Constellation Profile - Horologium

We are now out of the Lacaille constellations that are visible from Calgary.  However, if you are lucky you may be able to see Horologium from Alberta as there are some stars that reach up to 39.75°S.  If you are ever south enough to see the naked eye star Alpha Horologii you can find it by star hopping by drawing a line from Betelgeuse through Alnitak (Easternmost star of Orion's belt) about 50°.  The constellation is quite long by the measure of celestial latitude .  You can just barely see it from the Alberta/US border and even if you go all the way down to Key West you will still not fully see it.  Only when you drop below 23°N can you see the entire constellation.  The map below shows where it is in relation to some familiar constellations in our sky.

Star-hop to Horologium

Horologium is originally etymologically derived from Ancient Greek and is the Latin word for 'clock'.  This may be familiar to anyone who follows a 'Horoscope'.  A horoscope simply means time observation.  Horologium continues the theme of enlightenment laboratory equipment that Lacaille chose to honour.  The constellation is supposed to represent a 18th century pendulum clock as drawn by Lacaille below.

Lacaille Horologium

As with all of the constellations, Johann Bode went on to improve the depictions in his work: Uranographia.  His version is shown below.

Uranographia Horologium

Unlike previous Lacaille constellations we have heretofore discussed Horologium has quite a number of deep sky objects.  These objects are great targets for amateur astronomers throughout the United States and South.  NGC 1261 also known as Caldwell 87 is a globular cluster that makes its home within the constellation.  Many galaxies reside in this region that can be viewed with large backyard telescopes.  The Horologium Supercluster is located here and contains several tens of thousand giant galaxies and many more dwarf galaxies.

Although I may never get the opportunity to see this constellation for myself, I drew a map of it to add to my collection.

Horologium

If I lived in the Southern Hemisphere I would notice that the Large and Small Magellanic Clouds will straddle the southernmost point of Horologium.  I have seen pictures of southern hemisphere skies and I can only imagine how beautiful it would be to see with my own eyes.

Another final interesting fact about this constellation is there is a star located within its boundaries known as R Horologii.  This variable star fluctuates in apparent magnitude from the naked eye 4.7 to dimmer than Pluto on a good night at 14.3.  This cycle lasts just over 400 days.