Yes. A practical approach is to trigger each bulb exposure inside a shell loop rather than relying on a single gphoto2 command to handle the whole sequence.

Example:

for i in $(seq 1 30)
do
  gphoto2 --set-config bulb=1 --wait-event=120s --set-config capturetarget=1
  sleep 1
done

This runs 30 exposures, each held for 120 seconds, with a 1-second pause between shots. The short sleep helps define the interval explicitly.

For star trails, shooting a sequence of separate long exposures is a common method, and keeping the gap small minimizes breaks in the trails. Saving to the SD card is handled by setting the capture target to the camera/card.

If you still see issues, verify that bulb mode is enabled on the camera itself and that your camera’s gphoto2 support includes remote bulb control.