It has been a great privilege for me to have known three of the world’s greatest stellar photometrists of the second half of the twentieth century. They are Albert Whitford, Olin Eggen and Alan Cousins. In this article I will say a little about each of these great astronomers and how I came to know them. Sadly none of them is still alive today – they all died within a few years of each other close to the turn of the century.

I came to know Albert Whitford (1905-2002) when I was a graduate student at Mt Stromlo Observatory in Australia about 1969 or 1970. I was just starting my career as an astronomer, Whitford was a staff astronomer at Lick and close to retirement. He came to Mt Stromlo as a visitor after relinquishing the directorship of Lick Observatory in 1968, the year I started my PhD. Whitford himself had been a graduate student in Wisconsin in the 1930s, working with the great Joel Stebbins. He was the first person to use a triode valve as an amplifier in photoelectric photometry, a project that he undertook for his PhD in 1932. Later he developed the 6-colour UVBGRI system with Stebbins, using an S-1 Cs-O-Ag photocell. This was the very first multi-colour photoelectric system. And he used the new system of photometry for observations of interstellar reddening caused by interstellar Galactic dust. The famous Whitford 1/lambda interstellar extinction law dates from 1943.

Albert Whitford in 1938 (courtesy of AW)

As I mentioned, I met Albert Whitford in the late 1960s and early ‘70s when he visited Mt Stromlo Observatory in Australia on a number of occasions, and later on I corresponded with him a number of times. He was a reserved man who used words sparingly in conversation. But as a young graduate student, I had the benefit of several rewarding conversations with him. I greatly appreciated his readiness to give time to a young student, then a novice in astronomy. Stories arising from Whitford’s Australian visits include how he fell from an observing platform at night and ended up with broken bones, convalescing in Canberra Hospital (a true story), and that concerning an encounter with an intrepid kangaroo one dark night while walking to the telescope at Siding Spring Observatory (accuracy unconfirmed!). He continued as an active observer for many years beyond retirement.

My Stromlo years (1968 – 1972) were also the time when I met Olin Eggen (1919-98), who was then director of Mt Stromlo. In fact he was my thesis supervisor during these years. Olin was one of the most interesting astronomers I have encountered, and stories about his workaholic lifestyle and past career are legendary. It is on reliable record that while a graduate student at Wisconsin, he worked as a barman and as a pianist in a night club, and during the war he was a secret agent behind German lines, posing as a ball-bearing salesman. After the war, Olin wrote science fiction under the pseudonym of Nilo Negge (his name backwards). There is also a well-documented story of how he stole 150 kg of valuable archives from the Royal Greenwich Observatory in the 1960s relating to the discovery of Neptune. These documents were discovered in Chile in 1999 (where he worked at the time of his death in 1998), in spite of him several times denying any knowledge of them!

Olin Eggen at work in his Stromlo Observatory office

I knew Olin quite well, as I was one of his few graduate students. But to consult him, I had to go to his office at 3 o’clock in the morning, as he was on permanent night shift and spent half his life observing. He nearly always wore a tie but loosely tied, and often smoked a pipe. The photograph herewith is absolutely characteristic. In fact he was an observer workaholic and did photometry on some 100,000 stars, all reduced from strip-chart records with a pencil, ruler and slide-rule. Only a fraction of these data were published in Olin’s lifetime, even though from 1960 to 2000 ADS shows 329 Eggen papers, all but 35 being sole author papers and nearly all having Eggen as the first author! He kept a famous card index of all his observations, and AAVSO is currently processing some 100,000 hand-written cards (one per star) so that the unpublished photometry will in future be available for all.

Olin had a gruff and hard-to-get to know exterior, and many who encountered him never got further than that, or knew of the kind and compassionate man beneath. When I was a postdoc in Paris, he came to our home on a visit, and he told me he had tried wine, women and work (the three Ws) but only work did him any good! He was delighted by our 12-mohth old daughter, so I asked him how many children he had, and his reply was ‘None to speak of’ (though in fact I believe he had two grown-up daughters).

Olin’s most famous paper was in fact co-authored with Donald Lynden-Bell and Allan Sandage in 1962 on the chemical and dynamical evolution of the Galaxy, but his principal output was papers on multi-colour stellar photometry and correlations of photometry with the dynamical properties of stars. The so-called moving groups of field stars were his favourite topic, which he pioneered in a long series of papers.

Some have criticized Eggen’s data for being often careless and error-prone, which, if true, might be a consequence of his dislike of computers. On the other hand, his prodigous output and work ethic surely made up for the occasional slip.

It is interesting to compare Olin Eggen with the other extraordinarily dedicated photometric observer of the later twentieth century, Alan Cousins (1903-2001) in South Africa. I didn’t meet Alan until 1996, by which time he was already ninety-three, but still working as long hours as an astronomer half his age. But he complained at not having the stamina for working full nights at the telescope that he had in previous years. He observed half nights instead! Whereas both Whitford and Eggen were shy men with few words, Cousins was famous for his loquacity. I spent six months at the South African Astronomical Observatory in 1996 and had many wonderful conversations with Alan. But everyone who spoke to him knew that if you started a conversation, there was little chance of getting away for the next two hours!

Alan Cousins

Like Eggen, Cousins was an absolutely dedicated observer, and did much to establish a system of standard stars for photoelectric photometry in the southern hemisphere, notably in the Harvard E regions. Although he had been an amateur astronomer since his early years, he only had a professional position at the Royal Observatory at the Cape from 1947, having been an electrical engineer before then. Unlike Eggen, his photometry was known for the extraordinary care and precision with which it was executed. Few observers could match Alan’s reliability and precision, even for astronomers half his age. His colleague, Michael Feast wrote of Alan in his obituary: “He was invariably polite, but no attempt to steer a conversation away from his chosen topic, or to end it, was possible. His frugality was legendary – not to say notorious. At one stage he was using the chart rolls on which the photometric traces were recorded four times; both sides and two different colours of ink. These characteristics are those of a man who lived his life according to clear principles; a rectitude inherited perhaps from one grandfather and a persistence inherited from the other.”

I feel greatly privileged and enriched to have known three of the greatest stellar photometrists of the latter half of the twentieth century. Three men very different in personality, but in all cases they were absolutely dedicated to astronomy and wonderful, though perhaps somewhat daunting, role models for others to follow.

(written 8 May 2009)

This entry was posted on Thursday, May 28th, 2009 at 12:00 am and is filed under History of astronomy, JBH, Photometry. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.