I am often contacted by people for advice on buying telescopes, particularly as gifts around Christmas. So if you are one of those lucky people with a shiny new telescope (or just want to have a fun night observing) then your eyes are about to be opened to a wonderful Universe. But what can you point your 'scope at? Deciding what to look for can be tricky, so here are my top ten objects for beginners.
Obvious perhaps, but choosing the right time to look at the moon is crucial to what you will see. The worst time to study the Moon is when it is full because very few shadows are being cast except around the very edge or limb. Shadows are great at enhancing surface detail so avoid a full moon. Concentrate study along the line between the dark and light -- this is called the "terminator" and its here where surface detail is enhanced well. Experiment between low and high magnification.
The largest planet in the solar system is very well placed this time of year for observations. Not only will you be able to pick out detail in the cloud belts of this gas giant but at certain times you will be able to see the Great Red Spot, a hurricane larger than Earth that has been raging for centuries. Look for the four Galilean moons either side of the planet to and notice how they change their position night after night. Medium to high magnification.
This beauty is a morning object but well worth getting up early for. With a magnification from around 25x and above you will be able to detect the stunning ring system the planet is famous for. If the atmosphere is steady and you use a high enough magnification you can even see gaps in the rings such as the Cassini Division. Just like Jupiter, Saturn has a family of moons but fewer are visible with smaller telescopes. Medium to high magnification.
One of the most underrated stunners of the night sky is this multiple star system. It's found in the constellation Andromeda to the East of the famous Andromeda Galaxy. Through small telescopes the widest components can be seen as beautiful golden yellow and blue stars. Larger telescopes and good viewing conditions will reveal the blue star is actually another binary star. Medium to high magnification required and a large aperture telescope to reveal third star.
Perhaps the best of all the nearest major galaxies is the Andromeda Galaxy which lies a staggering 2.3 million light-years away. As its name suggests it is found in the constellation Andromeda on its western side, just off the north east corner of the Square of Pegasus. Keep magnification low for this object and larger aperture telescopes will reveal more detail. See if you can spot the satellite galaxies M32 and M110. Low magnification.
One of the real jewels of the sky is the Orion Nebula. Found just below the famous three star belt in Orion, the nebula is a vast stellar nursery. It can just be seen with the naked eye but binoculars or small telescope reveal it in its fully glory. Medium sized telescopes and modest magnifications will show the stars inside the nebula called the Trapezium. Don't expect to see it in all its colourful glory like the pictures. Cameras are more sensitive to color in low light levels than the human eye so it will only appear as grey/green. Low to medium magnifications.
Perseus Double Cluster
This is a great target for smaller telescopes, which will often give a nice wide field of view on the sky. The Perseus Double Cluster is, as its name suggests, a couple of star clusters around 7,000 light-years away. A wide field of view is the best way to see the two clusters so low power eyepieces are essential. There are around 200 stars in each of the clusters that are separated by just a few hundred light years. Low magnification.
Found in Pegasus over in the western sky in winter evenings, this is amongst the best of the globular clusters in the sky. Its quite easy to spot. Just off to the north west of the orange star Enif. Small telescopes will show it only as a fuzzy blob but telescopes of at least 15cm aperture are needed to reveal individual stars. Medium to high magnification.
Probably the finest open cluster in the sky, the Pleiades or Seven Sisters can be seen with the naked eye to the north west of Taurus the bull. This is a great example of how high magnification isn't always necessary in fact low magnification is essential to see this cluster at its best.
Credit: Ian O'Neill
Take a break from night time observing and have a peek at the sun. Do not use your telescope to look directly at the sun! It's far too bright and will result in blindness. Instead, cut a disk out of thick card no larger than about 75cm and place the card with a small hole cut out over the sunward end of the telescope. You can now use this slightly modified telescope to point at the sun and project an image through the eyepiece and onto another piece of card held about a foot away. Don't leave the telescope pointed at the sun for long periods as I have seen the glue inside eyepieces start to melt, so use great caution when studying the sun. Make sure have also put lens caps on your finder telescopes so you don't accidentally get a glimpse of the magnified sun. Experiment with magnifications from low to high.
Were you lucky enough to get a new telescope for Christmas? If so, I'm guessing that if you're reading this then you may be getting annoyed that you can't see anything through it or you may still have to unwrap the thing, daunted by the astronomical learning curve that lies ahead.
Using a telescope for the first time isn't always as easy as it sounds, but fear not! This Discovery News "Telescope Primer" will get you started so you can not only enjoy 'first light,' but also get your new 'scope ready for searching out countless wonders in the night sky.
First things first, what kind of telescope is it? Take a look down the open end and you will either see 1) a lens, 2) a lens and a mirror or, 3) just a mirror. If it's either of the first two then you can skip the next bit.
If you have a telescope with just mirrors (3) then you have a reflecting telescope and you will need to check its collimation! Oh no! I hear you cry. But don't panic! It's not as scary as it sounds; collimation just means you need to check the mirrors to see if they are all aligned properly. If they are not then you will not get the best image.
Rough collimation can be done during the day but more accurate alignment needs to be done with a star. Details of performing collimation are quite lengthy but I have a good description on my website so head over there to check yours.
Assuming you have now collimated your reflecting telescope then the rest is now the same whatever telescope you have.
Stay Focused and Centered
The next thing you need to do is get the focus in roughly the right place. If you fail to do this, it becomes a "chicken and egg situation": you can't focus on a star at night because you cannot find one and you cannot find one because you are out of focus! Take your telescope out during the day and point it at a tree or chimney a long way off in the distance; the further the better.
Now place a low-power eyepiece in the telescope and adjust the focus until it is nice and sharp. Re-center the object in the eyepiece and now take a look through the finder telescope (the small telescope on the side). You will probably notice that the object you were looking at through the main telescope is not in the center of the telescope. Adjust the screw on the side of the finder telescope to bring the object in the center. You are aiming to have it simultaneously in the center of the main telescope and the finder telescope. Doing this will greatly aide finding things at night.
Now that you are roughly focused, and your finder telescope is aligned, you are ready to wait until nightfall.
If you can, it is best to leave your telescope outside as night falls so it cools down with the dropping air temperature, this prevents condensation (dew) forming on the optics.
Once night falls, it should simply be a case of lining up the finder telescope on your target and getting it nicely centered. A good tip here is to get down low and sight along the edge of the telescope tube to line up roughly. Then it should be visible within the finder telescope or at least, very close to it. Move it to the center and hey presto! you should have the target in the field of view of the main telescope.
If you have more than one eyepiece, try swapping for a higher power eyepiece. You will find the atmospheric conditions need to be pretty good for higher powered eyepieces so there will only be a few nights where you can use the higher power, and you will have to rely on low to medium power eyepieces for the other nights.
If you follow these simple steps then I guarantee you will not only be able to find objects in the night sky but line up your telescope to get a closer look. You will be amazed at the views that even a small beginners telescope will show you so get out there and enjoy the Cosmos.