December 07 – Discovery of Asteroid 423 Diotima (1898)

Asteroid 423 Diotima was discovered from Nice by Auguste Charlois on December 7th, 1898. It’s in the main belt, is a C-type, is fairly large (approximately 170 by 140 km) and rotates once about its axis every 4.8-ish hours.

Diotima has a semi-major axis of a little over 3 AU.  Semi-major axis sounds worse than it is. It’s just the longest radius of of an elliptical orbit.

Diotima of Mantinea
Diotima of Mantinea

Diotima was named, by the Heidelberg Astronomisches Rechen-Institut, or Astronomical Calculation Unit, after one of Socrates’ teachers, Diotima of Mantinea, a woman whose existence remains uncertain; the jury is still out on whether or not she was simply a creation of Plato. It is from the teachings of Diotima that we get the concept of platonic love. I can’t help thinking there’s a clue to her existence (or lack of it) in that name. Surely it would have been diotimic love?

November 22 – Asteroid 156 Xanthippe

Asteroid 156 Xanthippe was discovered by Johann Palisa on November 22nd 1875. It has been classified as a C-type, with a diameter of about 116km and a rotation period of 22.5 hours.

Xanthippe, whose name means “yellow horse”, was the wife of Socrates, and is a woman about whom we know little from historical sources. Even Plato, a man with an interest in Socrates bordering on the obsessive, mentions her only briefly in his Phaedo. In Xenophon’s writings she is shown to be a little on the argumentative side, and this view of her has been embroidered upon, probably unfairly, down the years, until by Shakespeare’s time her name had become synonymous with an aggressive, bad-tempered woman.

Socrates and Xanthippe
Socrates and Xanthippe

The engraving above, by the Dutch artist Otto van Veen, is of Xanthippe emptying a chamber pot over the head of Socrates (supposedly the outcome of one of their many arguments).

1944 Death of Arthur Eddington, aged 61, the man who gave us the Eddington limit, the maximum luminosity achievable by a star.

1969The Skynet 1A satellite was launched from Cape Canaveral on behalf of the Ministry of Defence. This was the first of a series of British satellites providing a means of communication for the armed forces. Being British, of course, it broke after about a year (probably just after the warranty expired) but is still in orbit, and is likely to remain there, according to the UK Space Agency’s “UK Registry of Outer Space Objects” for upwards of a million years.

August 17 – Discovery of Asteroid 295 Theresia (1890)

Main belt asteroid 295 Theresia was discovered on August 17th 1890 by the Austria astronomer Johann Palisa, a familiar name in these pages thanks to his enormous haul of asteroid finds.
This particular body is unusual among the earlier named asteroids in that even now, over a century later, almost nothing is known about its physical characteristics.  So the best I can do today is say that it is about 28km in diameter and has an,absolute magnitude of 10.19.

What I can tell you though, is that the name Theresia is in honour of Maria Theresa Walburga Amalia Christina, daughter of Charles VI, Holy Roman Emperor.  She and her husband, Francis I, Holy Roman Emperor, had sixteen children, one of whom was christened Maria Antonio Josepha Johanna, but became better known later in life as Queen Marie Antoinette of France.


Johann Palisa was born in the region called Austrian Silesia (nowadays part of the Czech Republic), and Maria Theresa’s desire to regain control of this region, following its loss by her father in the War of Austrian Succession, helped bring Prussia and the Habsburg Monarchy to blows in the Seven Years War (known as the Third Silesian War in that neck of the woods).

August 09 – Discovery of Asteroid 165 Loreley (1876)

Asteroid 165 Lorely was discovered today in 1876 by C H F Peters.

Named after the Lorelei of Germanic legend, a siren, similar to Wagner’s Rhine maidens, who sat above the rock of the same name on the Rhine and distracted sailors with her looks and song.


Today’s photograph features (centre) the great German soprano Lilli Lehmann (1848-1929), one of the singers at the first Bayreuth Festival of Richard Wagner’s music, and who helped popularise Wagner in the United States. She is shown here as part of the 1876 premiere cast of the Ring.

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ALSO TODAY . . . .
1975 – Launched today, into an eccentric orbit (to keep it out of the way of the Earth’s radiation belts) was the COS-B spacecraft, an ESA mission with the sole aim of measuring gamma-rays using a spark chamber,
in which the incoming rays were converted into an electron and a positron (causing the spark). Analysis of the spark allowed Cos-B to calculate the direction from which the gamma-ray had come. Cos-B was highly successful, not least in terms of lifespan. This had been estimated at 2 years, but ended up at over 6 years.

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