6. Useful tables

6.1 Tables for the geographical latitude of all the larger metropolitan cities

In order to carry out the procedures for the adjustment of the telescope onto the celestial pole, the degrees of latitude of various metropolitan cities are given in the table below. If you wish to determine the geographical latitude of an observation site and its degree of latitude is not listed in the table, then first select a city, which is close to you. Then, for example, you can visit data bases or web pages in the internet, such as for instance www.heavens-above.com, or you can proceed in accordance with the following method:

Fig. 73: Schematic view of the coordinate system

6.1.1 Observers in the northern earth hemisphere (N):

If your observation site is further north than the specified city , add one degree of latitude for each 110Kms. If your observation place lies further south than the specified city, then you should subtract a degree of latitude for each 110km.

6.1.2 Observers in the southern earth hemisphere (S):

If your observation site is further north than the specified city is, subtract one degree for each110Kms. If your observation place lies further south than the specified city, then add a degree of latitude for each 110Kms.

6.2 Table of prominent stars

In the following you find a listing of bright of stars with their coordinates in RA and DEC, in addition the seasons of the northern hemisphere of the earth are shown, when these are particularly conspicuous in the night sky. This list will help you to find suitable guiding stars for the different seasons. If, for example, you are experiencing a high summer evening in the northern hemisphere, then Deneb in the constellation of the Swan would offer itself as an excellent guiding star. Betelgeuse is not suitable in this case as guiding star, because it belongs to the winter constellation of Orion and at this time is below the horizon.

6.3 Distances in the universe

In the universe there are infinite distances! Storytellers of well-known science fiction series already know that. Others will find it impossible to imagine just how far “far” actually is. With a quick overview we would like to give an impression of the distances involved in the universe.

Measurable in Kilometres (Kms): The distance between the Earth and the Moon amounts to about the same distance that a good car would cover in its very intensive lifetime , i.e. on average 383,000 km.

Measurable in astronomical units (AU): The distance from the earth to the sun amounts to a AU, one “astronomical unit “. These are 149 million Kms. The AU serves particularly as the unit for distances within the solar system. The last planet of our solar system Pluto is about 40 AU from us.

Measurable in light years (ly): One light-year is the distance that light travels in one year in the vacuum of the universe. That is 9.46 x 1015 m = 9.460.000.000.000 (9.46 trillion) Kms. Or 63,490 AU. We now leave our solar system and look at the nearest star Alpha Centauri which can only be seen from the Southern Hemisphere. This is 4.3 light-years distant from us. This distance is so enormous that, in a model, in which the earth would be 25mm from the sun, the distance to the next star would amount to over 6,5km!

Distances in the galaxy