[Tex/LaTex] How to shorten natbib bibliography authors to et al

Question

I'm using aastex (which uses natbib) with zotero (which outputs a bib file).

I've gone into the natbib abbrvnat.bst file and removed isbn, url & doi etc.

At the moment it reads:

M. G. Abadi, B. Moore, and R. G. Bower. Monthly Notices of the Royal
Astronomical Society, 308 (4):947–954, 1999.

I need it to read:

M. G. Abadi et al. Monthly Notices of the Royal Astronomical Society,
308 (4):947–954, 1999.

How do I force et al?
And how do I get rid of the double spacing between bibliographic items?

Answer 1

Use and others after the name of the first Author. (This only works with BibTex) like:

Author="John Doe and others"

You will get:

J. Doe et al.