Yanking Markarian's Chain

Markarian's Chain, a remarkable arc of bright galaxies, is your ticket to the Virgo Cluster. Hop aboard!

More than 2,000 galaxies festoon the Virgo Cluster. Most are faint dwarf ellipticals, but a 6-inch telescope in dark skies will show at least 150 galaxies across a 10°-wide swath from central Virgo to Coma Berenices. The question is, where to start.

The Virgo Cluster, located about 60 million light-years away, contains several subgroups or clumps. Among them are: Virgo A, centered on M87; Virgo B, on M49; Virgo C, on M60; and a final subgroup centered on M86. One of the best ways to tackle Virgo is to take the scenic route along a favorite galactic avenue called Markarian's Chain, named for Armenian astrophysicist Benjamin Markarian, who discovered that this string of bright galaxies shares a common motion through space. Markarian is also the namesake of the Markarian catalog of bright, compact galaxies. many of which show up in the fields of view of more familiar NGC and Messier galaxies.

Most sources list eight physically-related members in the arc, but a 1983 paper by E. Lizroth in the Astronomische Nachrichten removes M84 because its motion doesn't jive with that of the rest of the group. Visually however, it looks like it belongs, so we can hardly ignore it. The graceful symmetry of the chain is certainly eye-catching and highlighted by dual pairs of interacting galaxies — NGC 4438 and NGC 4435, also known as "The Eyes," and NGC 4461 and NGC 4458. A half-dozen additional galaxies enrich the view, making this 1.5° porthole of sky one of the richest in bright galaxies.

I first came to know the asterism by following its galaxy-sized steppingstones to a group I nicknamed "Nine in a View." At my lowest magnification of 64×, yielding a field of view 55′ (arcminutes) wide, I can hold nine galaxies in a single glance. I still regard it as one of the finest fields in the sky and make sure I stop by for a look at least once a season. If your telescope has a 1.5° field of view you should be able to squeeze in all 14 galaxies in the area.

M84 and M86 are side-by-side 10th-magnitude fuzzy patches each with a prominent bright nucleus. M84, a giant elliptical, is more elongated than its neighbor, a lenticular galaxy. Save their intense nuclei and contrasting shapes both appear virtually featureless. In your mind's eye try to picture the 1.5-billion-solar-mass black hole that's holed up M86's core. M86 is unique in being the Messier object with the highest blue shift. As it falls toward the center of the Virgo Cluster from the other side, the galaxy zooms toward us at 244 km per second.

About 22′ east of M86 expect a hot stare from the "Eyes," a pair of 10th-magnitude interacting galaxies otherwise known as NGC 4438 and NGC 4435. While NGC 4435 looks like a small, symmetrical oval with a bright nucleus, NGC 4438 clearly reveals a distorted disk, the result of a gravitational tug-of-war with its neighbor. The nucleus of NGC 4438 is quite faint and set in a roughly circular, brighter inner disk resembling a planetary nebula. The wispy outer disk extends northwest and southeast of the nuclear region. Using 242× and averted vision I can tease out the eastern tidal tail/warped disk as a faint, fuzzy extension "bending" toward the northeast. A fascinating object!

The interacting duo NGC 4461 and NGC 4458 make a second closer set of eyes 20′ further northeast. NGC 4461, an 11th-magnitude lenticular galaxy, is pleasingly elongated with a bright, near-stellar nucleus. Nearby NGC 4458 is an elliptical with a round shape and bright core and a full magnitude fainter. While neither looks distorted, the latter's faintness is related to a tidal interaction with 4461 sometime in the past.

With its brilliant nucleus rivaling those in the giants M84 and M86, the 11th-magnitude elliptical NGC 4473 is one of my favorites. Its hub glows with a wonderful intensity perhaps inspired by the galaxy's supermassive black hole. Yes, it seems black holes are everywhere. With a mass 100 million times solar and estimated at 4.46 a.u. across, it would reach all the way to the asteroid belt if put in place of the Sun.

The 11.4-magnitude NGC 4477 marks the end of the line 17′ farther northeast. NGC 4477 is a barred lenticular with a near-stellar nucleus. I can distinguish the bar as a narrow, north-south elongated streak of enhanced brightness around the nucleus at 242×. Smaller, fainter, and unrelated, NGC 4479, also a barred lenticular, begs a look 5′ southeast of NGC 4477. The12.5-magnitude puff reveals a faint stellar nucleus at medium and high magnifications.

Several additional unrelated galaxies, centered in the Nine-in-a-View region back to the west, include NGC 4402, a 12th-magnitude edge-on spiral that looks like a faint puff of cigar smoke. Even after a careful study up to 357× I couldn't convince myself of seeing the equatorial dust lane. But I did make out subtle hints of texture along its length. NGC 4387 is a small but relatively bright elliptical, while NGC 4388, an 11th-magnitude barred spiral, added some zest with its extended, bright inner disk. Very pretty!

While you're in the area be sure to take the optional excursion to the titanic elliptical galaxy M87 (magnitude 8.6) 1° southeast of the chain's midway point. During an April 10, 2019 press conference, astronomers shared the first image of its 6.5-billion-solar-mass black hole. Incredible that it looks almost exactly as models predicted. Wow!