What does it take to be a "star" on TV?

An audience.

To modify the previous response somewhat: it takes “enough of the right audience”. That is, as to the particular demographics (and quantity!) of audience. No one seems to want an audience that isn’t sufficiently representative of the market segment that the show’s advertisers are trying to reach.

A telescope?

This is sloppy reporting/writing. “The Bachelor” isn’t the star, he is not even the contestant. He is merely the prize!

What makes a star is being the principal actor in a production, and one is not really a star unless the show or movie is successful.

To be a star, one must have lasting appeal, not just some random appearances.

That’s like the show Dancing With the Stars. Charo? Really? Gary Bussey? Really? A guy that rode in a rodeo. A guy that was hurt in Afghanistan. Those are not stars. Those are random people. It should be renamed to Dancing With Random People.

If a star can be described as a big ball of hot orange gas, then all it has to do is be a relentlessly self-promoting egomaniac, and lose the popular vote.