by Glenn Chaple
NGC 3893 and NGC 3896 – Galaxy Pair in Ursa Major
NGC 3893: Magnitude 10.5; Size 4.5’ X 2.8’ -- NGC 3896: Magnitude 13.6; Size 1.4’ X 0.9’
This month and next, the Observer’s Challenge will feature galaxy pairs in Ursa Major. This month’s galactic twosome is comprised of the 10th magnitude spiral NGC 3893 and its 13th magnitude lenticular partner NGC 3896. William Herschel discovered them on February 9, 1788 and cataloged them as Class II (Faint Nebulae) objects. NGC 3893 is located at the 2000.0 coordinates RA 11h48m38s and DEC +48o42’39”, about one degree north-northeast of the golden yellow 4th magnitude star chi (χ) UM.
In my 10-inch f/5 reflecting telescope at 139X under magnitude 5 skies, it appeared as a roundish glow, bright enough to be seen with direct vision. There was no sign of NGC 3896, which lies 4 arc-minutes further southeast at RA 11h48m56s, DEC +48o40’28”. Under dark skies, NGC 3893 should be visible in a 4 to 6-inch scope, while NGC 3896 will require twice that aperture.
NGC 3893 and 3896 are about 50 to 55 million light years distant. The former has a calculated diameter of around 75,000 light years, some three times larger than NGC 3896.