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"

32485 results found.

  1. EP260723a: further EP-FXT follow-up observation
  2. EP260725a: EP-FXT follow-up observation and association with a bright flaring star
  3. GRB 260616A: cubesat Avion detection
  4. EP260723a: Continued Liverpool Telescope observations suggest hours long optical plateau or rebrightening
  5. GRB 260602B: cubesat Avion detection
  6. GRB 260601A: cubesat Avion detection
  7. EP260723a: EP-FXT follow-up observation
  8. IPN triangulation of GRB 260706B
  9. GRB 260718A: SVOM/ECLAIRs refined analysis
  10. EP260723a: SVOM/VT optical observation
  11. EP260723a: COLIBRÍ optical observations
  12. EP260723a: NOT optical conterpart confirmation
  13. EP260723a: Liverpool Telescope likely optical counterpart
  14. IceCube-260722A: Upper limits from a search for additional neutrino events in IceCube
  15. IceCube-260722A: One candidate from the Zwicky Transient Facility (ZTF)
  16. Konus-Wind detection of GRB 260721A
  17. IceCube-260722A - IceCube observation of a high-energy neutrino candidate track-like event
  18. GRB 260721A: NuSTAR detection of prompt emission
  19. Konus-Wind detection of GRB 260714B
  20. SVOM trigger sb26071506: SVOM/VT confirmation of a stellar flare
  21. GRB 260705A: Retraction of optical counterpart
  22. GRB 260714B: Insight-HXMT/HE detection
  23. GRB 260718A: EP-FXT follow-up observation
  24. Fermi GRB 260718A: Global MASTER-Net observations report
  25. GRB 260718A: LCO optical upper limits
  26. GRB 260711A: SVOM/GRM observation
  27. GRB 260710A: SVOM/GRM observation
  28. GRB 260718A: Fermi GBM Observation
  29. GRB 260718A : GRANDMA and KNC upper limits
  30. GRB 260718A: SVOM/VT optical upper limits
  31. GRB 260718A: SVOM/VT optical upper limits from VHF data
  32. GRB 260718A: SVOM detection of a burst
  33. GRB 260714B: SVOM/GRM observation
  34. GRB 260310A / AT2026fgk: Late-time Chandra Detection
  35. GRB 260714B: GECAM-B observation of a burst
  36. GRB 260618B: EP-FXT follow-up observation upper limit
  37. GRB 260714B: COLIBRÍ optical counterpart candidate
  38. IceCube-260708A: Follow-up studies of cosmic-ray origin of high-energy neutrino alert
  39. SVOM sb26071506: Global MASTER-Net observations report
  40. IceCube-260712A: No candidates with the Zwicky Transient Facility (ZTF)
  41. EP260703a: SVOM/ECLAIRs Upper Limit
  42. GRB 260710A: AstroSat CZTI detection
  43. GRB 260709A: AstroSat CZTI detection
  44. GRB 260714B: AstroSat CZTI detection
  45. GRB 260714B: Fermi-LAT detection
  46. IceCube-260712A: Upper limits from a search for additional neutrino events in IceCube
  47. IceCube-260712A: LAST optical follow-up observations of the IceCube neutrino candidate
  48. GRB 260706A: ATCA detection of possible radio counterpart
  49. GRB 260705A: ATCA radio observations
  50. GRB 260619A: SVOM/VT continuous optical observations
  51. GRB 260618B: SVOM/VT optical observations indicate shallow decay and reddening
  52. GRB 260708A: slowly decaying X-ray emission observed by EP/FXT
  53. EP260623a: KAIT optical observations
  54. EP260711a: EP-FXT follow-up observation
  55. GRB 260708A: GRANDMA Optical Observations
  56. Fermi-LAT Gamma-ray Observations of IceCube-260712A
  57. Fermi-LAT Gamma-ray Observations of IceCube-260708A
  58. GRB 260710A: Insight-HXMT/HE detection
  59. Fermi-LAT Gamma-ray Observations of IceCube-260704A
  60. IceCube-260708A: Upper limits from a search for additional neutrino events in IceCube
  61. IceCube-260712A - IceCube observation of a high-energy neutrino candidate track-like event
  62. GRB 260708A: LCO optical observations
  63. GRB 260710A: Fermi GBM Detection
  64. GRB 260709A: SVOM/GRM detection
  65. GRB 260709A: GECAM-B observation
  66. IceCube-260708A: Observations with the Vera C. Rubin Observatory
  67. EP-WXT trigger 0170924151 : RAPAS optical counterpart candidate detection
  68. GRB 260705C: AstroSat CZTI detection
  69. GRB 260708A: Glowbug gamma-ray detection
  70. GRB 260704A: SVOM/ECLAIRs refined analysis
  71. GRB 260706A : GRANDMA Upper limits
  72. GRB 260708A: Kilonova-Catcher optical afterglow detection
  73. GRB 260708A: GECAM-B observation of a burst
  74. IceCube-260708A: One candidate from the Zwicky Transient Facility
  75. GRB 260708A: Fermi-GBM observation
  76. Fermi LAT GRB 260708A: MASTER OT J150237.02-435307.7 optical counterpart detection
  77. IceCube-260708A - IceCube observation of a high-energy neutrino candidate track-like event
  78. GRB 260708A: Fermi-LAT detection
  79. GRB 260705B: SVOM/GRM observation
  80. GRB 260706A: Further EP-FXT follow-up observation
  81. GRB 260706A: SVOM/VT optical upper limits
  82. EP260707a (by EP-FXT): NOT optical upper limit
  83. EP260707a is not a real source
  84. EP260707a: LCOGT Optical Upper Limit
  85. EP260707a: TRT optical upper limit
  86. GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
  87. GRB 260705C: Glowbug gamma-ray detection of a short burst
  88. GRB 260706A: SVOM/ECLAIRs refined analysis
  89. GRB 260704A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  90. GRB 260706A: SVOM/GRM observation
  91. GRB 260706A: REM optical/NIR observations
  92. IceCube-260704A: No candidates from the Zwicky Transient Facility
  93. GRB 260706A: LCO optical upper limit
  94. GRB 260706A: EP-FXT follow-up observation
  95. GRB 260706A: Fermi GBM Observation
  96. IceCube-260704A: Upper limits from a search for additional neutrino events in IceCube
  97. IPN triangulation of GRB 260627A
  98. GRB 260705A: SVOM/ECLAIRs refined analysis
  99. GRB 260706A: SVOM detection of a burst
  100. The EP-WXT trigger 01709274014: KAIT confirmation of a stellar flare

Advanced

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