by Alain Dussault
These pages are an adaptation to the Internet, of a serie of ten courses, I have given in my area. Except for the Planisphere chapter, you will not find any images or photos here. Instead I have suggest a lot of pertinent links, according to the subject treated, where you would get them. If you are new to astronomy, and will like to get a feeling to how easy it is then follow me up and read every chapter.
Astronomy is a scientific hobby. As all technical pastime, astronomy used it's own vocabulary and it's definitions. We will define or explain certain of these terms in the following chapters.
1- The Planispheres. We will learn how to use it in the next chapter.
2- Binoculars. If we have some. We will look at them in the fourth chapter.
3- If you own a tripod for photography, it will be very useful for observing
with binoculars.
4- If you want to go a step further, a Sky Atlas and a telescope.
For observing, we practice this hobby outside, when the sky is clear and inside when it is cloudy. Outside we use our eyes, binoculars or a telescope for viewing the sky. Inside we use a computer with specific softwares or do research on the internet.
As you are already on the internet, reading this, you will find Web interesting sites which will cover different aspects of astronomy. As in the course of these chapters on the Initiation to astronomy, I will refer to you many appropriate sites which will be concerned with the subjects.
To begin with, here are some web basic pages:
On the history of astronomy:
http://www.astro.uni-bonn.de/~pbrosche/astoria.html
http://www.astro.uni-bonn.de/~pbrosche/hist_astr/ha_general.html
For more informations on articles on amateur astronomy for beginners, many of which will be covered here:
In the following chapters, others sites will be given.
There are many things that we can do to learn astronomy, with a computer. There are many softwares which are either freeware or at affordable prices, like the shareware. We will see them in the fifth chapter.
We will together learn to read the Sky, in looking at it with new eyes, and also using binoculars. Astronomy will be demanding, at beginning. Patience and perseverance will be required.
In your first tries, in the visual observation, the deep sky objects, that I will suggest to you, and the way to find them, will seem difficult at first. Although they will be easy objects to locate. Naturally, the Moon is easy to see. Certain important planets, like Jupiter, Mars, Venus and Saturn, when they are visibles, appear to the naked eye as very brilliant stars, so easy to locate.
A star twinkle because the light it emit is affected by atmospheric perturbations. The planet twinkle much less because it reflect the light received from the Sun in a larger light ray, which is less affected by atmospheric perturbations. So, in looking at what we thing is a star, for a little while, if we observe that the light do not twinkle or just a little, it is a planet. Also, generally, a planet look like the most brilliant star, and become visible before the others. If we observe a planet with binoculars, in certain case, like Jupiter, we distinguish a dish. A star even at great magnification look always as a point of light.
Concerning the lights from your neighbours, you must learn to live with. Or try to persuade them to shut them when it is a proper night for observation. The best way to do that is to invite them to share your experiences.
Even if the eye pupil adapt rather rapidly to the dark, the eye retina will demand an adaptation which will take 20 to 40 minutes, to allow the chemical products to get use to darkness. If after the required adaptation to darkness, you look at a bright object, like the Moon, the period of adaptation of the eye will have to be redone again.
It is the same thing for binoculars or a telescope. These instruments need also an acclimatation time with the external temperature. This time is more or lest longer, depending of the differential of temperature between the place where the instrument is store and the outside temperature. In winter, it take more time than in summer. It is preferable to keep its instrument outside, in a shed, or get it outside at least one hour in advance, before using it.
As in practicing this hobby, we do not move much, it is very important to dress more warmly than usual for the same temperature. You need also to wear warmer boots or shoes.
Another site is about mythology and folklore of the constellations at:
http://www.hawastsoc.org/deepsky/
There is approximately 2600 visible stars to the naked eye in the northern sky. Ancients people have regroup them by imaginative lines, that we called constellations, and have attribute to them names according to what they saw, be it a human figure, an animal or an object. Theses names come mostly from the greek mythology.
We count today 88 constellations. These constellations are divided in austral, equatorial or boreal constellations. We have access in the North hemisphere to the boreals and equatorial constellations.
Learning to recognize the principals constellations, in the sky, is the inevitable basic to properly orient ourself and, from there be able to find interesting objects.
We will begin by the constellations that are always visibles in the northern hemisphere, that is the circumpolar constellations. They are Ursa Major, Ursa Minor, Draco, Camelopardis, Cassiopeia, Lynx and Cepheus.
I give here only the Latin names because those are the ones used mostly in the specialized magazine like Sky & telescopes.
I will often refer to Messier objects. Messier was a French astronomer of the 1800 century, who was searching
for comets. In his search, he came upon objects, which at first sight, looks like comets, but were not. Each time
he sweep the sky, at the same places, the same objects came in his sight. To avoid confounding them again, he took
notes of them in a small booklet. This has become with the passing years the Messier catalog. This catalog is the
starting point for all amateurs astronomers. It contains 110 objects, the majority of them, visible in binoculars.
You will recognized them on sky charts by the capital letter M followed by a number, like M45or M-45.
There are two exceptions, M40, which is a double star, and M73, a 4 stars group which look nebulous in poor quality telescope, like those in the epoch of Messier.
A best site for the Messier catalog is:
http://seds.lpl.arizona.edu/messier/Messier.html
There you can print a poster of the different Messier objects. The photos provided where taken by large instruments or CCD. Do not expect to see them like that in binoculars or small telescope.
There is only one easy object for binoculars and for those with good eyes in Ursa Major, it is the double stars Mizar and Alcor. These stars mark the fold in the handle of the pan.
Of a similar form as Ursa Major, but inverse, at the end of its tail, we found the Pole star. This constellation do not contain any object accessible to binoculars.
The Pole star indicate approximately the North pole. This star is about 0.8 degree from the celestial north pole. It is its great quality and interest.
There is no visible object for binoculars in this constellation. Only 4 of its 12 stars are bright enough to help the observer.
Cassiopeia is locate opposite of Ursa Major. It is easy to find by it's form like a big W or M, depending of the season we are.
The Cassiopeia region is rich in observable objects for binoculars and telescope. This constellation contains two Messier objects. They are M52 and M103, both open clusters.
Next chapter, Planisphere and search by Star Hopping
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Last update February 2nd 2008
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