Showing posts with label eyes. Show all posts
Showing posts with label eyes. Show all posts

Saturday, January 7, 2012

Learn to Use Your New Telescope!

Did you get a new telescope recently? This is the time when the most new telescope owners are made!

Using a telescope isn't entirely natural and easy, no matter what scope you have. In fact, the scopes with the most "ease of use" features are often the hardest to get started with.

A local astronomy club is a good way to find others who can help you learn more about how the get the most out of your telescope. They're using their own telescopes, they will know some good places to use them, vital accessories for them (very few telescopes are sold with everything they really need to be useful), and have tips. The club may have formal classes, or just give you the chance to meet up with others with like interests to yours, and more experience.

There's information available online, but having someone who can actually be there with you and your scope, even if just for a short observing session or daytime practice session, can be invaluable. They can see things in a moment that you won't know to mention online. They can tell you things just as quickly that would make for long murky postings online. The "personal touch" makes all the difference.

Also, don't beat yourself up while you're learning. Learning to see things through a telescope is something you have to do. It's not natural like looking with your eyes without an instrument. If you're experienced with using other optical instruments like binoculars or microscopes it'll help, but a telescope is still a different animal that takes getting used to.

Don't set yourself up for failure by expecting to see observatory photograph views of difficult objects. The Horsehead Nebula doesn't look like the pictures to eye, and it's very, very hard to see even with the correct telescope and accessories. Start by looking at things chosen from a naked-eye astronomy book or binocular astronomy book. Train yourself to find the objects, keep your scope on them, and see the detail in them.

Each scope behaves differently, and you will want to get experience seeing what your scope shows. It's a matter of experience, and you'll find there are several different levels you can achieve as your skills develop. Regular repetition with the right equipment is the key to developing. Each new level brings a new level of enjoyment. Things that didn't look like much before suddenly become far more interesting, even if the equipment hasn't changed at all. You learn to see an notice things that weren't apparent before.

Plus you'll need to learn to be patient and give your eye the time to see what you're looking at. Most beginners spend far too little time actually looking through the eyepiece and relaxing once they've got something to see in it. Your relaxed eye will see far more than an eye that is rushed through a quick "there it is!" look.

Keep your scope stored in a state and location where you can easily use it. Its size and type matter far less in its performance than whether it is simply taken out an used regularly.

If you seem to be hitting a wall, there may be something that needs to change with the equipment, or that you need to know about how to use it. Don't be discouraged, find an answer. Astronomy is not supposed to be difficult. If you find that it is, suspect that there's something else you could be doing other than what you are doing.

Don't be daunted by the fact that there are things to learn. The process of learning them is (or should be) a pleasure in itself. There are many ways to approach doing astronomy, none of the good ways require an overabundance of patience or muleheadedness or a giant egg-shaped head. All they take is normality, an interest, and the ability to ask questions and occasionally follow directions.
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Sunday, November 6, 2011

Observing the Deep Sky with a 60mm Telescope

"Deep Sky" observing is not normally associated with a telescope as small as a 60mm (2.4 inch). There are many nice objects that can be viewed well with a small telescope, however. This is part of a series of articles on this blog about observing with the 60mm telescope. The information also applies to larger scopes, which can get even more out of these objects with their greater observing power.

There are a good number of objects that most any 60mm scope can show well, so long as they have a decent mount. The Lagoon and Trifid Nebulas, the Hercules Cluster, the Great Orion Nebula, the Crab Nebula, and many star clusters are all wonderful objects to show off the abilities of your small scope.

60mm scopes with the highest quality optics and very good mounts can show objects that are usually thought of as objects requiring larger telescopes. Better mounts give a steadier view, and allow you to relax more while looking. Better optics improve the contrast of the image, which makes it easier to find and see the object you're looking for, and to see more of the detail in it.

Star Clusters
Star clusters are the deep sky objects your small scope is most suited for. They are relatively bright, and very numerous, meaning there'll almost always be plenty of them in the sky to choose from. There are two basic types of star cluster, the "open" cluster, which is a general group of stars that happen to be near each other, and the "globular" cluster, which is a group of stars whose mutual gravity has pulled them together into a globe shape.

Both types are visible in your 60mm telesccope. In my first article in this series I listed a good selection of star clusters that can be viewed with a 60mm scope. Here's I'll describe some of my favorites, and observation tips that apply to all clusters.

Globular Clusters
M13, the Great Hercules Cluster, is a showpiece object for northern hemisphere astronomers. It's a big glowing ball of stars in the Keystone of Hercules. Different globular clusters look different. Some have a very even brightness across the face of them, others are brighter at the center then the brightness tapers off as you go outward. M13 is one of these, much brighter at the center. Its brightness drops off regularly from center to edge. Individual stars can be picked out at the edges, with tendril-like streams of stars flowing outward around M13s boundaries.

Compare this with M22, near the top of the Teapot in The Archer, visible to observers north and south. It is about the same brightness as M13 overall, but the bright wash of its center extends well across its diameter. Only the outer parts dim. Southern observers can also enjoy the enormous globular Omega Centauri. M13 and M22 are both visible to the naked eye, but not like Omega Centauri! In the telescope, Omega Centauri shows enough detail to spend a lot of time enjoying it.

Open Clusters
Star Clusters with no particular form are also beautiful in a 60mm. A good night with high contrast skies will show these the best, making more stars visible in the cluster as well as making them stand out clearly from the background sky.

The Beehive Cluster and Alpha Persei Moving Group are beautiful groups of bright yellow stars. As is the case for star clusters in general, they should be viewed at the lowest power you've got for your scope. This would be the eyepiece with the longest focal length. This is the number shown on the eyepiece, usually given in millimeters (mm). Sometimes a viewing angle or other number is listed as well, but the focal length is usually listed most prominently in this case. The one with the largest number gives the lowest power views. For example, a 25mm eyepiece will give lower power magnification than a 15mm eyepiece.

The Seven Sister, or Pleiades (M45) are spread out too far to be seen all at once in nearly all telescopes. But the area can be scanned at low power. About 40-some stars are visible in all under the best conditions, and faint nebulosity (cloudiness) is visible in this area as well.

M39 is a nice, tight cluster at the edge of the area of sky that holds The Swan. It is easily contained in the telescope's field of view, and stands out nicely from its background.

Nebulas
Nebulas are clouds of gas and dust. There are several different sorts. Planetary nebulas are ones that tend toward being round, looking a little like "planets", which is why they have that name. They have nothing to do with planets other than looking a little like the disk that a planet shows. Supernova remnants are clouds of material that have been blown into space by an exploding star. Most commonly seen nebulas are general clouds of gas and dust in the spiral arms of our galaxy. Many of these are places where new stars are being formed, so they are often associated with nearby star clusters.

There are a few bright star clusters that look really good in a 60mm telescope. Most, however, are faint, show little detail, and are very hard to see in a small scope. The Great Orion Nebula near the belt of Orion, and the Lagoon and Trifid Nebulas in The Archer are among the best. On a clear night with a dark sky they show up clearly, with traceries of their gas and dust forming streamers and shapes inside and around them. At their best, they can show a faint greenish color, though they'll usually just show shades of gray in a 60mm.

The Crab Nebula, M1, in Taurus, is a fine supernova remnant for small telescopes. It is relatively easy to find, near the tip of one of The Bull's horns.

Fainter nebulas can be seen as small cloudy shapes. They are a good way to develop your skill as an observer, both in finding them and in observing their form. NGC 6334 lies near the star cluster M6, and is a good starting point for seeking more challenging nebulas.

Many planetaries are very nice to observe in a 60mm scope. Their compact form and well defined edges make them easier to see than a lot of the more "gaseous" looking nebulas.

The Saturn Nebula, NGC 7009, in Aquarius the Water Bearer, is very bright and has a nice green color visible even in small scopes when the sky is good. The Eskimo Nebula, NGC 2392, in Gemini the Twins, is fainter, but its form can be made out easily once found. The Ring Nebula, M57, in Lyra is a favorite of small scope owners. It looks like a smoke ring. It is bright enough to take your scope to its highest magnification, as is the Saturn Nebula.

In the next article I'll cover the final sort of deep sky object you can see with a 60mm: galaxies.
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Sunday, October 30, 2011

Observing the Moon with a 60mm Telescope

This article is part of a series on using and observing with a 60mm telescope, one of the most common of beginner telescopes. The information also applies to larger scopes, which can show more detail and find objects that are difficult with a 60mm scope more easily.

The 60mm scope can be a very rewarding scope to use, however, especially when getting started. They are compact, often inexpensive, even for quality scopes, and easy to use when well designed. They remain useful even when there are better scopes in the house because of their small size, light weight, and general ease of use.

I used a 60mm scope as my primary telescope for over 10 years. My first scope was a 60mm telescope, unfortunately mated to an extremely poor mount. I fought the mount for many years, if I had been less mule-headed I would have probably given up on astronomy. Fortunately, I finally decided to rebuild my mount using wood from my school's wood shop scrap bin. It looked awful, but held the scope on target and steady. The optics were actually pretty good, once they stayed where they were put.

Observing The Moon
A 60mm is enough scope to enjoy practically everything the Moon has to offer. The craters, valleys, walls, ridges and seas of the Moon will all stand out nicely at low to medium powers (25 to 150 powers). If your telescope has a clock or computer drive you will also be able to use higher powers on the Moon (150 to 250 powers). It is one of the few objects that is bright enough for high powers for a small telescope. But it will be a lot harder to get a sharp focus and to stay on your target at higher powers.

The best place to look on the Moon's surface for nice detail is near the dividing line between night and day on the Moon. This is where the contrast is the sharpest. Plus, you can see changes as time passes in these places. One of my favorite things to do is find a crater where the rim is in sun, but the floor is still in darkness. Sometimes, every so often, I can watch the Sun illuminate the central peak of a crater as I watch. It'll go from darkness to a sudden spot of light in the middle of the crater. Other times I'll look at an area, go look at other things elsewhere, then come back an hour or so to see if anything has changed in areas I've looked at earlier in the night.

Many parts of the Moon will be too bright to show much detail, or will be so bright in the telescope that it'll ruin your night vision. In this case the little Moon filters that come with many telescopes, designed to be fitted to the eyepiece, can be helpful in cutting the light down to a more tolerable level and help bring out some contrast. Unlike the little solar filters, these are safe to use. If a Moon filter didn't come with your telescope, there are many color and "neutral density" filters available that you can get inexpensively.

Neutral density filters are strictly "black and white" filters that cut down brightness without changing the colors of what you're looking at. They are my favorite for using on the Moon, especially when I'm looking for color on the Moon. One sort is a polarizing filter, which can be adjusted to different darkness levels. These are also useful for seeing cloud details on Venus, but they tend to be expensive.

Color filters also work well on the Moon. Darker colors often come in packs of different color filters that are commonly sold. About the only object these darker filters are useful on is the Moon. Dark red, orange, green, and yellow filters will each have a different effect.

Light color filters are nice for bringing out detail in areas of the Moon where there is some color in the soil. These colors are very faint, and the filter will eliminate the ability to see the colors directly, but they will bring out more detail of the surface in these areas.

Be careful of trying to take the magnification too high. It's tempting on the Moon, but more detail will actually be seen at moderate powers by relaxing (a couple of deep breaths are always good) and taking the time to let the subtle details of the image "sink in" as you view.
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Monday, August 9, 2010

How to See Through Your Telescope

When I take my telescope to star parties, to show off the sky to the public, I get two types of people at the scope. One type of attendee approaches the scope, darts their eye toward the eyepiece, then is away again almost immediately.

"Did you see it?" I'll ask.

"Yeah, I saw it," they'll say as they buzz away, as if they're in a hurry to get somewhere.

Yet they'll have been at the eyepiece so briefly that they'll not really have even had a chance for their eye to focus properly. They've glanced at the image like a quick glance at a picture in a book. They saw the light, but not the object itself. They didn't give themselves a chance to see whatever it was I had in the scope, its shape, color, or any detail. Even when I know what I'm looking at, I can't really see it that fast.

The second type of viewer takes their time. They allow their eye to adapt to the view through the scope. Looking at an image in a telescope is not like looking at a TV screen, or a book, or at something that we see without any assistance in front of our eyes. It takes a moment for our eyes to adapt. The second type of viewer gives their eye a chance to adapt to the view.

They actually get to see what's in the scope.

When the object I'm presenting has fine detail to it, I make suggestions to the viewers who are willing to take the time to really look. I ask them if they can see some specific detail, to give them an objective. "Can you see the light yellow bands on Saturn?" "Can you see the dim star just below the brighter star? It's hard to see in the glare of the brighter star." "Can you see the dark area just below the bright nucleus?" And so on. Then I tell them to take their time to allow their eye to relax, since a relaxed eye is more sensitive to detail.

Learning to See All Over Again

When you're learning to use a new telescope, really taking time to learn to see is important to getting the most out of your scope. A lot of it is simple experience, coming from looking at many different objects and types of objects. Part of it is using good practices, giving yourself a chance to get better at it. With time, you'll find that you learn to see more of what you look at. You'll see more detail, and see more of what distinguishes one object from another. The galaxies won't all just look like "gray fuzzies" any more. You'll be able to make out the weather patterns on planets, and so on.

The Downside

The downside to this is that you may find that you notice flaws with your telescope that you didn't notice before. There are some instruments that this may never happen with, the fine ones at the top of the market, for example. But even some of these will show imperfections if they're of a sort that need adjustments to the optical train, like a Newtonian reflector.

Many telescope flaws are easily fixable. But with some telescopes the limitations may be something you can't overcome. In some cases, you may simply find that the scope, while fine for some types of observing, no longer fits your preferences for the type of observing you do.

Remember how I've recommended not to bet everything on your first telescope? This is why. No matter how good your first telescope is, it may not end up fitting your preferences that develop as your observing experience grows. Also, a scope that looks optically perfect to an untrained eye may look very different to a more experienced eye later on.

So be prepared to have your taste in telescopes change. Don't worry, it's a good thing.

Give Your Eye A Chance

Here are some practical things to do to allow yourself to get better views through your scope:

  • Allow yourself to look long enough at each object.
  • Make it so that you can relax while you observe.
  • Read other observer's reports, so you have specific details to look for.
  • Try observing the same object under different conditions, either by using filters or different magnifications during one session, or on different observing sessions at different times of year or under differnt sky conditions.
  • Observe reasonably often, if possible. You "forget" if you go too long between observing sessions. If you can do a number of sessions over a short period of a few weeks, then go without for a while, you'll get more than from the same number of sessions spaced out widely in time.
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