To increase the brightness, use high ISO (like maybe ISO 3200) and wide open lens, like f/2.8. Depth of Field is not an issue for stars at distance of infinity.
You of course also need the seconds of exposure, and 30 to 60 seconds may normally be enough for ISO 3200 f/2.8, but the Earth will rotate 1/4 degree in 60 seconds, which will cause a trailed blur for a camera on a fixed mount. A very short lens focal length (wide angle view) will minimize that trail, and any longer lens will emphasize it.
There is an old rule of thumb (for 35 mm film size) called 500 Rule that says
Seconds = 500 / focal length
will be acceptable blur (but probably not sufficient exposure time). This 500 Rule is for 35 mm film size. Smaller sensor frames will be worse blur (longer trails) than larger 35 mm frame size (only because smaller frames must be enlarged more for viewing).
My site at https://scantips.com/lights/stars.html offers some calculation help with this in regard to actual sensor size and focal length.
An astronomy motorized mount can solve the motion issue.
But also see Google for
https://www.google.com/search?q=star+tracking+camera+mount
which is a very simple DIY "barn door" tracker where you can manually turn a screw a bit maybe every 10 or 15 seconds to also track the rotation, giving blur results like only 10 or 15 seconds. The dimensions calibrate the screw thread pitch to the Earths rotation speed. General design is one 360 degree turn of screw follows 60 seconds of sky rotation. Fancy designs put a 1 RPM motor on the screw, but the entire duration might be only about 1 minute, so manual turning can work too (don't shake the camera though). The links there show many versions of it.