Symbol Δ E
Δ E is part of the quantity the equation computes from the expression on the right.
Read this term in its guide →Published equation contexts
Why this formula appears here
The mechanism behind that contradiction is simple enough to state in one line, and the paper’s authors compute it carefully because the commonly quoted version understates it by an order of magnitude. Surface rotation Doppler-broadens any spectral line by a fraction of its energy equal to the star’s equatorial velocity over the speed of light, E/E /c = 2 R/c 1.310^{-1}(/500\,)(R/12\,) , where is the star’s spin frequency and R its radius.
Read the representative guide
Symbol E
E is part of the quantity the equation computes from the expression on the right.
Read this term in its guide →Symbol v_eq
q is part of the quantity the equation computes from the expression on the right.
Read this term in its guide →Symbol c
c is part of the quantity the equation computes from the expression on the right.
Read this term in its guide →Symbol pi
pi is one of the signed contributions combined to compute the quantity on the left.
Read this term in its guide →How to interpret it
Its accuracy depends on the assumptions and range of use described in the article. Read it with the definitions, units, and assumptions supplied by the article.
Research cited beside this formula
Published contexts (1)
A symbol can carry a different meaning in another article. Each occurrence keeps its own guide and term definitions.
Equation 20 · Crossed Fields
A Neutron Star Is a Redshift Standard
This equation gives an approximation: it relates the quantities while allowing an approximation.
The mechanism behind that contradiction is simple enough to state in one line, and the paper’s authors compute it carefully because the commonly quoted version understates it by an order of magnitude. Surface rotation Doppler-broadens any spectral line by a fraction of its energy equal to the star’s equatorial velocity over the speed of light, E/E /c = 2 R/c 1.310^{-1}(/500\,)(R/12\,) , where is the star’s spin frequency and R its radius.