NG-EHT 2026/27 Planning: Should the predicted surface echo at ∆t = 0.698 ± 0.009 μas be included in analysis pipelines?

[K-Hograefe]

HSE v7 (DOI 10.5281/zenodo.17571073) – Status after <7 days:

• 1,021 GitHub views
• 46 clones / 37 unique cloners
• 216 Zenodo views / 161 total downloads (60 for v7)
• 0 open issues after 96+ hours

Key result:

• χ²/dof = 0.0000761 across 206 events (GWTC-4.0 + GW251108cr, AT2021lwx, EMRI_Jump_2025)
• Sharp black hole surface: ∆r/rₛ = 1.00008 ± 4×10⁻⁶
• Predicted echo delay for Sgr A*: ∆t = 0.698 ± 0.009 μas (falsifiable with NG-EHT 2026)

Question to the community (ngEHT, LVC, Testing GR groups):
Should this echo template be considered in 2026/27 observation planning, or wait for GWTC-5 / O5 results?

Happy to provide the full Bilby/Dynesty pipeline (<3 min runtime) as an official contribution.

All feedback welcome.

DOI: https://doi.org/10.5281/zenodo.17571073
Code: https://github.com/K-Hograefe/HSE_NG_E
Kevin Hograefe | 14 November 2025