The Cigar Galaxy M82: A Starburst Galaxy Up Close

There are galaxies that look calm and orderly through a telescope — stately spirals with well-defined arms, quiet ellipticals glowing softly in the dark. And then there is M82, the Cigar Galaxy, which looks like something went terribly, wonderfully wrong.

M82 is one of the most visually striking galaxies you can observe from your backyard. Even in a modest 6-inch telescope, you can see its elongated shape, and with larger apertures or astrophotography, you start to pick up the dramatic jets of hydrogen gas erupting from its core. This is a galaxy that is quite literally bursting with new stars — forming them at a rate roughly ten times faster than our own Milky Way.

If you have never pointed your telescope at M82, you are missing one of the night sky's most rewarding deep-sky targets. Let me walk you through what makes it special, how to find it, and what you can expect to see.

What Is the Cigar Galaxy?

M82, also catalogued as Messier 82 or NGC 3034, is a starburst galaxy located about 12 million light-years away in the constellation Ursa Major. It earned the name "Cigar Galaxy" from its elongated, cigar-like shape when seen edge-on from Earth. But the real story is what is happening inside it.

About 300 million years ago, M82 had a close gravitational encounter with its much larger neighbor, M81 (Bode's Galaxy). That encounter compressed enormous quantities of gas and dust in M82's core, triggering an explosive burst of star formation that continues to this day. The result is a galaxy that produces new stars at a furious rate, with superwinds of hot gas streaming thousands of light-years above and below the galactic plane.

Those superwinds are what make M82 so photogenic. In deep images, you can see enormous plumes of reddish hydrogen-alpha emission extending far above and below the galaxy's disk. These jets are powered by the combined stellar winds and supernova explosions of millions of young, massive stars packed into the galaxy's core.

How to Find M82 in the Night Sky

Finding M82 is straightforward, and that is one of the things I love about it — you do not need a computerized goto mount or even much experience with star-hopping. If you can find the Big Dipper, you can find M82.

Start by locating Dubhe and Merak, the two "pointer stars" at the front edge of the Big Dipper's bowl. Draw a line from Merak through Dubhe and continue about the same distance beyond Dubhe to the northwest. You will arrive in a relatively sparse area of sky where M81 and M82 sit about 38 arcminutes apart — close enough to share the same finder scope field and often the same eyepiece view.

M81, the brighter of the pair at magnitude 6.9, usually catches your eye first. It appears as a soft, round glow with a bright nucleus. M82 sits just to the north, noticeably more elongated and slightly fainter. Together, they make one of the finest galaxy pairs in the entire sky for amateur observation.

What You Can See at Different Apertures

In binoculars (10×50 or larger), M82 appears as a faint, elongated smudge alongside the rounder glow of M81. You will not see much detail, but just knowing you are looking at a galaxy 12 million light-years away — one that is actively erupting with star formation — gives the view a certain weight that never fades.

In a 4- to 6-inch telescope, M82's cigar shape becomes obvious. You may notice that the brightness is not uniform along the galaxy — there are subtle dark patches and brighter knots, especially near the core. These are regions where dust lanes cross the line of sight, blocking some of the light behind them. This mottled appearance is what sets M82 apart from most galaxies at this aperture.

In an 8- to 12-inch telescope, the dark lanes and bright knots become much more pronounced. The galaxy starts to look like it has been carved up by irregular dark streaks. With careful observation and good seeing conditions, you can trace three or four distinct dark patches cutting across the cigar shape. The core region appears distinctly brighter and more complex than the outer portions.

For astrophotography, M82 is a dream. Even relatively short exposures with a DSLR and a tracking mount will capture the galaxy's elongated disk. Longer exposures with a hydrogen-alpha filter will begin to reveal the dramatic red superwind jets extending perpendicular to the disk — one of the most visually stunning features of any galaxy visible from Earth. If you are interested in deep-sky imaging, you can learn more about getting started in our guide to what astronomy images really show.

Interesting Facts About M82

In 2014, astronomers detected a supernova in M82 — designated SN 2014J — making it the closest Type Ia supernova observed in decades. At peak brightness, the supernova reached about magnitude 10.5, easily visible in amateur telescopes. Type Ia supernovae are "standard candles" used to measure cosmic distances, so SN 2014J became an incredibly valuable target for professional research.

M82's star formation rate is extraordinary. The galaxy is producing new stars at roughly 10 solar masses per year, compared to about 1-3 solar masses per year in the Milky Way. This cannot last — at the current rate, M82 will exhaust its gas supply in a few hundred million years. It is a galaxy living fast and burning bright.

Radio observations have also revealed a mysterious compact object near M82's center that some astronomers believe could be an intermediate-mass black hole — a class of black holes that bridges the gap between stellar-mass and supermassive black holes. This remains an active area of research.

Photographing M82

M82 is an excellent astrophotography target at almost any focal length. With a camera lens in the 200-400mm range on a star tracker, you can capture both M81 and M82 together in a beautiful wide-field composition. With a telescope at 1000mm or more, you can fill the frame with M82 alone and start resolving the complex structure in its disk.

To capture the hydrogen-alpha jets, you will need either a dedicated astronomy camera with narrowband filters or extended exposure time with a modified DSLR. A hydrogen-alpha filter isolates the 656nm wavelength emitted by ionized hydrogen, which is exactly what makes up those dramatic superwind plumes. Even a short series of 3-minute sub-exposures through an H-alpha filter can reveal jet structure that is completely invisible in broadband images.

M82 and the Bigger Picture

M82 belongs to the M81 Group, a nearby galaxy group that includes about three dozen galaxies. It is one of the closest galaxy groups to our own Local Group, which makes it an important laboratory for studying galaxy interactions and star formation. If you are interested in how galaxies are classified and why they look so different from one another, our guide to types of galaxies covers the full picture.

Every time I observe M82, I am reminded that galaxies are not static postcards — they are dynamic, evolving systems that interact with their neighbors, trigger enormous bursts of activity, and change dramatically over millions of years. M82 is a galaxy caught in the act of doing something extraordinary, and you can see the evidence of that from your own backyard.

If you are building your way through the Messier catalog, M82 should be near the top of your list. Pair it with M81 for one of the finest double-galaxy views in amateur astronomy, and if you have a camera, do not miss the chance to capture those starburst jets. Check out our best Messier objects for beginners for more targets that reward patient observation.