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“Miss Leavitt
inherited, in a somewhat chastened form, the stern virtues of
her puritan ancestors. She took life seriously. Her sense of
duty, justice, and loyalty was strong. For light amusements she
appeared to care little. She was a devoted member of her
intimate family circle, unselfishly considerate in her
friendships, steadfastly loyal to her principles, and deeply
conscientious and sincere in her attachment to her religion and
church. She had the happy faculty of appreciating all that was
worthy and lovable in others, and was possessed of a nature so
full of sunshine that, to her, all of life became beautiful and
full of meaning.”
Written obituary of Henrietta Swan Leavitt by Solon Bailey as
quoted by George Johnson in Miss Leavitt’s Stars.
"When the Smithsonian Institution’s Air and Space Museum opened
in 1976, its first planetarium show concerned the universe-and
credited Hubble with discovering the period-luminosity law for
Cepheids. My letters to the directors of the museum and the
Harvard College Observatory solicited some activity, but the
conclusion was that the program taped by a famous movie star
could not be corrected.” Vera Rubin (2005)
1. Introduction – Henrietta Leavitt and
her legacy
Figure 1. Henrietta Leavitt.
From: http://www.aavso.org/vstar/vsots/0900.shtml
Henrietta Leavitt (1868-1921) was a quiet,
hard working, modest individual who never sought fame or
honors. She was burdened in her later life with considerable
health problems and was deaf for a significant portion of her
adult life. For nearly three decades she toiled away on the
tedious task of measuring the brightness of star images on
Harvard’s large collection of photographic plates, initially as
an unpaid volunteer. Yet, by the end of her lifetime, Henrietta
Leavitt had achieved world fame in astronomical circles even if
it was far less than she deserved because of the poor treatment
afforded women astronomers in the early 20th
century. She was even nominated for a Nobel prize, and her
legacy endures to this day (Johnson, 2005; Papacosta, 2004;
Moore, 2002).
Leavitt published approximately 35 papers,
several of which were printed posthumously.
Table 1 summarizes
her publications. All her papers detail her variable star work,
and her posthumous publications were catalogs of data that she
had worked on during her lifetime that had not been fully
completed or had been overlooked for publication.
Leavitt discovered half the world’s known
variable stars in her lifetime, and her discovery of the Cepheid
period-luminosity relationship is one of the most important
astronomical discoveries of the 20th century. Her
Cepheid legacy remains with us today nearly 100 years after its
discovery. It is one of our most important tools for examining
the Universe. If one uses the NASA Astrophysics Data System
(ADS) hosted by the Computation Facility at the
Harvard-Smithsonian Center for Astrophysics to search for
references having the word “Cepheid” in their abstract for the
period January 1, 2005 through August 31, 2005, 1026 selections
are found. This truly reflects the importance of Cepheid
variable stars.
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2. Henrietta Leavitt’ early life and
education
Henrietta Leavitt was born in July 4th
1868 in Lancaster, MA, into a family with ties to early Puritan
ancestors and with ties to four centuries of Leavitts in
Yorkshire, England. In the 1880’s her father was the pastor at
the Pilgrim Congregational Church in Cambridge, MA. Her
mother’s name was also Henrietta Swan, and she was named for her
mother. Henrietta was the eldest of seven children of the
Reverend George Roswell Leavitt and Henrietta Swan [Kendrick]
Leavitt. At least two of young Henrietta’s siblings would die
at an early age (Johnson, 2005; PBS). The Leavitts were
relatively affluent and well educated.
After the family moved to Cleveland in
1885, Henrietta enrolled in Oberlin college and completed two
years of an undergraduate education there. She returned to
Cambridge in 1888 and enrolled at the Society for Collegiate
Instruction of Women (later Radcliffe College) and graduated in
1892 at the age of 24. Her degree was a certificate that stated
if she were a man she would have been awarded a bachelor of arts
degree from Harvard. Leavitt did not concentrate on science,
but her courses included natural history and analytic geometry
and differential calculus. In her senior year she also took a
course in astronomy at Observatory Hill which is just up Garden
Street from Radcliffe (Johnson, 2005; PBS). For the next two
years she earned graduate credits in astronomy and worked for
free at the Harvard College Observatory.
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