The Star Book: Stargazing throughout the seasons in the Northern Hemisphere. Peter Grego

      

       THE STAR BOOK STARGAZING THROUGHOUT THE SEASONS IN THE NORTHERN HEMISPHERE

       PETER GREGO

       Contents

       How to Use This Book

       Introduction

       Northern circumpolar constellations

       Northern winter stars (midnight, 1 January)

       Northern spring stars (midnight, 1 April)

       Northern summer stars (midnight, 1 July)

       Northern autumn (fall) stars (midnight, 1 October)

       Afterword: Light Pollution

       Glossary

       Picture Credits

       LOVED THIS BOOK?

       Copyright

       How to Use This Book

      The star charts in this book show all the naked-eye stars (down to magnitude +5) visible under dark skies from both the northern and southern hemispheres. If a bright star isn’t on the chart, it’s more than likely to be one of the five bright planets – Mercury, Venus, Mars, Jupiter or Saturn, each of which can grow bright enough to be visible from urban locations.

      Complete coverage of the Northern celestial sphere is given by the wide-angle star charts featured in this eBook. All of the Northern constellations are depicted, labelled in abbreviated form. Each chart overlaps slightly with its neighbours, enabling them to be referred to more easily. Identification of the constellation patterns is made easier with the inclusion of joining lines. On each chart we highlight several of the more prominent constellations, accompanied by a tour of their bright stars, multiple stars, variable stars and deep-sky objects of interest; some of these are naked eye objects, while others require binoculars or a telescope. Reference is sometimes made to smaller, easily recognized patterns of stars such as the ‘Keystone’ of Hercules and the ‘Plough’ in Ursa Major; known as asterisms, these patterns are a great help in locating individual constellations and objects.

      Instead of being an all-encompassing guide to the sky, our selective survey of the heavens serves as an ample taster for what the night skies have to offer the keen observer. If you like what you see, there are many avenues along which you can pursue your interest in astronomy to a greater depth.

      For practical purposes, the Northern hemisphere begins with a chart showing the circumpolar constellations, followed by four seasonal views representing the sky above the southern horizon at midnight local time on 1 January (northern winter, southern summer), 1 April (northern spring, southern autumn/fall), 1 July (northern summer, southern spring) and 1 October (northern autumn/fall, southern spring). Representative horizon lines have been selected; for the northern hemisphere these are London (52°N) and New York (39°N). The band of the Milky Way features on the charts, and so too does the line of the ecliptic, near to which the Moon and planets can always be found.

      The illustrations alongside each entry come from a variety of sources, but all of them are the work of amateur astronomers keen to capture the beauty of the night skies.

       Labelled hypothetical constellations, stars and deep-sky objects with explanatory key.

       Introduction

      This eBook will help you get to know the brighter stars and constellations visible throughout the year in the Northern Hemisphere. Some constellations cover a wide swathe of sky, while others are small enough to be easily obscured by the outstretched hand. Once the names and locations of the brighter stars and constellations are known, they can be used as pointers to less conspicuous celestial objects. This eBook also contains a taster of some of the brighter deep-sky treasures to be found in selected constellations – there are countless more celestial delights awaiting the eyes of the curious stargazer wishing to take their enjoyment of astronomy to the next level.

      Most northern constellations are as familiar to today’s stargazers as they were to the ancient Greeks.

       Orion and Taurus take centre stage. Imaged using an undriven digital compact camera, 15 second exposure. Overlay of Taurus from Bode’s Uranographia.

       Northern circumpolar constellations

      From northern temperate climes a number of large constellations — most of them easily identifiable – remain constantly above the horizon throughout the year as they wheel anticlockwise (counterclockwise) around the north celestial pole.

      Polaris, the tip of Ursa Minor’s tail, is conveniently located just one degree from the north celestial pole. The star is easily found by tracing a line from Merak and Dubhe in Ursa Major, two stars known as the Pointers. These two stars are part of the famous Plough, alternatively known as the Big Dipper or sometimes the Saucepan. One of the sky’s most easily identifiable asterisms, the Plough forms the tail and hindquarters of Ursa Major. At midnight during the autumn (fall) the Plough is at its lowest, scraping along the northern horizon, while it soars high overhead at springtime. On the other side of the north celestial pole can be found another prominent asterism, the W of Cassiopeia. The Plough and the W take turns throughout the year in gaining the high celestial ground.

      Much of the relatively star-sparse region between the Pointers and the W is filled by the large but ill-defined constellation of Camelopardalis, while another large, faint constellation, Lynx, borders Camelopardalis and Ursa Major. Somewhat easier to trace is the House asterism of Cepheus, which lies between Cassiopeia and the pole. Between Cepheus and the tail of Ursa Major, skirting around the edge of Ursa Minor, is the sprawling constellation of Draco, covering an area of more than a thousand square degrees. Despite being so large, Draco contains only a few reasonably bright stars ranging between the second and third magnitude.

      By way of contrast, on the other side of the celestial pole and nestled snugly between Cassiopeia and Auriga, lies beautiful Perseus. For the most part a circumpolar constellation from northern temperate regions, Perseus has a number of bright stars sprinkled along a section of the Milky Way and is one of the loveliest areas to scan with binoculars.