mupwI':

Antares vertaHbogh vIHtaHghach'a'

SuStel:

I'm not fond of this; it looks like a very forced -ghach. How about just saying Antares mI'rab'a'

What do you mean by saying "a very forced -ghach" ?

Someone was trying hard to turn vIH into a noun and turned to the only tool they could find that does that in vaguely the right way.

-ghach is meant to be used when you're primarily interested in the intervening verb suffix. People often toss a -taH in there just to satisfy the requirement that there be a suffix there, and this is bad practice.

When you combine this verb with this suffix, what is the "thing" that results? That's what -ghach is supposed to answer.

-- 
SuStel
http://trimboli.name