A recent
observation of the red giant—the largest in the constellation Scorpio—shows
that from its cosmic depths, the star is expelling unknown matter as it
approaches the end of its life. In the insides of the star Antares lies a
powerful and hitherto unknown force that astronomers have not seen until now.
Judy Schmidt
/ Infrared Image provided by Rho Ophiuchi Complex
Someday,
sooner or later, the sun we see every day will become a giant star and grow to
such an extent that it will swallow the Earth and other planets in the inner
solar system. For scientists, this inescapable fate involves the challenge of
looking beyond our solar system to decipher and understand the evolutionary
cycles of these incandescent stars and their mechanisms at each stage.
Antares is HUGE!
In order to
find out as much as we can about stars and red giants, a new study, supervised
by Keiichi Ohnaka, a researcher at Chile’s Universidad Católica del Norte
(UCN), attempts to understand how and why the red supergiant Antares can expel
so much matter off its surface as it nears the end of its life and nears its finale as a spectacular supernova.
The enormous
size of Antares, 883 times greater than the sun, makes it the ideal candidate
for the study of what could happen one day to our Sun, and eventually the Earth
as our star grows.
Antares is
also known as Alpha Scorpii, which means it is the brightest star in the
constellation Scorpio. Red in color, it is visible in the night skies of
August.
In an
interview with Space.com, Professor Ohnaka said: “With this study, we can open
a new window to observe stars other than the sun … in a similar way that we
observe the sun. We can then
apply this technique to investigate other problems — not only supergiants, like
Antares but also other types of stars and other unsolved problems.”
The team of
astronomers led by Keiichi Ohnaka published in the journal Nature a study that
presents a new vision of the supergiant.
For their
observations, scientists used the VLT observatory, a system of four telescopes
measuring eight meters each, capable of working in combination as a single
instrument, making it the largest optical telescope in the world (hence its
name: Very Large Telescope ‘, or VLT).
The behavior
of the spectrum of CO emissions allowed astronomers to estimate the density and
velocity of Antares plasma flows. And it is at that point that they were caught
off guard noticing something totally weird: the density is significantly higher
than expected.
This means
that the substance expelled from the depths of the star to its surface is
quantitatively far superior to what was thought possible according to previous
concepts.
Comparison of sizes between Antares and the Sun. The black circle represents the size of the orbit of Mars.
At the
moment, this can only be interpreted like this: in the insides of the star
Antares lies a powerful and hitherto unknown force that astronomers have not
seen until now.
This study
was presented in the Journal Nature and can be accessed by clicking here.
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