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"

26528 results found.

  1. EP 260225.148: COLIBRÍ Confirmation of flaring star
  2. EP260223a: Xinglong optical upper limit
  3. The EP-WXT trigger 01709258631 is likely a flaring star
  4. GRB 260223A: Glowbug gamma-ray detection
  5. EP260213a: Mephisto optical upper limits
  6. EP260223a: EP-FXT follow-up observation
  7. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  8. sb26021801: SVOM/C-GFT upper limit
  9. EP260223a: COLIBRÍ optical upper limits
  10. EP260223a: Einstein Probe detection of an X-ray transient
  11. GRB 260223A: SVOM/GRM observation
  12. GRB 260223A: COLIBRÍ further optical observations and a brightening
  13. EP260221a: Optical upper limit with Kinder observations
  14. GRB 260223A: COLIBRÍ optical observations
  15. GRB 260223A: DDOTI Optical Candidate
  16. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  17. EP260221a: COLIBRÍ optical counterpart candidate
  18. EP260221a: Gemini South z-band upper limit
  19. EP260221a: EP-FXT follow-up observation
  20. EP-WXT01709258519: Xinglong optical upper limit
  21. EP260221a: Xinglong optical upper limit
  22. ZTF26aaglqak/AT2026dbl: COLIBRÍ Optical Observations
  23. EP260221a: GOTO optical upper limit
  24. EP260221a: COLIBRÍ optical upper limit
  25. SVOM alert sb26021801: LCO optical upper limit
  26. EP260221a: Einstein Probe detection of an X-ray transient
  27. IceCube-260217A: Upper limits from a search for additional neutrino events in IceCube
  28. GRB 260219A: GECAM-B observation of a long burst
  29. SVOM alert sb26021801: LAST optical upper limit
  30. sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  31. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  32. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  33. sb26021801: SVOM detection of a long faint X-ray transient
  34. The EP-WXT trigger 01709258455 is likely a flaring star
  35. EP-WXT 01709258455: NOT optical upper limits
  36. EP260214b: Mondy optical observations
  37. EP260214b: 1.3m DFOT optical upper limit
  38. EP260210a: Mondy optical upper limits
  39. Konus-Wind detection of GRB 260212A
  40. GRB 260208A: AbAO and Terskol optical upper limits
  41. GRB 260208A: continued Mondy optical observations
  42. IPN triangulation of GRB 260212A
  43. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  44. EP260214b: Liverpool Telescope optical observations
  45. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  46. EP260214b: Optical upper limit with Kinder observations
  47. EP260214a: Optical upper limits with Kinder observations
  48. EP260214b: EP-FXT follow-up observation
  49. EP260214b: DDOTI Optical Detection
  50. EP260214b: GROWTH-India Telescope optical upper limit
  51. EP260214a: VLT near-infrared observation
  52. EP260214a: NOT optical upper limits
  53. EP260214a: COLIBRÍ optical upper limits
  54. EP260214b: OHP/T120 optical observations
  55. EP260214a: refined analysis of the EP-FXT observation
  56. EP260214b: LCO optical counterpart detection
  57. EP260214b: COLIBRÍ optical observations
  58. EP260214b: NOT optical counterpart detection
  59. EP260214b: Einstein Probe detection of a fast X-ray transient
  60. EP260214a: Einstein Probe detection of an X-ray transient
  61. GRB 260212A: AstroSat CZTI detection
  62. GRB 260212A: Fermi GBM Observation
  63. EP260213a: Liverpool Telescope optical upper limits
  64. EP260213a: COLIBRÍ optical upper limits
  65. GRB 260212A: GECAM-B observation
  66. EP260213a: Optical upper limits with Kinder observations
  67. EP260213a: Mondy R-band optical upper limit
  68. EP260213a: SVOM/C-GFT upper limit
  69. EP260213a: refined analysis of the EP-FXT observation
  70. EP260213a: Einstein Probe detection of a fast X-ray transient
  71. EP/WXT 01709258378: NOT optical upper limits
  72. GRB 260212A: SVOM/GRM observation of a long burst
  73. GRB 260211A - SVOM/ECLAIRs refined analysis
  74. GRB 260212A: Glowbug gamma-ray detection
  75. GRB 260211A: LAST optical upper limit
  76. GRB 260210A: SVOM/GRM observation
  77. Konus-Wind detection of GRB 260207B
  78. GRB 260211A: LCO optical upper limits
  79. GRB260131A/B: 3.6m DOT Optical Observations
  80. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  81. GRB 260211A: SVOM detection of a burst
  82. Konus-Wind detection of GRB 260209B
  83. Konus-Wind detection of GRB 260127B
  84. EP260209a: COLIBRÍ optical upper limit
  85. EP260209a: LCO optical upper limits
  86. EP260210a: refined analysis of the EP-FXT observation
  87. GRB 260208A: LCO detection of the optical counterpart
  88. EP260209a: Einstein Probe detection of a fast X-ray transient
  89. EP260210a: Optical upper limits with Kinder observations
  90. IPN triangulation of GRB 260207B (short/hard with EE)
  91. GRB 260210A: Glowbug gamma-ray detection
  92. GRB 260210A: AstroSat CZTI detection
  93. EP260210a: COLIBRÍ optical upper limit
  94. EP260210a: SVOM/C-GFT upper limit
  95. GRB 260208B: refined analysis of the EP-FXT observation
  96. EP260210a: Einstein Probe detection of an X-ray transient
  97. GRB 260208C: SVOM/GRM observation
  98. GRB 260204A: Swift-XRT afterglow detection
  99. GRB 260208B: AstroSat CZTI detection of a bright long burst
  100. GRB260208A: Liverpool Telescope optical follow-up observations

Advanced

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