: Patrick Moore
: The Amateur Astronomer
: Springer-Verlag
: 9781846282867
: 12
: CHF 48.60
:
: Astronomie: Allgemeines, Nachschlagewerke
: English
: 293
: Wasserzeichen/DRM
: PC/MAC/eReader/Tablet
: PDF

This 2000 Edition of Sir Patrick Moore's classic book has been completely revised in the light of changes in technology. Not only do these changes include commercially available astronomical telescopes and software, but also what we know and understand about the universe.

There are many new photographs and illustrations.

P cks a great deal of valuable information into appendices which make up almost half the book. These are hugely comprehensive and provide hints and tips, as well as data (year 2000 onwards) for pretty well every aspect of amateur astronomy.

This is probably the only book in which all this information is collected in one place.
Chapter 15
Variable Stars(p.139-140)

Fortunately for us, our Sun is a steady, well-behaved star. It may have periods of unusual activity, when its disk is disturbed by spot-groups and flares, but at least its output of energy does not alter greatly over the lapse of hundreds of centuries. Other suns are not so quiescent. Some of them vary in brightness from day to day, even from hour to hour, either regularly or in an erratic manner.

They swell and shrink, and their temperatures change with their fluctuations, so that any planet circling round them would be subject to most uncomfortable changes of climate. Variable stars are important both to the professional and to the amateur, and the owner of a small instrument can do useful work, particularly as his telescope need not be so perfect as that of the lunar or planetary observer (though, of course, the better the telescope the better the results).

It is true that the regular variables of short period have been closely studied at the great observatories, but there are other stars which seem to delight in springing surprises, so that they need constant watching. Variable stars are of many types, but it is not difficult to give a general classification. First there are the eclipsing binaries, such as Algol in Perseus,which are not true"variables" at all, even though they do seem to alter in brightness.

Perhaps the most important of the true short-period variables are the Cepheids, so named because the star Delta Cephei is the best-known member of the class; the periods range from a few days up to six or seven weeks. Of much shorter period are the RR Lyrae stars, whose periods range between 30 hours and less than 2 hours. Then there are the long-period variables, usually Red Giants of great size and comparatively low temperature,with periods ranging from 70 days to over 2 years. Irregular variables, as their name suggests, behave in an unpredictable manner. Lastly come the violently explosive"temporary stars" or novae. There are several variables which can be followed without any telescope at all.

The most famous of these is Betelgeux, the Red Giant in Orion. It belongs to the irregular class, though there is a very rough period of from 4 to 5 years, and it changes in brightness from magnitude 0 down to 1, so that whereas it may sometimes almost equal the glittering Rigel it may at others be comparable with Aldebaran, the"Eye of the Bull;". The alterations are slow, but they become noticeable over a week or two, and the beginner who estimates the magnitude of Betelgeux every few days will soon be able to detect the fluctuations.

However, most of the interesting variables cannot be followed without a telescope or at least binoculars, since when near minimum they are below naked-eye visibility. Before coming to the proper variables, it will be of interest to say something about the"fake variables", or eclipsing binaries. These might well have been described in the chapter dealing with double stars, but since they do seem to change in brilliancy they come under the scope of the variable star enthusiast. The best-known of these"fakes" is Algol, which lies in the constellation of Perseus and is shown in Map VII. In mythology, Perseus was the hero who slew the fearful Gorgon, Medusa, whose glance turned the hardiest onlooker to stone, and it is fitting that Algol should mark the Gorgon’s severed head.
Publisher’s Note5
Preface to the First Edition7
Preface to the Twelfth Edition9
Contents11
1 Astronomy as a Hobby14
2 The Unfolding Universe16
3 Telescopes and Observatories30
4 The Solar System44
5 The Sun54
6 The Moon64
7 Occultations and Eclipses80
8 Aurorae and the Zodiacal Light90
9 The Nearer Planets96
10 The Outer Planets106
11 Comets and Meteors118
12 The Stellar Sky132
13 The Nature of a Star140
14 Double Stars146
15 Variable Stars152
16 Star Clusters and Nebulae162
17 Galaxies172
18 Beginnings and Endings180
Appendicies182
1 Planetary Data182
2 Planetary Satellites of Magnitude 14.5 or Brighter183
3 Minor Planet Data184
4 Elongations and Transits of the Inferior Planets185
5 Map of Mars187
6 Jupiter: Transit Work189
7 Saturn: Intensity Estimates191
8 Forthcoming Eclipses192
9 The Limiting Lunar Detail Visible with Different Apertures193
10 The Lunar Maps194
11 Some of the More Important Annual Meteor Showers206
12 The Constellations207
13 Proper Names of Stars210
14 Stars of the First Magnitude217
15 Standard Stars for Each Magnitude218
16 The Greek Alphabet220
17 Stellar Spectra221
18 Limiting Magnitudes and Separations for Various Apertures222
19 Angular Measure223
20 Test Double Stars224
21 Extinction225
22 Bright Novae226
23 Messier’s Catalogue228
24 The Caldwell Catalogue231
25 The Star Maps234
Map235
Map I. Key Map: Ursa Major ( The Great Bear)235
Map II. Key Map: Orion237
Map III. Ursa Major, Ursa Minor, Draco, Cepheus, Camelopardus239
Map IV. Orion, Lepus, Eridanus, Taurus, Cetus, Auriga, Columba, Caelum, Fornax242
Map V. Gemini, Cancer, Canis Major, Canis Minor, Monoceros, Hydra246
Map VI. Leo, Virgo, Coma Berenices, Corvus, Crater, Leo Minor250
Map VII. Cassiopeia, Cepheus, Lacerta, Perseus, Andromeda, Lynx, Triangulum253
Map VIII. Cygnus, Lyra, Sagitta, Vulpecula, Delphinus, Equuleus, Capricornus, Aquila, Sagittarius, Scutum, Serpens, Aquarius256
Map IX. Boötes, Corona Borealis, Hercules, Serpens, Ophiuchus, Libra, Scorpio261
Map X. Pegasus, Andromeda, Pisces, Triangulum, Aries, Cetus, Aquarius, Sculptor, Pisces Australis265
Map XI. Key Map: Crux Australis ( The Southern Cross)268
Map XII. Key Map: Orion271
Map XIII. Crux, Centaurus, Lupus, Circinus, Triangulum Australe, Norma, Ara, Telescopium, Sagittarius, Corona Australis, Scorpio273
Map XIV. Carina, Vela, Puppis, Pyxis, Volans, Antila277
Map XV. Octans, Apus, Musca, Chamaeleon, Mensa, Hydrus, Reticulum, Dorado, Pictor, Eridanus, Horologium280
Map XVI. Pavo, Indus, Tucana, Grus, Phoenix, Microscopium283
26 The Observation of Variable Stars286
Binocular Variables289
Telescopic Variables293
27 Some Periodical Comets298
28 Amateur Observatories299
29 Astronomical Societies301
30 Bibliography302
Index304