Auth Middleware from filter

AuthCheck.php

<?php

namespace App\Http\Middleware;

use Lang;
use Closure;

class AuthCheck
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle($request, Closure $next)
    {
        if ($request->is('panel*')) {
            config()->set('auth.model', 'Serverfireteam\Panel\Admin');
        }

        if (is_null($request->user())) {
            $message = session('message', Lang::get('panel::fields.enterEmail'));

            return redirect('/panel/login')
                ->with('message', $message)
                ->with('mesType', 'message');
        }

        return $next($request);
    }
}

Do you need a single 'auth' middleware that can be used for the front side and the panel backside?
And if that is the case, where do you want the users who are not authenticated redirected to on the front?