<p>I've been looking into the tidal mechanism for a binary star system and seem to have hit a brick wall. In the literature (see below), little explanation is given to justify the equations (9.60), (9.61) and (9.62). I would be grateful if someone could talk me through where these equations came from, as my efforts to find a complete and concise explanation online have thus far been fruitless. Note that I've had to cut some of the text at the top where the page turns over, but this is just a brief introduction to the use of Legendre polynomials in providing a tide raising part of the potential.</p>

<blockquote>
  <p><a href="https://i.sstatic.net/GKAbt.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/GKAbt.png" alt="enter image description here"></a>
  Eldridge and Tout, <em><a href="https://doi.org/10.1142/p974" rel="nofollow noreferrer">The Structure and Evolution of Stars</a></em>, 2019</p>
</blockquote>

CC BY-SA 4.0
2019-09-21T04:44:57.940Z
Can you cite the source of your screenshot? It's always important to credit the original source of borrowed material, and it's possible it will help someone formulate an answer. It looks like it might be [The Structure and Evolution of Stars](https://www.worldscientific.com/worldscibooks/10.1142/p974)
https://doi.org/10.1142/p974 January 2019 by J J Eldridge and Christopher A Tout. Is that right? Note, the passage is viewable here: https://books.google.com/books?id=4miMDwAAQBAJ&pg=PA290&lpg=PA290
uhoh
CC BY-SA 4.0
2019-09-21T15:33:32.657Z
Yes, that's right.
user29126
CC BY-SA 4.0
2019-09-22T00:30:46.060Z
looks good, thanks!
uhoh
<star><binary-star><star-systems><tidal-forces>
Derivation of a formula for the mass of a tidal bulge and tidal torque
user29126
# Derivation of a formula for the mass of a tidal bulge and tidal torque

(Asked by: username_0 on 2019-09-21)

I've been looking into the tidal mechanism for a binary star system and seem to have hit a brick wall. In the literature (see below), little explanation is given to justify the equations (9.60), (9.61) and (9.62). I would be grateful if someone could talk me through where these equations came from, as my efforts to find a complete and concise explanation online have thus far been fruitless. Note that I've had to cut some of the text at the top where the page turns over, but this is just a brief introduction to the use of Legendre polynomials in providing a tide raising part of the potential.

> [![enter image description here](https://i.sstatic.net/GKAbt.png)](https://i.sstatic.net/GKAbt.png)
> Eldridge and Tout, *[The Structure and Evolution of Stars](https://doi.org/10.1142/p974)*, 2019

**Tags:** star, binary-star, star-systems, tidal-forces

> **Comments:**
> **username_1**: Can you cite the source of your screenshot? It's always important to credit the original source of borrowed material, and it's possible it will help someone formulate an answer. It looks like it might be [The Structure and Evolution of Stars](https://www.worldscientific.com/worldscibooks/10.1142/p974) https://doi.org/10.1142/p974 January 2019 by J J Eldridge and Christopher A Tout. Is that right? Note, the passage is viewable here: https://books.google.com/books?id=4miMDwAAQBAJ&pg=PA290&lpg=PA290  
> **username_0**: Yes, that's right.  
> **username_1**: looks good, thanks!  

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## 0 answers

