Orbits and masses of spectroscopic binaries [@TaurisvandenHeuvel+2023]

This is generally all math that I either know from astro classes, or is so specific id need to revisit it to use anyway

$\frac{L}{L _{⊙}} = \frac{M}{M _{⊙}}^{3.5}, M > 1.3 M_{⊙}$

Very massive stars

Most massive has $L \sim 1 0_{⊙}^{L}$
Because of the high ( $\sim 50000 k$ ) temps, they have strong stellar wind, and thus very similar spectra to WR-star, which they are distinguished from by the presence of hydrogen
Denoted as WNh

Rad Vel curve must be off due to a difference in eccentricity values derived from the rad curve and the light curve
Rotation effect \begin{list}{-}{}
when the stars are eclipsing the rotational Doppler shift can be added (if the half spinning away from us is obscured) or subtracted to the shift, leading to different rad velocity measurements. This is called the Rossiter-McLaughlin effect. (This is actually a super neat and intuitive process which i feel like the book just sorta skips and doesnt explain, maybe wanna write out/make some graphics bout this sometime)

\item presence of gas streams

wow they could have said literally anything about what a gas stream is in this case
im guessing it means some sort of flow of mass coming off of the binaries, maybe in accretion, maybe in jets???

\item reflection effect \item heating effect

Both the reflection and heating effect are caused by that the stars will cast light on each other, both heating and causing reflection

\item deformation effect

the above effects cause the curve to be shifted from the c.m., leading to wonky radial vel curves

\item this is actually pretty important when it comes to HMXBs and properly measuring NS and BH masses \end{list}

$> 70%$ of massive o-type stars are members of binaries so close that they’ll exchange mass or merge before either star explode as a SN

the rest of this section follows the “way too niche of math to write down” thing