If it is a typical burgandy star, then it is a reef safe star, and will not typically respond to any spot feeding, unlike chocolate chip, generals, bahama, etc stars. They do not eat detritus, or anything of the sort. They are not scavengers. They must have a lot of mature LR in a large tank (75g- 100lbs) min for long term success, and without other similar species of star (other reef safe forms). The tank should be at least 6 months old. They require a very slow drip acclimation, and are very sensitive to any changes in water parameters. If the animal appears to melt in the next month, it died of salinity shock. Most die within a year, of starvation, unless in a very large tank.
Can you find a picture, for a positive ID? Generally, if it doesn't have big knobs on it, it is probably a Tamaria or Echinaster sp. Reef safe. No spot feeding works in most cases.