Hello everyone, I'm Darrell Heath with the UA Little Rock College of Arts, Letters and Sciences.
Welcome to The Night Sky.
Many years ago I received my first telescope as a Christmas gift,
an eight inch Dobsonian.
I've owned several other telescopes since,
yet it's still that first one that I use the most.
But when I first got it I wasn't ready to use it.
I didn't know the first thing about telescope mounts,
finder scopes, eyepieces, filters, or star charts.
Outside of the Moon I didn't even know where to look in the sky to find things like
the Orion Nebula or the Andromeda Galaxy.
Over the years I've meta lot of other folks who had the same experience that I did.
And frustrated with learning lots of unfamiliar jargon and concepts,
most of them confessed to me that the telescope got stored away
in a closet or ended up in a yard sale.
Astronomy can be a challenging hobby to get into but with patience and the
desire to learn more about the universe in which we all live it can easily become
a rewarding lifetime adventure of discovery.
In this episode of The Night Sky, I want to provide you, the first time telescope owner,
with a few basic tips that can help you get the most
from your use of the scope and from your observing.
Okay, so you've got the telescope and you're eager to take it outside and
begin to explore the cosmos from the backyard. I applaud your enthusiasm but,
before you do that, I'm going to suggest that if you haven't done so already
get to know the sky first. In fact if you haven't yet bought a telescope my advice
is to hold off until you familiarize yourself with the sky using nothing more
than your unaided eye or maybe even a pair of binoculars.
Learn how and why the stars rise in the east and set in the west from night to night.
Or why the stars and constellations change from one season to the next.
Learn why the stars, for those of us here in the northern hemisphere,
all rotate around Polaris, the North Star.
Before even trying to learn the constellations I suggest that you get to know the brightest stars
as well as a few of the bright star patterns or asterisms they form.
Things like the Big Dipper, the Summer Triangle and the Winter Hexagon.
Once you master these, the constellations will fall into place all the easier for you.
A good place to start learning this kind of information
is by making trip to your local library or bookstore.
Invest in a good field guide to the night sky or a book about the basics of stargazing,
such as Terrence Dickinson's Night Watch.
Use an astronomy app or software that will show you what's up in your sky no matter your location.
A fantastic, free, open-source planetarium software that's available for your computer or smart device is
Stellarium. And I highly recommend that you check it out.
It will render you a realistic depiction of the sky showing you the stars, planets, constellations,
and deep-sky objects all in real time.
This video is not intended to be a how-to on setting up and using a telescope.
there are just too many different kinds of
scopes and too many different styles of mounts for that to be practical.
But the important tip that I want to impart to you here is, that before taking the scope
outside, read your instruction manual very carefully. And do a setup inside
before going out in the dark to use it.
You'll find that it's much easier to set up on the first night out if you familiarize yourself
with all the components.
Align the finder scope during the day. And if necessary, already be
familiar with a few bright stars before trying to align the mount.
A common complaint that I hear from folks who use a reflector telescope is,
"I set the telescope up properly but when I look through it everything's blurry."
There's usually a very simple reason for this. You didn't give the scopes optics
Enough time to acclimate to the ambient air temperature.
The amount of time it takes for this process to occur will depend to a large
extent on the size of the mirror and tube. But could take anywhere from
30 minutes to an hour or more.
Chances are your scope came with at least one eyepiece, but you'll soon want to get more
and you'll need to be selective about it.
Quality eyepieces can make a huge difference in your viewing experience
compared to using cheaper eyepieces. But quality is also going to mean more money.
We would need an entire episode on eyepieces
to do the subject justice but here are a few things you need to know.
Magnification is not an inherent property of your scope. It depends on
what size eyepiece that you're using. To determine the magnification, you'll first
need to know the focal length of your telescope tube.
This can be found in the owners manual and it's also likely to be printed somewhere on the tube.
The focal length of the scope is simply the distance, usually in millimeters, from the
primary lens or mirror to the point where it forms an image of the object
you're looking at. Likewise the eyepiece has a focal length as well. Again, it's a
number that's going to be printed or stamped on to the side something like
say twenty or twenty-five millimeters. Just divide the focal length of the tube
with that of the eyepiece. For example, if the telescope's focal length is
1,200 millimeters and your eyepiece has a focal length of 25 millimeters, then just
divide 1200 by 25 and you get a magnification of 48 times.
It seems logical to think that if you increase the magnification that you're going to
get better views. But that's not the case because as you increase magnification
you are going to decrease the brightness of that object as you're now spreading
out its light over a larger area.
So just be aware that there are going to be
limitations on just how much magnification a particular telescope or
even a particular celestial object can handle.
Now when it comes to which
eyepiece to choose in order to get either higher magnifications or lower
magnifications just remember there's a general rule of thumb.
The higher the number that stamped on your eyepiece the lower the power will be.
While lower numbers on the eyepiece will yield higher magnification powers.
Let's say that you have a 25 millimeter eyepiece and a five millimeter eyepiece.
Which one will yield the lowest power?
If you said the 25 millimeter eyepiece then you're correct.
And always remember this important tip... start out using your
lowest power eyepiece when you begin observing. Why? Because the
lower power eyepiece will yield a wider field of view then does a high power eyepiece
making it much easier to find your chosen target.
Having three or four eyepieces of varying focal lengths is a good rule of thumb, but if you can't
afford to invest a lot of money in them I might suggest purchasing a zoom eyepiece.
Zoom eyepieces are single eyepieces that in essence act as several
different eyepieces all rolled into one.
You aren't going to get high quality images,
but for casual observing I find zoom eyepieces to be both convenient and affordable.
Invest in a few filters. One of the most rewarding celestial objects
you can explore with your telescope is the moon. But the moon can be blindingly
bright in a telescope so you'll want to reduce its glare. I strongly urge you to
purchase a neutral density moon filter that will allow you to observe the
varied lunar terrain in comfort.
There are basically two types of moon filter...
neutral density filters permit only fixed amounts of light to pass through them
while polarizing filters have two polarized surfaces that allow you to
vary the angle between them thus controlling the amount of transmissible light.
The planets of course will also provide you with hours of fun too.
But to see details on them, especially Mars, will require patience and perhaps a good filter.
You can buy colored filters from most telescope manufacturers and supply shops.
As to which filter to use will depend to a large extent on which planet
you are observing and which features you want to see. For example when looking at
Mars you may find that a red filter works great for bringing out the polar caps,
while a blue filter is best for observing the clouds in the Martian atmosphere.
My advice is to play around with them all and see which works best for you.
Be aware that there are many other types of telescope filters out
there but for the beginner I think the most important ones to start out with
are going to be the moon and the colored planetary filters.
Okay, so you've got all your gear and you know how to use it.
What next? Well, finding things like the moon and the planets is pretty easy.
And once you know a few bright stars and the constellations to which they belong you
can also easily find some of the brighter deep sky objects things like
the Orion Nebula and the Andromeda Galaxy and the Pleiades Star Cluster.
But finding others might be more challenging, especially if you don't have a
computerized go to telescope that will simply guide you to an object with the push of a button.
This is where having a good Star Atlas and knowing how to use it will come in handy.
I recommend Sky and Telescope's Pocket Sky Atlas.
Alternatively and with much more enthusiasm I would strongly
urge you to learn how to find objects by star hopping.
This is pretty much what it sounds like.
Find a difficult target by using brighter more familiar celestial objects
as your stepping stones to finding the harder objects.
To my mind the best guide book you can get for star hopping is
Turn Left at Orion by Guy Consolmagno and Dan M. Davis.
This is an indispensable reference for the beginning observational astronomer.
Armed with a good navigational aid and the right equipment there's no stopping you and
your explorations of the cosmos.
But wait, there's still more that you can do.
First off, don't allow your observing sessions to be purely arbitrary.
Compile a list of targets that you want to see on any given evening and have a plan on how to find them.
Choose a good, safe, dark sky site to observe from.
You'll want to escape the light pollution of cities in order to see the most objects.
And if deep sky objects are your targets, then you're going to need to plan your
observing sessions around the phases of the Moon.
In order to preserve your dark-adapted vision, avoid the use of cell phones
and steer clear of any bright lights.
Use a red filtered flashlight to see with in the dark as the
longer wavelengths of red light will preserve your night vision and still
allow you to see under low-light conditions.
Weather is obviously going to be a big factor in planning your observing sessions.
Before setting up your scope be sure and visit a website such as cleardarksky.com.
Even though the sky might be clear from your observing location that
doesn't mean that it's going to be great for making telescope observations.
Consider keeping a journal of your observing sessions. Make note of things
like the time, weather, scene conditions, etc. but also pay attention to what's
going on around you. Observing on a spring night, record things like that
chorus of frogs you hear from a nearby pond or that owl that's calling from a
tree on the edge of your observing field or the heady aroma of soil after an
afternoon rain. These kinds of details would not only enhance the pleasure of
your observing runs but will also be great fun to look back on years later.
And even though you might not be an artist, try sketching what you see at the
telescope. They don't have to be master works to be displayed at your local art
gallery. They're being made to help make you a better observer. Plus the more
often you do it the better you're going to become at it.
Get involved in your local astronomy club. You'll likely not find a better source of information and
wisdom than the folks who have been doing this kind of thing for many years.
And, in my experience, you'll be hard-pressed to find a group of folks
more generous with their time and knowledge than that of seasoned stargazers.
There are many more tips that I can impart to you but I'm afraid my
time is up. Please feel free to comment on the videos or ask questions if you have any.
Also visit the night sky website (ualr.edu/tv/night-sky) to see my monthly observing features
Remember just take a little bit of time to go outside and look up in both awe and wonder.