Solar System

(The Clock)

Horologium is one of the many faint southern constellations devised by Nicolas Louis de Lacaille. This constellation was originally called Horologium Oscillatorium and it was a tribute to the invention of the pendulum clock in 1656.

The deep sky objects in Horologium are not very well known and they include faint galaxies and globular clusters such as NGC 1261. The brightest deep sky object is the variable star R Horologii, this star has one of the largest brightness ranges.
The magnitude varies from a naked eye visibility of magnitude 5 to a dim telescopic visibility of magnitude 14 in a period of little over a year.

NGC 1512:
A bright barred spiral galaxy that lies 30 million light years distant. It is very large at a width of 70 000 light years. One of the most fascinating aspects of NGC 1512 is a starburst circumnuclear ring of blue star clusters that encircles the core. This galaxy has an elliptical companion called NGC 1510.

AM-1 is a globular cluster that was discovered by Barry Madore and Halton Arp during their compiling of candidates for their southern peculiar galaxy catalogue. It isn't very well known but it is actually the most distant globular cluster in the Milky Way at an astounding distance of 398 000 light years!

Needless to say, crystal clear pitch black skies as well as a large telescope and an adequate supply of patience and persistance is required to find this magnitude 15 globular cluster. The view isn't exactly spectacular but the amazement that stems from seeing this object is derived from the fact that you are observing a globular cluster that is so far away that it is further than the distances of both the Magellanic Clouds combined!

AM-1 lies in the fringes of the Milky Way and belongs to a class of globulars known as Outer Halo Globular Clusters. There are very few that belong to this category and are known to observers who specialise in observing obscure objects for multiple reasons that include seeing things that very few others have seen or to challenge themselves. The brightest globular that belongs to this rare class of clusters is called Djorgovski 2 and shines at an acceptable magnitude 10. You might assume that it is easy to find due to its magnitude but what contributes to the difficulty in locating it is that it resides in the vast Milky Way fields of Sagittarius near the Inkspot Nebula (B86).