If you can also make the probe survive a close flyby by the star (that should ideally require just a good sun shield & robust orientation control) you could the

If you can also make the probe survive a close flyby by the star (that should ideally require just a good sun shield & robust orientation control) you could the so called solar Oberth manuever - basically this[0] but to slow down an incoming interstellar probe, not to launch one. A simple storable high thrust solid rocket motor would be ideal for this. [0] https://www.centauri-dreams.org/2021/10/06/assessing-the-oberth-maneuver-for-interstellar-probe/ https://www.centauri-dreams.org/2021/10/06/assessing-the-obe...