No 658755664: Global MASTER-Net observations report
  28. GRB 211115A: MAXI/GSC detection
  29. Fermi trigger No 658214822: Global MASTER-Net observations report
  30. Fermi GRB 211109B: Global MASTER-Net observations report
  31. GRB 211023A: SAO RAS optical observations
  32. Swift Trigger 1082569 is probably not a GRB
  33. GRB 211023B: Subaru optical observation
  34. GRB 211024A: MITSuME Akeno optical observation
  35. GRB 211023B: MITSuME Akeno optical upper limits
  36. Fermi GRB 211031A: Global MASTER-Net observations report
  37. GRB 211023A: 1.3m DFOT Optical Observations
  38. GRB 211023A: Terskol optical observations
  39. Fermi GRB 211027A: Global MASTER-Net observations report
  40. GRB 210610B: Sintesz-Newton/CrAO optical observations
  41. GRB 211023B: BOOTES-4/MET and 1.5m OSN optical upper limit
  42. GRB 211018A: Fermi GBM observation
  43. GRB 211018A: Fermi-LAT detection
  44. Fermi trigger No 655401471: Global MASTER-Net observations report
  45. Fermi trigger No 654854799: Global MASTER-Net observations report
  46. GRB 210928A: Fermi GBM observation
  47. GRB 210927A: GIT optical follow-up of ZTF21acdwctm.
  48. Fermi GRB 210929B: Global MASTER-Net observations report
  49. GRB 210919A OSN 1.5m Source Confirmation
  50. IceCube Alert 210922.76: Global MASTER-Net observations report
  51. GRB 210919A: Swift detection of a short burst
  52. Konus-Wind observation of the recent SGR 1935+2154 activity
  53. Fermi GBM observation of another bright burst in the direction of SGR 1935+2154
  54. GECAM observations of bursts from SGR J1935+2154 (2021-09-11T07 to 2021-09-12T08)
  55. Fermi trigger No 653084584: Global MASTER-Net observations report
  56. Fermi trigger No 653083551: Global MASTER-Net observations report
  57. Fermi trigger No 653066130: Global MASTER-Net observations report
  58. Fermi trigger No 653022153: Global MASTER-Net observations report
  59. IPN triangulation of a bright burst from SGR 1935+2154
  60. Fermi trigger No 652944960: Global MASTER-Net observations report
  61. Fermi trigger No 652906639: Global MASTER-Net observations report
  62. Fermi trigger No 652585475: Global MASTER-Net observations report
  63. Fermi GRB 210903A: Global MASTER-Net observations report
  64. GRB 210827A: BOOTES-5/JGT optical upper limit
  65. Integral GRB210829.14: Global MASTER-Net observations report
  66. Fermi GRB 210827A: Global MASTER-Net observations report
  67. GRB 210824A: Fermi GBM Observation
  68. GRB 210822B: DDOTI Upper Limits on the Afterglow
  69. Fermi GRB 210822B: Global MASTER-Net observations report
  70. Fermi GRB 210821A: Global MASTER-Net observations report
  71. GRB 210821A: Fermi GBM Final Real-time Localization
  72. Fermi trigger No 651110719: Global MASTER-Net observations report
  73. Fermi GRB 210813A: Global MASTER-Net observations report
  74. GRB 210807A: Tautenburg observations
  75. GRB 210807A: Swift-BAT refined analysis
  76. GRB 210807C: Fermi GBM detection
  77. Fermi GRB 210807C: Global MASTER-Net observations report
  78. Swift GRB 210807A: Global MASTER-Net observations report
  79. IPN Triangulation of a bright burst from SGR 1935+2154
  80. Fermi trigger No 649814537: Global MASTER-Net observations report
  81. GRB 210731A: MeerLICHT optical afterglow detection
  82. GRB210731A: Enhanced Swift-XRT position
  83. Fermi trigger No 648959581: Global MASTER-Net observations report
  84. Fermi trigger No 648868114: Global MASTER-Net observations report
  85. Swift GRB210724.84: Global MASTER-Net observations report
  86. Fermi trigger No 648602917: Global MASTER-Net observations report
  87. Fermi trigger No 648278666: Global MASTER-Net observations report
  88. GRB 210715B: DDOTI Upper Limits on the Afterglow
  89. Fermi trigger No 647942198: Global MASTER-Net observations report
  90. Fermi trigger No 647805873: Global MASTER-Net observations report
  91. Fermi trigger No 647641569: Global MASTER-Net observations report
  92. Fermi trigger No 647624281: Global MASTER-Net observations report
  93. Fermi GRB 210709A: Global MASTER-Net observations report
  94. GRB 210708B: Swift detection of a possible burst
  95. Fermi trigger No 647365516: Global MASTER-Net observations report
  96. Integral GRB210707.02: Global MASTER-Net observations report
  97. Fermi trigger No 647108723: Global MASTER-Net observations report
  98. Fermi trigger No 647120009: Global MASTER-Net observations report
  99. GRB210702A: MeerLICHT multi-colour photometry
  100. GRB 210702A: Swift detection of a burst with a bright optical counterpart

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