Welcome to this first Utah Skies Report.
We’re broadcasting from beautiful Park City, “View-tah”.
Utah Skies is a local astronomy club whose mission is to share the beauty of the night sky with our friends and neighbors.
Well, it doesn’t look like the weather is going to cooperate with astronomers this weekend. It looks like your best be for viewing will be Monday evening.
Sunrise 6:49am/Sunset 6:26pm
Moonrise 6:42pm/Moonset 7:09am
Astronomical Twilight begins at 7:57pm and ends at 5:16am
Astronomical twilight refers to the time after sunset when it finally gets dark until the first hints of sunrise begin to lighten the morning sky. It is during these hours that we typically get our best views of those elusive faint fuzzies.
The moon is full tonight, and (if your could see it ;) it would have an approximate visual magnitude of almost –13, the full moon dominates the nighttime sky. This makes tonight an excellent time to go outside and view our nearest neighbor, located a mere 250,000 miles away.
Look up at the moon and you will see the scars of billions of years of meteor bombardment. All those craters are the remains of the countless direct hits the moon has taken. Since the moon has no atmosphere, every object that comes its way scores a direct hit on the surface. Most meteors approaching our planet burn up in the Earth’s atmosphere fortunately. These can be seen sporadically throughout the year, and in sometimes intense outbursts called meteor showers.
Keep looking at the moon and you’ll notice some additional features. Notice the darker, smoother areas. These areas were thought by ancient astronomers to be oceans. They subsequently named these features Mare, which translates to “sea”. One look in a telescope will clearly show that these Mare are not oceans, but simply dark, flat areas on the lunar surface. It turns out that these are areas where lava once flowed. The moon once had a significant volcanic activity.
The moon is the easiest telescopic object of the night. It is so close, its features so easily visible and detail so abundant that the is almost something new to examine on its surface.
If you plan on observing the moon with your telescope, it is best to use some sort of polarizing filter. This helps to reduce the moons overpowering brightness enabling you to make out loads of detail. Typically the best way to observe the moon is before or after full moon. The smaller lunar phases project less light and are therefore less overwhelming to the eye. The most detail is typically found along the lunar terminator…. Terminator… no, not Arnold. The lunar terminator is the line where dark meets light on the lunar surface. It is along this line that the most detail can be observed.
Ok… so I mentioned that the moon had a visual magnitude of –13… what exactly does that mean? Well… visual magnitude describes the brightness of an object. For historical reasons, the scale runs backwards to what you might expect – the brighter the object, the lower its magnitude number. Each jump of one on the scale represents a difference in brightness of 2.5 times; five magnitude steps is equal to a brightness difference of 100 times. The sun has a visual magnitude of –27. Going in the other direction, The Hubble Space Telescope has imaged objects as faint as mag –30. To give an example of just how faint a mag –30 object is, imagine standing on the beach in California and being able to see the head of a lit cigarette on the beach in Japan!
Our planetary report focuses on various aspects of planetary observation. Our goal is to help people new to the sky to be able to locate many of the planets. For those of you with binoculars or a telescope, we hope that you’ll be able to discover new details about or closest neighbors
Venus can be seen dominating the western sky in the early evening for the next couple of months. To find Venus, simply face towards the west (west is the direction that the sun sets). Shining near its peak visual magnitude of about –4.6. Venus has already begun it’s slow descent towards the sun and will disappear into the solar glare by late spring.
Venus is currently sporting a slender crescent shape, down considerable from the nearly ½ illumination earlier this winter.
At a distance of only 34 million miles away… Venus is our nearest planetary neighbor.
Venus is quite a beautiful naked eye subject, so… get out on your deck or porch and check it out tonight. Venus’ beauty belies its harsh reality.
Venus is covered with dense clouds, so don’t expect to see much surface detail. Early astronomers envisioned a lush tropical paradise under this. Nothing could be further from the truth. As planets go, Venus is nothing short of hellacious. Daytime temperatures exceed 800* while nighttime temps can drop to below –200*. Yikes. Not exactly hospitable.
Next we move on to our Constellation report.
Our Constellation report is an easy way for people to become familiar with the nighttime sky. We’ll discuss myths associated with the various constellations as well as describing the numerous deep sky objects residing in the area. No equipment is required to view the constellations, though a star chart can be quite helpful. This ease of observing makes constellations a natural place to begin your journey to the stars. This weekend we’ll focus in on the constellation Perseus.
To find Perseus, turn again to the west and look up. You should be staring straight up at Perseus.
Perseus is high in the sky to the northwest. It sits just below or to the south east of the big W (No not the president) the other big W, the constellation Cassiopeia.
I often describe Perseus as resembling the mathematical pi symbol. It has two sides running basically north/south capped with an arc running east to west along the upper or northern edge. Perseus is full of many beautiful and interesting deep sky objects, which we’ll visit shortly.
Mythical Perseus was one of the greatest of the ancient Greek heroes and the grandfather of the mighty Hercules. As was typical of Greek heroes, he was partially descendant of the gods. His father was reputed to be none other than Zeus himself.
Our Deep Sky report examines Perseus in more detail.
First stop is Alpha Persei. At mag 1.8 this is the brightest star in the constellation Perseus. This star is a giant among stars, with a luminosity or brightness of over 4000 suns. Alpha Perseus lies directly in the Milky Way, appearing at the center of a beautiful star field. Point your binoculars at this object for a nice treat.
Stop number 2 is Algol or Beta Perseus. Algol is another bright star shining at about 100 times the brightness of the sun. The diameter of this giant is estimated at about 2.6 million miles. As a point of reference, the earth is about 8,000 miles in diameter. So we are talking really huge here.
Algol, also known as the “Demon Star” is what astronomers refer to as an eclipsing variable star. The brightness of Algol varies from magnitude 2.3 to 3.5 in only 4.5 hours. As each jump in magnitude represents a change in brightness equivalent to roughly 2.5x, Algol’s brightness fluctuation is about a factor of 3 . That means that Algol is 3 times brighter at its brightest than at its dimmest. This fluctuation occurs about every 3 days.
Moving on, we come to our next stop on the journey…the Double Cluster in Perseus.
The Double Cluster is made up of two rich star clusters.
NGC 869 at mag4.3 and NGC 884 mag4.4
NGC, for those who don’t know stands for New General Catalog. The famous astronomer William Herschel created this catalog of deep sky objects back the late 18th century. The NGC contains over 13,000 deep sky wonders.
The Double Cluster in Perseus is one of the most spectacular objects in the night sky. Visible to the naked eye just north of the body of Perseus, the Double Cluster is an impressive site in binoculars or a telescope. It resembles two handfuls of diamonds on a black velvet background. Each cluster contains dozens of visible stars. This is truly a must see object, so… dust off your telescope this afternoon as this object is at its best visibility early in the evening. Choose a low power eyepiece so that you can see both objects in the same field of view.
Next stop…M34 (mag5.2) A beautiful open cluster made up of about 80 or so bright stars. The famous astronomer Charles Messier discovered this object in 1764. Actually, the M in M34 stands for Messier. The Messier objects are a group of 110 objects that Messier included in his list of “non-comets”. Messier was a comet hunter. He logged the entries on this list so that if he saw one of them, he would know it was not a comet and hence could be ignored. While Messier found many comets in his career, it is for his list of non-comets that he is most famous.
Back to M34. You will find M34 located between Algol and the beautiful double star Gamma Andromeda. From Algol, look about 5 degrees to the northwest. To help you gauge this spread, the width of 3 fingers held at arms length span approximately 5 degrees. Estimates place M34 at a distance of around 1500 light years. As a quick FYI, 1 light year is approximately 6 trillion miles. So 1500 light years translates into 9,000,000,000,000,000 (9 Quadrillion) miles. That’s a 9 with 15 zeros. Sounds pretty far away, huh? Actually this object is relatively close by astronomical standards. M34 resides within our own Milky Way galaxy.
This is an easy object for a small telescope or binoculars.
NGC 891, a more challenging but worthwhile object in Andromeda lies 3* to the west-southwest of M34. This 10th magnitude spiral galaxy is seen exactly edge on. It has a dark dust lane running through it’s center. NGC 891 is listed at 43 million light years distant. This means that you are seeing this galaxy as it appeared 43 million years ago. Wow!
Moving back within the bounds of Perseus, we come to our next stop.
M76 The Little Dumbbell Planetary Nebula (mag10.1) This is the faintest object on the Messier list, but due to its small size ought to be relatively easy to find. Small telescopes will reveal this as a squarish smudge of light, while larger instruments should be able to pull out considerable detail. M76 features 2 prominent nebulous patches. In searching for this object, use a low power eyepiece and sweep the sky slowly and use averted vision.
What’s averted vision you ask? Averted vision allows the observer to pick up fainter objects than can be seen by looking at them directly. The technique is simple. Look away from the object under study while continuing to concentrate on it. Averted vision is most effective if the observer looks at a point halfway from the center to the edge of the field of view. Essentially, you are utilizing some of the more light sensitive areas of your eye, enabling you to see fainter objects than could be view directly.
Next stop is NGC 1499, The California Nebula. This is a very large object with low surface brightness. Hence it can be difficult to locate. The California Nebula gets it name from it’s shape. I generally of resembles the state of California. While this might seem like a bit of a stretch, it does have a cutout right where the San Francisco bay is located. Your best chance at spotting the nebula will require dark skies and a nebula filter.
Our final stop in Perseus is our Deep Sky Challenge of the week. NGC 1275. This mag 11.9 galaxy requires at least an 8” telescope just to glimpse it. Generally 12 to 16” or more is required for a good look. With these larger apertures, you’ll notice that NGC 1275 is the largest and brightest of a rather large group of galaxies. These galaxies make up what is known as the Perseus Galaxy Cluster. Hubble Telescope images have revealed in excess of 3000 galaxies in this cluster. To find it, sweep 2 degrees east of Algol, and then ½ degree to the north. If you are able to find this object, you may be one of the few, the proud, the Deep Sky Obsessed. E-mail your findings to DeepSkyObservations@UtahSkies.org.
Rapid growth in the area is threatening our skies. We need people to take a more active role in protecting and preserving our skies. In many areas of the country starry skies are a thing of the past. Let’s not let this happen here. It would be unfortunate if we lost our link to the skies.
How can I help you ask? Simple. Use lighting only when and where it is needed. Also, use only as much light as is needed. Replace your 100 watt bulbs with 40 watt bulbs. You’ll be surprised at how well you’re still able to see. You’ll also probably notice that the exterior of your home no longer has a harsh appearance typically caused by overlighting. You’ll also save a couple of bucks in the process. All in all I’d say it’s a “win-win” situation.
Are you considering the purchase of a telescope? If so, here are a couple of thoughts to keep in mind. First off. The primary purpose of a telescope is to gather light. Your pupils will dilate to about 6-8mm. Binoculars typically range from 35-70mm. Telescopes range from about 85mm or 3” up to 625mm or 25” and even larger.
So… binoculars will show you quite a bit more than your unaided eyes will see. Telescopes will take you even further. So… with that said, bigger is better. But don’t get a telescope that is too big for you to conveniently transport and setup. A telescope that is too big won’t get used as often as a smaller more manageable one. So, check out several before you purchase. Attending Star Parties is a great way to “try before you buy”. Utah Skies is planning on holding several star parties this year which will be open to the general public. Be sure to check our website at UtahSkies.org for details on upcoming events.
Secondly. Magnification is beneficial, but only up to a point. Stay away from those cheap telescopes that claim mind-boggling levels of magnification. Advertisements touting a $99 dollar telescope that provides 600x or 700x are a joke. You won’t see anything but a blur at these levels of magnification. As a general rule, expect that a telescope of reasonable quality can handle magnification levels of about 50-60x per inch of aperture. So, a good 5” scope should readily handle 250-300x before image degradation sets in. Also remember that these numbers describe performance under optimal conditions. Your views will only be as good as the skies above you. If the jet stream is overhead, or a storm is quickly moving in, expect to operate in the 100-200x range, regardless of telescope size.
As a quick test of sky conditions, look up at the sky. If the stars are twinkling noticeably, you’re probably going to be struggling with atmospheric turbulence. If you have trouble detecting any twinkle in the stars it’s gonna be a great night, so… call me right away so that I can set up and view as well.
Next week we’ll cover some very well known astronomical objects, from everybody’s favorite plant Saturn to a slew of star clusters and Nebula in the constellation Auriga.
This “Star Cast” has been presented by Utah Skies. View-tah’s Astronomy Home. Utah Skies can be found on the World Wide Web at www.UtahSkies.org. Visit our site and discover the cosmos. We have numerous of images of deep sky objects such as galaxies, nebulas and star clusters. We also have lots of astronomy-related information as well as links to other astronomy sites. Utah Skies is also your best source of information on light pollution.
This is Anthony Arrigo wishing you clear skies.