Strange Mobile device tried to connect to my iMac via Bluetooth! Should I be concerned?

I woke up this morning with a pop-up message saying that a mobile device tried to pair with my system but was rejected most likely from an incorrect password. I've always had "bluetooth" enabled. Never used it though, I have a wired mouse and keyboard. I never thought about possible threats occuring from this until now. I originally had all default settings turned on for bluetooth but no sharing enabled. I clicked off "discoverable" and turned bluetooth off altogether. My concern is that I am seeing a "T-Mobile myTouch Q" Smartphone in the list. I don't own this type of phone. I've never had a t-mobile phone or know anybody who does. I tried to "browse" the device but I get an error. I am unable to remove the device from my list.

It doesn't appear to be connect or ever have been connected to my knownledge but I would like it taken off.

Is there any way somebody can hack your iMac via a mobile device? I went on a researching rampage this morning but am unsure of what to think at this point. If bluetooth only operates up to 30 feet of range, who could possibly have wanted to connect at 4-5 am in the morning? Also, if they were paired, exacly what information can they gain from being paired via bluetooth to a mobile device?

Should I be concerned about this? I have Mac firewall enabled in stealth mode. Have Sophos installed and up to date and running. All sharing is turned off. What else can I do and how can I remove this device from the list so I can use bluetooth in the near future without any worries?

Thanks for any help!