The constellation Dorado was introduced at the end of the 16th century by Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman and by Bayer in 1604. Dorado is easily located in our Southern sky due to part of the Large Magellanic Cloud (LMC) lying in the southern part of the constellation .The remainder of the LMC is in the constellation Mensa.
The brightest stars Alpha Doradus Mag 3.3 is a blue-white star at 176 ly, and
Beta Dor a yellow-white supergiant 1040 ly away is a bright Cephieid variable going from mag 35. to 4.1 every 9 days 20 hours.
R Dor (4h37m -62°.1’, 204 ly away) is an orange-crimson irregular Mira-type variable star varying between 4.8 and 6.6 mag. over 338 days.
S Doradus (05h18.6m -69°15’) super luminous variable star ranging from mag 8.6 to 11.7, located in the southern part of cluster NGC1910. It is one of the brightest stars in the LMC.
h3683 (04h39.4m -59°02’)is a yellow binary mag. 7 / 7.5.
The Large Magellanic Cloud is a large, irregular spiral satellite galaxy of our local group, orbiting the Milky Way. The Magellanic Clouds were named for the Portuguese explorer Ferdinand Magellan after his 1519 circumnavigation voyage, when they were first described by European observers, although they had been long know to southern hemisphere inhabitants. The LMC can be seen in the southern sky on any clear dark night as a large hazy region. There are a multitude of gaseous nebulae, open and globular clusters in the LMC. Over 200 objects are listed in the New General Catalogue – you could spend many nights observing this region alone. The Tarantula Nebula (NGC 2070) 05h38.6m –69°05’over 20’ across at 160,000 ly away is the most spectacular object to observe in the LMC. Also known as 30 Dorado. Viewed with fairly low power of 86 x to 130 x magnification with my 5 inch (128 mm) refractor, this emission nebula shows extensive tendrils of bright bluish haze amongst dark background regions. With a UHC filter (or OIII filter if you have larger aperture) the series of loops off the central starry region stand out and almost come to life.
NGC 1763/1769 (04h56.8m -66°24’) mag. 8 – 10, are bright well-defined emission nebulae enhanced by dark surrounding regions. The rich open cluster NGC 1761 lies to the south. 1763 is the larger nebula and described by Hartung as bean-shaped, 4’x2’. A 20 cm (8inch) scope makes this group more interesting to observe. Located at the north-western edge of LMC.
NGC 1566 (04h20.0m –54°56’)a mag. 9.5 face on Seyfert Spiral Galaxy, 70 million ly away. 2 short spiral arms with and a bright central nucleus are visible with a moderate sized scope of 30 cm. In the 5 inch it was observed as an irregular hazy patch.
NGC 1549 & 1553 (04h14.7m -55°42’) Mag 9.9, 3.70’ in size & mag. 9.5, 4.10’ are two bright elliptical galaxies approximately 13’ apart. These are visible with even a 7.5cm scope. They are the brightest of a small group of galaxies south-west of Alpha Dor.
NGC 1672 (04h44.9m –59°20’)mag. 11, 4.80’ a barred spiral galaxy is only a hazy spot with my 5 inch. 30 cm should show a bright haze with a well defined nucleus.
NGC 1617 (04h30.6m –54°42’)is another faint mag. 10.4, 4.70’ galaxy just north west of Alpha on a line towards Gamma.
Sources: Hartung’s Astronomical Objects for Southern Telescopes, 2nd Ed 1995;Atlas of the Southern Night Sky, S Massey & S Quirk, 2007; The Night Sky Observers Guide, Vol.2 G.R. Kepple & G.W Sanner, 2000; Burnham’s Celestial Handbook, Volume 2, 1966/1978; Collins Stars and Planets, Ridpath & Tirion 3rdEd 2000;Star Atlas Pro Version 6.2; Photos from Digital Sky Survey www.ngcic.org/dss.