Staring and starring are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway. Similarly, autocorrect on mobile phones might suggest one word instead of the other, it would be easy to do since both words start with “s-t-a-r.”
Staring is a gerund form of the verb stare. Staring means looking at something or someone for a very long time. How long? So long that you’re sure to be noticed by who or what you’re looking at.
Starring is a gerund form of the verb star. Starring is another way of listing cast member credits in a theater or film production. Typically, people starring in a film are listed either in the opening or closing of TV, film or web show, or in live theater, in a printed program or magazine handed out as the audience walks in.
The following story uses both words correctly:
Sergei didn’t hear their conversation. He was too busy staring at all the famous names starring in the next superhero film coming out next month.