How scientists took the first detailed image of star outside our galaxy

Context: For the first time, scientists have succeeded in taking a zoomed-in
picture of a star in another galaxy. The star, known as WOH G64, is located
160,000 light years away in the large magellanic cloud. This discovery was possible
with the help of the European southern observatory’s very large telescope
interferometer (VLTI). VLTI comprises four 8-meter diametric telescope which is
situated in Cerro Paranal, Chili. The interferometer is called GRAVITY that
combines the light from the telescopes to achieve the resolution of a much
larger telescope.

Key points

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Overview: WOH G64 was discovered in
the 1970s by Bengt Westerlund, Olander, and Hedin. The name "WOH" in
the star's name is an acronym for the names of its three discoverers.

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WOH G64 star: The WOH G64
star is located 1,60,000 light years away from Earth in the 'Large Magellanic
Cloud', a satellite galaxy of the Milky Way. It is a 'Red Giant' star, whose
size is about 2,000 times larger than our Sun. This detailed image clearly
shows a star in its dying phase, surrounded by gas and dust as it heads towards
its death in a massive explosion called a supernova.

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Very Large Telescope Interferometer (VLTI): It is the
world’s most advanced optical instrument, consisting of four Unit Telescopes
with main mirrors of 8.2m diameter and four movable 1.8m diameter Auxiliary
Telescopes. The telescopes can work together, to form a giant ‘interferometer’,
the ESO Very Large Telescope Interferometer, allowing astronomers to see
details up to 25 times finer than with the individual telescopes.

Features - The VLT consists of four
individual telescopes. They are generally used separately but can be used
together to achieve very high angular resolution. The four separate optical
telescopes are known as Antu, Kueyen, Melipal, and Yepun, which are all words
for astronomical objects in the Mapuche language.

Significance - The light beams are combined in the VLTI using a
complex system of mirrors in underground tunnels where the light paths must be
kept equal to distances less than 1/1000 mm over a hundred metres.