Dorado is a very important southern constellation near the south celestial pole. Its importance is due to it containing the wreathing mass that is the Large Magellanic Cloud. This is not actually a cloud, it has the misty appearance of a cloud and is one of the satellite galaxies of the Milky Way.
Other less known objects in Dorado include beautiful spiral galaxies that have been imaged by observatories that have the capability to image southern objects such as the Anglo Australian Observatory.
|The Large Magellanic Cloud is a plethora of opulent treasures. This dwarf galaxy has hints of barred spiral structure that was discovered fairly recently. Because of its close distance, nearly 500 star clusters and nebulae with 400 in the NGC and IC catalogues can be observed with a medium sized telescope. There are at least a thousand more objects that have been detected with observatories. The Tarantula Nebula, which is the largest nebula visible in the image can even be seen with the naked eye from a dark location. Hover your mouse over the many objects to find out what they are.|
|Image copyright R. Gendler|
|Overshadowed by its more thoroughly explored neighbour, the LMC, NGC 1566 is a gorgeous bright blue Seyfert spiral. It has very faint outer arms that enshroud the main structure, which makes it slightly similar in shape to NGC 210 in Cetus.|
|A magnificent barred spiral galaxy that is also classed as Seyfert. It lies at the distance of 60 million light years and is populated by many HII regions and multiple star clusters. These line the thick opaque form of dark dust lanes that meander their way through the two spiral arms.|
|Large Magellanic Cloud:|
Under a dark southern sky, glimpsing in the direction of Dorado might reveal a misty patch that appears to be a terrestial cloud. In fact it is an extragalactic entity, a dwarf galaxy that is a companion of the Milky Way. It is very nearby at 180 000 light years away and this factor has allowed very detailed studies of the various HII regions that are sprinkled across its surface.
Historically this galaxy has been known since 964 AD when it was observed by the Persian astronomer Al Sufi. The name comes from the explorer, Ferdinand Magellan who was the first person to reveal the existence of the LMC as well as the Small Magellanic Cloud in Tucana to the western world in 1519.
Twenty years ago, a supernova blazed forth near the quivering mass of the Tarantula Nebula. Observations were made before and after the supernova, so for the first time in recorded history, the star that exploded as the supernova could be identified. This is an amazing but underrated astronomical achievement of the 20th century. The name of the supernova is 1987A because it exploded in 1987 (actually it exploded
Although not very apparent, the LMC is actually interacting with the Milky Way and there is even a bridge of gas between the Large Magellanic Cloud and the Small Magellanic Cloud.
Many nebulae and star clusters are found in the LMC and some of them are described below. Some of them are very unique and don't have a counterpart in our native galaxy. The proximity of the LMC has allowed hard working astronomers the chance to scrutinise offshoots of regular objects that don't exist in the Milky Way such as supermassive HII regions, supershells and young primordial star clusters.
|Tarantula Nebula (NGC 2070):|
Gigantic is an understatement when describing the size of this huge HII complex in the LMC, it is 75 times larger than the Orion Nebula. The wrangling mass of crimson tendrils and loops give it the appearance of a galactic tarantula and the large size of the nebula is apt since tarantulas tend to be larger than other creepy crawlies.
The honeycomb style web of nebulosity enshrouds a super star cluster known as R136. The radiation released by the cluster is in such abundance that it has contributed to the Tarantula Nebula being the most luminous HII region in the local galaxy group that the Milky Way and Magellanic Clouds belong to. This is known quite simply as the Local Group and other famous cosmic landmarks that belong to the group are the Andromeda Galaxy and the Triangulum Galaxy.
R136 contains many Wolf Rayet stars and the largest one is 133 times the size of the Sun! The cluster is similar to a globular cluster as the central region is very compact with 120 stars packed into an area that is only 15 light years wide. In comparison the entire Tarantula Nebula extends for a staggering 3000 light years.
|An enchanting globular cluster near the centre of the LMC's bar, this is not an ordinary cluster. Globular clusters are usually hives of a old age stellar population but this is a collection of stars that are only 50 million years old. A young population usually indicates the stellar size to be small but there have been some giant stars that have exploded and left their legacy behind as strands of blue wispy nebulosity to the left of the cluster.|
Not to be confused with 'NGC', the 'N' is a shortened form of Henize, which is a southern nebula catalogue.
N44 is at first glance dwarfed by a large gaping cavity that will continue to expand under the strong effects of the stellar winds ejected by massive young stars that are highly energetic with a strong presence in ultraviolet light.
The Henize catalogue was a huge undertaking by astronomer Karl Henize who published this huge catalogue of nebulae and clusters in both the LMC and SMC. It was completed in 1956 and was so extensive that there were five sets, three for the LMC and two for the SMC.
|NGC 2014 and NGC 2020:|
A mysterious area towards the north of the LMC, NGC 2014 and NGC 2020 make a strange but intriguing pair. NGC 2014 is a large sized star cluster embedded in red nebulosity that is only visible due to the ionizing nature of the ultraviolet radiation released in swathes by the hot young stars. The stellar winds produced by the stars are so intense that they affect the hydrogen gas. This in turn would lead to the formation of a gas bubble.
NGC 2020 is one such bubble shaped nebula that was produced by only one star. Surrounding the star appears to be a hollow cavity that the bubble seems to encircle in a vague ring like structure. The bright green hues of the bubble give an endorphin inducing appearance of a planetary nebula and the rare colour might be because of the ultraviolet radiation. A similar bubble shaped nebula with the imaginative moniker of the Bubble Nebula is found in the Milky Way but this is caused by a central Wolf Rayet star as opposed to a regular star in the case of NGC 2020. Also the Bubble Nebula's colour is an overfamiliar shade of red, which is derived from the hydrogen gas.
A cocoon shaped wreath like nebula that consists of many different components. At the centre lies a cavity with a bright blue star cluster, which gives it an appearance similar to that of N44. A trio of oval shaped patches lie at the top with two containing embedded star clusters. All the separate parts combine to form a magnificent spectacle that is best appreciated in very long exposure astrophotography.
NGC 1763 is the designation for one of the three patches with the entire complex being referred to as N11 with one of the northern extensions being catalogued as N11B. The whole entire complex is the second largest HII region in the LMC but is snubbed in favour of the Tarantula Nebula.
The 1000 light year wide cloud is centered around the star cluster NGC 1760. At the heart of this cluster is an OB association called LH9. Research has determined the age of LH9 to be approximately 3.5 million years old, this means that the N11 complex is much older than the Tarantula Nebula.
Investigations have revealed the more evolved nature of N11, it is likely that a 2nd generation of star formation is taking place. Evidence of this is a lack of infrared sources, a greater abundance of these is found in less evolved nebulae. Further adding to this is that many of the infrared sources in N11 share the chracteristics of young stellar objects and protostars.
Short for Henize 70, this ultra luminous superbubble of rapidly expanding gas is being blown by the stellar winds of a conglomeration of massive stars. This process must have been occuring for many millions of years as the expansion has caused the size of the ring shaped bubble to be one tenth the diameter of the Tarantula Nebula.
The appearance of the bubble isn't smooth, it is an interweaving of web like filaments. At the centre of the bubble is the ionizing source, an OB association called LH 114. The influence from the surrounding environment goes beyond the mere shaping of the shell, the south western part emits a copious amount of x-rays. It is probable that this is due to supernova explosions.
Some amateur astronomers in the south are discouraged from exploring the hundreds of nebulae in the LMC and tend to only view the prominent Tarantula Nebula. The discouragement is due to many factors such as confusing mazes of star clusters that make locating a specific object difficult, separate parts of nebula complexes being given their own designations instead of one single designation for the whole nebula and print based star charts only mapping a few objects. The main problem is that the profusion of objects takes many weeks of observing to fully comprehend and some observers might repeat their observations unintentionally.
Even though is seems unlikely, NGC 1910 could help alleviate the most severe problem by being used as a navigational landmark. Since it is near the centre of the LMC, it could be used to start an observing path that stops at other highlights such as the Tarantula Nebula and some observing sessions could be concluded with one of these more easily located objects and the next observing night could be resumed from the previous highlight object.
Another way that NGC 1910 could be used in an observing plan is by starting from the north and progressing towards NGC 1910 near the centre and then going onwards to the Tarantula Nebula and from there towards the south and towards the opposite side of the Tarantula Nebula. The downside of this approach is that this might skip some wondrous objects but it does reduce the misuse of observing time and provides some basic organisation to a multi night observation.
NGC 1910 is a bright U shaped cluster and contains the ultra luminous supergiant
|The brilliance of NGC 2014 and
NGC 2020 is not diminished by the spectacle of the Tarantula Nebula because of their unconventionality.
|NGC 1763 is a different sight compared to the more placid shaped nebulae situated in the Milky Way. Click the image for an unbelievably serene false colour version by Don Goldman.||Image copyright D. Goldman/SSRO|
|Image copyright E. Trimarchi|