Nicholas Ulrich Mayall, May 9, 1906January 5, 1993 | By Donald E. Osterbrock | Biographical Memoirs

Courtesy of the Mary Lea Shane Archives of the Lick
Observatory
|

Nicholas Ulrich Mayall
May 9, 1906 January 5,
1993
By Donald E. Osterbrock
|
NICHOLAS U. MAYALL WAS born in the Midwest near
the beginning of the twentieth century and died
in Arizona near its end. He was an outstanding observational astronomer
of gaseous nebulae, globular clusters, and galaxies. A product of the
University of California, he joined the staff of its Lick Observatory
even before he completed his Ph.D. and remained a member for more than a
quarter of a century, obtaining with its small reflecting telescope
excellent data on objects too faint for most astronomers to see. During
World War II, he did important weapons development work at Cambridge,
Massachusetts, and then at Pasadena, California. He helped launch the
Lick Observatory's large, new, postwar telescope and then left the
University of California to become the director of the still very young
Kitt Peak National Observatory. He built it up into an important
research institution, with large telescopes in both hemispheres, the
National Optical Astronomy Observatories of today.
Mayall was born in Moline,
Illinois, on May 9, 1906, the first of two sons. His father, Edwin L.
Mayall, Sr., was an engineer who worked for a manufacturing firm in
Illinois. His mother, Olive Ulrich Mayall, although she did not go to
college, had a visionary understanding of higher education and set high
standards for her two sons, Nicholas and Edwin, Jr. The family moved to
the central valley of California sometime between 1907, when Edwin, Jr.,
was born, and 1913, when Nick began first grade at a small rural school
near Modesto. By 1917 they had moved to Stockton. Except for one year
back in Peoria, Illinois (1918-19), they stayed there through 1924, when
Nick graduated from high school. Sometime along the line, probably while
Nick was in high school, his parents were divorced.
In his senior year at Stockton High School, Nick
arranged for the science club, of which he was secretary, to visit Lick
Observatory, atop 4,200-foot-high Mount Hamilton, near San Jose. He was
allowed to drive his father's auto and take a car full of boys up the
winding mountain road, at that time unsurfaced dirt and gravel. It was
his first sight of the observatory where he was to be a student and
spend so much of his professional career. The visit inspired him to read
all the astronomy books in the high school and local public libraries,
but he had never thought of making astronomy his profession.
In the fall of
1924 Mayall entered the University of California in Berkeley as a
freshman in the College of Mining. He lived with his mother in an
apartment on Durant Avenue and worked in the stacks at the university
library to earn the money they needed to survive. Mayall was a good
student, who ultimately was elected to Phi Beta Kappa and Sigma Xi, but
by the midterm examinations in the first semester of his sophomore year
he was heading for poor marks in mineralogy and chemistry laboratory.
The dean called him in and found that Mayall was color-blind. He could
not see the subtle color changes in flame and bead tests, nor in
titrations and precipitations. His adviser told Mayall that there was
nothing to do but change his major; a mining engineer had to be able to
do those tests to graduate.
At this point Mayall
decided that maybe astronomy was for him after all. He consulted his
mother, who urged him to do what interested him most but, whatever it
was, to do it well. First, he investigated carefully, asking several
professors in the Berkeley astronomy department if they were happy in
their work and making a decent living. Receiving affirmative answers, he
transferred to the College of Letters and Science and majored in
astronomy. This did not delay his progress, for nearly all his freshman
work had been in mathematics and basic physical sciences. He found he
liked astronomy very much and decided to go on to graduate work and a
career as a research scientist.
In 1928, when
Mayall finished his undergraduate work and received his A.B., the
University of California had the most outstanding graduate astronomy
program in the country. All the courses were taught by the professors in
the Berkeley department on the campus, but many of the students did
their thesis work on Mount Hamilton, under the tutelage of a Lick
astronomer who became a member of their thesis committee. The founder
and long-time chairman of the Berkeley department, Armin O. Leuschner,
was an expert on celestial mechanics. Most of the other faculty members
in the department were his former students, selected much more for their
teaching ability than their research qualifications. What research they
did do was also in celestial mechanics, except for C. Donald Shane,
another Berkeley product who had done his thesis on carbon stars at Lick
and who taught all the astrophysics courses in the department,
undergraduate or graduate. The graduate students were very well trained
in the "theoretical astronomy" of that day (celestial mechanics),
especially "Leuschner's method" for determining the orbit of a newly
discovered comet or asteroid from three observations of its position.
Mayall received a teaching fellowship (making him
equivalent to a teaching assistant of today, worth $600 a year then) for
his first year as a graduate student, 1928-29. He enjoyed the course
work, especially in astrophysics, and learned to calculate orbits
rapidly and accurately. In the summer of 1928, before beginning as a
graduate student, Mayall worked as the grader for an astronomy course
taught in the Berkeley summer session by Seth B. Nicholson of the Mount
Wilson Observatory staff. He was a Berkeley product himself, who in 1914
at Lick discovered Jupiter IX, a small faint moon of the giant planet.
Its orbit became the subject for his 1915 Ph.D. thesis. Nicholson told
Mayall that there would be an opening for a computer (a job held by a
human being at that time) at the Mount Wilson Observatory offices in
Pasadena the following year. By then Mayall was tiring of course work;
he applied for the Mount Wilson position and got it. He worked there two
years (1929-31), learning research by doing it. His job was to assist
Nicholson and several other staff members, including Edwin Hubble,
Alfred H. Joy, and Director Walter S. Adams, by measuring and reducing
their observational data. When Clyde Tombaugh discovered Pluto at Lowell
Observatory in 1930, Mayall, working with Nicholson, demonstrated that
Leuschner had taught them well. They used the first preliminary orbit
for the new planet, calculated by Ernest Clare Bower and Fred L. Whipple
at Berkeley, to search along its early path for a direct photograph in
the Mount Wilson collection that would provide an early position of it.
They found it, a very faint object in a crowded field, on a plate taken
in 1919, measured it, and quickly calculated and published the first
definitive orbit with an eccentricity. It showed that Pluto was
certainly a planet whose orbit crossed that of Neptune. But Mayall
managed to get to Mount Wilson often himself, working with the staff
astronomers on all the telescopes and using most of them on his own as
well. He became especially close to Milton L. Humason and was inspired
by Edwin Hubble. Mayall decided he wanted to make his career in nebular
spectroscopy and research.
When he returned to
Berkeley in the fall of 1931 to complete his graduate course work,
Mayall had a Martin Kellogg Fellowship (worth $1,000 per year) and a
prospective thesis topic, suggested by Hubble. It was to count the
number of galaxies per unit area on the sky, as a function of position,
on direct plates taken with the Crossley (36-inch) reflector, on Mount
Hamilton, to supplement the counts Hubble himself was making with the
60-inch and 100-inch telescopes at Mount Wilson. Mayall did very well in
his courses and went to Lick Observatory in the summer of 1932 to begin
the main part of the observational work. He had learned well from his
Mount Wilson mentors and was an expert at obtaining first-class direct
photographs with the ancient and tricky Crossley telescope. Mayall made
the counts on his own plates, after closely inspecting earlier ones
taken by his predecessors at the instrument, Heber D. Curtis, Charles D.
Perrine, and James E. Keeler, the latter the second director of Lick
Observatory, who had put the Crossley into operating condition and with
it first discovered (at the turn of the century) the very large number
of spiral "nebulae" in the universe.
Mayall
finished his thesis and received his Ph.D. degree at the 1934 Berkeley
commencement. Hubble praised his work, which was in fact excellent
technically. However, the whole program, on which Hubble himself spent
years, never achieved very significant results. It was flawed by the
lack of accurate magnitude standards for the faint galaxies at which it
was aimed and by the then-unrecognized very strong clustering tendency
of galaxies.
Mayall's thesis adviser, William H. Wright, a
University of California graduate and a Lick Observatory staff member
since 1897, was a nebular researcher and spectroscopist himself and a
great friend and admirer of Hubble. Mayall wanted to design and build a
small fast spectrograph, optimized for nebulae and galaxies, to use at
the Crossley to make it competitive for at least some of the spectacular
work that Humason and Hubble were then doing with the larger telescopes
at Mount Wilson. Wright and Joseph H. Moore, the head of the Lick
stellar spectroscopy program, encouraged Mayall to go ahead with the
design and then had the spectrograph built in the observatory shop.
Though there was no opening on the staff for even the most junior
astronomer, they kept Mayall at Lick as an observing assistant after he
got his Ph.D. It was the same position he held for the final year of his
thesis work and in reality allowed him to devote most of his time to his
own research. The job paid very poorly, but the Great Depression was at
its height (or in its depth), and there were few available alternatives,
none for Mayall, who was committed to a research career with the
spectrograph he had designed. He had hoped for a position at Mount
Wilson, but there were no openings at all there because of the
Depression.
As he began his postdoctoral career at
Lick, Mayall married Kathleen (Kay) Boxall of Los Angeles on June 30,
1934. They met during his two years in Pasadena, according to family
legend, at a field hockey game, probably at Tournament Park, very near
Caltech. Whether it was a mixed game or Mayall was a spectator was not
reported. They moved into a small apartment in the little astronomy
village on the summit of Mount Hamilton, where all the astronomers
lived.
One year later, on July 1, 1935, Robert G.
Aitken, the elderly director of Lick Observatory, retired, and Wright
succeeded him in the post. The two of them, and Moore, had managed to
keep Mayall and his good friend Arthur B. Wyse, who had also received
his Lick Ph.D. in 1934, on the staff, initially as observing assistants.
Now as assistant astronomers they replaced Aitken and Robert J.
Trumpler, who moved to Berkeley in 1935.
Mayall
began using his new nebular spectrograph at the Crossley. Although it
was not competitive with Humason's instrument on the much larger
100-inch telescope for stars or elliptical galaxies, with their
condensed, relatively bright nuclei, the Lick spectrograph was actually
faster for extended, low-surface-brightness gaseous nebulae and
irregular galaxies. This was particularly the case in the ultraviolet,
for Mayall, with Wright's strong encouragement, used quartz and
ultraviolet transmitting optics, in contrast to the Mount Wilson
spectrographs with their heavy glass lenses and prisms. With it Mayall
got the first really good spectrum of the Crab nebula. From it and the
previously published angular rate of expansion of the nebula, he was
able to estimate its distance. With this data, Mayall became the first
to recognize and prove the Crab nebula to be the remnant of a supernova
observed and recorded by Chinese astronomer-astrologers in 1054, rather
than an ordinary nova. He also found important new results on emission
nebulae in the nearby spiral galaxy M 33 and various irregular galaxies
and on the unexpected occurrence of forbidden emission lines of ionized
oxygen in the spectra of the nuclei of many galaxies, a sign of the
frequent presence of ionized interstellar gas even in the centers of
these objects. With Hubble's encouragement Mayall measured
spectroscopically the rotational velocities of several spiral galaxies.
Wyse collaborated with Mayall on several papers on the interpretation of
the measured radial velocities of the H II regions in M 31 and M 33 in
terms of the rotation of these two especially nearby spiral galaxies,
the gravitational field that it implied, and hence the distribution of
mass within them. They made a good team, Wyse more theoretically
inclined, Mayall an exceptionally skilled observer with the Crossley
reflector he knew so well. His color blindness stood him in good stead
here, for along with it he apparently had much more acute sensitivity to
very low light levels than most mortals. Certainly he could see on the
slit and in the periscope eyepiece of his spectrograph objects that were
too faint for most other astronomers who observed with him, including
myself.
Among the California graduate students who
worked with him in those early years at Lick, the closest to Mayall were
Daniel M. Popper and Lawrence H. Aller (who finished his Ph.D. at
Harvard but came back to Mount Hamilton to observe several times). They
both admired him greatly for his observational skills, his dedication to
astronomy, and his warm, friendly personality. He was a good adviser to
them and a realistic one.
Jan H. Oort, the
outstanding Dutch astronomer, collaborated with J. J. L. Duyvendak, an
Oriental scholar, in establishing the identity of the Crab nebula with
the "new star" recorded by the Chinese a millennium ago. After Holland
was overrun by the Nazis early in World War II, Oort, by correspondence,
suggested to Mayall further ancient sources, including Semitic records,
which might contain information. Mayall helped track them down at
Berkeley and published the results in a joint paper with Oort.
The Mayalls had two children, Pamela and Bruce, who
grew up on the mountain and attended its one-room school. When they
graduated from eighth grade, they had to go away to boarding schools.
Mayall took the hour-a-day job as postmaster on Mount Hamilton to help
pay the associated costs.
World War II abruptly put Mayall's research career on
hold, just as he was getting established. Well before America entered
the war both he and Wyse applied for Naval Reserve commissions, to be
called to duty as navigation instructors if needed. Mayall was rejected,
because his color blindness prevented him from passing the required
physical examination. In the fall of 1941 Wyse joined a wartime Navy
antisubmarine technical project at San Diego as a civilian scientist. He
was killed in sea trials of a proposed new submarine detection system in
June 1942 in a collision of two dirigibles over the Atlantic Ocean. He
had been Mayall's close friend. Mayall, along with nearly everyone else
who knew Wyse, expected that he would someday become director of Lick
Observatory.
Even before Wyse's death, Mayall
accepted a position at the Radiation Laboratory in Cambridge,
Massachusetts, to work on radar development. Gerald E. Kron (who
recruited him) and Hamilton M. Jeffers, of the Lick staff, both single
men, had begun working there before Pearl Harbor. Mayall worked on
testing and calibrating the accuracy of the positions of airplanes
provided by the early radar systems, comparing them with optical,
visual, and photographic positions. However, the Boston climate,
changeable and extreme compared with the California weather to which
Mayall was accustomed, caused him and his family many colds and
illnesses and aggravated his arthritis and sciatica. He felt he could
not make real contributions at the Radiation Laboratory, dominated by
electronic and antenna experts.
In mid-1943 Mayall
arranged to transfer to the Mount Wilson Observatory offices in
Pasadena, where several wartime Office of Scientific Research and
Development projects concerned with optics, aerial gunnery, bombing
tactics, and aerial photography were under way. There, in the atmosphere
of California and astronomy, Mayall's health was restored. In one of the
ironies of the war, he ate lunch daily with the two German-born Mount
Wilson Observatory staff members--Rudolph Minkowski, a naturalized
American citizen who was working with him on the OSRD projects, and
Walter Baade, still a German national, who could not participate in or
even know of the war work. Presumably, Mayall and Minkowski "buttoned up
their lips" (as the wartime posters urged them to do) and did not pass
any military secrets to Baade. His enemy alien status meant he was
restricted to Los Angeles County, and, as practically the only member of
the Mount Wilson staff not doing any war work, Baade had nearly
unlimited use of the 100-inch telescope. Under the wartime brownout in
Los Angeles, the night skies were unusually dark, and Baade was able to
take direct photographs of the nearby Andromeda galaxy, M 31, and its
companions, which showed stars to a fainter level than he had been able
to reach before. This observation was the final evidence in his great
discovery of the "two stellar populations," young stars and old. Mayall
was on the scene in the late summer and fall of 1943 as Baade did this
work and discussed it daily with him. Astronomical observations were not
military secrets, and the enthusiastic Mayall kept the few elderly Lick
astronomers still on the job at Mount Hamilton informed of Baade's
epochal results.
Mayall enjoyed the Mount Wilson
Observatory atmosphere, especially when he was even allowed to work with
the 60-inch telescope for two nights during his Christmas vacation! But
he believed that, owing to mismanagement in the higher levels of the
OSRD optical instruments division, he and the Mount Wilson group were
not being given a chance to make a really effective contribution to the
war effort. Hence, he welcomed an opportunity to transfer in February
1944 to the California Institute of Technology, whose big rocket
development project was clearly providing immediately effective weapons.
Several other astronomers were working there, including Kron, who had
moved there earlier; Horace W. Babcock, who did his Lick Ph.D. thesis
under Mayall's supervision; and John B. Irwin, a former Berkeley and
Lick graduate student. Mayall, who worked on the Caltech campus and
sometimes at the more open testing areas at Inyokern, in the Mojave
Desert, soon made himself a highly productive member of the project. He
became an expert at high-speed photography, necessary to study and
understand rocket trajectories and impacts. After the German surrender
in the spring of 1945, Mayall was transferred to an ultrasecret group
working on very-high-speed photography for the atomic bomb project, in
connection with the plutonium implosion weapon. He made at least two
trips to Los Alamos, one at about the time of the Trinity test, but he
was not there for the firing. Probably he had briefed the Los Alamos
high-speed photography group or discussed some of their results with
them. Mayall, a confirmed believer in security to the end of his life,
steadfastly declined to discuss this aspect of his wartime career.
Soon after the war ended, Mayall was released from his
post, and by October 1, 1945, he was back in astronomical research at
his beloved Mount Hamilton. During his three years with the OSRD, Mayall
had made important contributions to the war effort, particularly at
Caltech and Inyokern. In addition, he had gotten out of the comfortable
little world of astronomy and had greatly broadened his outlook on
science, research, and leadership. At the Radiation Laboratory and at
Caltech, Mayall saw big science in action, in its wartime version, and
he made many contacts with physicists with whom he would interact
frequently in his later years as director of Kitt Peak National
Observatory.
During World War II, Mayall played an important role
in determining the future of Lick Observatory. From the time he returned
to Berkeley and Lick in 1931, after his two years as an assistant at
Mount Wilson, he felt acutely the need for a larger telescope at Mount
Hamilton. The Lick astronomers prided themselves on getting important
results with their small, 36-inch Crossley reflector, which had been
dwarfed by the Mount Wilson 60-inch since 1908, the Dominion
Astrophysical Observatory 72-inch since 1917, and the Mount Wilson
100-inch since 1919. Mayall became an expert observer with the Crossley,
but he realized that it could never really compete with a telescope with
three times its diameter, nine times its collecting area. It would be
even worse when the Palomar 200-inch came into use. Mayall and the other
younger Lick faculty members believed that the older astronomers, Wright
and Moore, were too committed to the small telescopes and should have
worked harder to get a larger reflector for Mount Hamilton. Wright was
proud of what he had accomplished with the Crossley and tended to scoff
at the big-telescope mystique, but actually behind the scenes he and
Aitken, his predecessor, had tried hard to raise the money for a larger
reflector from private sources and also to persuade University of
California President Robert G. Sproul to put it in the budget. They
failed in each attempt, largely because of the Great Depression.
However, unknown to Mayall, Sproul changed his mind in 1942, after his
first choice for a director to succeed Wright, Paul W. Merrill of Mount
Wilson Observatory, declined to leave the big telescopes even for the
directorship of the University of California's famous research
institution. Sproul, shaken by Merrill's refusal, told the regents that
they must raise the money somehow after the war ended. At the same time,
he either secretly appointed Shane, by then chairman of the Berkeley
Astronomical Department, as postwar director of Lick, or promised him
the post.
In September 1944 news of the planned
big postwar telescope but not of the new director surfaced in the
University of California's budget proposals. Moore, by then the interim
wartime director, and Wright, seventy-two years old but still very much
on the scene as a retired astronomer recalled to service, thought of it
as an 85-inch or 90-inch telescope, the largest instrument that they
believed could be built for the funds specified in Sproul's budget
proposal. Mayall and the other young Lick astronomers and former
graduate students now in Pasadena, all of whom longed to return to Mount
Hamilton and who discussed frequently everything that happened there,
believed that Moore and Wright were out of touch with the real needs of
astronomy. Emboldened by the wartime emphasis on youth and on cutting
through red tape to get results, Mayall resolved to go straight to the
president of the university himself. He wrote Sproul, asking for an
appointment to see him on one of his regular monthly visits to the
University of California at Los Angeles campus. Kron also signed the
letter, in which they said that, "as younger members of the [Lick]
staff, who hope to use the instrument," they wished to discuss "what
kind of telescope" the University of California should build when the
war ended. Sproul welcomed them to his Los Angeles office in December
1944. Mayall did most of the talking. He emphasized the need for a
telescope bigger than a 90-inch. In Pasadena he had seen the 120-inch
glass disk originally intended for testing the 200-inch Palomar mirror,
then nearly finished in the Caltech optical shop. He urged Sproul to
make the Lick reflector that large. To Mayall and Kron's surprise,
Sproul quickly assented and in turn urged them to keep up the pressure
on "the old men."
In early 1945 Sproul appointed a
committee, chaired by Shane, then on leave at Los Alamos as assistant
director for scientific personnel, to plan the postwar Lick telescope.
He also appointed Moore and Mayall to the committee, as well as Mount
Wilson Observatory Director Walter S. Adams and Caltech physicist Ira S.
Bowen, who would succeed Adams and become the first director of Mount
Wilson and Palomar Observatories at the war's end. The committee worked
mostly by correspondence, and Mayall's first letter helped to persuade
Shane that it was reasonable to hope for a 120-inch rather than settle
for a 90-inch, as he had earlier thought. Mayall, on the scene in
Pasadena, was invaluable in providing liaison between the strong
telescope group there and Shane, whose expertise was much more in
teaching and university administration than in instrument design. Adams
and John A. Anderson, executive officer of the 200-inch project, made
their drawings, plans, and experience freely available to the California
astronomers. Mayall was present at the one actual meeting of the
committee, in Pasadena on March 6, 1945, when Shane could get away from
Los Alamos briefly. On that day the committee made all the basic
decisions for what eventually became the Lick 120-inch reflector. Shane
and Mayall went on to Mount Hamilton the next day and there, with Moore
(who had not been able to get to Pasadena) and Wright, picked out the
spot where the telescope would be erected.
After
the war Shane guided the 120-inch project through the university and
helped Sproul sell it to the legislators and the governor. Caltech made
its disk available at cost, which bypassed the delay that ordering a new
one would have caused. Mayall, as the most experienced big telescope
user on the Lick faculty, who often went to Mount Wilson and later even
to Palomar to observe with Baade, Minkowski, and Humason, made many
suggestions that were incorporated into the Lick reflector. It was safe,
sound, conservative, and productive--his style exactly.
The
120-inch telescope was years in the building. Meanwhile, Mayall worked
actively on research with the Crossley reflector. He began obtaining the
integrated spectra of globular clusters with his fast spectrograph well
before the war. Now he finished this work and published the results--the
radial velocities of the first fifty clusters. The result was important
in proving that the system of globular clusters shares only slightly in
the galactic rotation exhibited by the flattened system of young stars
and interstellar matter in the Milky Way. This work, like all of
Mayall's, was very well suited to his small telescope and fast
spectrograph, optimized for extended, low-surface-brightness nebulae,
galaxies, and clusters.
Much of Mayall's best work
was done in collaboration with or at the suggestion of his friends and
mentors at Mount Wilson Observatory. Although he still idolized Hubble,
who had been on leave as director of the Army's Ballistics Research
Laboratory at Aberdeen, Maryland, for the duration of the war, by the
time the 200-inch telescope went into operation in 1948 the great
observational cosmologist was tired and ill. He suffered a heart attack
in 1949, never fully recovered, and died in 1953. Baade had become
Mayall's chief source of inspiration during World War II. He wrote
frequently to his younger friend at Mount Hamilton, and they had long
discussions at the informal Lick-Mount Wilson and Palomar nebular
research conferences that Shane and Bowen arranged. With Baade's
continued encouragement and advice, Mayall carried out a long, important
program of spectroscopy of the H II regions in the spiral arms of M 31,
to better define its rotation curve.
One very
important paper Mayall published in observational cosmology, with
Humason and the young Allan Sandage as coauthors, was a catalog of the
Lick, Mount Wilson, and Palomar redshifts of galaxies. It contained the
redshifts of more than 800 galaxies observed over the years from 1935 to
1955. Humason provided the data on the ellipticals and distant spirals
for which the 100-inch and 200-inch telescopes and their spectrographs
were so well suited, Mayall for the irregulars and nearer spirals, and
Sandage provided most of the magnitudes. He was also chiefly responsible
for the discussion in terms of the velocity-distance relationship. This
paper enormously strengthened the observational evidence for a linear
velocity-distance relationship. The value they determined for the Hubble
constant, 180 km/sec/Mpc was a step along the way from the outstanding
observational cosmologist's early value of 530 km/sec/Mpc to the
currently accepted values of 50 to 100 km/sec/Mpc.
The great expert on spectral classification of stars,
William W. Morgan, worked with Mayall and his collection of galaxy
spectra during a visit to Lick. They published a joint paper on the
results, a spectral classification of galaxies that showed many of the
population and heavy-element abundance differences between spiral and
elliptical galaxies, much later made quantitative by detailed CCD
spectrophotometry. Mayall and Kron, again with the very active
encouragement of Baade, collaborated on measuring the colors of globular
clusters in our own Galaxy and in M 31 and its companions, for
information on interstellar extinction and the stellar populations of
these clusters.
From the end of World War II,
Mayall was the editor of all the Lick Observatory scientific
publications and hence a member of the editorial board of the
Astrophysical Journal. He devoted considerable effort to this
task and greatly improved the clarity and accuracy of presentation of
several of his colleagues' papers.
As the 120-inch
telescope approached completion on Mount Hamilton, Mayall was
responsible for taking the test exposures that showed how close the
primary mirror was to the correct form and what additional figuring was
necessary to bring it to the final ideal paraboloid. On this project he
worked with Stanislavs Vasilevskis, who measured the plates and reduced
the numerical results to quantify the form of the mirror.
In 1958 with the telescope still not completed, Shane
stepped down as director. Albert E. Whitford, his successor, was brought
from the University of Wisconsin to finish the task and put the 120-inch
into operation. The opticians finally figured the mirror correctly, as
the test plate Mayall took on June 17, 1959, confirmed. Then the mirror
could be aluminized and the auxiliary instruments installed. By early
1960 the 120-inch was in regular operation. Mayall began taking direct
exposures of nebulae and galaxies at the prime focus, but only a few
months later, in September 1960, he left Lick Observatory and Mount
Hamilton.
| KITT PEAK NATIONAL OBSERVATORY
|
Mayall left the University of California, where over a
span of more than a quarter of a century he had been undergraduate,
graduate student, and assistant and held every rank from assistant
astronomer to astronomer, to become the second director of Kitt Peak
National Observatory. The national observatory concept had only become a
reality a few years before. Under the financial sponsorship of the
National Science Foundation, a group of universities organized a
consortium, Associated Universities for Research in Astronomy, to build
and operate a research observatory for all American astronomers to use.
The first director, Aden B. Meinel, located the site, Kitt Peak, a
7,000-foot mountain near Tucson, Arizona. He selected and recruited the
first staff members and built the first telescopes. But in the spring of
1960, as the Kitt Peak 84-inch reflector was completed and dedicated,
the AURA Board of Directors decided that Meinel was not the person to
manage it. He resigned, and the board named Mayall to succeed him.
Shane, who represented the University of California on the AURA board
and was its president at that time, played the major role in persuading
him to take the job.
Mayall had never had any
previous administrative experience, but he was an excellent choice for
the post. Then fifty-four years old, he was ready for a change, and,
after only a brief hesitation, he accepted the proferred appointment. He
gave Kitt Peak instant credibility, in a way that Meinel, a postwar
Ph.D., and the few young staff members he had assembled could not do.
Several of the Lick, Mount Wilson, and Palomar astronomers, comfortable
with the idea of an elite few having the largest telescopes in the world
at their disposal, had scoffed at the concept of an observatory for
everyone (although Bowen, Shane, and Whitford all supported the project
strongly). But no one could scoff at Mayall, one of the most respected
research astronomers in America. A member of the National Academy of
Sciences since 1949 and chairman of its astronomy section, former
president of the Astronomical Society of the Pacific, and president of
the International Astronomical Union Commission on Extragalactic
Nebulae, he clearly belonged. He could recruit new staff members who
would come firm in the knowledge that he would be there for years and
that the national observatory was there to stay.
In his early years Mayall received frequent advice
from Shane, but he quickly picked up the skills needed to direct Kitt
Peak National Observatory. He was particularly effective in handling its
external relations, with NSF administrators, university vice-presidents
and business managers, and Arizona and government officials. The 1960s
were the post-sputnik era in American science. The country was
prosperous and eager to support research. Mayall saw to it that Kitt
Peak got its share of the available funding. He knew well all the
astronomers who represented their various universities on the AURA board
and could work effectively with them.
Mayall
delegated almost all the responsibility for designing new instruments
and operating the telescopes to the younger staff astronomers. Some met
the challenge; others did not. As the staff grew, Mayall brought in some
first-rate scientists who were willing to give their time and effort to
make it possible for short-term visitors from all over the country to
get important scientific results. Everyone who worked under Mayall at
Kitt Peak considered him kind and gentle, and some thought that he was a
little too gentle--with others. One administrator, not a scientist, was
a continual source of problems, but he was useful, too, and Mayall never
got rid of him.
As director, Mayall presided over
the building of the 4-meter reflector, Kitt Peak's largest telescope. It
was a huge team-engineering project that had been planned even before he
came on board. Some of his former Lick colleagues and students were
surprised and somewhat disappointed that he never began a research
program of his own with the big Kitt Peak reflector, but he felt that he
had too many other responsibilities that had to come first.
Mayall was much more personally involved in the
expansion of the national observatory to the southern hemisphere, in the
Chile project that eventually became Cerro Tololo Interamerican
Observatory. He and Shane went to Chile two months after he accepted the
directorship and scouted the prospective sites. Mayall reported that he
favored the one that was subsequently chosen, on Cerro Tololo. He
strongly believed in the southern hemisphere observatory, as he
demonstrated by his frequent trips to Chile and almost daily radio and
telex contacts with the CTIO director, Victor Blanco. Mayall helped it
grow, and its 4-meter reflector was well under way when he retired in
1971, at the age of sixty-five.
Mayall's
retirement was marked by a scientific symposium, held in Tucson, at
which Morgan, Minkowski, Sandage, and Margaret Burbidge were the invited
speakers. He and his wife remained in Tucson, and, when the Kitt Peak
4-meter reflector was completed and dedicated in 1973, it was named the
Mayall telescope for him. He was present for its "first light" on
February 27 of that year. The telescope was in full operation by 1974,
as was the Cerro Tololo 4-meter telescope the following year. Mayall had
lived to see his work bear fruit. In retirement he corresponded
frequently with Shane and Frank K. Edmondson, the long-time AURA
representative of Indiana University who was one of the strongest early
proponents of the cooperative or national observatory concept. Mayall
kept in touch with the observatory and his many friends on its staff. He
had suffered from diabetes for thirty years and died at his home in
Tucson on January 5, 1993.
In summary, Mayall was
an outstanding observational astronomer. At Lick Observatory he made
many contributions to our knowledge of gaseous nebulae, supernovae, the
motions within spiral galaxies, and the redshifts of the galaxies in the
universe. In eleven years as director of Kitt Peak National Observatory,
he built it and Cerro Tololo Interamerican Observatory into first-rate
research observatories, with world-class telescopes. Throughout his
career he remained a kind, considerate person who was respected and
admired by all who worked for him.
THIS BIOGRAPHICAL MEMOIR IS based largely on
the written record of Mayall's research, given in his published
scientific work, and of his other accomplishments and his life, drawn
from hundreds of letters to, from, and about him in the Mary Lea Shane
Archives of the Lick Observatory, going back to the 1924 letter that he
wrote as secretary of the Stockton High School science club. These
include a great many letters from his own personal scientific
correspondence, which he presented to the archives. Some of the material
on his student days is from his autobiographical chapter in a University
of California centennial volume.1 I knew Mayall personally
since 1957, had many conversations with him in his later years about his
scientific life, and interviewed him extensively in 1987, just before
the Lick Observatory centennial. In addition, I received letters and
messages from many of Mayall's former colleagues at Lick, Kitt Peak, and
the wartime Caltech project, giving their reminiscences of him. I am
greatly indebted to all of them, as I am to Kay and Bruce Mayall, who
kindly provided additional information, particularly on this great
astronomer's early life.
1 Nicholas U. Mayall. In There Was Light,
Autobiography of a University: Berkeley: 1868-1968, ed. I. Stone,
pp. 107-19. Garden City: Doubleday & Co., 1970.
- 1928
- With H. G. Miles and F. L. Whipple. Elements and
ephemeris of comet k 1927 (Skjellerup). Lick Obs. Bull.
13:120-22.
- 1930
- With S.
B. Nicholson. The probable value of the mass of Pluto. Publ. Astron.
Soc. Pac. 42:350-51.
- 1931
- With S. B. Nicholson. Positions, orbit, and mass of Pluto.
Astrophys. J. 73:1-12.
- Recent novae in the great
spiral nebula in Andromeda (M 31). Publ. Astron. Soc. Pac.
43:217-20.
- 1934
- A study
of the distribution of extra-galactic nebulae based on plates taken with
the Crossley reflector. Lick Obs. Bull. 16:177-98.
- The spectrum of the spiral nebula NGC 4151. Publ. Astron.
Soc. Pac. 46:134-38.
- 1935
- An extra-galactic object three degrees from the plane of the
galaxy. Publ. Astron. Soc. Pac. 47:317-18.
- 1936
- A low dispersion UV glass spectrograph
for the Crossley reflector. Publ. Astron. Soc. Pac. 48:14-18.
- 1937
- The spectrum of the
Crab nebula in Taurus. Publ. Astron. Soc. Pac. 49:101-5.
- 1939
- The Crab nebula, a
probable supernova. Astron. Soc. Pac. Leaflet 3:145-54.
- With L. H. Aller. Emission nebulosities in the spiral nebula
Messier 33. Publ. Astron. Soc. Pac. 51:112-14.
- The occurrence of *3727 [O II] in the spectra of
extragalactic nebulae. Lick Obs. Bull. 19:33-39.
- 1940
- With L. H. Aller. The
rotation of the spiral nebula Messier 33. Publ. Astron. Soc. Pac.
52:278.
- With J. H. Moore and J. F. Chappell.
Astronomical Photographs Taken at the Lick Observatory. Mount
Hamilton: Lick Observatory.
- 1941
- With A. B. Wyse. Increased speed of two Lick Observatory
spectrographs treated with non-reflecting films. Publ. Astron. Soc.
Pac. 53:120-22.
- The radial velocity of IC 10.
Publ. Astron. Soc. Pac. 53:122-24.
- With E.
Hubble. Direction of rotation of spiral nebulae. Science 93:434.
- 1942
- With L. H. Aller.
The rotation of the spiral nebula Messier 33. Astrophys. J.
95:5-23.
- With A. B. Wyse. Distribution of mass in the
spiral nebulae Messier 31 and Messier 33. Astrophys. J. 95:24-43.
- With J. H. Oort. Further data bearing on the
identification of the Crab nebula with the supernova of 1054 A.D. Part
II. The astronomical aspects. Publ. Astron. Soc. Pac. 54:95-104.
- 1946
- The radial
velocities of fifty globular star clusters. Astrophys. J.
104:290-323.
- 1951
- With W.
Baade. Distribution and motions of gaseous masses in spirals. In
Problems of Cosmical Aerodynamics: Proceedings of the Symposium on
the Motion of Gaseous Masses of Cosmical Dimensions Held at Paris,
August 16-19, 1949, pp. 165-84. Dayton: Central Air Documents
Office.
- Comparison of rotational motions observed in the
spirals M 31 and M 33 and in the Galaxy. Publ. Obs. Univ.
Michigan 10:19-24.
- 1956
- With M. L. Humason and A. R. Sandage. Redshifts and
magnitudes of extragalactic nebulae. Astron. J. 61:97-162.
- 1957
- With W. W. Morgan. A
spectral classification of galaxies. Publ. Astron. Soc. Pac.
69:291-303.
- 1960
- With S.
Vasilevskis. Quantitative tests of the Lick Observatory 120-inch mirror.
Astron. J. 65:304-17.
- With G. E. Kron.
Photoelectric photometry of galactic and extragalactic star clusters.
Astron. J. 65:581-620.
- 1962
- The story of the Crab nebula. Science 137:91-102.
- With A. de Vaucouleurs. Redshifts of 92 galaxies. Astron.
J. 67:363-69.
- 1970
- With P.-O. Lindblad. Mean rotational velocities of 56
galaxies. Astron. Astrophys. 8:364-74.
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