Solar System

(The Furnace)      

Many of the southern constellations were devised in more recent times when the explorers of northern countries journeyed to map out the parts of the world that were unknown to them. Because of this, most of the southern constellations represent technology or machines that were from that time. In contrast, the northern constellations were devised by ancient civilisations at a time when myths and legends about gods and heroes were prevalent. This is why most northern constellations have an interesting backstory.

The story about Fornax is that it was invented by Nicolas Louis de Lacaille in 1752 to honour the beheading of the chemist Antoine Lavoiser during the French Revolution.

Even though it is southern, some of its deep sky objects can be seen in the north although near the horizon rather than high in the sky where there is less atmosphere for the light to penetrate. There are many weird bizarre galaxies as well as the giant barred spiral NGC 1365 that some consider to be the greatest barred spiral in the sky.

NGC 1365:
A hugely venerable barred spiral galaxy, many regard it to be the greatest of its type. A behemoth of a galaxy, it is so large that it spans 200 000 light years at a distance of about 60 million light years! It is a member of the Fornax galaxy cluster and is incredibly active. Two dark brown dust lanes swirl around a very energetic nucleus that is very likely to contain a supermassive black hole. Evidence for NGC 1365 being abnormally active is the detection of radio and x-ray jets emitted by the core region.
NGC 1360:

A highly enchanting planetary nebula, NGC 1360 is another giant amongst the many galaxies of Fornax as it is very large in size. It is likely to be the largest southern planetary nebula.

It has an amorphous shape and was only found to be a planetary when it was analysed and doubly ionised oxygen was detected. The oxygen gives the shell a wondrously vivid turquoise colour.

A bizarre aspect to NGC 1360 is a jet of material emanating from the northern part. The general consensus is that this is gas ejected by the central star prior to morphing into its current state.

NGC 1316-7:

One of many radio sources in the sky, NGC 1316 is an extremely disturbed elliptical galaxy that is currently merging with a spiral galaxy. This merger has caused concentric shells of gas and stars to ripple outwards as well as distorting the smaller NGC 1317 above it. These qualities are sufficient enough for it to have been classed as peculiar by Halton Arp, it has the alternative designation of Arp 154.

Scientific observations have detected enormous lobes visible in radio waves. Because it is a radio source, it is also called Fornax A. Another southern galaxy with these is Centaurus A.

NGC 1097:

Another barred spiral, the difference between this and the more popular NGC 1365 is that it has weak flimsy spiral arms. They accentuate the dazzling bar that has a black hole at the centre, the effects of this can be seen as rivers of dust twirling towards the core. The black hole is very energetic as four jets of gas blasting outwards into space were discovered in 1975.

The edges of the bar and the areas where the bar and spiral arms meet up are home to multiple sites of star formation. This is most likely to be caused by the interaction with the galaxy's elliptical companion NGC 1097A. The effects of the interaction are strongly felt by NGC 1097, the spiral arm that faces the companion is more distorted than the other one. Due to this interaction, Halton Arp considered this galaxy to be peculiar and put it in his Arp Atlas at number 77.

Fornax Dwarf:

Discovered in 1938 by Harlow Shapley, this dwarf spheroidal galaxy is fairly unremarkable except for one fact, it is home to the brightest extragalactic globular cluster after NGC 1850 in the LMC.

NGC 1049, a magnitude 12.7 globular is one of six that were found in this galaxy. Large telescopes are required to resolve it into stars and it is possible to see at least three of the others. Surprisingly, NGC 1049 is actually brighter than its host galaxy and was discovered more than 50 years prior to the discovery of the galaxy.

Extragalactic globulars are great challenge objects for experienced observers. They are extremely difficult to find and very detailed finder charts are a must have as they look like stars due to the vast distances of the galaxies that contain them. Galaxies that contain extragalactic globulars that are brighter than magnitude 20 include the Andromeda Galaxy, Triangulum Galaxy, NGC 2403 in Camelopardalis and another dwarf galaxy, the Wolf Lundmark Melotte galaxy in Cetus.

NGC 1365    
NGC 1365 is an exquisite barred spiral galaxy that is visible to southern observers. It is one of the largest and is considered as one of the best alongside NGC 1300.
Image copyright R. Gendler