極短週期 (Ke̍k-té-chiu-kî)或生 (he̍k-chheⁿ) (ultra-short-period planets) 是 (sī)軌道 (kúi-tō)週期 (chiu-kî) (orbital period) 無 (bô)到 (kaù)1kang的 (ê)惑星 (he̍k-chheⁿ),怹 (in)咧 (leh)踅 (se̍h)的青 (chheⁿ)定著 (tiāⁿ-tio̍h)無到0.88倍 (poē)日頭 (ji̍t-thaû)質量 (chit-liōng)。怹並 (phēng)別 (pa̍t)獎 (chióng)惑星閣較 (koh-khah)倚 (oá)咧踅的青。
現此時 (Hiān-chú-sî)佇 (tī)銀河系 (gîn-hô-hē)有 (ū)揣 (chhoē)着 (tio̍h)5粒 (lia̍p)極短週期或生。