Psi2 Aquarii

Psi2 Aquarii, Latinized from ψ2 Aquarii, is the Bayer designation for a star in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent visual magnitude of 4.4. Based upon parallax measurements made during the Hipparcos mission, the distance to this star is roughly 400 ly.

This is a B-type main sequence star with a stellar classification of B5 Vn. The 'n' suffix indicates that the absorption lines in the spectrum are being broadened by Doppler shift from the star's rapid rotation rate. The projected rotational velocity of the star is 341 km/s. Psi2 Aquarii is 4.6 times as large as the Sun with an effective temperature of 15,212 K in its outer envelope.

It is a λ Eridani variable, or periodic Be star, with a pulsation cycle lasting 1.073 days. The amplitude of the variation is 0.024 in magnitude.