Astronomy
 
 
Astronomy is perhaps the oldest known science that we Homo sapiens indulge in. We have always looked to the skies with wonder, amazement, and curiosity. Over thousands of years, different cultures have developed myths, legends, folklore's and superstitions from celestial objects. Now we peer at planets, stars, and galaxies with a variety of light detecting instruments to gather knowledge about our universe and our existence.

The intent of this page is to provide a basic outline of how to get started in astronomy. There are many aspects of the hobby and profession and as you begin to experience astronomy, you can decide which path(s) of astronomy you want to explore and the depth that you choose to pursue it. If you are a student in my physics class, during the course of the school year there will be interesting activities you can pursue for credit.
 

How do you get started in astronomy?           At what level would you like to practice astronomy?

Start with a lounge chair and your two eyes. On a clear dark night, lean back, relax and look at the stars. You will see bright stars, dim stars, white, bluish, orangish stars. Look for planets in our solar system. At different times of the evening and different times of the year you can easily see Mars, Venus, Jupiter and Saturn. Do this with a companion. Hint: At this point do not rush out and purchase a telescope, no matter the price. Even a good one is frustrating to use until you know your way around the dark sky.

Next get a star chart or planisphere, get comfortable in the lounge chair, and learn to identify various constellations and stars. A tip about the chart or planisphere - Looking at white dots (stars) on a black or blue background is difficult at night. I find it easier to have black dots on a white background. Use a red flashlight instead of a white light. The bright white light at night will cause you to temporarily loose your adaptation to night vision while glancing from the chart to the dark sky.
        Summertime: Start with the Big Dipper, the Little Dipper and the summer triangle. Add in Bootes, Cygnus, Draco, Hercules, Lyra, Sagittarius, and Scorpio  Identify the stars Polaris, Arcturus, Vega, Altair, Deneb, and Mizar (double star).
        Wintertime: Start with Orion, and Pleiades, these two will be the most recognizable. Add in Taurus, Gemini, Cancer, and Leo. Identify Polaris (again), Aldebaran, Belelgeuse, Rigel, Sirus, Pollux, Procyon, and Regulus. A couple of tantalizing extras  to locate are the Andromeda Galaxy and the Orion Nebula.
        Anytime: Check on the visible planets during your viewing session.
 
 

During your observation sessions concentrate on learning a  constellation and a couple of stars.  Learning really takes place if you sketch the constellation as you see it from the night sky. Also keep a log of your observing session no matter how short the session is. The log would include date, time, location, light pollution, sky and weather conditions and your sketches.

Nebulae, galaxies, comets, open clusters, globular clusters, double stars, variable stars, what are these things? Aren't stars just stars? These terms are applied to objects and a variety of groupings of stars that are enjoyable to observe with good binoculars or a good basic telescope. The Pleiades (M45) is a classic example of an open cluster of stars and  is easily visible to the naked eye. A nebula is a generalized term for a gaseous structure and nebula have several classifications. The Orion nebula (M42) is easily visible with good binoculars, it is a very hot star forming region.

M31, NGC 2451, Herschel objects ... What are these nomenclatures you see on star charts and planispheres? The "M" indicates a Messier object. Charles Messier (1730  to 1817) of France spent much of his time observing the night sky for comets. He produced a catalog that detailed 110 objects that are designated M1 to M110.  Another notable astronomer was Sir William Herschel, born in Germany in 1738 and died in England in 1822. He used a 48" reflecting telescope and tediously scanned and mapped the dark skies from England and his son John did the same from South Africa. John Herschel published "The General Catalog of Nebulae" that contains over 5000 objects, most of which were discovered by John and his father. Later this catalog was revised and renamed the New General Catalog.

Now it is time to become familiar with a few important astronomical terms. Start with these:
 
                                       declination                                             elliptical orbit
                                        light-year                                               magnitude
                                        right ascension                                      zenith

Binoculars should be your first device to observe objects in the celestial sphere. Many amateur astronomers specialize in only binocular usage. Almost every household will have one. I started with my great grandmother's opera binoculars. Yes, I could see stars and objects that I could not see with my unaided eyes. Grab it and your star chart and go to the lounge chair (on a clear dark night). With your binoculars you will be able to see more details of the moon, resolve a few double stars, see the Orion Nebula and see the faint, fuzzy outline of the Andromeda galaxy. 

If you are going to purchase binoculars for star gazing here are a few important items to look for. What do the numbers on the binocular mean?    7 X 35 or 10 X 42    The first number is the magnification and the second number is the diameter of the opening in millimeters. The larger the second number, the greater light gathering capabilities. Always purchase binoculars with fully multi-coated objectives. If the binoculars are of the prism type, go for the "BaK-4" type prism.

Larger more powerful (magnification and light gathering) binoculars are available for astronomical usage. My personal binocular for viewing the skies is the Celestron 20 X 80 Sky Master. This is a large, heavy binocular and a tripod is required for viewing. I can easily detect the rings of Saturn, Jupiter and four of it's moons, the Orion Nebula, Andromeda Galaxy, and numerous star clusters from my light polluted neighborhood with this unit. With a friend's 10 X 50 Bausch & Lomb binocular I could barely see one of Jupiter moons. Hint: Now think about that first telescope.

Telescopes come is a variety of sizes, shapes, designs and purposes. The cost can range from less than $100 to thousands of dollars. It can be a daunting task to decide how and what to buy. Do not purchase the cheap department store telescopes that advertises high magnification numbers. Yes, it might have that magnification but the optics will be very poor and the telescope may be  wobbly. These inexpensive telescope are very frustrating to use.

Before deciding on a telescope to purchase, think about what you want to observe the most. Planets? Variable Stars? Double Stars? Nebulae? Galaxies? Clusters? One of the most important factors of a telescope is the light gathering ability, not just the magnification. If it can't gather enough light for you to see the object, then you can't see it. The two fundamental types of telescopes are refractors and reflectors. The larger the mirror or the larger the lenses, the more light is gathered. The best place to seek information would be with the local astronomy club. Attend a star party and talk to the owners of the different types of 'scopes. Ask them what they like and don't like. Ask why they purchased a particular scope. Ask if you can look through their scope (Always ask first!). I have started out with a Celestron C-5 purchased used from a member of the astronomy club I belong to. The C5 is a small Schmidt-Cassegrain telescope but most importantly it has quality optics and includes the capability of tracking stars and doing a bit of astrophotography. Because of the size, this telescope is very easy to transport to dark viewing areas away from Houston. The 5 means it has a 5" primary mirror for light gathering. The Houston Astronomy Club that I belong to has a telescope loaner program. You can try out the different scopes and that really helps you decide what scope is best for you. Read this article, it provides an excellent insight for that first telescope purchase. Choosing Your First Telescope    

Links:

   16 Free courses on Astronomy and the Universe    
    Astronomy Picture of the Day - From NASA ... Pretty Cool Stuff!
 

    Astronomical League
    ClearDarkSky
    Constellation Guide - Facts and Myths about constellations    
    EarthSky

    George Observatory
    How to Choose Binoculars for Astronomy   and Skywatching      
    Hubble Telescope Site

    Lunar Reconnaissance Orbiter
    McDonald Observatory
    NASA
    NASA International Space Station
    NightSkyLive
    Sidewalk Astronomers
    Scale of the Universe   
  
Sky Maps - down load a free monthly star chart 

    Sky-Map
    SpaceWeather
    Space Weather Satellite Tracker
    Stellarium - Planetarium for your computer  
    The Sky Live    
    Uncle Al's Star Wheel - Download, Print, build it!    
    Whats Out Tonight