Remembering a guy named M27


By Tom Burns - Stargazing



Back in my graduate-student days (a long, long time ago), I was not a very attentive student. Perkins Observatory was mostly to blame. I often set up my telescope in the parking lot and observed the night away. Members of the Columbus Astronomical Society often joined me. Technically, we had an informal arrangement with Ohio State University’s Astronomy Department, which ran the place at that time, to do so.

Ohio State astronomy graduate students were often doing research with the big telescope in the dome or in the spooky haunts of the library. Most of them kept the doors firmly locked to keep out amateur riffraff like us.

There was, thank goodness, one notable exception. I’ll call him Doug, because, in fact, that is his real name. He was not a graduate student. Instead, he was a lowly member of the Columbus Astronomical Society. But he knew his way around a telescope, and one of the OSU astronomers had hired him to do research grunt work alone in the dark, echoic dome.

All-night observing can be a lonely preoccupation. At first, Doug let me in to use the bathroom, then to talk for long hours, and finally to use the telescope on my own as he snoozed on the floor of the library downstairs.

Among the other members of the astronomy club, Doug had the unusual nickname of M27.

He had “borrowed” from OSU an antique telescope built in the latter part of the 19th century. The telescope was a thing of beauty — all brass and glass and polished wood. It didn’t hurt that it had been lovingly handcrafted by Alvan Clark, the greatest of all lens makers of the 19th century.

“The Clark,” as he lovingly referred to it, wasn’t very large by modern standards. Only a limited number of objects looked good when viewed through it. One of them was M27, a planetary nebula in the obscure constellation Vulpecula, the “Little Fox.”

So, Doug often showed beginners that beautiful little cloudy patch in his “borrowed” ‘scope. M27 didn’t look like much in a 100-year old refractor, and some of us became convinced that it was the only astronomical object Doug knew how to find.

No one who knew him ever complained though. Doug’s owned a large collection of firearms, which included M-1 and M-16 rifles and an ever-changing array of Civil War muskets. Doug “borrowed” bricks of slightly radioactive lead from Ohio State’s Van de Graaff generator to pour his own musket balls.

Occasionally, the sound of musket fire could be heard outside as I drowsily used the Perkins telescope. As the sound echoed loudly in the dome at 3 a.m., I was startled magically awake. The combination of gun Doug’s hobby and his somewhat unstable character inspired a high level of tremulous respect.

In any case, I learned to find M27 under Doug’s tutelage. First, he’d have to find Vulpecula, which was no easy task. It is one of the faintest and least conspicuous constellations in the sky.

Vulpecula is not one of the original constellations passed down to us from the ancients. The great star mapper Hevelius added it in the 17th century.

In 1687, he filled the space between Cygnus, the Swan, and Sagitta, the Arrow, with a new constellation he called Vulpecula cum Ansere, a fox with a goose in its jaws.

The fox must have eaten the goose because modern astronomers have dropped it from the name. Vulpecula, the “Little Fox” is all that’s left.

The best way to locate it is to look for the constellation Lyra, the Lyre, almost straight overhead once the sky has gotten good and dark (around 8 p.m.). Directly to the east of Lyra is Cygnus, the Swan, which will look like a cross lying on its side. Directly to the left from the star at the base of the cross is a flat triangle of stars — that’s Vulpecula.

M27 is just below the left star in the triangle. It can also be found by looking for the “point” star in the small constellation Sagitta, the Arrow, and moving up. It will look like a small, fuzzy star in binoculars. In a telescope larger than The Clark, it looks like a slightly larger fuzzy thing – but spectacularly so.

In a small telescope at low power, M27 looks like a small grayish disk of light.

Early users of telescopes noted that the small class of objects like M27 looked a bit like the planets Neptune and Uranus. They called them planetary nebulae on the basis of that superficial similarity of appearance.

Some even argued that they might be planets that were in the process of forming. They were wrong about that, of course.

Planetary nebulae like M27 turn out to be shells of gas that are rapidly expanding from a very hot star that is in the process of dying. Here’s what happens: Stars like our own sun burn so brightly because they are fusing their hydrogen into helium. That doesn’t sound like much, but it’s essentially the same process that a hydrogen bomb uses to produce its thermonuclear reaction.

When stars only a bit larger than our sun begins to run out of hydrogen, they swell up to 1,000 times their original size. These so-called “red giant” stars then collapse to an extremely dense sphere, called a “white dwarf,” only about the size of a small planet like Earth. As they collapse, they eject their outer shell, about 10 or 20 percent of their substance, into space.

In a trillion years or so, the white dwarf will eventually fade to black, a light-and-heat-giving star no more. The outer shell of gas will continue to expand. In time, it will become too faint and spread out to be seen.

M27 is important because it is one of the closest of the planetary nebulae in our galaxy. It is only about 850 light years away from Earth. (A light year is about 6 trillion miles.) If that sounds like a long way, remember that our galaxy of 300 billion stars is about 100,000 light years in diameter.

M27 is expanding at around 17 miles per second. It has been doing so since the cataclysmic expansion of its central star about 50,000 years ago. The expanding shell of gas is about two and a half light years in diameter, or about 15 trillion miles across. Our own solar system is only about seven and a half billion miles across — the diameter of dwarf-planet Pluto’s orbit.

If M27’s central star had been our own sun, Earth would have been burnt up in the initial expansion of the star into a red giant, and the shell of hot gases would have reached far past the orbit of Pluto.

At high magnification M27 looks pinched in the center. It resembles one of those little barbells that people use to exercise their arms and wrists. Barbells of the type we are talking about used to be called dumbbells. Thus, M27 is thus almost universally called the Dumbbell Nebula.

Doug moved away years ago. Sadly, he took his “borrowed” Alvan Clark with him, and we have not seen it since. Truth be told, one of the goals I set for myself when I became the director of Perkins Observatory 25 years ago was to return the telescope to its rightful home here at Perkins. One of my great regrets about my tenure, now ended, is that I failed miserably at that task.

Just before Doug left town, I invented the “M27 Award.” Every so often, I gave it to one of the members of the Columbus Astronomical Society. It honors the dumbest thing that any member has done in the past year and consisted of a large button with a photo of M27 emblazoned on it. I regretfully confess I had Doug in mind when I invented it.

I suppose that when we called Doug M27, we were directing an unforgivable insult at him. But Doug never said a word about it. He just kept pointing the venerable Clark ‘scope at the Dumbbell Nebula and waiting for the gasp of appreciation and awe that arose from those who viewed it.

A lot of years have passed since then, and Doug may have at last disappeared from the planet or sold the telescope. But if he has not, I’ll wager that he is doing so still.

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By Tom Burns

Stargazing

Tom Burns is the former director of the Perkins Observatory in Delaware.

Tom Burns is the former director of the Perkins Observatory in Delaware.