If I use Tor to log into my personal accounts (gmail, facebook, hotmail) I know I won't be anonymous anymore but is there any way they can trace my IP address? Either my ISP or anyone else? I"m mostly concerned about someone finding my location rather than knowing which sites and when I visit them. Thank you
This may not be exactly what you are looking for, but hope that it can help you to get some basic ideas.
An attack called Correlation Attack can be employed to trace where you are if the Autonomous Systems between you and the Guard node, and the Autonomous Systems between the Exit node and the final destination are controlled under one person (lets assume: maybe only Government Agency like NSA, CIA or FBI has that kind of power)
However, if you are using gmail, facebook, hotmail, I do recommend that you should create those accounts in Tor environment without providing any real information about yourself, and only log into those accounts within the Tor environment.
For this task, you may need a temporary and unregistered phone number to verify the account. Since most of those services like Gmail and FB will ask your phone number while registering via Tor to send a code for verification purpose. After creating the accounts, you should destroy the SIM card of that phone number and never use or register the phone number if you want to stay anonymous.
P/S: if you log into your account from a non-Tor IP, then the next time you log into the account via Tor, your account may get blocked. So do remember that if you create the account from Tor-IP, then next time you log in, your account will not be blocked. For your ready reference, here it Onion site of Facebook, you should create an account from this site so that your account will not be blocked or ask for some secret question or verifying some friends' photos. https://facebookcorewwwi.onion/
The short answer is yes it is possible to track your IP address as Windy has explained. However, There is a procedural enhancement you can apply to remedy this situation. What you need to do is to create an additional barrier to make it difficult to locate you. This is done by going to a public place like a starbuck coffee bar and connect to web site of your choice from there. Try not to choose an establishment you decide to go to, too close to your actual place of residence or temporary residence. If you are in a large metropolitan area, like NewYork city, 20 miles or so from your place of residence or temporary residence suffices, however, if you are in rural area, you may go as far as 100 miles away from your place of residence or temporary residence. If where you are is somewhere in between these cases as far as concentration of population is concerned, choose some distance in between these numbers. Doing so will create an additional barrier to locate you. Now even if your IP address is discovered, only a public place IP address is discovered, not your actual place of residence or temporary residence. Do remember to change these public places often. The best practice is to use each location only once and never connect to internet again in that particular place. Finally, you should view Tor as a tool among many that you may use to enhance your anonymity with. You should not look at Tor as a panacea to all your anonymity and/or security issues.