How to use the telescope is one of the fundamental aspects for those who want to approach the amateur observation of the cosmos, or for those who are already passionate about the observation of celestial bodies. Have you also decided to buy a telescope, or do you want advice on how to organize your observing evening? We provide you with a general overview on how to use the telescope, starting from the main models and then moving on to the pre-observation and observation phase.
Preliminary to a purchase of a telescope is the knowledge of the various types of telescopes. There are three main types:
Reflectors – they only use mirrors.
ADVANTAGES: ease of use; fast acclimatization, high image quality.
DISADVANTAGES: more frequent collimations; lack of pursuit; unsuitable for astrophotography.
Refractors – use only lenses.
ADVANTAGES: ideal for astrophotography; ease of use; high image quality.
DISADVANTAGES: higher price compared to the opening dimensions; small opening; false colors.
Catadioptrists – use mirrors and lenses. For this reason they are a “hybrid” form between reflectors and refractors.
Another aspect to consider when buying a telescope is the mount that can be of two types:
Equatorial: type of mount that allows you to follow a celestial body in the sky.
Altazimuth: gives the possibility to follow parallel movements (Azimuth) and perpendicular to the horizon (height).
After having planned the observing evening in advance of the beginning of the astronomical night, to use the telescope in the best way, you must first acclimatize the instrument. When we transport a telescope from one place to another, the optics need some time to adapt to the outside temperature.
Collimation is the preliminary step to get the best possible image quality and to use the telescope in the best way. It means aligning the mirrors and the lenses of the instrument along a common optical axis. To correctly align a Newtonian reflector, follow these steps:
The “star-hopping” method. Is the method that allows you to identify stars, celestial objects starting from a brighter star and moving with the seeker following a trace of weaker stars, until you reach the desired object.
Given the light of inhabited places, observing the objects of the deep sky from the courtyard or home is not always possible. The most easily identifiable objects with a medium-sized telescope are: the Moon, the planets and some double stars, planetary and emission nebulae, globular clusters. We must know well what to look for and in this case we can orient ourselves with the Moon, thus printing celestial papers to identify the position of stars and planets.