December 22 – Asteroid 264 Libussa

Discovered on December 22nd 1886 by C H F Peters, asteroid 264 Libussa is an asymmetrical S-type main belt asteroid of somewhere between 50 and 60 km diameter.

It was named after Libussa (Lubossa or Libuše), a half-elf  daughter of the mythical Czech king Krok.  She eventually became the founder of the city of Prague, and ancestor of the whole Czech nation.

Libuse (photo credit: Palic Kap)

Libuse (photo credit: Palic Kap)

Today’s photo shows a detail from the Octárna Hotel, Kroměříž, Czech Republic.  This is alunette (a half moon shaped space) by local artist Max Švabinský. It shows Princess Libuse prophesying the glory of Prague.

There’s not a great deal more to say about Libussa, so it’s back to orbital characteristics.  To date we have come across aphelion (3.18 AU for this particular rock), perihelion (2.42 AU), semi-major axis (2.8 AU), longitude of ascending node (49.8°), and inclination (10.4°).  Today we add another important element of an asteroid’s orbit: the argument of perihelion.  For Libussa, this is 339.27°, and in orbital calculations it is depicted by the letter  ω.  It’s not a “w”, by the way, but a lower-case omega (the word means “great o”) the last letter of the Greek alphabet.  Remember that, because one of these days I’m going to work out how to put some of these calculations in this blog in the form of a table.

The argument of perihelion is the angle between the perihelion and the ascending node.  So if, for example, the value was 90°, that just means that the asteroid would be at perihelion when it reached the northerly point in its orbit.

1981  ⇒  Asteroid 323 Brucia becomes the first asteroid to be discovered by astrophotography, by Max Wolfe.