180pc是多少ly？
180pc = 587.0815ly
是587.0815ly，所以说成587ly也没问题——四舍五入的误差在0.5%以内。
反过来，180ly是多少pc？
180ly = 55.1883pc
计算公式: ly = pc × 3.261564
该数值前后的 pc → ly
90 pc293.5407ly
100 pc326.1564ly
110 pc358.772ly
120 pc391.3877ly
130 pc424.0033ly
140 pc456.6189ly
150 pc489.2346ly
160 pc521.8502ly
170 pc554.4658ly
180 pc587.0815ly
190 pc619.6971ly
200 pc652.3128ly
210 pc684.9284ly
220 pc717.544ly
230 pc750.1597ly
240 pc782.7753ly
250 pc815.3909ly
260 pc848.0066ly
270 pc880.6222ly
280 pc913.2379ly