Star Clusters

All stars are born in groups. The origin of these groups has long been a key question in astronomy, one that interests researchers in star formation, the interstellar medium, and cosmology. This volume summarizes current progress in the field, and includes contributions from both theorists and observers. Star clusters appear with a wide range of properties, and are born in a variety of physical conditions. Yet the key question remains: How do diffuse clouds of gas condense into the collections of luminous objects we call stars? This book will benefit graduate students, newcomers to the field, and also experienced scientists seeking a convenient reference.

Star clusters are at the heart of astronomy, being key objects for our understanding of stellar evolution and galactic structure. Observations with the Hubble Space Telescope and other modern equipment have revealed fascinating new facts about these galactic building blocks. This book provides two comprehensive and up-to-date, pedagogically designed reviews on star clusters by two well-known experts in the field. Bruce Carney presents our current knowledge of the relative and absolute ages of globular clusters and the chemical history of our Galaxy. Bill Harris addresses globular clusters in external galaxies and their use as tracers of galaxy formation and cosmic distance indicators. The book is written for graduate students as well as professionals in astronomy and astrophysics.

I have spent many wonderful nights observing at a variety of places around the world, but many of my fondest memories come from those made at the Custer Observatory in Southold on Long Island, where I grew up. I was only perhaps a dozen years old when I started out, and now more than three decades later I have logged millions of miles on the various telescopes there. Some of the best memories are of observing and discussing astronomical topics with the many really terrific people who make up Custer. It truly holds a special place in my heart. Star clusters were always among my favorite objects to observe and discuss there. This book is the result of the exposure to these objects, many of which I observed for the first time at Custer. The Custer Institute Observatory was founded in the 1920s by local resident Charles W. Elmer of Perkin-Elmer Corp. fame. The original crew met at his house in Cedar Beach a few miles down the road from the institute. In the 1930s the group built an observatory complete with Mr. Elmer’s donated 5” Alvan Clark refractor. Later the observatory expanded to include a 6” Clark refractor and other even larger instruments.

Star clusters are important to many areas of astronomy, and as the basic building blocks of galaxies, they can be used as key diagnostic tools within a wide range of disciplines in astrophysics. Star cluster populations are powerful tracers of the formation, assembly and evolutionary history of their parent galaxies. Although their importance has been recognised for decades, only in recent years has this area seen a major investment in time and effort. IAU Symposium 266 consolidates the expertise of leading researchers from a variety of topical subfields in astrophysics, to provide a comprehensive presentation of cutting-edge developments in theory, observations and simulations of star clusters and star cluster systems across a range of sizes and epochs. This volume gives an account of this forefront research, answering fundamental questions that will improve our understanding of numerous related issues and show how this field will take its next major step forward.

The emphasis in these proceedings of lAD Symposium No. 113, Dynafrri-,'!s of Star Clusters. and·.~.Le. mab rPIHlon for orZ'lnizinp: thE" symposium in the spring of 1984, was the rapid increase during the preceeding year in our understanding of core collapse. The last I.A.D. Symposium to discuss the dynamics of star clusters at length was No.69, Dynamics of Stellar Systems~ held in Besan~on in 1974. For a few years afterwards, globular clusters receiveu much attention due to the discovery of X-ray bursters and the mounting evidence that X-ray sources in globular clusters were formed in completely different ways than those within our galaxy. Globular clusters, which until this time had a reputation for sedate old age, turned out to lead violent private lives at high energies. However, in the early 80's globular clusters seemed to lose some of the glamor of the 70's. The grand speculations of heavy black holes lurking in their centers had to make way for a variety of observational evidence which indicated that the X-ray sources are low-mass close binaries instead. But, though dynamical fashion turned to heavy galac tic halos and so on, some of the unsolved theoretical problems regard ing the evolution of star clusters kept their fascination for a number of relatively isolated workers. After several years of inconspicuous labor, a number of preprints suddenly appeared in the spring of 1983 that studied the evolution of globular clusters after core collapse.

Nebulae, star clusters, and galaxies are outside our solar system. They belong to the 'deep sky' and lead the observer to great distances and at the same time the view goes far into the past. The light of the most distant galaxies took billions of years to reach us. No less fascinating is our home galaxy, the Milky Way, offering many bright nebulae and star clusters. The book covers three important topics related to deep-sky objects: history, astrophysics, and observation. When beginners observe an object visually, not knowing anything about it, they will only perceive a faint spot of light - nothing really exciting. So, to get the right 'cosmic' feeling, the view should be enriched with stories about the object's discovery, distance, physical nature, or evolution. Supplied with this kind of information, deep-sky observing becomes a fascinating activity - braving the cold and darkness. Over time, advanced fields such as observation techniques or astrophotography come into play. The book informs the reader about all these topics and offers a comprehensive collection of interesting targets.

Astronomy enthusiasts will all appreciate the detailed yet easily-assimilated description of star clusters, how they were formed as our Milky Way galaxy, how they evolved, and how they are classified. The latest research has revealed a vast amount of fascinating information about the clusters, along with some spectacular photographs. Modern commercially-made telescopes enable amateur astronomers to see a surprising amount of detail, and to record – using CCD cameras, video, webcams or even film – some remarkably beautiful and detailed images. Contained here also is detailed information on using refractors, reflectors, and, of course, Meade and Celestron’s ubiquitous range of computer-controlled SCT telescopes.

Amateur astronomers of all expertise from beginner to experienced will find this a thorough star cluster atlas perfect for easy use at the telescope or through binoculars. It enables practical observers to locate the approximate positions of objects in the sky, organized by constellation. This book was specifically designed as an atlas and written for easy use in field conditions. The maps are in black-and-white so that they can be read by the light of a red LED observer’s reading light. The clusters and their names/numbers are printed in bold black, against a “grayed-out” background of stars and constellation figures. To be used as a self-contained reference, the book provides the reader with detailed and up-to-date coverage of objects visible with small-, medium-, and large-aperture telescopes, and is equally useful for simple and computer-controlled telescopes. In practice, GO-TO telescopes can usually locate clusters accurately enough to be seen in a low-magnification eyepiece, but this of course first requires that the observer knows what is visible in the sky at a given time and from a given location, so as to input a locatable object. This is where "The Observer's Guide to Star Clusters" steps in as an essential aid to finding star clusters to observe and an essential piece of equipment for all amateur astronomers.