Shoot high for celestial treasures
This week in Starwatch I want you to go sky-high to dig for some of the great visual treasures waiting for your eyes.
And now that it gets darker a lot sooner in the evening, it’s easier to get out there and stargaze before the sandman starts working on your eyelids. You can spend a lot more time with your telescope and even just a nice pair of binoculars.
There are a lot of celestial treasures among the constellations in the late summer Butler sky. Star clusters, nebulae, double stars and even whole other galaxies outside our Milky Way are buried to the naked eye, but with a little patience and optical aid you can dig them out.
I also want to put in another word about smart photographic telescopes, which came out about three years ago. They are fantastic! I truly believe that in time, they’ll be much more popular than conventional visual telescopes.
You can easily operate them with a smartphone or tablet. In a matter of minutes, they’ll point themselves to any celestial object you want and take images of it that will blow you away — in color! They also work well in areas of moderate to heavy light pollution. Best of all, the most expensive ones are less than $600. I highly recommend either the ZWO SeeStar S50 and the ZWO SeeStar S30.
Three of the nicest jewels of the heavens right now are nearly overhead at the end of evening twilight, around 9 p.m. The easiest one to see is the star Albireo, the second brightest star in the constellation Cygnus the Swan. Within Cygnus is the very easy-to-see pattern of the “Northern Cross.” Albireo marks the foot of the cross.
The best way to find it is to face south and look directly overhead. The brightest star you see is Vega, the brightest star in the constellation Lyra the Lyre. Make a fist and extend your clenched fist at arm’s length. About two fists at arm’s length to the left of Vega look for the Northern Cross and Albireo.
To the naked eye, Albireo looks like any other star in the sky, but with even a pair of binoculars, you can see that not only is Albireo a double star, but a colorful pair. One star has a golden hue and the other is distinctly blue. I guarantee you’ll love what you see.
The double stars of Albireo are considered a binary star system — just over 400 light-years away, with just 1 light-year equaling nearly 6 trillion miles.
There’s debate among astronomers as to whether the two stars are gravitationally bound and are rotating around each other. It’s extremely difficult to tell exactly, but it’s estimated that the two stars are separated by about 20 light-years. If the two stars are rotating around each other, it’s thought that their orbital period is about 100,000 years. Don’t wait up for that, because that’s well past your bedtime!
The next celestial treasure to search for is more elusive and you'll need at least a small to moderate telescope. It’s the Ring Nebula, more formally known as Messier object 57, or M57. It really looks like a ring and with its slightly bluish tint that reminds me of a little cosmic smoke ring.
The Ring Nebula lies in the constellation Lyra the Lyre between two of the four stars that make a little parallelogram allegedly outlining the little celestial harp. Just keep scanning between the two stars that make up the end of the parallelogram opposite the bright star Vega. At first, the Ring Nebula looks like a faint, blurry star, but if your scope is powerful enough, you may be able to resolve the ring.
M57 is what astronomers call a planetary nebula, a dying star shedding off the last of its hydrogen, helium and other gases as it collapses into a white dwarf star, about the size of our Earth. Our own sun is headed for this fate in about 5 to 6 billion years.
The final celestial treasure I have for you is also in the high south sky. It’s Messier object 13, better known as the great Hercules Cluster, one of the sky’s true wonders, residing in the faint constellation Hercules the Hero. The best way to find that is to face south once again and find the bright star Vega. Look just to its lower right for a trapezoid of four moderately bright stars you should be able to see with the naked eye, unless you really have a lot of light pollution. That trapezoid is pretty much the center of the Hercules constellation.
About one-third of the way from the upper right to the lower right side of the trapezoid you’ll find the Hercules cluster. You won’t see it with the naked eye, but with a good pair of binoculars or, even better, a telescope, you’ll see what at first looks like a spherical fuzzball.
If you have powerful enough optics, and especially if you can see it from darker countryside skies, you’ll see that it’s a cluster of many, many stars, known as a globular cluster. This is one of the best clusters in the skies.
Astronomers figure it’s about 25,000 light-years away, which equals about 145,000 trillion miles. There may be up to a million stars crammed in an area a little over 800 trillion miles wide. Through even a moderate telescope you can see some individual stars at the edge.
As it is with all telescopic objects, look at the cluster for extended periods through the eyepiece of your scope to let your eyes get used to the darkness of the eyepiece field. I absolutely love showing off the great Hercules cluster with giant telescopes at my star party programs.
Set your alarm for this coming Friday morning, Sept. 19, to see an absolutely spectacular conjunction between Venus, a very thin waning crescent moon and the bright star Regulus in a very tight triangle. It’ll be a sight to behold!
Venus and the moon will be practically touching each other, only about a quarter degree apart. This is the closest Venus and the moon will be to each other this year.
To make it even sweeter, you can see the moon’s disk not lit up directly by the sun, in ghostly earthshine.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is also the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and at adventurepublications.net. Contact him at mikewlynch@comcast.net.
