Aspire E15 randomly shutting down

So I've been having this problem within the last month or so where my laptop will randomly shut off - keyboard lights go off, screen goes dark, and when I hit the power button it starts up again as though it was waking up from sleep or something. I don't get any kind of pop ups saying that it was shut down improperly, and all windows I had open were closed and chrome asks to restore everything that was open.

It used to only happen once every week or two, but it's happening more frequently now (happened four times today while I was trying to complete my CSS profile and once a couple hours before while I was taking notes) but I have no idea what is causing it. I check the temperature and the laptop is hardly ever even warm when it happens, and it doesn't matter whether the battery is full or running low. I could have tons of tabs and windows open or only a couple, doesn't matter. 

Anybody else have any idea what's going on with this? I've only had the laptop for less than a year and the most taxing I do with it is play Stardew Valley for a few hours a couple times a week. Otherwise I just surf the web, read and write papers, and take notes.