Leo contains many fine galaxies, five of which made Messier’s list. Don’t overlook NGC 2903, however, which shines brighter (magnitude 9.0) than any of that quintet save M66. It measures a worthy 12.0' by 5.6'. Through a 10-inch scope, look for a halo that surrounds a bright core. Be patient and look closer for the central bar and the spiral arms. Larger scopes show dust lanes and emission nebulae throughout NGC 2903’s arms.
Next up is irregular galaxy Sextans B. To find this object, aim 6° north-northwest of magnitude 4.5 Alpha (α) Sextantis. Through a 12-inch scope, you’ll see a magnitude 11.3 rectangular (5.5' by 3.7') smudge of light dotted by faint foreground stars. Can you tell that the central region is ever-so-slightly brighter?
Look for the next target, magnitude 10.9 barred spiral NGC 3079, 2.2° northeast of Phi (φ) Ursae Majoris. I love observing galactic “splinters,” and NGC 3079 appears more than five times as long as it is wide (8.0' by 1.5'). Through a 12-inch scope at 300x, the bright center stretches two-thirds of the galaxy’s length.
Not only is the Spindle Galaxy (NGC 3115) the showpiece of Sextans, at magnitude 8.9 it’s one of the sky’s brightest galaxies. Through a 4-inch telescope, you’ll see an object four times as long as it is wide (8.1' by 2.8') with a bright center. Through a 12-inch scope at 300x, the core looks more distinct, surrounded by an oval bulge.
Our next target is dwarf spheroidal galaxy Leo I. It’s easy to find, only 20' due north of Regulus (Alpha Leonis). But that brilliant star’s glare through the eyepiece makes Leo I difficult to see, so keep Regulus outside the field of view. At a dark site, an 8-inch telescope at 150x reveals a uniform, magnitude 10.2 mist measuring 12.0' by 9.3'.
Follow Leo I with the Little Pinwheel Galaxy (NGC 3184) in Ursa Major. It glows at magnitude 9.8 and measures 7.8' by 7.2'. This is a gorgeous galaxy through a large scope. NGC 3184 has wide arms, so use high power — above 400x — to spot the dark regions that divide them from the nucleus.
Next up is the spring sky’s showpiece planetary nebula, the Ghost of Jupiter (NGC 3242) in Hydra. With a magnitude of 7.8, it’s bright. At low power through a 6-inch scope, you’ll see the 16"-wide, blue-green disk. Through larger scopes, and at powers in excess of 200x, the center looks like an eye surrounded by a faint spherical shell 40" across. For best results, use a nebula filter.
Although our next object is called Coddington’s Nebula (IC 2574), it’s a magnitude 10.4 spiral galaxy in Ursa Major. Look for it 5.7° west of Lambda (λ) Draconis. Through an 8-inch scope at 75x, it appears twice as long as it is wide (13.5' by 8.3'). The central region glows a bit brighter and looks offset to the southwest.
Although you’ll need to head to Leo Minor for the Sliced Onion Galaxy (NGC 3344), the best way to find it is to look 6.3° east-northeast of Zeta (ζ) Leonis. This spiral glows at magnitude 9.9 and measures 6.9' by 6.4'. An 8-inch scope shows a bright core. Double the aperture and NGC 3344’s many arms wind tightly around the core, making the galaxy appear circular.
Our next target is spiral galaxy NGC 3521 in Leo. Because it lies just 28 million light-years away, it appears big (12.5' by 6.5') and bright (magnitude 9.0). NGC 3521 sits in a small region of Leo between Sextans and Virgo 4.5° northwest of Phi Leonis. Through a 10-inch telescope, you’ll see the bright, extended core surrounded by a diffuse halo. With a 16-inch scope, NGC 3521 will look nearly twice as long as it does through the smaller instrument.
Drop south to Hydra for the Frame Galaxy (NGC 3621), a magnitude 8.9 spiral that lies 3.3° west-southwest of Xi (ξ) Hydrae. This object is twice as long as it is wide (9.8' by 4.6') with a broad, evenly lit core. The halo, however, reveals mottling, which suggests spiral structure. NGC 3621’s common name comes from a parallelogram of stars that surrounds it, making the galaxy appear framed.