Q & A - For The Beginners

What is collimation?

Collimation is lining up the optical components in their appropriate position. If the collimation is off the image quality will suffer. Newtonian, Schmidt-Cassegrain, and refractors all need collimation, but they all have different optical components that need different types of adjusting.

What is the M in M42, M101, M82, etc?

The 'M' stands for Messier after the name of French astronomer Charles Messier. Messier cataloged objects in the sky that resembled comets, but were not comets. Messier's first edition covered 45 objects, M1-M45, but his total list contained 103 objects. Other astronomers continued the catalogue. All of the Messier objects were seen in the northern hemisphere from the north celestial pole to the celestial latitude of about -35.7°. Because of the time period these objects were discovered they are all possible to find in small telescopes.

What is NGC?

NGC stands for New General Catalogue, which consists of nebula and clusters of stars. NGC contains 7,840 objects. The catalogue was compiled in the 1880's by J.L.E. Dreyer using observations from William Herschel and his son John, among others. The NGC catalogue was published in 1888, and was later expanded with two Index Catalogues (known as IC I in 1896 & IC II in 1905) which added another 5,386 objects. Most of the later discoveries had been made possible due to photography which helps by taking a long exposure to allow more light than what our eyes can see, making even the dimmest faintest fuzzy object appear brighter than you could see looking through the eyepiece of a telescope.

How do you determine eyepiece magnification?

Magnification is determined by the focal length of your telescope and the focal length of an eyepiece. Focal length of telescope ÷ Focal length of eyepiece = Magnification. The best way to explain it is a quick example:

My telescope has a focal length of 1,000. Let's say I use a 32mm eyepiece.
1000÷32=31.25

The 'mm' of your eyepiece is the focal length of it. Let's try again with a 6mm eyepiece on the same telescope:

1000÷6=166.6666667

How long is a lightyear?

For starters a light-year is a measure of distance, not time. A light-year is determined by how long of a distance light traveled in one years time. The distance can be calculated by starting with the speed of light in a vacuum, since space is a vacuum. Inside a vacuum the speed of light is 3×10^8 m/s. Multiply that value with the number of seconds in a year and we'll get our answer.

There are 60 seconds in a minute, and 60 minutes in an hour. There is 24 hours in a day and roughly 365.25 days in a year, which is why we have leap year.
60secons x 60 minutes x 24 hours x 365.25 days = 31,557,600. Meaning there is 31,557,600 seconds in a year. Multiply this value with the speed of light in a vacuum we get 9,467,280,000,000,000 miles (9,467,280,000,000km).

What is waxing and waning?

Waxing and Waning are phases of the moon. When the shadow on the moon recedes, it is waxing. When the shadow of the moon advances, it is waning.
Waxing = surface glow of the moon growing larger
Waning = surface glow of the moon growing smaller

How do I check light pollution for my area?

This map here the data was collected during a time when there was a good deal of snow cover on the country – Dark Sky Finder
This map's data was collecting during a time when there was little to no snow cover on the country – Google Maps Light Pollution Overlay

To determine was each color means I listed them below:
White – Too much light pollution, even constellations are drowned out by the city lights. Limiting magnitude of 3-4
Red – Sky is gray along the horizon, milkyway hard to see, if at all. Limiting magnitude 5-5.5
Orange – Milkyway washed out when looking straight above, clouds are brighter than the sky. Limiting magnitude 5.6-5.9
Yellow – Washed out milkyway toward horizon, zodiacal light hard to see. Limiting magnitude 5.9-6.2
Green – Zodiacal light can be seen on a clear night. Dark lane structure visible in milkyway. Limiting magnitude 6.2-6.5
Blue – Globular cluster M15 can be seen with the naked eye. Milkyway shows a bulge into Ophiuchus. Limiting magnitude 6.6-7
Grey – Faint shadows cast by milkyway visible on white objects. Clouds are black holes in the sky. Limiting magnitude 7.1-7.5
Black – Rising milkyway causes some into thinking it's dawn. Limiting magnitude 7.6-8.

Note: Above limiting magnitudes are based on naked eye viewing, NOT through a telescope.

What are the different types of telescopes?

Refracting telescopes – Refracting telescopes us an objective lens and an eyepiece to gather more light than the human eye could collect on it's own. They refract or bend light causing parallel light rays to converge at a focal point.
Reflecting telescopes – Using a single or combination of curved mirros that reflect light and form an image. It uses a large ground mirror and a small diagonal mirror to reflect the light into an eyepiece. Reflecting telescopes are also known as Newtonian telescopes due to Isaac Newtan building the first reflecting telescope in 1668.
Catadioptric telescopes – combine reflection and refraction via lens and curved mirrors.

What are the different mounts?

Altazimuth Mount – also known as alt-az. This mount allows the telescope to move in altitude, up and down, and azimuth, side to side.
Equitorial Mount – Has a rotational axis parallel to the Earth's axis of rotation. This allows the telescope to stay fixed on an object in the sky. Equitorial mounts are fixed with ascension and declination and usually have setting circles which allow you to manually aim at a coordinate to get it in view; as long as the telescope is properly aligned to the polar axis of Earth.
Dobsonian Mount – Is an altazimuth design, and is one of the simplest versions of it. The telescope is on a rocker box that pivots in a circle on it's base.
German Equitorial Mount – Consists of a T-shaped mechanism where the lower bar is the right ascension axis and the upper bar is the declination axis. This style mount can have a clock drive (motor drive) added to one or both axis, or you can use slow motion cable to control it (a turning knob). These mounts are great for astrophotography, although they can have you contorting your body in some uncomfortable positions when viewing through the eyepiece.
English Fork Mount – Frame shaped like a tuning fork. Right ascension axis bearings at the top and the bottom with the declination axis at it's midpoint.
Open Fork Mount – It resembles the altazimuth but the azimuth axis is tilted and lines up to match the Earths rotation axis with a device called a wedge.

What can I expect to see with my telescope?

It really depends on many things; your telescope, eyepieces, light pollution, focal length, etc. One thing to keep in mind is that nothing you view through your telescope will look like anything the Hubble has taken images of. There isn't much, if any, color in nebula; that is all done through long exposure photography and photo editing programs. Galaxies will appear as faint fuzzy objects that might make you think you have a smudge on your eyepiece. Nebula are a bit more defined than a galaxy through your eyepiece but may still only look like faint fuzzy smudges. Don't let it deter you from getting into the hobby, seeing with your own eyes is more amazing than any photograph. That's not just my opinion, but many other amateur astronomer's opinions also.
If you are having a hard time getting objects into focus, or even in view, check to make sure you aren't in a highly light polluted area, and if you are move to a dark sky location for viewing. Going from light pollution to a dark sky area will make quite a difference in what you see through your telescope.

Any tips or tricks you know of to make my viewing better?

Practice! Believe it or not it's almost like you have to train your eyes to see what's up there. Through more time spent viewing the easier it'll be to spot some of the faintest fuzzies up there that your telescope is capable of viewing.
I also recommend that you let your eyes adapt to the darkness before you start surfing the skies. Give your eyes at least 15-20 minutes outside away from lights to adjust to the darkness. It will make the light gathered by your telescope a bit brighter and defined if your eyes are used to the dark. Think of it being in a dark room then walking into a well lit room, and how much brighter that lit room is when your eyes were used to the dark.
If you are in an area that is dark enough for seeing constellations and for using your telescope but you have a pesky street light shining at you, try using something like a dark cloth to block out all surrounding light when viewing through your telescope. Kind of like photographers used to use (the little “blanket” that they put their head into to view through the cameras eyepiece.

Why are things upside down when I look at them through the telescope?

In space there is no up, down, left, or right, so technically nothing is upside down.
Eyepieces for telescopes lack the corrector lens that flip the image to be right side up. The reason for this is, because the more glass used the less light that reaches your eyes. In astronomy the more light you can collect with your telescope the better the image you will see.

Comments