Ingemar Karl Furenlid passed away on February 11, 1994, in Cambridge, Massachusetts, at the Harvard-Smithsonian Center for Astrophysics, on leave from Georgia State University. His death at age 59 resulted from brain cancer. Ingemar was known to all stellar spectroscopists, not only from his nine years on the staff of Kitt Peak National Observatory, but also for his diverse and innovative research.
Born in Orebro, Sweden on May 26, 1934, Ingemar followed his father's footsteps into a career in the Swedish railway. His astronomical interests dated back to his days in gymnasium when he and his friends braved cold winter nights to use his school's rooftop telescope. Encouraged by his wife Kerstin V. Furenlid, whom he first met as a young teenager in Orebro, Ingemar entered Stockholm University in 1956 determined to become an astronomer. He ultimately received four degrees, culminating with the PhD in 1970 under Bertil Lindblad. His studies at Stockholm were interrupted in 1959-60 by his first U.S. trip as a teaching assistant at Harvard College Observatory.
During their Stockholm years, Ingemar and Kerstin jointly wrote hundreds of popular astronomy articles for a syndicated newspaper column, built a house entirely with their own hands, and produced their only child Lars. Ingemar enjoyed recalling the assessment of a stiff "luxury" tax on their newly built house overlooking the Stockholm archipelago, promptly followed by a notice that their tax-reduced income now qualified them for welfare support! This plus a very positive second Harvard experience under a Donald H. Menzel fellowship in 1968-69 help convinced Ingemar and Kerstin to emigrate.
In 1971, Ingemar resigned his post-doc at Stockholm for a research associateship at Kitt Peak National Observatory where, in 1974, he became a Support Scientist with responsibility for the Coudé Feed Telescope and Spectrograph. This instrument was widely used for quantitative stellar spectroscopy and radial velocities, and Ingemar trained dozens of visitors on its use and the detailed reduction of data using analysis and calibration tools he had devised and software he had written. Visitors invariably remember him for his kindness and patience and his eagerness to see them successfully through their observing runs at the expense of his own nights and weekends. On many occasions, Ingemar and Kerstin provided food and lodging in their home for visitors to the national observatory.
His own research at Kitt Peak was driven by his desire to optimize the Coudé Feed's performance and by his deep interest in stellar astrophysics. He explored the photographic process as it pertains to the interpretation of spectra and was the first to properly define the signal-to-noise ratio in a photographic measurement, enthusiastically encouraging others to treat photographic data more quantitatively. He subsequently, and just as eagerly, was among the first to use modern solid state detectors for stellar spectroscopy, initiating the replacement of photography with CCD's at the Coudé Feed.
Ingemar's scientific papers from his Kitt Peak years, often written in collaboration with Kitt Peak staff or visitors, range from evaluating various photographic emulsions to interpreting data using model atmospheres calculations. A productive collaboration with Arthur Young dealt with pulsational properties of (β Cephei stars and particularly the complex phenomena exhibited by BW Vul). In 1980, Ingemar co-authored with Robert Kurucz a monumental spectral atlas of Sirius and was working with Kurucz on a sequel at the time of his death. Ingemar was among the first to experiment with digital cross-correlation radial velocity techniques simplified by transforming to a log λ scale, now standard in the field.
Ingemar joined Georgia State University in 1982, bringing to a young program an expertise crucial to our fledgling astronomy doctoral program. His teaching at all levels was characterized by a conscientious and compassionate dedication to serving his students just as he had previously served visiting scientists at Kitt Peak. Some 30 publications, even more diverse than his Kitt Peak papers, appeared after his arrival at GSU. He developed an efficient fiber-fed spectrograph following a modified Ebert-Fastie design and then collaborated with Mexican astronomers in building a working version of this instrument for the 2.1-m telescope near Cananea, Mexico. A similar instrument is also part of GSU's 48-in equivalent aperture "Multi-Telescope Telescope." Ingemar, with William Bagnuolo, was a principal designer of this unusual spectroscopic telescope.
At GSU, Ingemar continued work with Young and others on BW Vul, initiated abundance analyses of α Cen A with his only PhD student, Thomas Meylan, and published a paper with his son Lars on a variant of the cross-correlation method. After planting the seed in the writer's mind in the late 1970's to pursue long-baseline optical interferometry, Ingemar contributed greatly with his technical insight, occasional outspoken criticism, and continuous encouragement to a 10-year effort towards an optical interferometric array, a project finally funded by the NSF seven months after his death.
After losing his beloved Kerstin to cancer in 1992, Ingemar longed to return to Harvard where he and Kerstin first found their future together in the U.S. Ingemar and Lars, who obtained a physical chemistry PhD at Georgia Tech in 1988, were especially close, and Cambridge would bring Ingemar nearer to Lars and his wife Karen, who both work at Brookhaven National Laboratory. Thus in the summer of 1993, Ingemar departed for a much anticipated year's leave at Harvard. The weekend after Thanksgiving 1993, he suffered an apparent stroke and appeared to be recovering in early 1994 when a setback was finally traced to a brain tumor.
Ingemar was a wonderful friend and colleague to many people. His high standards of personal and scientific integrity as well as his wonderful sense of camaraderie and humor added immeasurably to astronomy at Georgia State, where he will be deeply missed.