How, exactly? I see you cite spectrographic parallax. Fine, for starters that depends on the assumption stars are the same as earth area!!!!
"The Hertzsprung-Russell diagram is a graph illustrating star luminosity versus temperature. It is explored thoroughly in the NAAP
Hertzsprung-Russell Diagram Module. It is a significant tool in distance determination because
astronomers assume that stars nearby the earth are essentially like the stars very far from the earth. Thus, if one can plot a star's location on the HR Diagram, its absolute magnitude can be read off."
Spectroscopic Parallax - Cosmic Distance Ladder - NAAP
" Information garnered from the spectrum is used to find the star's position on the HR Diagram."
Then there are other built in assumptions.
"
This definition is convenient because the observed
brightness of a light source is related to its distance by the inverse square law (a
source twice as far away appears one quarter as bright) and because brightnesses are usually expressed not directly, but in
magnitudes.
Absolute magnitude {\displaystyle M}
is defined as the apparent magnitude of an object when seen at a distance of 10
parsecs. Suppose a light source has luminosity L(d) when observed from a distance of {\displaystyle d}
parsecs, and luminosity L(10) when observed from a distance of 10 parsecs."
Distance modulus - Wikipedia
A parsec is a distance...so when we use a parsec in math with brightness and etc to GET distance that is circular.
" One parsec is equal to about 3.26
light-years(31 trillion km or 19 trillion miles) in length. The nearest star,
Proxima Centauri, is about 1.3 parsecs (4.2 light-years) from the
Sun.
[2]Most of the
stars visible to the
unaided eye in the
night sky are within 500 parsecs of the Sun."
Parsec - Wikipedia
The method you cite id deceptive, and absolutely inbred. It believes stars are the same far away to start, then the inverse square law assumes things about time and space in the far universe, by saying light would appear the same! Then you add in light years or prasecs to the equation...etc!
Sorry you are busted.