DEEP-SKY TOUR
Take a look at fascinating objects near the Sickle asterism in Leo, the Lion
1 NGC 3226/3227
Our first targets lie 0.8° to the east and a bit north of the double star Algieba (Gamma (γ) Leonis), which is part of the Sickle asterim. Here you’ll find the two interacting galaxies, NGC 3226 and 3227. NGC 3226 is a dwarf elliptical galaxy that shines with an integrated magnitude of +11.4. NGC 3227 is brighter at mag. +10.8 and is a spiral galaxy with an active nucleus that has been identified as a variable X-ray source. Both galaxies can be seen as faint, indeterminate smudges through a 150mm scope, while a 250mm scope will show NGC 3226 to have a more circular form, situated northwest of NGC 3227’s elongated core. SEEN IT
2 NGC 3193/3190
Our next target consists of multiple galaxies too. Located midway between Algieba and Adhafera (Zeta (ζ) Leonis), you’ll find, in order of brightness, NGC 3193, 3190, 3185 and 3187. NGC 3193 and 3190 have magnitudes of +10.9 and +11.0 respectively. Edge-on spiral NGC 3190 is the easiest of the four to see. NGC 3193 is an elliptical and together with 3190 can be seen using a 150mm scope. NGC 3185 is a mag. +12.2 face-on barred spiral requiring at least 200mm of aperture. NGC 3187 is a mag. +13.1 barred spiral, but it appears faint and it will give even a 300mm scope a run for its money. The four galaxies are gravitationally bound, forming a group catalogued as Hickson 44. SEEN IT
3 NGC 3162
Centre your telescope on mag. +3.4 Adhafera and slew 1° to the southwest to point at our next target, spiral galaxy NGC 3162. Listed at mag. +11.6, NGC 3162 is large, its total size approaching 3 arcminutes across. It’s a distorted face-on galaxy which has a low surface brightness. A 150mm scope will just about show it, but it will
This Deep-Sky Tour has been automated ASCOM-enabled Go-To mounts can now take you to this month’s targets at the touch of a button, with our Deep-Sky Tour file for the EQTOUR app. Find it online.
Adhafera
Near the star Adhafera (Zeta (ζ) Leonis) you will find a host of multiple galaxies with a telescope, with the edge-on spiral NGC 3190 being the easiest to spot appear little more than a large, faint ‘ghost-like’ object. A 250mm telescope shows an object about 80 arcseconds across, which has a well-defined core with a star-like nucleus. SEEN IT
4 NGC 2916
We head further west for our next target, a 12th magnitude spiral galaxy with an active nucleus catalogued as NGC 2916. The best way to locate it is to identify mag. +4.3 Alterf (Lambda (λ) Leonis). Alterf lies 3.2° west and 0.7° south of Algenubi (Epsilon (ε) Leonis), the last star in the Sickle’s ‘hook’. NGC 2916 sits 1.4° south-southeast of Alterf. A 150mm scope will just about show it as a circular glow and although increased aperture helps, a 250mm scope won’t show much more than a brighter, elongated glow. A 300mm scope shows the galaxy’s stellar core and hints at mottling across its misty appearance. SEEN IT
5 NGC 2903
Our next target is a beauty. NGC 2903 is a bright, barred-spiral galaxy located 40 arcminutes west-southwest of NGC 2916 or, 1.5° due south and a fraction to the east of Alterf. It shines with an integrated magnitude of +8.9 and is easy to see with a 150mm scope. Such an instrument reveals an object 8x4 arcminutes in size and shows an unevenly lit core. A 250mm scope picks out what appears to be the galaxy’s star-like nucleus well. A 300mm instrument shows this core to be extending, measuring 0.5x0.3 arcminutes. With such an instrument, the mottled outer halo appears brightest and easiest to see on the western side. SEEN IT
6 EGB 6
Our last target is a challenge. Ellis 6 also known as EGB (Ellis-Grayson-Bond) 6 is a faint planetary nebula near Regulus (Alpha (α) Leonis). It sits 4.1° west-northwest of Regulus, or for a better guide, imagine the mid-point of a line between Eta (ε) Leonis and Omicron (ο) Leonis. EGB 6 lies 0.3° west-northwest of this point. It’s listed as mag. +10.3, but because it’s large with a diameter around 12 arcminutes, it has a low surface brightness. A 200mm instrument can show it, but you’ll need to use averted vision along with an OIII (Oxygen III) filter. SEEN IT