Competition

Huggins served two years as president of the Royal Astronomical Society, 1876-1878. The work that he would be best known for was behind him his collaboration with Miller who had died suddenly in 1870 exploring stellar spectra, his discovery of the emission spectra from planetary nebulae, and his bold application of theory to develop a method of measuring stellar motion in the line of sight. He had reached the pinnacle of his scientific career. Thanks in part to Margaret's assistance, Huggins...

Notes for chapter

H N Russell to H Shapley, 17 September 1920. Quoted in Smith (1982) p 89 2. Letter from H Shapley to J C Kapteyn, 6 February 1917. Quoted in Gingerich (1970) p 346 5. Quoted in DeVorkin (2000) p 104 8. Landi, 2001. Reference Archivist, University of Missouri-Columbia. Personal communication 9. Shapley (1969) p 24 10. Kopal (1981) p 261 13. See DeVorkin (2000) p 257, and references therein 14. Lorett Treese, Bryn Mawr College Archivist (2001). Personal communication 15. Matthews (2001). Personal...

Shapley to Harvard

The immediate outcome of the debate for Shapley was that he almost lost the Harvard job to his former teacher Russell. Russell himself was not eager to take on the administrative responsibilities that came with the directorship of Harvard College Observatory. His position at Princeton suited him very well, as he could leave the running of its small observatory to Dugan, and his teaching duties left him time to pursue his research. He warned Shapley that the Harvard job might cost him the...

Globular cluster distances

Omega Centauri, the Hercules cluster, M3 together with 47 Tucanae, visible from the southern hemisphere, these are three of the biggest, brightest, and most beautiful of the globular clusters. On dark, moonless nights, they are visible to the naked eye for northern hemisphere observers, M3 and the Hercules cluster are high in the sky on summer nights, while Omega Centauri, at a declination of about 47 , is visible to an observer at the latitude of Mount Wilson, in the spring, above the southern...

The galactic center

The very heart of the Milky Way, at the center of both the disk and bulge, is almost impossible to study in the visible wavelengths. Interest in this region has been high, however, since the 1950s. That's when astronomers found a strong, compact radio source in the direction of the constellation Sagittarius a radio signal not associated with any known star or stellar remnant. The source is known as Sagittarius A*, pronounced ''Ay-star.'' The unusual characteristics of Sagittarius A* have long...

Star streaming and the plan of selected areas

In their characteristically modest way, Kapteyn and his wife Elise set off by bicycle from their home near Groningen. (One must presume that they sent their luggage on ahead ) They caught a train, then boarded a ship in Rotterdam for their first trip to the United States. A few weeks later they arrived at the scene of unparalleled festivities. The focal point of the 1200-acre St. Louis Exhibition was Festival Hall, a temporary but extremely ornate building set behind an artificial lagoon and...

Jeans nebular theory

Sometime between May 1922 and April 1923, after his return from the IAU meeting in Rome and the publication of his classification system, Hubble must have studied the nebular theory developed earlier by Jeans at Cambridge, for the theory began to influence his research. Jeans began with the premise at the heart of Laplace's nebular hypothesis, that the solar system originated out of a rotating nebulous mass of gas, but he sought to apply this premise to the origin of the spiral nebulae, which...

The bulge

The boundary between the galaxy's disk, comprising the arms and inter-arm dust lanes, and the amorphous central bulge is a blurry one. Lacking a clear-cut transition or precise definition, astronomers commonly refer to the bulge as the luminous mound in the middle of a galaxy that would be left over if one subtracted the disk. In the case of the Milky Way, most of the light from the bulge is contained within a radius of about 1500 light-years from the galactic center. The bulge becomes...

Bessels influence

Struve accepted the faculty position at Dorpat, but arranged for a leave of absence in the summer of 1814 to return to Altona and see Figure 5.3 Friedrich Wilhelm Bessel (1784-1846). (Credit Institute of Astronomy, Cambridge, UK.) Figure 5.3 Friedrich Wilhelm Bessel (1784-1846). (Credit Institute of Astronomy, Cambridge, UK.) his family. On this long-awaited vacation, he met two people who would become very important to him Emilie Wall, the teenage daughter of family friends and his future...

Hertzsprung

Back in the Netherlands after his summers in the United States, Kapteyn discovered that his ties to Mount Wilson naturally made him the contact person of choice for northern European astronomers who dreamed of access to the world's largest telescope. Among these was Adriaan van Maanen, who later played a prominent, if not infamous, role in twentieth-century debates concerning island universes. Between 1908 and 1910, van Maanen, although enrolled as a student at the University of Utrecht,...

Sky surveys

According to Henrietta, an article Kapteyn read during one Christmas vacation changed the course of his professional life and provided his entree into a career of universe-charting in the tradition of William Herschel and Wilhelm Struve. The article, written by Kapteyn's acquaintance David Gill, described a new project to photograph the southern sky, frame by frame, to produce a catalog that would complement existing catalogs of the northern sky. David Gill, a Scotsman, had taken charge of...

Early interest in astronomy

Hubble (figure 9.1) was the second son and third of eight children born to John and Virginia Hubble. His father had attended law school, although without earning a degree, and had run a legal practice for a few years. During Hubble's childhood he worked for a number of insurance companies and was often away from Marshfield on business travel for weeks at a time. His children feared his return as much as they looked forward to it he was stern and religious, although if they behaved themselves,...

Astronomy and astrotheology

A number of Wright's ''schemes,'' as he called his illustrations, served as the basis for didactic works on astronomy, including The Universal Vicissitude of Seasons, articles about comets in the Gentleman's Magazine, and diagrams explaining the appearance of lunar and solar eclipses. These broadsides would have made impressive visual aids for a lecturer, and are works of art in their own right. In 1742, he finished a set of four plates, each 2 feet by 3 feet, illustrating a large number of...

Missouri childhood

Harlow Shapley (figure 8.1) and his fraternal twin brother Horace were born on 2 November 1885, on a farm near the small town of Nashville, Missouri. The family included an older sister, Lillian, and, later, a younger brother, John. Their father grew hay and occasionally taught school in Nashville. Their mother, a descendant of New England abolitionists, read to the children and encouraged them to ''amount to something, get somewhere, go Figure 8.1 Harlow Shapley (1885-1972). (Credit AIP Emilio...

Laplaces nebular hypothesis

Laplace independently developed a theory about the origin of the solar system that resembled Herschel's sketchy theory of nebular evolution. He first brought out his thesis in 1796, in his Exposition du Syst me du Monde (contemporaneous English translation The System of the World), a few years after Herschel's planetary nebula paper appeared. He enlarged on his theory in subsequent editions of his book, and it became widely known as ''Laplace's nebular hypothesis'' or ''nebular theory.''...

Margaret

Huggins' personal and professional life changed radically in the mid-1870s. Sometime in the early 1870s, probably in the home of mutual friends in London, he met Margaret Murray (figure 6.6). She had an interest in astronomy and an unusual and no doubt latent aptitude for laboratory work. He married her in Figure 6.6 Margaret Lindsay Murray Huggins (1848-1916). (Courtesy of Wellesley College Archives.) Figure 6.6 Margaret Lindsay Murray Huggins (1848-1916). (Courtesy of Wellesley College...

The big galaxy hypothesis

Sometime before November 1916, Shapley came up with a distance measurement that surprised him even more than the globular cluster distances had. Looking in the plane of the Milky Way or what Shapley called the galactic system in the direction of Scutum, near Sagittarius, he examined the stars of the open or galactic cluster known as M11. He found faint blue stars there, similar to the ones in the globular clusters. Applying the same techniques he had used on the globular clusters, he was forced...

Bessels heliometer

While Struve traveled and recovered from the loss of his brother and two children, his sympathetic friend Bessel enjoyed some productive years. Beginning in 1821, he had begun to compile a catalog of the tens of thousands of stars brighter than ninth magnitude, lying between declination 15 and +45 . He had continued to pursue sources of error in observing star positions, and had refined his studies of the rate of Earth's precession. As a foundation for his own and others' future work on...

A return to classification

In other papers published in the 1920s, Hubble solidified the case for extra-galactic nebulae as stellar systems comparable to, or somewhat smaller than, the Milky Way, lying at distances measured in millions of light-years. He enlarged the number of known Cepheids and novae in these remote systems and, as the data accumulated, he repeatedly pointed to what he called the principle of the uniformity of nature. The period-luminosity relation for Cepheids ''functioned normally'' in the ever more...

Visionary Of Stellar Systems

''Who in England is so peculiar as to be bothered by the apparent irregularity of the Milky Way '' Abraham Gotthelf Kaestner, unsympathetic reviewer of Wright's book, An Original Theory or New Hypothesis of the Universe, 17521 On a damp and windy night in September 1729, around the time of his eighteenth birthday, Thomas Wright ran away from his first job as an apprentice. Scandalous rumors about his involvement with a young woman buzzed about the northern English town of Bishop Auckland....

The Milky Way Revealed

Four Arm Spiral

''What we know is little, what we do not know is immense.'' The Andromeda galaxy, which we perceive with our unaided eyes only as a faint oval nebula, is both neighbor and kin to our home galaxy, the Milky Way. Viewed with binoculars or a small telescope, the Andromeda galaxy distinguishes itself from the foreground stars of our own galaxy as a glowing ball of light encircled by a wide, thin disk. The light from the disk shines feebly compared to that from the central part of the Galaxy the...

The dimensions of the Milky Way galaxy

Milky Way Bulge Size

In 1930, when Lick Observatory astronomer Robert Trumpler proved that obscuring dust particles are widespread in the interstellar medium, our gauges of galactic dimensions began to attain modern standards of accuracy. Previously (as we saw in chapters 7, 8, and 9), estimates of stellar distances based on apparent brightness tended to run too high, because the unsuspected dust dimmed the visible light reaching us from the stars. Accounting for dust allowed astronomers to correct the scales of...

The beginnings of spectroscopy

Kirchhoff and Bunsen began publishing accounts of their epoch-making experiments in 1859. The experiments consisted of vaporizing various chemical compounds using a gas burner (known to high school chemistry students everywhere as the Bunsen burner), and analyzing the light the compounds gave off. In the case of sodium chloride, for example, they would deposit a little pellet of salt on a platinum wire loop, and then hold the loop in the gas flame. As the salt compound glowed in the flame, the...

From amateur to professional

The three-year period from 1779 to 1782, culminating with the discovery of the seventh planet of the solar system and events in the wake of that discovery, marked Herschel's transformation from amateur to professional astronomer. His friend William Watson played an important role in helping him make this transformation by introducing him to the philosophical societies in Bath and London. But even before he met Watson on the street outside his house in Bath, Herschel had begun to formulate lofty...

The Great Debate

On the evening of 26 April 1920, members of the National Academy of Sciences and their guests, and interested members of the public, made their way to the Smithsonian's Natural History Museum and through its cavernous rotunda to hear Shapley and Curtis speak on the scale of the universe. The debate began at 8 15 p.m. in the museum's auditorium. Each speaker was allotted 40 minutes. Shapley spoke first. Historians are not aware of any newspaper or eyewitness account of the debate, but it appears...

Later years the Kapteyn universe

After Kapteyn's retirement from the University of Groningen in 1920, he took a part-time position at the University of Leiden, where he had carried out some research during the dismal early days of his career at Groningen, and where his former student de Sitter was director of the observatory. As a favor to de Sitter, Kapteyn filled a post in positional astronomy until university officials could find a permanent replacement. His bimonthly trips to Leiden allowed him to visit with Henrietta,...

The Nakedeye View Of The

''No more of the universe is visible to our unaided eyes than to the eyes of our Neanderthal ancestors. But science, the product of our imagination, has immensely extended the range of our imagination. Our inward eye can range beyond the dome of visible stars to the unseen realm of the nebulae and galaxies.'' On late fall or winter nights I like to go out and look for the Andromeda nebula. This fuzzy patch of light among the glittering stars gets its name from its appearance and location nebula...

Parallax

By the spring of 1835, Struve's affairs were settling and he could look forward to a resumption of his studies of double stars and the search for parallax. He had married Johanna Bartels, and she expected the birth of their first child in the fall. Johanna, about 28 years old, restored order to the large household. Astronomers who knew her later described her as quiet and pious, but well-loved and respected. Otto described her as ''the refuge of all who needed help and council.''13 Beginning in...

Kant reads Wright

Far from London in the East Prussian capital of Konigsberg, the philosopher Immanuel Kant, 13 years younger than Wright, read a review of Wright's Original Theory of 1750. The review appeared in a periodical, and summarized Wright's models without reproducing his engraved illustrations. Therein lies the root of a deep misunderstanding, because without Wright's illustrations to guide him, Kant formed an erroneous impression of the details of Wright's models. Kant's imagination was fired by a...