David Levy's Guide to Variable Stars / Edition 2

Paperback (Print)
Buy New
Buy New from BN.com
Used and New from Other Sellers
Used and New from Other Sellers
from $1.99
Usually ships in 1-2 business days
(Save 96%)
Other sellers (Paperback)
  • All (21) from $1.99   
  • New (9) from $3.94   
  • Used (12) from $1.99   


Found throughout the universe, variable stars are fascinating objects to observe. Their brightness changes over time and they can easily be seen with even the most basic equipment. David Levy explains how to begin electronic (or CCD) observing, as well as how to observe variable stars through a small telescope or binoculars. Featuring a section on Southern hemisphere stars, this book covers various types of objects that can be observed by amateur astronomers, including more exotic phenomena like gamma ray bursts, blazars, and polars. It will motivate anyone with even a basic interest in astronomy to begin observing variable stars.

David H. Levy is one of the most successful comet hunters in history. He has discovered twenty-one, eight of them using a telescope in his own backyard. With Eugene and Carolyn Shoemaker at the Palomar Observatory in California, Levy discovered Shoemaker-Levy 9, the comet that collided with Jupiter in 1994, and is currently involved with the Jarnac Comet Survey, based at the Jarnac Observatory in Vail, Arizona.

In addition to being the author or editor of 31 books and other products, David Levy is the Science Editor for Parade magazine and contributing editor for Sky and Telescope magazine and the Canadian periodical, SkyNews. Frequently interviewed in the media, he has given almost a thousand lectures and appeared on many television programs. His most recent CUP book is David Levy's Guide to Observing and Discovering Comets (Cambridge, 2003). First Edition Pb (1989) 0-521-62755-9

Read More Show Less

Editorial Reviews

From the Publisher
"One of the most successful comet discoverers in history, Levy has produced a very readable account of his fascination with comets...highly recommended to amateur astronomers and others wishing an introduction to the scientific process of discovery."

"...as a simple guide for the novice observer, this volume has no rival."

"...marvelous and enchanting book about amateur astronomers and variable stars."
Sky & Telescope

“Levy's fascination with these stars and his clear text and illustrations make this an excellent book for the beginning observer.”

‘A well-written guide, by one of this country's most enthusiatic amateur astronomers …’ Andrew Fraknoi, Mercury

‘If you think variable star observing is boring, this book will convince you otherwise. Most importantly, Observing Variable Stars will get you outside looking at the sky.’ Deep Sky

‘This new book is delightful … The work is well researched, thought out, and executed … For those of you who have not yet been introduced to variable stars, enjoy this introduction. For those already acquainted with ‘variables’, give yourself a few cloudy nights with this delightful book!’ The Strolling Astronomer

'… there is always the promise that the observer will make a truly important astronomical discovery. … this book provides all the necessary advice and instructions for the variable star novice … also offering some interesting reading for those already acquainted with this topic. … here is a real opportunity to leave your mark in the heavens.' Astronomy & Space

'This is by far the most accessible book for beginning variable star observers in print. Everything you need to know to get started in variable star observing is laid out in an easy to follow, logical progression. Levy describes things in a non technical manner that makes it understandable to everyone. More importantly, his enthusiasm for the subject is infectious and his personal stories and experience make the book that much more readable. …If you are just getting started, or contemplating observing variable stars, buy this book first. By the end you will be hooked … and well on you way to enjoying a hobby that will keep you busy and happy for years to come.' American Association of Variable Star Observers Bookstore

Read More Show Less

Product Details

  • ISBN-13: 9780521608602
  • Publisher: Cambridge University Press
  • Publication date: 12/15/2005
  • Edition description: 2ND
  • Edition number: 2
  • Pages: 276
  • Product dimensions: 6.85 (w) x 9.72 (h) x 0.59 (d)

Meet the Author

David Levy is one of the most successful comet discoverers in history, and the author or editor of 31 books and other products.
Read More Show Less

Read an Excerpt

Cambridge University Press
0521608600 - David Levy's Guide to Variable Stars - Second Edition - by David H. Levy



Beginning with the Big Dipper

The best way to get a good start on observing is to discover the stars for yourself. Becoming familiar with the sky - on your own terms - is an important first step toward useful observation.

We do need a place and time to start, so let's try your backyard, under an evening sky of late spring or early summer. High in the west will shine the seven bright stars of the Big Dipper, possibly the best known asterism, or group of stars, in the entire sky. Since Roman times they have been part of Ursa Major (UMa), the Great Bear. The Dipper's handle represents the tail of the Bear, while the feet and nose are shown by fainter stars to the south and west of the bowl (Fig. 1.1).

1.1 The Dipper as a road sign

Much as I have tried, I have never seen a bear in the region of Ursa Major, or a plough. The seven stars of the Big Dipper, however, are easy to spot. At any time of night and in any season of the year, the two stars at the end of the Dipper's bowl point towards Polaris, the North Star. All the stars in our sky, the Sun included, circle the celestial poles, and for our lifetimes Polaris will stay within a degree of the true North Celestial Pole. Polaris is the brightest star of another constellation, Ursa Minor or the Little Bear. This Little Dipper is bent back, resembling a spoon bent by a child. Except for Polaris itself and the two stars at the end of the bowl, the Little Dipper's stars are faint.

We can use the Big Dipper to locate several nearby constellations. In northern-hemisphere spring, try the handle, which curves, like an arc of a circle, to the southeast. Start by joining the stars of the handle with an imaginary curved line,

Figure 1.1. North circumpolar stars.

Image not available in HTML version

and "arc" to Arcturus, a bright yellow-orange star in the constellation of Bootes (Fig. ). Although this constellation is known mythologically as the Herdsman, it is easier to identify as a kite. Once you have seen Arcturus, why don't you keep your curved line moving in the same direction, for further along you will find Spica, a bright bluish star that is at the head of Virgo the Virgin. Next, draw a line from Gamma in the bowl through Eta, the end star of the handle, and continue across most of the summer sky towards Antares in Scorpius (Fig. ). If you join the the two inner stars of the bowl (Gamma and Delta Ursae Majoris) with a line that continues north, you will eventually reach the summer triangle of Vega, Deneb, and Altair (Fig. ).

In fall, join the two stars at the end of the handle, Eta and Zeta, and continue above the bowl to Capella (Fig. ). In late winter, when the Dipper is high in the sky, a line from Eta through Gamma will lead across the sky in the direction of Procyon. This brings us back to spring, when we also can use the Dipper in a different way. Fill the Dipper's bowl with water, and then poke some holes through the bottom. As the water gushes out, note who is sitting below, comfortably showering himself: it's Leo the Lion! The bright star at the foot of the backward question mark that forms Leo's head is called Regulus (Fig. ).

Figure 1.2. The sky, January to March.

Image not available in HTML version

1.2 Your own constellations

Thousands of years ago the Egyptians, Greeks, and Romans placed their heroes in the sky. These figures are still with us because they offer an easy and familiar way of finding our bearings. Before you learn the standard constellations, why not make some up for yourself? This way, you can become familiar with the sky on your own terms, requiring no textbooks or charts; at this stage you are better off without them. And what is most surprising of all, when you begin to learn the classical groups you may be surprised at how closely your personal circus resembles that of tradition.

Figure 1.3. The sky, April to June.

Image not available in HTML version

After a night or two of this you should be ready to begin your voyage to the constellations. You will now need a good star chart or atlas. Learning the sky by going from one constellation to another is a process that requires patience and will occupy the starlight nights of at least four seasons. The stars of spring with the Lion and the Crab give way as the year progresses to the Swan and the Harp of summer, and with the cooling air of autumn comes Pegasus, the mighty flying horse, and Andromeda, the princess in chains. Finally, the two hunting dogs of Orion romp through the snowy sky of winter. Then, on late winter nights you can look towards the east and see the

Figure 1.4. The sky, July to September.

Image not available in HTML version

spring stars on display once more as another orbit of your life comes full circle. As you proceed, you may find that learning the constellations is like making new friends who will be there to greet you on schedule at their appointed times.

1.3 Southern Cross

Just as the Big Dipper points the way to so many northern hemisphere constellations, Crux, the Southern Cross, guides you to constellations around

Figure 1.5. The sky, October to December.

Image not available in HTML version

the south pole. When it is high in the southern-hemisphere autumn sky, follow the short arm towards Centaurus, and the long arm toward the pole and its faint constellations of Musca and Octans. Canopus and the delights of Carina also grace the fall sky.

Figure 1.6. South circumpolar stars.

Image not available in HTML version

The southern sky is a busy place, with more bright stars than northern-hemisphere observers are used to. The Milky Way is magnificent, particularly in the southern part of Carina, where stars and clouds of gas combine to paint a pretty celestial picture. Our two nearest galaxies, the Large and Small Magellanic Clouds, are also visible only from southern latitudes, the Large Cloud in fall, the Small Cloud in spring.

If you have ever seen the constellation of Sagittarius on a July evening under a dark sky, you probably noticed the Milky Way in its background, bright as a cloud. From the southern hemisphere, Sagittarius is virtually overhead, shining so brightly I have seen it cast a shadow. The reason the Milky Way is so bright in that part of the sky is that Sagittarius marks the central hub of our Milky Way galaxy.


Magnitude, color, and distance

What is the first thing you notice about the stars? Quite likely, it is their differing brightnesses. Although this appears obvious, it is the single most important concept with which you should become familiar before you can be a variable-star observer.

2.1 Magnitude

Why do stars differ in brightness? Is it because they are at different distances from us, so that the farther stars appear fainter, like the glow from lamps at the far end of the street? Or are the stars themselves of different brightnesses? As you have likely guessed, both are correct. Sirius, a blue star off the southeast corner of Orion the Hunter, is normally the brightest star in the night sky, not so much because it is actually large and bright, but because it is close. At a mere 8 light years away, Sirius is one of our nearest neighbors. However, there exists a star only a little farther away; Wolf 359 is a "red dwarf " star whose intrinsic brightness is so low that it cannot be seen with the unaided eye. Famed in Star Trek legend as the site of a Borg battle, Wolf 359 is a red dwarf star. Meanwhile, the brightest star in Cygnus the Swan, Deneb, is well over 1000 light years away from us, and is one of the intrinsically brightest stars in the sky. S Doradus is even brighter, but it appears to us as a faint star because it is so far away, actually in a neighboring galaxy.

To reconcile these two factors, astronomers have created two independent systems of describing brightness or "magnitude." It is possible that the earliest magnitude scale dates back to the ancient Hebrew custom of locating three stars in a sky dark enough to be certain that the Sun has set, thereby confirming that the Sabbath or festival has ended. The brightest stars and planets, it was understood in those ancient times, could conceivably be viewed just before sunset, and waiting for the faintest stars to appear meant waiting too long. So a crude brightness scale was devised; when three stars of the middle brightness level were seen, that marked the end of Sabbath.

© Cambridge University Press
Read More Show Less

Table of Contents

Foreword to first edition; 1. Getting to know the sky; 2. Magnitude, color, and distance; 3. A word on binoculars and telescopes; 4. Learning to see; 5. Getting to know the variables; 6. Getting started with cepheids; 7. Algol, the demon of autumn; 8. How to estimate a variable; 9. Names and records; 10. How your observations help us understand a variable star; 11. Observing hints; 12. Observing with CCDs; 13. Stately and wonderful; 14. Stars of challenge; 15. Bright, easy, and interesting; 16. Betelgeuse: easy and hard; 17. Not too regular; 18. Nova? What nova?; 19. Supernovae; 20. Clyde Tombaugh's star and the family of cataclysmic variables; 21. A Nova in reverse?; 22. RU Lupi?; 23. Orion, the star factory; 24. Other variable things; 25. The Sun; 26. Suggested variables for observation throughout the year; 27. January, February, March; 28. April, May, June; 29. July, August, September; 30. October, November, December; 31. Southern Sky notes; 32. Stars and people; 33. Hands-on astrophysics for the next generation; 34. Going further; 35. Glossary and abbreviations.
Read More Show Less

Customer Reviews

Be the first to write a review
( 0 )
Rating Distribution

5 Star


4 Star


3 Star


2 Star


1 Star


Your Rating:

Your Name: Create a Pen Name or

Barnes & Noble.com Review Rules

Our reader reviews allow you to share your comments on titles you liked, or didn't, with others. By submitting an online review, you are representing to Barnes & Noble.com that all information contained in your review is original and accurate in all respects, and that the submission of such content by you and the posting of such content by Barnes & Noble.com does not and will not violate the rights of any third party. Please follow the rules below to help ensure that your review can be posted.

Reviews by Our Customers Under the Age of 13

We highly value and respect everyone's opinion concerning the titles we offer. However, we cannot allow persons under the age of 13 to have accounts at BN.com or to post customer reviews. Please see our Terms of Use for more details.

What to exclude from your review:

Please do not write about reviews, commentary, or information posted on the product page. If you see any errors in the information on the product page, please send us an email.

Reviews should not contain any of the following:

  • - HTML tags, profanity, obscenities, vulgarities, or comments that defame anyone
  • - Time-sensitive information such as tour dates, signings, lectures, etc.
  • - Single-word reviews. Other people will read your review to discover why you liked or didn't like the title. Be descriptive.
  • - Comments focusing on the author or that may ruin the ending for others
  • - Phone numbers, addresses, URLs
  • - Pricing and availability information or alternative ordering information
  • - Advertisements or commercial solicitation


  • - By submitting a review, you grant to Barnes & Noble.com and its sublicensees the royalty-free, perpetual, irrevocable right and license to use the review in accordance with the Barnes & Noble.com Terms of Use.
  • - Barnes & Noble.com reserves the right not to post any review -- particularly those that do not follow the terms and conditions of these Rules. Barnes & Noble.com also reserves the right to remove any review at any time without notice.
  • - See Terms of Use for other conditions and disclaimers.
Search for Products You'd Like to Recommend

Recommend other products that relate to your review. Just search for them below and share!

Create a Pen Name

Your Pen Name is your unique identity on BN.com. It will appear on the reviews you write and other website activities. Your Pen Name cannot be edited, changed or deleted once submitted.

Your Pen Name can be any combination of alphanumeric characters (plus - and _), and must be at least two characters long.

Continue Anonymously

    If you find inappropriate content, please report it to Barnes & Noble
    Why is this product inappropriate?
    Comments (optional)