外屏七 (α Psc / 双鱼座α) 是双鱼座的一颗恒星，俗名Alrescha (Al Rescha, Alrischa, Alrisha)，源于阿拉伯语 الرشآء al-rišā’，意为“井绳”。还有一些不常用的名字如Kaitain 以及Okda，后者源于阿拉伯语عقدة ‘uqdah "绳结"。

外屏七是一个双星系统，由目前相距1.8"的两颗恒星组成。主星视星等为+4.33，光谱型为A0p，伴星视星等为+5.23，光谱型为A3m。二者绕行周期超过700年，到2060年左右它们相距最近。它们中有一颗或者两颗都可能是分光双星。主星和伴星的质量分别为2.3和1.8个太阳质量，总光度分别为31和12倍太阳光度。

Alpha Piscium (Alpha Psc, α Piscium, α Psc) is the Bayer designation for a star in the equatorial constellation of Pisces. It has the traditional name Alrescha (Al Rescha, Alrischa, Alrisha).

The distance to α Psc is about 139 light years. The system comprises a close double star with angular separation of presently 1.8" between the components. The main star is of magnitude +4.33 and spectral type A0p, while the companion is magnitude 5.23 and belongs to spectral class A3m. The two stars take more than 700 years to orbit one another and they will make their closest approach to each other around 2060. One or both of the stars may be a spectroscopic binary as well. The stars have masses of 2.3 and 1.8 solar masses respectively and shine with a total luminosity of 31 and 12 times that of the Sun.