NGC 3718 (Ursa Major)
Fig. 1: A highly disturbed spiral galaxy with an unusual, warped shape: The galaxy NGC 3718 in Ursa Major (the largest object in the image), photographed with a 16-inch f/4.5 Dob on an equatorial platform. To the right above the galaxy is the Hickson 56 group of galaxies and below NGC 3718 is the galaxy NGC 3729.
| Object name: | Constellation: | Coordinates: | Apparent size: | Visual brightness: |
|---|---|---|---|---|
| NGC 3718 | Ursa Major | 11h33m / +53°04' | 2.9' x 2.4' | 10.6 mag |
| NGC 3729 | Ursa Major | 11h34m / +53°07' | 2.8' x 1.8' | 11 mag |
| Hickson 56 | Ursa Major | 11h33m / +52°56' | 1.1' x 0.2' (56A) | 14.8 mag (56A) |
The warped galaxy NGC 3718 (top) and the barred spiral galaxy NGC 3729 (bottom) in the constellation of Ursa Major. It is possible the two galaxies interacted in the past, accounting for the peculiar appearance of NGC 3718. NGC 3718 is about 52 million light-years away from earth, NGC 3729 about 65 million light-years. To the upper right of NGC 3718, the Hickson 56 group of galaxies can be seen. It lies approximately 400 million light-years away. NGC 3718 and NGC 3729 were discovered by William Herschel in 1789 (source: https://apod.nasa.gov/apod/ap130803.html, Wikipedia).
Exposure time: 3h 27min (63x approx. 3min) at ISO 800, taken on March 8 / 9, 2014. Processing with Deep Sky Stacker and Photoshop. No calibration frames were taken. Note: Out of the 63 images, only 21 were used for the dark background of the image. For the galaxies, all 63 exposures were used.
Equipment: Canon EOS 450D Baader modified camera, TeleVue Universal Paracorr coma corrector, 16" f/4.5 "Ninja" dobsonian telescope riding on a dual-axis Tom Osypowski equatorial platform, Lacerta MGEN autoguider, Lacerta off axis system.
Field of view comparison: image of the moon with the same setup.
Fig. 2 - Search chart for NGC 3718 and NGC 3729. Copyright 2025 'The Mag-7 Star Atlas Project', www.siaris.net.