Deep-Sky Tour
Dig deep into Virgo for this gamut of galaxies, all within Markarian’s Chain
Tick the box when you’ve seen each one
1 M84 This month’s targets all belong to Markarian’s Chain, a 1.3º curving line of galaxies in the Bowl of Virgo. Locate it midway between mag. +2.1 Denebola (Beta (`) Leonis) and mag. +2.8 Vindemiatrix (Epsilon (¡) Virginis) both of which are shown on our All-Sky Chart. The chain starts with mag. +10.1 M84, a face-on lenticular galaxy 60 million lightyears away. A 6-inch scope shows it as a hazy, 2.5x2arcminute patch that brightens towards a starlike point at its core. Larger instruments show the core as extended rather than stellar, but reveal little else. For a long time M84 was incorrectly classified as an ‘E1’ type elliptical, because being face on it is hard to distinguish from that class of galaxy. 2 M86 Due to the relatively small size of Markarian’s Chain, locating other members is easy. Our next stop, M86, sits 17 arcminutes east of M84. Here the elliptical/lenticular confusion continues: M86 is listed variously as an E3 elliptical or an S0 lenticular, though modern classifications favour the latter. It’s fractionally brighter than M84 at mag. +9.9, and appears larger and more elongated. That said its overall guise isn’t dissimilar to M84, with a 6-inch scope revealing little more than a hazy halo brightening to a star-like point. Through a small scope M86 appears to be 2x1.5 arcminutes in size, but this increases with aperture. A 12-inch scope reveals it as a 3x5-arcminute haze. 3 NGC 4388 Many of the members of the Virgo Galaxy Cluster are ellipticals, but NGC 4388 is a notable exception. It forms an approximate equilateral triangle with M84 and M86, NGC 4388 marking the triangle’s southern point. At mag. +11.0, it’s dimmer and harder to see than the two previous galaxies, but really stands out because of its lovely shape. It is an edge-on spiral galaxy with a bright active nucleus. Through a 6-inch scope the galaxy looks like a needle of light, 3x0.5 arcminutes in size, the core region causing a slight bulge. The arms present a mottled appearance through an 8-inch or larger scope, which will also show the core offset to the west of centre. 4 NGC 4438 & 4435 Up next is a galaxy pair, NGC 4438 and 4435, which can be found 22 arcminutes east of M86. Together these are known as ‘Markarian’s
Eyes’ or simply ‘The Eyes’. NGC 4438 is the brighter of the two at mag. +11.0, NGC 4435 being +11.7. There is uncertainty as to what is precisely happening between the two galaxies (and possibly M86), but it appears that NGC 4438 is a spiral galaxy gravitationally affected by an interaction with NGC 4435. The pair is separated by 4.3 arcminutes. A 6-inch scope shows NGC 4435 as a small, 1-arcminute haze and NGC 4438 as a larger 3x1 arcminutes. Averted vision really helps with the latter, as NGC 4438’s larger size lowers its surface brightness. 5 NGC 4473 We pass mag. +13.0 NGC 4458 and mag. +12.1 NGC 4461 to reach target five, NGC 4473; it is 40 arcminutes northeast of NGC 4438. Here, we’ve just slipped over the border from Virgo into Coma Berenices. An 8-inch scope shows an elongated haze measuring 1.5x1 arcminutes, with a bright core that appears to have been stretched east-west for a distance of 3-4 arcseconds. This is an elliptical galaxy, which unusually appears to have been flattened into a more disc-like structure. This suggests that it may have been the result of a merger between several galactic nuclei. Don’t be afraid to pile the magnification on here to reveal the elongated core. 6 NGC 4477 & 4459 The penultimate marker of the chain is NGC 4477, a mag. +11.4 barred-lenticular galaxy that lies 12 arcminutes to the north and slightly west of NGC 4473. NGC 4477 is similar to but appears more obvious than 4473. It’s reasonably bright and appears larger than 4473. Its core is bright with a mottled surrounding halo when seen with larger instruments. The chain ends with the mag. +11.3 lenticular galaxy, NGC 4459 lying 25 arcminutes northnortheast of NGC 4477. This galaxy is relatively small and concentrated, appearing 1.1 arcminutes across through an 8-inch scope. A mag. +8.7 star, HIP 60918, appears to touch the edge of the galaxy and acts as a useful marker to show you are looking at the right object.