Astronomy

High-Energy Astronomy (Astronomy In Space)

We now discuss the techniques and instruments used by astronomers observing at wavelengths shortward of 91.2 nm. Temperatures in excess of 105K, or non-thermal mechanisms, are required if significant emission is to occur at these wavelengths, and thus we may consider ourselves dealing with high-energy astronomy. Extreme ultraviolet (100 —10nm), soft X-ray (10 —1nm), X-ray […]

Filed under: Astronomy | Comments Off on High-Energy Astronomy (Astronomy In Space)

Telescopes In Space (Astronomy In Space)

We have already emphasized, in the introduction to this chapter, the great value of launching telescopes into space. This section concentrates on the infrared, optical and ultraviolet wavebands. It is unlikely that radio telescopes will be placed in orbit in the near future, owing to the enormous size necessary for reasonable angular resolution, but several […]

Filed under: Astronomy | Comments Off on Telescopes In Space (Astronomy In Space)

Exploring The Solar System (Astronomy In Space)

The results of many of the space missions to the Moon and planets have already been detailed in the chapters on the Solar System. In the present section we outline some of the methods by which these results were obtained. The pattern of study of a planet by subsequent spacecraft generally parallels that applied to […]

Filed under: Astronomy | Comments Off on Exploring The Solar System (Astronomy In Space)

Space Travel And The Space Environment (Astronomy In Space)

The orbit of an artificial satellite about the Earth, or any other body, can be treated mathematically in exactly the same way as the motion of binary stars, or the planets. The orbit is an ellipse obeying Kepler’s laws. The period of a satellite grazing the Earth’s surface (if it were possible) is 84.3 minutes, […]

Filed under: Astronomy | Comments Off on Space Travel And The Space Environment (Astronomy In Space)

Introduction (Astronomy In Space)

The science of space astronomy is relatively young, and yet it has given astronomers some of the most exciting findings about our own Solar System and the high-energy Universe beyond. Were it not for the development of a camera that could be operated across 200 million km of interplanetary space we would know hardly anything […]

Filed under: Astronomy | Comments Off on Introduction (Astronomy In Space)

Observatories (Ground Based Astronomy)

Once the telescope has been acquired, it may well be necessary to construct a simple observatory or telescope housing. Telescopes are not elegant additions to domestic furnishings, and one with an. aperture above 150mm is likely to be awkward to manoeuvre. Local climatic conditions will to some extent dictate the type of observatory to be […]

Filed under: Astronomy | Comments Off on Observatories (Ground Based Astronomy)

Telescopes (Ground Based Astronomy)

The first decision must be: which type of telescope – reflector or refractor? The advantages and disadvantages can be summarized briefly as follows: Newtonian reflectors produce images that are free of chromatic aberration (false colour). They are relatively cheap, and it is fairly easy to re-align the optical system. Among the disadvantages are the need […]

Filed under: Astronomy | Comments Off on Telescopes (Ground Based Astronomy)

Binoculars (Ground Based Astronomy)

Binoculars can be used for everyday observing, such as sporting events and nature study, as well as astronomy. They are classified according to their magnification and the diameter of the objective. A 10 X 50 pair magnifies 10 times (100 areas) and has objective lenses 50mm in diameter; note, however, that in cheaper binoculars the […]

Filed under: Astronomy | Comments Off on Binoculars (Ground Based Astronomy)

Galactic Coordinates (Ground Based Astronomy)

Another coordinate system is sometimes preferred when astronomers are studying the structure of the Galaxy. This system uses the plane of the Galaxy as the reference plane and the centre of the Galaxy as the arbitrary reference point. The coordinates are both expressed in degrees. They are the GALACTIC LONGITUDE (1) and the GALATIC LATTITUDE […]

Filed under: Astronomy | Comments Off on Galactic Coordinates (Ground Based Astronomy)

Precession, Nutation And Aberration (Ground Based Astronomy)

The right ascension and declination are defined relative to the plane of the Earth’s equator and to the vernal equinox. Unfortunately, neither of these is fixed in the sky because of precession. The Earth is not quite spherical but is slightly oblate. Because of this, the gravitational force between the Earth and the Sun produces […]

Filed under: Astronomy | Comments Off on Precession, Nutation And Aberration (Ground Based Astronomy)

Categories

Links

Copyright © 2024 The Universe. All rights reserved.