NGC 3729 is a barred spiral galaxy located in the constellation Ursa Major.

The outer part of the galaxy is formed by an asymmetric faint nebulosity with condensations.

[5] In the centre of NGC 3729 is predicted to lie an intermediate-mass black hole, whose mass is estimated to be between 4 and 400 thousands M☉ (104.6 ± 1.0 M☉) based on Ks-band bulge luminosity.

[6] The galaxy has an inner ring which emits in far ultraviolet and H-alpha, which are considered to be markers of recent star formation activity.

[10] Although no supernovae have been observed in NGC 3729 yet, a luminous red nova, designated AT 2018hso, was discovered on 31 October 2018 (type LRN, mag.