对给定的文本进行自动摘要，输出摘要文本。


文本： "Researchers have developed a new way to determine the age of stars. The technique involves measuring the amount of lithium in the star, which depletes as it ages."
新方法利用星中锂元素的数量来确定其年龄。随着星的年龄增长，锂元素逐渐耗尽。