How do I defeat the "Death Star" (Orkulus Star Base)?

My fleet, which has destroyed all other enemy fleets it has encountered (including their capital and Titan ships) and has colonized the capital home world of two different players (random normal AIs), was on its way to one of the enemy Vasari player's planets. Upon appearing from phase space into this planet's gravity well, my fleet admiral uttered "It's a trap!"*

My fleet was welcomed by the Vasari "Death Star"* (Orkulus Star Base). My fleet engaged it and the remaining planet defense structures (the enemy didn't have much of its fleet left). I then found out that we were no match for it; most of the non-Titan and non-capital ships have been destroyed, and I had to order the retreat of some of the nearly destroyed capital ships.

I have managed to sneak in a Raloz Heavy Contructor and build an Argonev Star Base in the planet's gravity well that contains the Orkulus Star Base, and tried to retreat to its position once it was made and get it to attack the Orkulus Star Base, but alas, it too has been destroyed, along with some of my capital ships.

Screenshot before it was destroyed:

My fleet includes 6 capital ships (levels ranging from 1-8), and a Ragnarov Titan (level 1), and around a two dozen combination of Cobalt Light Frigates, Stilat Corvettes, Garda Flak Frigates and Percheron Light Carriers. It has faced and destroyed all other enemy ships, which includes enemy capital ships and higher level-Titan ships, that it has encountered but it can not fight this Death Star menace.

Before I load an earlier auto-save, I would like to know: What is the weakness of the Orkulus Star Base? Where is its reactor?* Any pro-tips in destroying this starbase? Who is the "Luke Skywalker" of the TEC Rebel fleet?* How can he use the Force?*

Note: I'm playing as TEC Rebel, in the Rebellion expansion.

^{* (Star Wars reference/joke)}

You'll need the anti-structure cruiser, introduced in Entrenchment, which acts as hard counters to Starbases and other defensive structures. The TEC's is the Ogrov Torpedo Cruiser, which is basically a giant moving missile platform that is ridiculously good against structures (including Starbases) and nothing else.

The Starbase you were facing appears to be very well upgraded, which means that you need a good number of these, plus a fleet to protect these against any other ships in the gravity well since they can't defend themselves.

There are several ways to hard counter star bases. As Yi Jiang pointed out, anti structure cruiers work really well.

The other way to counter them is to have massive amounts of fighters and bombers. Bombers, especially is the universal counter to all star bases as they all lack anti fighter capability and must rely on their squadrons (assuming it has them).

Note the star base, while mobile, is quite slow so you can easily out pace it using either strategy as the anti structure cruisers have a really long range.