diff --git a/constants/59a.md b/constants/59a.md
index 4981408..0254747 100644
--- a/constants/59a.md
+++ b/constants/59a.md
@@ -43,10 +43,10 @@ The exact value of $K_d$ is unknown for every $d>1$; in particular, the exact va
The best established range currently is
$$
-0.3006\ \le\ K_2\ <\ 0.3177.
+0.3006\ \le\ K_2\ <\ 0.3174541.
$$
-[Kne2025-lb-K2-0-3006] [BPWW2026-ub-K2-0-3177]
+[Kne2025-lb-K2-0-3006] [G2026-ub-K2-0-3174541]
## Known upper bounds
@@ -54,6 +54,7 @@ $$
| ----- | --------- | -------- |
| $1/3$ | [BK1997] | General upper bound $K_n\le 1/3$ (hence $K_2\le 1/3$). [BK1997-ub-1-3] |
| $0.3177$ | [BPWW2026] | Explicit construction giving $K_2<0.3177$ (Theorem 6.4). [BPWW2026-ub-K2-0-3177] |
+| $0.3174541$ | [G2026] | Degree-$(250,250)$ polynomial from a rational-inner Fejer averaging certificate. Exact integer verification gives $B\_{3174541/10000000}(p)>1$. [G2026-ub-K2-0-3174541] |
## Known lower bounds
@@ -118,6 +119,11 @@ $$
**loc:** arXiv v1 PDF p.18, Theorem 6.4
**quote:** “Theorem 6.4. $K_2<0.3177$.”
+- **[G2026]** Griego, Sebastian. Rational-inner Fejer averaging certificate for the bidisc Bohr radius bound $K\_2<0.3174541$, [submitted to this repository](https://github.com/teorth/optimizationproblems/pull/75) (2026).
+ - **[G2026-ub-K2-0-3174541]**
+ **loc:** pull request certificate and exact verifier
+ **quote:** “The exact integer verifier proves $B\_{3174541/10000000}(p)>1+1/7307638490$ and the rational-inner Fejer averaging certificate proves $\lvert p\rvert\le 1$ on the bidisc.”
+
## Contribution notes
-Prepared with assistance from ChatGPT 5.2 Pro.
+Prepared initially with assistance from ChatGPT 5.2 Pro and updated with assistance from ChatGPT 5.5 Pro.