Steward Observatory kicks off its yearslong centennial celebration with a lecture and star party Saturday in Oracle, where its namesake benefactor, Lavinia Steward, lived.

Steward moved to Oracle in 1895 with her nephew, Fred, who suffered from tuberculosis, said Steward Observatory astronomer Tom Fleming.

Her husband, Henry, joined the family in 1900 after retiring as a partner in the Peoria Oat Meal Mills, which later became Quaker Oats. He died a year later of heart disease.

In 1916, Steward, who enjoyed observing the dark skies above Oracle with her nephew, gave the University of Arizona $60,000 to buy a telescope and build an observatory in Tucson.

By 1918, Steward Observatory had been chartered as an academic unit of the university, with physics professor Andrew Ellicott Douglass as the first director.

In 1922, the telescope saw first light and, in 1923, it was formally dedicated.

Steward Observatory and the UA Department of Astronomy intend to celebrate all of those milestones as part of a rolling centennial celebration that begins with Saturday’s celebration in Oracle and continues on October 17 with a Steward Public Evening showing of a new film about the observatory’s history.

Lavinia Steward stepped in with her gift after the Arizona Territorial Legislature failed to fund the observatory, according to Douglass’ remarks at the 1923 dedication, from the Steward Observatory’s history website.

“President (Rufus) von KleinSmid thereupon used his good offices in an attempt to obtain by other means the items which the legislature had not provided. In this he was splendidly successful for in 1916 came the princely gift of sixty thousand dollars from Mrs. Lavinia Steward.

“Mrs. Steward was a charming and lovely character, deeply interested in the arts and sciences.

“She had books on astronomy and a portable three-inch telescope through which she delighted to show the wonders of the heavens to her grand-nephew and nieces.

“She had planned to do something for the University and felt a personal inclination towards some astronomical equipment. Thus all conditions were happily favorable for the beginning of the Steward Observatory.

“Mrs. Steward passed away in August, 1917. It is my deep regret that she did not live to look through this magnificent instrument.”

Contact reporter Tom Beal at tbeal@tucson.com or 520-573-4158. Follow him on Facebook or @bealagram on Twitter.