Astronomy - USA (2022-01)

(Maropa) #1

A dwarf irregular galaxy, the Large Magellanic Cloud (LMC) is one of the most stunning
deep-sky treasures of the southern celestial hemisphere. It is visible to the unaided
eye as a soft glow spanning 9° by 11° of sky across portions of Mensa and Dorado.
Its name, along with that of its companion the Small Magellanic Cloud (see #63),
were bestowed in honor of explorer Ferdinand Magellan. He and his crew were
the first to bring news of these sights to the Western world after their round-the-
world voyage from 1519 to 1522. Of course, Indigenous peoples from the Southern
Hemisphere had been familiar with both since ancient times.
Estimates place the LMC roughly 160,000 light-years away. It is home to approxi-
mately 30 billion stars — about one-tenth the Milky Way’s stellar population. The
LMC is also peppered with 700 open clusters and 60 globular clusters, and its many
regions rich in interstellar gas and dust make it a hotbed of star formation.
The pull of the Milky Way has distorted the LMC into the galactic mélange we see
in photographs. However, careful observational studies have shown that the LMC
possesses a subtle spiral structure with two truncated arms extending from a central
bar. The overall shape resembles a seahorse displaying its prominent tail.
That tail is one of the sky’s most magnificent HII regions: the Tarantula Nebula (see
#22). At its center, thousands of massive stars are blasting out intense radiation and
winds, heating the surrounding hydrogen gas to millions of degrees. — P. H.


80 Large Magellanic Cloud

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