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"

39175 results found.

  1. GRB 260708A: GECAM-B observation of a burst
  2. GRB 260708A: Fermi-GBM observation
  3. Fermi LAT GRB 260708A: MASTER OT J150237.02-435307.7 optical counterpart detection
  4. IceCube Alert 260709A: Global MASTER-Net observations report
  5. GRB 260709A: Fermi GBM Final Real-time Localization
  6. IceCube-260708A - IceCube observation of a high-energy neutrino candidate track-like event
  7. LAT GRB260708.42: Global MASTER-Net observations report
  8. GRB 260708A: Fermi-LAT detection
  9. GRB 260705B: SVOM/GRM observation
  10. GRB 260708A: Fermi-GBM detection
  11. GRB 260706A: Further EP-FXT follow-up observation
  12. GRB 260706A: SVOM/VT optical upper limits
  13. EP260707a (by EP-FXT): NOT optical upper limit
  14. EP260707a: TRT optical upper limit
  15. Fermi GBM trigger 805087514/260707142 (GRB 260707A) is not a GRB
  16. GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
  17. GRB 260705C: Glowbug gamma-ray detection of a short burst
  18. GRB 260706A: SVOM/ECLAIRs refined analysis
  19. GRB 260704A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  20. GRB 260706A: SVOM/GRM observation
  21. GRB 260706A: REM optical/NIR observations
  22. IceCube-260704A: No candidates from the Zwicky Transient Facility
  23. GRB 260706A: LCO optical upper limit
  24. GRB 260706A: EP-FXT follow-up observation
  25. GRB 260707A: Fermi GBM Final Real-time Localization
  26. GRB 260706A: Fermi GBM Observation
  27. IPN triangulation of GRB 260627A
  28. GRB 260705A: SVOM/ECLAIRs refined analysis
  29. GRB 260706A: SVOM detection of a burst
  30. GRB 260706A: Fermi GBM Final Real-time Localization
  31. The EP-WXT trigger 01709274014: KAIT confirmation of a stellar flare
  32. GRB 260705A: LCO optical upper limits
  33. GRB 260704A: NOT optical upper limits
  34. GRB 260705C: Fermi GBM Final Localization
  35. GRB 260705B: Fermi GBM Final Real-time Localization
  36. Fermi GBM Sub-Threshold Detection of GRB 260705A
  37. GRB 260705A: SVOM detection of a burst
  38. GRB 260704A: EP-FXT follow-up observation
  39. GRB 260629A: SVOM/GRM observation of a short burst
  40. GRB 260629A: GECAM-A observation of a short burst
  41. IceCube-260704A - IceCube observation of a high-energy neutrino candidate track-like event
  42. GRB 260629A: AstroSat CZTI detection
  43. GRB 260704A: SVOM detection of a possible GRB
  44. GRB 260703B: Fermi GBM Final Localization
  45. EP260628b: EP-WXT detection of an X-ray transient and EP-FXT follow-up observation
  46. Fermi trigger No 804738310: Global MASTER-Net observations report
  47. Fermi GRB 260703A: Global MASTER-Net observations report
  48. GRB 260703A: Fermi GBM Final Localization
  49. GRB 260610B: VLA detection
  50. GRB 260623A: Glowbug gamma-ray detection
  51. GRB 260614B: ATCA Radio Upper Limits
  52. GRB 260610B / AT2026owq: SAO RAS, CrAO and INASAN further optical observations and light curve
  53. Fermi trigger No 804552016: Global MASTER-Net observations report
  54. GRB 260701A: Fermi GBM Final Real-time Localization
  55. Fermi GBM trigger 804552016/260630945 is not a GRB
  56. Fermi-LAT Gamma-ray Observations of IceCube-260622A
  57. GRB 260629A: Fermi GBM Final Real-time Localization
  58. Fermi GRB 260628A: Global MASTER-Net observations report
  59. GRB 260628A: Fermi GBM Final Real-time Localization
  60. EP260626a: COLIBRÍ optical upper limit
  61. Konus-Wind detection of GRB 260623B / EP260623a
  62. GRB 260618A: Fermi GBM Observation
  63. MASS-Cube (GRID 2.0) detection of GRB 260616B
  64. GRB 260619A: SVOM/ECLAIRs refined analysis
  65. Fermi GBM trigger 804010507/260624677 is not a GRB
  66. Konus-Wind detection of GRB 260618B
  67. GRB 260624A: Fermi GBM Final Real-time Localization (Duplicate Submission)
  68. GRB 260624A: Fermi GBM Final Real-time Localization
  69. GRB 260617A: Glowbug gamma-ray detection of a short burst
  70. IPN triangulation of GRB 260605A
  71. GRB 260623A: Fermi GBM Final Real-time Localization
  72. EP260623a: TRT optical observations
  73. EP260623a: REM optical/NIR afterglow detection
  74. EP 260623a: COLIBRÍ optical observations
  75. GRB 260616B/EP260616a: Insight-HXMT/HE detection
  76. GRB 260614B: EP-FXT follow-up observation
  77. IceCube-260622A - IceCube observation of a high-energy neutrino candidate track-like event
  78. GRB 260618C: SVOM/ECLAIRs detection of a possible burst through on-ground search
  79. GRB 260619A: NOT optical observations
  80. GRB 260618B: LCO optical observations
  81. EP260618a: JinShan optical observations
  82. GRB 260616B/EP260616a: SVOM/GRM detection of a burst
  83. GRB 260618B: Fermi GBM Observation
  84. GRB 260619A: TRT optical counterpart confirmation
  85. GRB 260610B: Further GRANDMA Optical Observations and re-brightening detection
  86. GRB 260604B: 239Alferov CubeSat detection
  87. GRB 260604A: 239Alferov CubeSat detection
  88. GRB 260610B: VLT/FORS2 spectroscopic observation suggests the non-thermal nature of the optical rebrightening
  89. GRB 260619A: SVOM/VT optical counterpart confirmation
  90. Fermi-LAT Gamma-ray Observations of IceCube-260610A
  91. GRB 260618B: SVOM/VT optical candidate
  92. GRB 260618B: SVOM/VT optical candidate (duplicate Submission of 45001)
  93. GRB 260619A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  94. Konus-Wind detection of GRB 260617A
  95. GRB 260616B: AstroSat CZTI detection
  96. GRB 260616A: AstroSat CZTI detection
  97. GRB 260616A: SVOM/GRM observation
  98. GRB 260610B/AT2026owq: 1.3m DFOT optical rebrightening detection
  99. GRB 260619A: Kilonova-Catcher optical upper limit
  100. EP260618a: EP-FXT follow-up observation

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov