Superflares emit large amounts of dangerous high-
energy particles, but life on Earth is protected by a thick
atmosphere, and there are almost no effects. However,
now is the space age, and there are astronauts in space,
and maybe also on the Moon or Mars in the near future.
Superflares can cause risks for them since they don’t have
the shield of the thick atmosphere, so special preparations
should be done.
Although superflares do not affect survival for life
directly – of course, no life extinction is expected to occur
because of superflares – our daily life can be severely
damaged by superflares. Now our society and our daily
lives are strongly supported by technologies usingelectricity and satellite communication, for example,
GPS. Large plasma ejections, called coronal mass
ejections, or CMEs, caused by superflares can generate
a large magnetic storm in the Earth's magnetosphere,
and this can cause severe damage to electric equipment,
for example, transformers, and satellites. One example
is the large blackout in Quebec, Canada, in 1989 caused
by a relatively large solar flare. At this point, life on Earth- especially human life – could potentially experience a
severe solar eruption.
Dr Yuta Notsu is an overseas research fellow
at the University of Colorado Boulder and
focuses on the study of stellar activity
STARSIf the Sun erupted with a
'superflare', how harmful
would it be for life on Earth?
‘Cold quasars’
sweep around
material at a
galactic centre,
but still have
gas in the
outskirts
© Michelle VigeantWhatis a 'cold quasar'?
A cold quasar is a very active supermassive black hole whose host
galaxy still has a lot of cold gas in it. When supermassive black
holes, which lie at the heart of every massive galaxy, are actively
accreting new material, they are then known as an active galactic
nuclei (AGN). Every galaxy goes through an AGN phase. However,
the most massive of galaxies with the most massive of black holes
become quasars.
Quasars are the brightest objects in the universe due to how
quickly they are accreting material! This material is super-heated
as it swirls around the black hole at nearly the speed of light. This
turbulence can produce dramatic winds that sweep through the host
galaxy, preventing new generations of stars from being formed, and
essentially choking the host into becoming a passive, elliptical galaxy.
Usually when we see luminous quasars without any dust in the
very centre of the galaxy, the decline in star formation has already
begun. Cold quasars were quite a surprise! This rare quasar has swept
away dust from the galaxy centre, but the outskirts still have an
abundance of cold gas and dust, producing thousands of new stars
each year.
Cold quasars are likely at the very beginning of the end. The
quasar influence is marching through the galaxy, and soon the host
will lose the ability to form new stars and enter the passive phase of
its life.
Dr Allison Kirkpatrick is associate professor of
physics and astronomy at the University of KansasASTROPHYSICSASK
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