…continuedA Galaxy-Hop in Leo
A Beautiful Galaxy Trio
9. M65, M66, and NGC 3628. Work south to Theta (θ) Leonis, a 3.3-magnitude cold-white dazzle. Check in on the faint little double star a half degree due south of Theta, labeled Double A on the map. Continue on south-southeast and you'll hit our first Messier objects of the night.
What a beautiful scene this is, after the faint galaxies we've been logging up to now! Someone who starts the night by pointing straight at M65 and M66 might be impressed only by their dimness, but since we have been pushing our vision to the limit on fainter galaxies, these look big and bright by comparison. Both appear elongated, the first galaxies of the evening to show much real shape in my 6-inch. M66 has a brighter nucleus, shows signs of mottled detail, and seems more sharply bordered on its southwestern side. There is a nice sprinkling of stars around it.
M65 is in a blanker area. It appears larger and more elongated than M66 and is edged most sharply on the east. This indicates that the eastern side of the galaxy is closer to us; dark dust lanes are blocking the glow from parts behind, as confirmed on photographs. These two galaxies are a nice study in similarities and differences.
M65 and M66 are magnitudes 9.3 and 8.9, respectively, 9' by 2' and 8' by 4' in size, and have the same average surface brightness, 12.5 magnitudes per square arcminute. Both are type Sb, similar to the Milky Way, though M66 is the dustier and clumpier of the two.
There's more to this field. North-northeast by 0.6° is NGC 3628, an enormously elongated east-west pencil 14' by 4' in size, an Sb galaxy oriented edge on. Its total magnitude is 9.8, but it has such a low surface brightness (13.7) that it was not easy in the 6-inch. I thought I glimpsed signs of its two thin, unequal bands of light sandwiching a dark dust lane. It's halfway between two 10th-magnitude stars to the north and south.