January 13 – Discovery of asteroid 171 Ophelia (1877)

January 13th, 1877 marks the dicovery of asteroid 171 Ophelia, a member of the carbonaceous (C-type) Themis family, by Alphonse Borrelly. It was one of three he discovered that year, and was named after the daughter of Polonius in Shakespeare’s The Tragedy of Hamlet, Prince of Denmark.

The Themistians are one of the larger asteroid families, with close to 5000 members (still well short of the largest families though; the biggest two are the Vestians, numbering 15,000+, and the Nysians, with over 19,000 members). They orbit in the outer reaches of the asteroid belt, and are a collisional family, thought to have formed from the violent coming together of two bodies at some time in the distant past.

Ophelia (1894) by Waterhouse
Ophelia (1894) by Waterhouse

The accompanying illustration is by J W Waterhouse, and shows Shakespeare’s tragic heroine just before her death (she drowns, falling from a tree when a bough breaks).

Fell in the weeping brook. Her clothes spread wide
And, mermaid-like, awhile they bore her up;
Which time she chaunted snatches of old tunes,
As one incapable of her own distress,
Or like a creature native and indued
Unto that element; but long it could not be
Till that her garments, heavy with their drink,
Pull’d the poor wretch from her melodious lay
To muddy death.

January 13 – Discovery of Asteroid 141 Lumen (1876)

1876 – Discovery of C-type main belt asteroid 141 Lumen by Paul-Pierre Henry, or possibly his brother Prosper. This one was credited to Paul-Pierre, but in keeping with their credit sharing philosophy, the brothers never revealed which one of them actually made the find. Even while they were alive, it was impossible for astronomical journals to attach one brother to a specific discovery with any level of accuracy greater than 50%, so we have no chance now. As with several other of the asteroid discoveries of the Henry brothers, it borrows its name from a book by Camille Flammarion, Lumen: Récits de l’infini.

Cover of
Cover of “Lumen: Récits de l’infini”

You can download Lumen for free these days if you like, but its a bit weird.

141 Lumen is about 130km wide, and shares orbital characteristics with the Eunomia family of asteroids, but is defined as an “interloper”, because of its composition (Lumen is carbonaceous, whereas Eunomians are stony).


January 13 – Discovery of Asteroid 1999 AN10

Asteroid 137108, also known as 1999 AN10 was discovered on January 13th 1999 by the Lincoln Near-Earth Asteroid Research (LINEAR) project run by the USAF, NASA and MIT to discover and track near-Earth asteroids (NEAs).

On August 7th 2027, which is sooner than you think, it will zip past the earth at less than 250,ooo miles (that’s closer then the Moon) and should be visible in fairly modest binoculars.

1999 AN10 is part of the group known as the Apollo asteroids. These are a particularly interesting group for astronomers because they all have orbits which cross that of the Earth, making some of them potentially hazardous. The Apollos are named, as usual, after the first of their number to be discovered, 1862 Apollo, found in 1932 by Karl Reinmuth. The Chelyabinsk meteor that we all saw streaking across the Russian sky in February 2013 on dashcam footage is believed to have been an Apollo.


1901 – Discovery of asteroid 465 Alekto by Max Wolf. Alecto was one of the Furies of Greek mythology.


2003 – Launch of the Cosmic Hot Interstellar Spectrometer (CHIPS).