George Johnstone Stoney discovered NGC 7340, along with NGC 7336 and 7337, on 10 Sep 1849 and noted "4 knots following [NGC 7331]." A diagram was made 2 nights later and NGC 7340 was labeled "D".

200/250mm - 8" (8/28/81): extremely faint, very small, requires averted.

300/350mm - 13.1" (9/29/84): faint, small, round, bright core. Second brightest of four faint companions of NGC 7331.

400/500mm - 17.5" (8/27/87): fairly faint, small, round, bright core, stellar nucleus. This is the last of four galaxies following NGC 7331 and lies 8.1' E of center. Nearby are NGC 7337 4.2' SW and NGC 7335 5.6' NW. Collinear with two 10 stars 1.8' NNW and 3.6' NNW.

17.5" (9/14/85): fairly faint, small, round, bright core.

600/800mm - 24" (7/21/12): moderately bright at 322x, fairly small, slightly elongated ~N-S, 0.5'x0.4', sharply concentrated with a very small bright core that increases to the center. Second brightest of the four "companions" to NGC 7331. Collinear with a mag 11 star 1.8' NNW and a mag 10.3 star 3.6' NNW.

900/1200mm - 48" (10/24/14): at 488x; fairly bright, fairly small, slightly elongated, 35"x25", sharply concentrated with a bright core and sharp stellar nucleus.

Notes by Steve Gottlieb