How do you use a telescope?

Question

I am borrowing a telescope from my Aunt and she said it has a way that you can type in coordinates for a particular object in space and it will find it for you. I haven't heard of that before and how would I get the coordinates anyway?

I heard Jupiter and Mars and I think Venus are visible in the Western US sky after dark right now and I saw Jupiter with the naked eye a couple days ago. (A big, bright star in the eastern sky after sunset.) So would I need to use that feature anyway?

Answer 1

Look it up under nightsky, there you get coordinates and then it depends if the telescope is computer adjusted or manually. If manually, there are 2 wheels with degrees on it, on the computer just punch in the coordinates.

Answer 2

If you can see it with the unaided eye, you don't need the setting circles to aim the telescope at it. The finder scope and a low power eyepiece will do the job, if the finder scope is lined up correctly. An easy way to check and correct the aim of the finder scope is to look for Polaris and center it in the finder scope. If it's in the center of the telescope's field of view, the finder is correctly aligned. You can also use the finder scope to hop from star to star to get to an object you can't even see in the finder scope. Because your aunt's telescope is a "GOTO" telescope, you align it on two or three bright stars, then enter the object you want to observe with the controller that comes with the telescope. You need to know your way around the sky enough so you can tell stars such as Vega and Altair apart from each other, but once initialized locating galaxies, nebulae, even the outermost planets, asteroids and comets is child's play. All you need is a good sky atlas so you'll know which object to hunt for from your location. Right now the sky's very bright until very late at night, but in a couple of weeks, you can go for nebulae and galaxies  even if the telescope is small assuming your skies are dark and clear. I use digital setting circles on my largest telescope, which merely guide me to where any desired object in the computer's base is located. In this way, I located hundreds of galaxies with my 10-inch Dob.

Answer 3

Your second question first.  Venus is still just a scant nine degrees from the Sun in the sky--if you were to hold your fist out at arm's length, that's about nine degrees, so it's pretty close.  It's probably lost in the glare of the Sun, therefore, and you certainly shouldn't point your telescope at it, unless you're very sure of what you're doing.  At this stage, Venus is not going to be very interesting anyway: It's on the far side of the Sun, and it will be merely a small round dot of light.  Try Venus again in a few months.

Mars is a better shot.  It's about a third of the way up the sky at dusk, depending on your location (but you mention the Western U.S., so that's probably about right), close to the star Regulus, in the constellation of Leo the Lion.  The interesting thing about Mars tonight is that it's very close to Saturn--only about a degree away--the width of your pinky held at arm's length.  It's possible, depending your aunt's telescope, that the lowest-power (longest focal length) eyepiece will allow you to see both planets in the field of view at once.  Saturn is a wonderful sight in the telescope.

Jupiter is also a good sight.  It's the brightest thing going in the eastern sky after it rises around 8:00 p.m., so you're quite right that you won't need any computer pointing on this one.  You should be able to see the two main cloud belts, called the North and South Equatorial Belts (NEB and SEB).  The Great Red Spot (GRS) is surprisingly difficult to see, especially at powers below about 120x, and it's only well placed for about two hours each night.  Tonight, that's from about 9:00 to 11:00 p.m. PDT, but again, the GRS is difficult to see, so don't be surprised if you don't detect it.  It's on the southern edge of the SEB (toward the pole from one of the belts).  It's not really red--more like a pale salmon.

You should be able to see the four main satellites of Jupiter readily, unless they're hidden by Jupiter.  They're easily seen even through binoculars: Io, Europa, Ganymede, and Callisto.

Don't forget the Moon, which is just past first quarter and a fantastic sight.

Now, as far as the coordinates: The ones the computer wants are probably right ascension (RA) and declination (Dec), sort of like longitude and latitude, respectively, for the sky.  You can find these coordinates for celestial targets on-line.  If this is your first time out with a telescope, I'd start with the showboats.  Messier 8 (M8), the Lagoon Nebula is a good target, visible from even suburban skies.  It's in Sagittarius, and has coordinates RA 18h 4m, Dec -24° 23'.  This may be somewhat difficult to see if you're further up north.

Another interesting target is Albireo, easily seen from anywhere in the U.S.  This is a pretty gold-and-blue double star in the constellation of Cygnus the Swan, and has coordinates RA 19h 31m, Dec +27° 58'.

Somewhat more of a challenge is the Dumbbell Nebula, M27, in Vulpecula the Fox.  It has coordinates RA 20h 0m, Dec +22° 43'.  This is a planetary nebula, the gas cloud thrown off by a dying star.  Nearby is another planetary nebula, the Ring Nebula (M57), in Lyra the Lyre.  It has coordinates RA 18h 54m, Dec +33° 2'.  It's much easier to see than the Dumbbell, but it's also much smaller, so it almost looks like a star, and may be difficult to identify as a nebula, especially at low power.  You may want to look on-line for a wide-field view of M57, so you know what to look for.  It looks like a minuscule smoke ring.

Hope that helps.

Answer 4

It is called "go to" technology.  Different scopes do this differently, some still require polar alignment of the mount, some do not.  They all will require calibration to the sky, generally done by pointing to a star of known coordinates, and entering those coordinates, then repeating this on different stars, minimally two, more might give better accuracy. After that the thing will go to any coordinates entered, some will have a memory with objects loaded already, like the Messier objects.  You would need a reference source for these coordinates, many places on-line to find such info as well as books, sky atlases, or ephemerises (ephemeri?).  The planets move around enough that you would need coordinates for the date you are looking for them, but they are very bright, at least the ones mentioned Venus, Mars and Jupiter as well as Saturn, so it would be much simpler to just "point" the scope manually at these objects.

Ask your Aunt for instructions for the particular scope, you might be able to find it on-line otherwise.

Saturn and Mars are in the Western sky just after dark these days (setting before too late).  Jupiter is better placed, it was at opposition just two days ago, so it is high in the sky at around midnight and about as close as it gets.

Answer 5

Hi Kristee -

Good question. Saturn, Mars, and Jupiter are all visible, although Saturn and Mars are setting pretty early, and Venus is pretty close to the Sun. I have used charts for years, and I consider half the fun of the astronomy hobby to be involved with knowing where to look to find things. You can get a free download at stellarium.org that will show you what is visible and where to look for it. That program will also list the coordinates, if you click on each object (galaxies and clusters are toggled on by a separate "nebulae" link at the bottom). Most of those "GoTo" scopes don't even need the coordinates - you can type in "Saturn" and it will slew around to the target. But to paraphrase Terence Dickinson, you might as well place a bag over your head until the thing stops humming, then pull it off and look through the eyepiece. Do yourself a favor and get some charts or at least do a little homework before you get this wonderful opportunity. Get the big picture.

ADDED:  It was not my intent to sound argumentative or condescending. Certainly, GoTo scopes are excellent for folks with limited time (and I believe Mr Dickinson agrees with that as well). I personally prefer scopes without that feature, and I know a few people who regret that they purchased it. It will not help you to learn the night sky. Since you are not (at least for now) confronted with the purchasing decision, it's not even a serious concern. Whether you use it or not is ultimately your decision, which may be based on how much time you have to devote to it. Good Luck.

Answer 6

The good ol' debate about GOTO telescopes again.  When you don't have time to waste learning how to run a telescope that is not yours, you hope that it is a GOTO.

When you set it up (I hope that she will have showed you how), you will need to find three things you know, and then enter their names (or numbers or codes) on the keypad.  With that, the computer will understand exactly how the telescope is set up and which direction is which.

From then on, you enter the name (or number or code) of what you want to see and wait for the telescope to slew to the target.

No, you do not have to use the feature.  In that case, you will need to set up the telescope so that it can track the object you want to watch. Then you need to hunt down objects you are interested in or stay with very bright objects.  This may please Terrence and Larry454, but it will not make your brief time with your Aunt's telescope very enjoyable.

If you only have the telescope for a short time, enjoy the GOTO feature to the maximum.  There will be lots of time to learn your way through the sky afterwards, when you get your own telescope.