Dame Carole Jordan: A Legacy in Stellar Science
The world of astrophysics mourns the loss of Dame Carole Jordan, who died at the age of 84. An internationally acclaimed scientist, she dedicated her career to unraveling the mysteries of the outer atmospheres of cool stars, including our sun. Her pioneering research not only advanced astronomical knowledge but also broke barriers for women in the field.
Decoding the Sun's Atmosphere
When we look at the sun, we see the photosphere, a yellow layer at about 5,500 degrees Celsius. However, Carole Jordan's work focused on the layers beyond this visible surface. The chromosphere lies just above, and further out extends the corona, which reaches millions of kilometers into space and becomes visible only during solar eclipses. In this region, temperatures soar to an astonishing 1 million degrees, emitting light primarily in extreme ultraviolet (EUV) and soft X-ray wavelengths.
In 1962, as Carole began her PhD, a rocket experiment led by US astronomer Richard Tousey captured the EUV spectrum of the sun, revealing unidentified emission lines. Carole embarked on a mission to interpret these lines, eventually becoming a global authority on ultraviolet spectroscopy for the sun and other stars.
Groundbreaking Discoveries and Career Milestones
In her 1965 PhD thesis, Analysis of the Solar Ultraviolet Spectrum, Carole identified that several of the mysterious lines resulted from transitions in highly ionized iron. She astounded the scientific community by attributing some lines to 13 times ionized iron, Fe XIV. A visit to the Zeta experiment at the UK Atomic Energy Laboratory in Culham confirmed her findings, as the same lines appeared in lab spectra.
Her most-cited paper, The Ionization Equilibrium of Elements Between Carbon and Nickel, published in 1969, established a definitive guide to EUV spectroscopy by detailing ionization equilibria across temperatures for common heavy elements. This work laid the foundation for future studies in stellar atmospheres.
With the launch of the International Ultraviolet Explorer (IUE) satellite in 1978, Carole expanded her research to other cool stars, becoming an expert on their chromospheres. In the 1980s, she contributed to X-ray studies of solar flares, further showcasing her versatility in astrophysical research.
Advocacy and Recognition
Carole Jordan was a formidable advocate for women in science. In 1994, she made history as the first female president of the Royal Astronomical Society (RAS), a role she held until 1996. She also served as the society's secretary from 1981 to 1990 and was a vice-president of the Institute of Physics. Her outspoken criticism of the slow admission of women into the RAS Dining Club challenged traditional norms and inspired many.
Her accolades include the RAS gold medal in 2005, fellowship in the Royal Society in 1990, and being made a dame in 2006. Asteroid 8078 was named Carolejordan in her honor in 2000, cementing her legacy in the cosmos she studied.
Personal Life and Lasting Impact
Born in Pinner, northwest London, Carole was inspired by astronomers like Arthur Eddington and Fred Hoyle during her time at Harrow County Grammar School for Girls. She pursued astronomy at University College London, where she wrote her first scientific paper as an undergraduate in 1961.
Throughout her career, she held positions at institutions such as the University of Colorado, UCL, and the UKAEA Culham, before settling at Oxford University from 1976 until her retirement. She served as a tutorial fellow at Somerville College, reader in physics, and professor, also heading the Rudolf Peierls Centre for Theoretical Physics.
Carole married Richard Peckover in 1971, divorcing in 1983. Colleagues remember her as a warm and witty individual, with a love for cats, books, and music. Her dedication to science and gender equality left an indelible mark on the astrophysical community.
Dame Carole Jordan's work continues to influence our understanding of stellar atmospheres, and her advocacy paves the way for future generations of scientists. Her life and achievements remind us of the power of curiosity and perseverance in unlocking the secrets of the universe.
