Submissions are ranked according the the associated activity. It'll appear on the first page if it is ranked accordingly.

See the FAQ (https://news.ycombinator.com/newsfaq.html):

> "How are stories ranked?"

> "The basic algorithm divides points by a power of the time since a story was submitted. Comments in threads are ranked the same way."

> "Other factors affecting rank include user flags, anti-abuse software, software which demotes overheated discussions, and moderator intervention."

I also recommend reading the Guidelines:

https://news.ycombinator.com/newsguidelines.html