We,
the inhabitants of the earth, cannot imagine how many wonderful incidents have
been happening all over the universe for long ages. All of these things not
only just surprise us but increase the range of our knowledge too. Today we are
going to discuss about such a surprising fact.
One
of the many stars in the constellation Velpecula, about 64.5 light-years or
19.78 parsec from Earth, is HD-189733. (Light year: The distance that
light travels in a year. Parsec: The largest unit of distance in
space research. 1 parsec = 3.26 light years). The word HD here means Henry
Draper, an American doctor and amateur astronomer. This list includes stars
with certain characteristics when compiling names of stars. This HD-189733 star
is a combination of two stars. One of the stars is HD-189733A which is an
orange dwarf star and the other is HD-189733B which is a red dwarf star. These
two stars continue to orbit the common center of mass (Barycenter) between
them. Between these two stars, HD-189333A has a planet called HD-189733b. This
planet is our main discussible topic today.
The
annual motion of this planet is extremely terrifying. The planet orbits its
star HD-169633A once in just under 2 days and 5 hours as earth's time. During
this orbit, the speed of the planet is 152 km per second or 5,47,200 km per
hour. Another notable feature of this planet is that it is tidally locked with
its star, meaning that its diurnal motion and annual motion are equal. In other
words, one side of HD-189733b is always bound to its star HD-189733A or does
not rotate around its own axis. This feature is not found in any of the planets
in our solar system, but in the case of satellites, it is tidally locked with
its planet. It is not yet known whether HD-189733b has any satellites. If there
is, then the radius of that satellite cannot be more than 0.8 times the radius
of the earth. So far no ring around this planet has been discovered. Another
feature of HD-189733b that sets it apart from other distant planets is that
HD-189733b has been able to block most of light of its star out of all the
planets, discovered outside our solar system so far. Observations and
calculations show that the planet HD-189733b can block about 3 percent of the
light from its star. This phenomenon is called Photometric Transit Depth.
Initially,
scientists had been engaged in controversy over the planet's orbit for some
time. A group of scientists claimed that the brightness of a star suddenly has
increased when the planet reaches a particular point in orbit during rotation
around the star and the interrelationships between planets and stars are
actively involved in this phenomenon. Another group of scientists rejected the
claim that the excessive brightness was not the normal brightness of the star
but was responsible for the abnormal scattering of the X-rays from the star. Scientists
later observed that the brightness of a star has nothing to do with any particular
position on the planet because the brightness of the star also increases in
HD-189733A in addition to those specific positions of the planet. Their
hypothesis is that since stars and planets are very close to each other, the
brightness of stars may increase as a result of their own magnetic field or
some other reason.
The
atmosphere of the planet HD-189733b is quite amazing, which is why a strange
thing is happening here. But before talking about this, one has to have an idea
about the atmosphere of this planet. It has already been said that the
atmosphere of this planet is very hot and the heat, absorbed from the star,
spreads evenly all over the planet. HD-189733b has no stratosphere in the
planet's atmosphere. The presences of elements such as carbon monoxide and
carbon dioxide have been found in the atmosphere of this planet. The
concentration of carbon monoxide, however, is higher in the luminous part of
the planet. In 2006, scientists discovered through the Spitzer Space Telescope
that a significant amount of water vapor was present in the atmosphere of
HD-189733b. Within a few days, scientists discovered through the Hubble Space
Telescope that HD-189733b contained methane and a few other types of organic
matter in the atmosphere.
There
are indications of the presence of many astonishing phenomena in the atmosphere
of this planet that we cannot even imagine in the case of earth. Indications
for the presence of silicate, sodium, etc. have been found in the atmosphere of
HD-189733b. Fifteen years after the planet's discovery, in 2020, scientists say
potassium may be present in its atmosphere. However, the amount of potassium in
the air is very low. Substances that are estimated to be present in the
atmosphere of this planet are carbon, carbon monoxide, carbon dioxide, methane,
iron, hydrogen, water vapor, helium, potassium, sodium etc. Scientists have
further found that the presence of X-rays is three times greater than the
amount of visible light in the atmosphere of this HD-189733b planet. Maybe this
X-ray has something to do with the magnetic field of the planets and stars,
which causes the brightness of the star in HD-189733A to suddenly increase. The
atmosphere of this planet is constantly evaporating. Scientists estimate that
the release of 1-100 gigaton of alpha particles or the central part of the
helium atom from this HD-189733b planet may be due to this reason. (1 gigaaton
= 10,000,000 kg) This phenomenon was first reported in 2010. Atomic radiation
in the form of alpha particles is much higher than previous scientific report in
the atmosphere because the volume of atmosphere is much more than the
scientists have predicted which scientists estimate is much larger than the
planet's atmosphere. It is still unknown to us whether there is any relation
between this radiation with drawing of huge amounts of gas from the planet by
the star HD-189733A towards it.
Scientists
further speculate that at a certain height inside the planet, the atmosphere of
planet condenses and forms a semi-transparent fog like veil, and if we try to
see its star from the day-night junction of this planet, it can be seen red
like the sun at sunset from our earth.
We
have only been surprised by the extensive research and observations we have
made on HD-189333b since its discovery. This planet also has air currents like
our earth and it usually travels at a very high speed from the luminous region
to the dark region and slows down a bit and returns to the luminous region. The
speed at which air flows in the atmosphere of this planet is unbelievable. The
winds blowing here at any given moment can reach a maximum speed of 2.42 km per
second or 8,700 km per hour. This speed is about seven and an half times the
speed of sound on earth. Just as water falls to the surface of the earth
through precipitation at different times on our planet, so does the planet
HD-189733b, but it is a little different. Due to the intense heat, very strong
winds, the unusual intensity of X-rays and finally the presence of silicate in
the atmosphere, it has been raining molten glass all the time. It would be
impossible to predict all these unimaginable events from the earth, but it
would not be an exaggeration.
This
HD-189733b planet has a striking resemblance to our earth. This planet looks
just like our earth, looks like a blue sphere from space. The presence of the
ocean is responsible for the blue colour of our planet, and the presence of
silicate in the air is one of the reasons for the blue colour of this
HD-189733b planet. The resemblance of this planet to earth begins here and ends
now because this planet is never suitable for sustaining life and its full
development. Despite the presence of different types of organic particles, life
on this HD-189733b planet will not be in full swing.
However, there are still many questions in our minds about this planet, the answer to which we have not yet found, such as does this HD-189733b planet has any satellites? What is the source of so many X-rays in this planet? Why does this planet orbit its star so fast? Even though it is a planet, why is one side of it always fixed to its star? Why did the stars of this planet suddenly become bright? HD-189733b, what we call a planet today, the end of a brown star from the past that stopped before it fully developed into a star? For what reason could the HD-189733b not develop into a complete star? Or is it not a planet but a part of the star after the supernova explosion in HD-189733A? This planet has not been discovered for more than two decades, so it requires close observation and extensive research. In the days to come, with the help of more advanced technology, we will be able to unravel this mystery for sure, answer all our questions, and perhaps the long history of space will become clearer to us a bit.
