Low Mass Protostar NASA.gov

In the late Middle Ages, with a growing awareness of the infinite value of the Mass, came a growing desire to multiply its celebration. Spiritual, as well as material reasons were at hand. The most pronounced result of the multiplying of Masses was the increase in low Masses, since most of them were for private requests and had no public character. This trend to the private and the subjective, to an independence from the grand order of things was also displayed in another abuse, namely, setting aside the arrangement of the ecclesiastical year and confining oneself to Votive Masses either chosen at will or arranged according to the rules of the Mass series . Over time it became necessary for a variety of reasons to celebrate more than one on the same day. It also became customary for monasteries to ordain most of their monks, though originally monks were almost all laymen, and for every priest to say a daily Mass. For a while, concelebration, whereby several priests took a full priestly part in offering Mass, provided all with the possibility to celebrate Mass each day, but this custom died out. Low Mass is considered to be a necessity that falls short of the ideal, which is Solemn Mass.