GNOME Applications menu question

[Maccy]

Does anyone know how I can add another group under 'Applications' on the
top panel of the GNOME desktop?

I can easily add an item to the Applications menu by creating a .desktop
file in the /usr/share/applications directory. But I work in Astronomy and what I want to do is
create a new 'Astronomy' group containing links to the most popular
installed Astro software on one system, then distribute the relevant
config files to all my other machines.

Documentation seems scarce....

Thanks in advance for any advice,

Mark