Site last updated: Thursday, November 21, 2024

Log In

Reset Password
MENU
Butler County's great daily newspaper

Go the distance with the Andromeda Galaxy

How would you like to see the farthest thing visible to the naked eye? It’s possible, but you’ll need to bundle up and sit back on a lawn chair. Your neighbors may think you’ve cracked up sitting out there in the winter, but you’re on a mission!

You’re out in the cold to find the Andromeda Galaxy, the next-door neighbor to our own Milky Way Galaxy, home to our sun and possibly another 300 billion or so stars, and Lord knows how many other planets! It is possible to see the Andromeda Galaxy with the naked eye, but you need dark countryside skies to pull that off.

If you’re trying to spot Andromeda in areas compromised by light pollution, you better have a pair of binoculars or a small telescope. Just make sure you let your new telescope and all the eyepieces you will use sit outside for 30-45 minutes so the glass and mirrors can acclimate to colder temperatures. Otherwise, you can get some really blurry and funky views!

Once you settle into your lawn chair, try to give your eyes a good 15-20 minutes to adjust to the darkness and get your night vision. If you’re using any star map or the diagram included with this column, use a headband flashlight with a red lens to avoid ruining your night vision. You can buy those at a hardware store or anywhere that sells camping gear. You can use a smartphone app like Sky Guide to find it. It works great. Just make sure you put the screen in red night vision mode.

The best way to find the Andromeda Galaxy is to locate the constellation Andromeda the Princess, attached to the constellation Pegasus the Winged Horse in the early evening high Butler southeastern sky. In the constellation, Andromeda follows up to about the halfway point of the bright arc of stars of Andromeda to the moderately bright star Mirach. You'll see two much fainter stars just to the upper right of Mirach. Look for a tiny, faint, patchy cloud to the upper right of those stars. That’s it, the Andromeda Galaxy. You’ll probably need binoculars or a small telescope to find it.

You certainly won’t be blown away when you first spot it. All you’ll see is a ghostly patch of light and a bright nucleus. Even with my large telescopes that I bring to my stargazing parties you usually don’t see too much more than that, although through larger scopes in dark skies the galaxy will have a little more shape and definition. Astronomical photographs reveal more detail because they can gather and accumulate more light than our human eyes.

Nonetheless, that little ghostly patch of light is made up of the collective light of possibly a trillion stars at a distance of 2.5 million light-years away. Just one light-year equals nearly six trillion miles. Since a light-year is defined as the distance light travels in a year, the light from Andromeda has been traveling to your eyes for 2.5 million years. We don’t see the light as it is now but what it looked like 2.5 million years ago. From what astronomers know about galaxy lifetimes, it hasn’t changed much in appearance, even over a couple of million years.

The Andromeda Galaxy and the Milky Way are the closest neighbors despite that incredible distance. Still, without a doubt, Andromeda is a larger galaxy, possibly twice the diameter of our Milky Way. Like our home galaxy, most of the mass that makes up Andromeda is invisible, what astronomers call dark matter, which remains a big mystery.

The Andromeda Galaxy is very important to the history of astronomical discovery. Less than a hundred years ago, the Milky Way Galaxy was all we thought there was to the universe. What we now know as the Andromeda Galaxy was then considered to be just a big cloud of nebulosity.

That all changed in the 1920s when Edwin Hubble and his assistant Henrietta Leavitt discovered that the Andromeda Galaxy was much farther away than it was previously believed. They used what is known as Cepheid variable stars to gauge just how far away Andromeda was. Cepheid variable stars vary in size and brightness over a period related to average brightness. They’re what astronomers call “standard candles.”

As it turned out, through painstaking observation and photographic analysis, Cepheid variable stars were found in the Andromeda nebula. By observing their brightening and dimming cycle, it was determined that the Andromeda nebulae were way farther away than anyone ever thought. Furthermore, it was concluded that it was a whole other galaxy of stars independent of our Milky Way. Edwin Hubble gets all the credit for this discovery, but Henrietta Leavitt discovered the Cepheid variables in Andromeda and did most of the labor-intensive legwork.

The Andromeda Galaxy and the Milky Way Galaxy are on a collision course. They’re approaching at an estimated 60 to 80 miles a second! I wouldn’t let it worry you all that much because even at that speed, the two galaxies won’t any time soon. Give it a little more than four billion years.

Mike Lynch is an amateur astronomer and retired broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and adventurepublications.net. Contact him at mikewlynch@comcast.net.

More in Starwatch

Subscribe to our Daily Newsletter

* indicates required
TODAY'S PHOTOS