Jessica Alba's Baby News Shoots Her to Top of Online Buzz List

Which celebs have all the Internet buzz, and who is sucking online wind?

GossipCenter.com tracks celebrities' online popularity 24/7 with their Gossip Center Hot 45 List.

The Gossip Center Hot 45 List is calculated by looking at the popularity of the site's hottest stories, and determining which stars are on the rise, and who is crashing and burning.

All of the articles, pictures and videos on the Gossip Center Network are scanned for activity, and the rankings are updated several times daily.

As for the past seven days, the entertainment world certainly wasn’t shy of action – with the most activity being generated by top spot holder Jessica Alba. Not far behind, the always-popular reality star Kim Kardashian and “Firework” hitmaker Katy Perry snared the second and third slots, respectively.

Let’s see how this all played out.

Never descending too far down on the Hot 45 List, Miss Alba made the climb to the top spot upon announcing that she and husband Cash Warren are expecting their second child together. Dropping the news through a Facebook message on Wednesday, the 29-year-old told, “I thought I'd drop by to let you all in on some exciting news > Honor is going to be a Big Sister!"

Meanwhile, Miss Kardashian continued her attention-grabbing ways with a week that included a Grammy appearance along with a Valentine’s Day bash in Sin City while Katy Perry rose to claim the third position with her Grammy performance and the release of a new single featuring Kanye West titled “E.T.”.

As for the big movers and shakers of the week, Bruno Mars jumped from the 100’s all the way to No. 9 as he garnered the kind of attention celebrities -- or anyone else for that matter -- do not like to get, pleading guilty to cocaine possession.

“Jersey Shore” star Angelina Pivarnick also rose from obscurity to No. 10 after receiving a wedding proposal from boyfriend David Kovaks on the red carpet during Mercedes-Benz Fashion Week in New York City.

As for the big dropper, Jennifer Aniston quickly fled the spotlight - plummeting from No. 2 all the way to No. 56 during a week in which she avoided press after having spent the previous few weeks promoting her newly-released movie “Just Go With It.”

Click here for the complete, up-to-the-minute Gossip Center Hot 45 List to see who's on the rise, and who's sinking like a stone.