This month we venture to the southern region of Coma Berenices, which borders Virgo
1 NGC 4147
Recommended equipment: Small/medium or large scope
We start with the dim but rich globular NGC 4147, which has an apparent magnitude of +10.7 and is compact, with an apparent diameter less than 2 arcminutes across. It sits 6.5˚ northeast of Denebola (Beta (β) Leonis) or about one-third along the line from Denebola towards Beta (β) Comae Berenices. While a small scope shows a faint glow, 1 arcminute across, a 250mm scope increases the apparent diameter, and with over 250x magnification it should be possible to see some resolved stars.
2 M98
Recommended equipment: Small/medium or large scope
This region of sky has a good number of Messier objects, thanks to the presence of two large galaxy clusters in this direction: the Virgo and Coma galaxy clusters. Head 3.8˚ south of NGC 4147 to locate M98, an intermediate spiral galaxy which is a member of the Virgo galaxy cluster. M98 lies 6˚ to the east of Denebola and only 20 arcminutes to the north of the star. It’s a lovely object, shining with an integrated magnitude of +10.1. A small scope will reveal its elongated nature, and through a 150mm scope M98’s ellipse appears 6x 2 arcseconds in size, with the outer halo brightening to an elongated core leading to a star-like point.
3 M99
Recommended equipment: Small/medium or large scope
M99 is a face-on spiral galaxy, 1.3˚ east-southeast of M98. The integrated visual magnitude of M99 is mag. +9.8 and the galaxy is well suited for smaller instruments. A 150mm scope will reveal an object 3x 2 arcminutes in size. Its outer regions appear mottled, brightening to a distinct, broad core. Tidal disruption has upset the shape of M99 and one of its spiral arms appears more prominent than the rest, extending south from the core’s eastern side before curving north.
4 M100
Recommended equipment: Small/medium or large scope
Next in the Messier catalogue is M100, another face-on spiral in southern Coma Berenices. It is located 1.7˚ northeast of M99 and shines with an integrated visual magnitude of +9.3, making it another viable target for smaller instruments. Lying at a distance of 60 million lightyears, M100 is a lovely sight. With an apparent size around 5 arcminutes, its light appears spread over a large area, which results in a low surface brightness. A 150mm scope shows a uniform glow that brightens towards a small, bright core. Increased aperture produces a more granular texture within the glow, hinting at the presence of the galaxy’s spiral arms. M100 is symmetrical in terms of its structure.
5 NGC 4450
Recommended equipment: Small/medium or large scope
NGC 4450 sits 1.8˚ northeast of M100. Ranked at mag. +10.1, it appears as an extended glow through smaller instruments, roughly 2.5 arcminutes in size and elongated. The glow increases in brightness towards the galaxy’s centre, brightening to a star–like point. Larger instruments show a similar but brighter view, hinting at the presence of dark gaps within, in the main halo, caused by dust lanes between the galaxy’s spiral arms. What’s odd about NGC 4450 is that larger scopes don’t tend to reveal the usual mottling you’d associate with a spiral galaxy. NGC 4450 is what’s known as an anemic galaxy, a type of spiral that shows relatively smooth arms, largely devoid of bright star-formation.
6 M85/NGC 4394
Recommended equipment: Small/medium or large scope
M85 sits 1.3˚ to the north-northwest of NGC 4450. Alternatively, locate it 1.1˚ to the east and 0.3˚ north of mag. +4.7 11 Comae Berenices. This is a lenticular galaxy, a transitionary type of galaxy, between spiral and elliptical – although some believe it sits more on the side of elliptical. It’s bright at mag. +9.2 and appears as a haze brightening towards a bright core. The view through different apertures isn’t dissimilar, larger scopes delivering a brighter view with a larger overall apparent size. At a distance of 60 million lightyears, M85 is one of the Virgo galaxy cluster’s brighter galaxies.
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