Soon “Outstanding Southern Hemisphere Objects”: GALAXIES, CLUSTERS OF GALAXIES, STELLAR NURSERIES, PLANETARY NEBULAE, SUPERNOVA REMNANT and GLOBULAR CLUSTERS.
Omega Centauri globular cluster -NGC 5139-
Like several others globular clusters, this giant one in Centaurus, NGC 5139, was originally named as if it were a star. Omega Centauri is an old cluster, about 15 billion years old. It was formed very early in the history of the Galaxy, at a time when the matter in the Galaxy was a nearly pure mixture of hidrogen and helium, with only a very small percentage of heavier elements. The distance a Omega Centauri has been determined as 16500 light-years.
47 Tucanae globular cluster -NGC 104-
Far south in the constellations of Tucana and close to the SMC, we find NGC 104 or 47 Tucanae. After Omega Centauri it is the second brightest globular cluster in the sky, and to the naked eye it appers like a star of fifth magnitude. The 47 Tucanae globular cluster lies at a distance of 13000 light-years and it has a number of interesting features. It is among the “younger” globular clusters; about 10 billion years old.
Eta Carinae nebula -NGC 3372-
The heart of the Eta Carinae nebula is the star Eta Carinae itself, seen here to the left of the centre. Spectral measurements in the infrared show it to be a star with extreme characteristics. With a luminosity 5 millions times that of the Sun, it is one of the most luminous stars in the Galaxy. Its total mass is over 100 Solar masses, but it loses gas at a rate of 0.07 Solar masses per year, much more than any other known star.
Tarantula nebula in LMC -30 Doradus-
30 Doradus, which is also known as the Tarantula nebula because of its shape, is one of the most fascinating gaseous nebulae in the sky. Its size is enormous, and the mass of its luminous gas amounts to half a million solar masses. Some astronomers believe thata 30 Doradus is the nucleus of the LMC. If that is true, it would be unique among galactic nuclei by being so lightly obscured, and therefore so favourably placed for astrophysical studies, including by optical methods.
Jewel Box (K Crucis cluster) -NGC 4755-
Cruxis the smallest of all the constellations, and it is known not only for the Southern Cross, but also for this beautiful stellar cluster, famous under the appropriate name of the Jewel Box. The cluster is young and contains several blue supergiants, like K Crusis itself, and also a number of more evolved red supergiants. When viewed through a small telescope, it is an impressive cluster of differently coloured stars, and it is also dimly visible to the naked eye.
Helix nebula -planetary nebula -NGC 7293-
The Helix nebula is situated in Aquarius at a latitude of -57°. To visual observers, even to those who use a medium-sized telescope, the Helix nabula is not particularly impressive. It is large, with an angular diameter about half as large the disk of the Moon. However, photographic techniques reveal its complicated fine structure. This is particularly true when using a film sensitive to the red H line; the human eye is insensitive to faint light of this colour.
Centaurus A galaxy -NGC 5128-
NGC 5128 is a peculiar galaxy, which consists, in an unusual way, of two quite different components. The main component can be classified as an elliptical, or an SO galaxy, which is the reason for presenting this galaxy here. But this component is surrounded by a strange dark band of absorption. It is caused by the secondary component which has the form of a disk of stars, gas and dust, with a composition similar to that of the disk of a spiral galaxy.
barred spiral galaxy in Fornax cluster NGC 1365
Assuming it is a member, NGC 1365 is the largest and most impressive galaxy in the Formax Cluster. It is in fact one of the largest spirals in the southern sky. More specifically, it is called a barred spiral galaxy. It has a “bar” crossing the central part, and from the ends of the bar two distinct and quite open, spiral arms is a result of the orientation of the galaxy, relative to our line of sight. In fact, the disk of NGC 1365 is inclined at 55 degrees to the tangencial plane of the sky, and the north-west side of the disk is the one closest to us.
spiral galaxy in Sculptor Group -NGC 300-
NGC 300 is a pretty Sc galaxy in the Sculptor Group, very similar in appearance to the Local Group, galaxy M33 in the northern sky. It has a small nucleus and a faint. In this photo we can clearly recognize the S-shape of the inner part of the spiral structure. Its outer parts are fainter and more irregular. An overall asymmetry will be noticed, since the northeastern part of the galaxy is clearly brighter and more extended than the southwestern part.
Fornax Cluster of galaxies
Fornax is the Latin word for furnace, and is the name of a constellation in the southern sky. This picture shows the impressive Fornax Cluster at a distance of 60 million light-years. The galaxies in the photo are of different types. Some are spirals, like NGC 1437. Many are ellipticals, like NGC 1399, 1404 and 1427 – to mention the brighter ones only. At least one, NGC 1427 A, is of the irregular type.