[Bug]: ax.text() box size determined incorrectly for *-subscript (cuts off text at bottom) #31481

Bug summary

Hello everyone,

I have the case that I want to add some texual data to a plot. Therefore I need an subscript index for my math-symbol, which became *. It turned out that the text-box cuts off the bottom of the text when just givin * as subscript.

I have created a sample code below which shows the following behaviour:

I tried to overcome that issue by adding a protected space (~) behind * r"$\pm \sigma_{*~}$" but the space is ignored with respect to the box-calculation.

Best regards,
Deph

Code for reproduction

import matplotlib.pyplot as plt

fontSize = 40
fig, ax = plt.subplots(nrows=1, ncols=1)
ax.plot([0, 10],
        [0, 10],
        )
ax.text(0.175, 0.35, r"$\pm \sigma_{e*}$"                                           , transform=ax.transAxes, fontsize=fontSize, ha="left" , va="top")
ax.text(0.175, 0.19, r"$\pm \sigma_{*}$"                                           , transform=ax.transAxes, fontsize=fontSize, ha="left" , va="top")

Actual outcome

See screenshot.

Expected outcome

Text gets not clipped off at bottom

Additional information

Upgraded all packages before issue with pip freeze | %{$_.split('==')[0]} | %{pip install --upgrade $_}
Note: I tested rcparam useTeX=True which worked. However, by that the font changed to the TeX-font. If I consider now using the usetex option means I have to re-finetune the optic a ton of plots.

IDE: VS-Code 1.114.0 (system setup)
VS-Code Plugins: Microsoft Python Plugins Version 2026.4.0

Operating system

Windows 11

Matplotlib Version

3.10.8

Matplotlib Backend

3.10.8

Python version

3.14.3

Jupyter version

N/A

Installation

pip