Salt Lake Astronomical Society
Observing Tips
For a detailed list of things you can see on a particular day go to the space.com spacewatch sky calendar.
There are several useful observing tools and reference materials on Sky & Telescope magazine’s website:
Telescope Buying Guide
Before You Buy
- Read: Recommended magazines include Astronomy, an introductory-level publication, and Sky & Telescope. Both contain monthly star charts.
- Study: Find out more about the origins of the solar system or the distance between planets. "If that doesn't fire you up, you probably don't want a telescope," says Bob Tillotson of the Ogden Astronomical Society.
- Identify: Learn how to read a star chart and spot various objects in the sky. Sure, you know the Big and Little Dippers, but where's Vega or Antares? Visit. Hang out at a few star parties or visit astronomy club meetings. Both are good ways to increase knowledge of the sky and find out more about different types of telescopes. Some clubs even have telescope loan programs.
- Look: Start scanning the skies with a pair of binoculars, recommended by many experts as the best "first telescope."
When You Buy
- Make a selection: If you're interested in stargazing, you need an astronomical telescope. Terrestrial or spotting scopes are designed for looking at Earth-bound objects.
- Know the aperture: Get as wide an aperture, or opening, as you can afford. A 6- to 10-inch diameter is recommended. This measurement is the diameter of the primary mirror or lens, not the tube of the telescope.
- Know the mount: Make sure the telescope connects solidly with the tripod -- no wiggles or vibrations. The scope should scan steadily and smoothly.
- Know the type: Reflecting telescopes are good for beginners, particularly the simple Dobsonian style (named for inventor John Dobson, a monk). "Dobs" are easy to set up and provide quality optics and sturdy mounts.
- Watch the magnification: Steer clear of telescopes touting excessive magnification, such as 600 power. Astronomy buffs rarely use such high powers. The magnification of any scope can be changed by adding eyepieces.
- Consider the price: Expect to spend $400-$500 for a quality telescope. Most cheaper scopes don't give a budding Carl Sagan -- or an ordinary adult or child -- much to look at.
- Keep learning: Once you have a telescope, take it along and visit more star parties. Folks there can show you how to set up the scope and how to use it.
Questions About Telescopes & Equipment
A: No. Thousands of stars are visible to the naked eye. A small pair of binoculars will allow you to see many of the brightest nebulas, galaxies and star clusters. Fainter objects require a telescope. Constellations are too large to view with a telescope or binoculars and can best be viewed with the unaided eye.
A: That depends mostly on what type of objects you intend to observe as well as your budget. Refracting telescopes are good for observing the planets and moon, but are not as well suited as reflecting telescopes for viewing galaxies and nebulas. Reflecting telescopes can be significantly less expensive than refractors. Portability and accessories used must be considered as well.
Attending some star parties to get some comparisons before you purchase a telescope can help you make your decisions.
A: A trick question! Any telescope may have ANY power, depending upon the eyepiece used. A general rule of thumb is that one can use about 60 power for each inch of the diameter of the telescope mirror or lens (refractors can use higher power per inch than reflectors, due to their higher image quality). On a given night, the power that can actually be used is mainly dependent upon the stability of the atmosphere (seeing). The power of a telescope may be computed with:
P = focal length of telescope / focal length of eyepiece
Questions About The Night Sky
A: Look for a modest star due north, about 40 degrees up off the horizon. It is the end of the handle in the Little Dipper (part of the constellation Ursa Minor).
A: The brightest star visible from earth (besides the sun) is Sirius, in the winter constellation Canis Major (Big dog).
A: Because of light pollution. Light pollution is the effect caused by outdoor lighting that puts light up into the sky where it scatters, making the sky brighter than stars and other astronomical objects. Getting away from city lights will allow you to see a much more pleasing view of the sky.
Strange & Unusual
A: Most of the time, a telescope is looking at a very small part of the sky. Amateur astronomers see many strange or unusual sights that to the average person would be called UFOs, but are actually satellites and explainable phenomena.
A: Stars are essentially a point of light – even with the largest telescopes. Turbulence in the atmosphere causes the point of light to jump around, causing the effect we call twinkling. Planets are not points of light and though their images distort, they rarely twinkle unless the atmosphere is very bad.
A: The turbulence in the atmosphere near the horizon causes stars to "twinkle" much more than if they are overhead. This may cause them to appear different colors.
Binocular Information
Checkout this : Binocular Astronomy Resource Page
Scan The Skies With Both Eyes
Binoculars may be the best way for beginners to canvas the cosmos. They are an easy and affordable way to start cruising the cosmos. Many experts recommend using binoculars before -- or instead of -- buying a telescope.
Consider these guidelines when choosing binoculars:
- Size: Binoculars come in all sorts of sizes, from pocket-size 10-by-20s to large 25-by-100s. The first number refers to magnification. For astronomy purposes, get at least 7 power. Remember, the larger the number, the smaller your field of view (because of the enlargement). Binoculars with more than 12 power are too hard to hold steady, unless a tripod is used. The second number refers to the diameter of the lens opening. The larger the opening, the better the light-gathering ability. A good all-purpose pair of binoculars is 7-by-50 or 7-by-60.
- Mount: A way to hold binoculars steady is a must. Tripods are available with special adapters for binoculars; a good one is $50-$60. Or try using a sack of flour -- or anything firm but moldable -- to set on your car roof or other surface and rest the binoculars on it. Leaning your elbows on a hard surface and holding the binoculars won't be stable enough.
- Portability: A 7-by-50 or 7-by-60 pair of binoculars is easily transportable and can be used for purposes other than astronomy, such as sporting events or hiking. If you get too large a pair, they might be too big and heavy to lug around.
- Price: You can buy good quality binoculars for $100-$150. Avoid cheap off brands; many well-known camera manufacturers also make binoculars.
- Practice: It may take a few tries to get the hang of finding things in the sky. Start by fixing your eyes on the moon, then raise the binoculars to the fixed position of your gaze.
- Get Informed: Find out more with a book that focuses on binocular astronomy, or look through astronomy magazines or Web sites.
Sources: John Sohl, Ott Planetarium at Weber State University; Patrick Wiggins: NASA Solar System Ambassador