3 Piscis Austrini, also known as HD 201901, is a suspected astrometric binary[7] star system that, despite its Flamsteed designation, is actually located in the constellation Microscopium. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 5.41.[6] The system is moving closer to the Earth with a heliocentric radial velocity of −46 km/s.[2] It is following a highly elliptical orbit around the Galactic Center, moving between a pericenter of 2.6 kpc out to an apocenter of 7.6 kpc, with an orbital eccentricity of 0.49.[2]

The visible component is an evolved giant star with a stellar classification of K3 III.[3] The interferometry-measured angular diameter of the star, after correcting for limb darkening, is 2.03±0.04 mas,[8] which, at its estimated distance, equates to a physical radius of about 20 times the radius of the Sun.[4] It is radiating 174[2] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,050 K.[5]

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