We
don't know how many billions of stars are scattered all over the universe.
According to the common man, the number of sand particles in all the earth's
crust is nothing compared to the total number of stars in the entire universe.
We have learned very little about few stars in the ocean of these infinite
stars. Some of them are only a few light years away from the earth and some are
hundreds of light years away. Except for scientists and few space enthusiasts,
no one cares about these stars. Today we will discuss a star that is so little
known to ordinary people but important enough to scientists.
The
easiest and most acceptable unit for measuring distances in space is the light
year. The distance that light travels over a period of one year is called light
year. After passing a distance of 5.96 light years in a specific region of
space towards the northern hemisphere of the earth, we will reach a red dwarf
star. That star is the fifth closest star to earth after the sun, the three
stars in the Alpha Centauri system. We know this star as Bernard's Star. This
star is the closest star to the Northern Hemisphere.
In
1916, when the earth was burning in the flame of World War I, American
photographer and amateur astronomer Edmund Emerson Barnard discovered a very
fast moving faint star in the sky. A full 100 years after this incident, in
2016, a team responsible for naming stars of the International Astronomical
Union (Working Group of Star Names) decided to name the star, discovered by the
discoverer Bernard, as Bernard's Star and the name was approved on February 1,
2017. Observations revealed that the nature of this star in the Ophiuchus
constellation is very strange.
This
type of star was later classified into a special class which we know as Halo
Star. This type of star is one of the earliest stars in space. The age of some
Halo Stars is about the same age as our observable universe. Due to their
antiquity, their amount of fuel has decreased with time, so now they have
become a star of dim nature. Most of these types of stars are found in spiral
galaxies and orbit the galaxy in elliptical orbits. However, their orbits are
not always on the same plane as the galaxy. Sometimes their orbits are much
higher than the plane of the galaxy, and sometimes the opposite. Because they
orbit the galaxy in different planes, their kinetic energy is much higher than
that of other ordinary stars. This tremendous momentum and antiquity are the
most important features of the Halo Star that set them apart from other stars.
About 45 more stars, like Bernard's Star, have been found in our Milky Way
galaxy. (Link is provided for details on such unusually fast-moving stars is
given: https://spacejagat.blogspot.com/2021/01/classification-of-stars-according-to.html)
However, it is true that there are no abnormalities in their structure, just like
ordinary stars.
Judging
by age, the age of Barnard's Star is 7 to 12 billion years, or 700 to 1,200
crore years. This period is not far from the period of creation of the
universe, so Barnard's Star is considered to be one of the oldest stars in the
Milky Way galaxy. Due to its antiquity, the brightness of this star has
diminished today. At present its luminosity value is +9.5 so this star is
almost invisible to the naked eye. One thing should be mentioned here. The
lower the luminosity value of an object in the universe, the higher the
luminosity of the cosmic object. In the case of our sun, its value is -26.7. At
present, if Barnard's star were to replace the sun, the earth would not receive
brightness as much as the sun. Scientists say that the brightness of our
earth's day at equatorial region will then be equal to the light of 100 full
moons. This Barnard's star falls into the M category, and subcategory is 4 (Link
is provided to know about the birth and evolution of the star is given: https://spacejagat.blogspot.com/2020/06/the-brief-story-of-stellar-life.html)
The
mass of this star is only 14 percent of the mass of the sun and 20 percent of
the diameter. If Jupiter is compared to the Bernard's Star, then the mass of
this star is 150 times the mass of Jupiter but only 2 times the radius of
Jupiter due to its extreme density. The surface temperature of this star is 3,100
Kelvin or 2,826.9 degree Celsius. The metallicity of Barnard's Star is 10
percent to 32 percent. Metallicity here is the ratio of the mass of helium and
the heavier element than helium in the core of a star. The metallicity value of
Barnard's Star is much higher than that of the Halo star. At present the
velocity of this star is 110 km per second or 6,600 km per minute which is less
than half of the velocity of the fastest Halo star, Kapteyn's Star (245.2 km
per second or 14,712 km per minute) in this galaxy (Link is provided to know
about Kapteyn's Star is given: https://spacejagat.blogspot.com/2021/07/kapteyns-star-nearest-high-speed-cosmic.html) If
the sun were to be fixed, the velocity of Barnard's Star would be 142.4 to
142.6 km per second or 8,544 to 8,556 km per minute. This star has lost most of
its rotational energy due to this tremendous mobility. Where our Sun revolves
around its own axis once in 25 days relative to earth's time, it takes 130 days
for Barnard's star to revolve around its own axis once.
This
tremendous velocity of Barnard's Star is bringing it closer to the earth little
by little over time. It is estimated that in the next 11,800 AD, the distance
of our earth from this star will decrease by 3.75 light years. But in those
days the Alpha Centauri star system will also come closer to earth. So in the
future, as in the present, the title of the second closest star to earth will
be with Proxima Centauri. Even after coming so close to earth, the luminosity
value of Barnard's Star would increase by only 1 to +8.5. To see a cosmic
object with the naked eye, the minimum luminosity value needs to be +6. If it
is less than that, it is practically impossible to see the object without the
help of any aid. So even after 9,700 years, Barnard's Star will remain
invisible to our naked eye. Although these stars are not currently visible in
visible light, they can be seen well in infrared rays.
The
Dutch scientist Van der Kemp has been observing Barnard's Star for a long time
since 1938 with the help of his colleagues from the Sprawl Observatory at
Swartham College in Pennsylvania, USA and after 1969, it was announced that the
star could have two planets, one of which could be a gas giant planet. After
two decades of observation and research, a team of scientists led by Spanish
scientist Ignasi Ribas, following the scientist Kemp's theory, announced that,
there might be a giant planet which might be 3.2 times larger than earth and
situated 0.4 AU or 5,98,39,148 km away from Barnard's star (AU: Average
distance between earth and sun). This planet is named Barnard's Star b. The
average surface temperature of this planet probably is -170 degree Celsius.
Both this planet and the second planet are thought to be located outside the
habitable zone of Barnard's Star. The habitable zone of a star refers to the
specific distance where the most favorable environment for the origin of life
is present, such as the position of the earth in the case of our sun. But from
the very beginning a controversy arose over the planet of Barnard's Star, and
it still remains. Repeated observations of Barnard's Star with the help of
California's Lick Observatory, Hawaii's Keck Observatory, Hubble Telescope,
etc., have not been able to say for sure about the two planets. The existence
of planets of Barnard's Star was ruled out for the first time in the last
century and for the second time in 2021 of this century but the controversy did
not go away. This is not to say that planets have not been found before or
after this incident in M-class stars, but not all the rules apply to Barnard's
Star like other stars in this class.
Between
1973 and 1978, Barnard's Star was observed in the Daedalus project. At the
time, scientists had a number of plans centering on the star's planet, such as
sending an unmanned spacecraft in the future that would run on nuclear power
and using advanced technology to bring its velocity to 12 percent of the
velocity of light. At high speeds, the spacecraft will be able to reach that
distant planet within a person's lifetime. According to scientists, the
spacecraft will be able to reach the Barnard Star's planet in the next 50 years
after the launch of the spacecraft. Since then, various scientists have
expressed various ultra ambitious plans in public, but where the existence of
the planet has been questioned, it is only natural that these plans should
remain only on paper and on computer hard disks.
There
is one more thing we must consider when discussing Barnard's Star otherwise,
this discussion will remain incomplete. On 17th July 1998, a stellar flare was
observed in this star. At that time the temperature of that flame rose to
7,726.9 degree Celsius. This event is very rare in such an ancient star. This
phenomenon could not be fully understood due to distance and dullness. However,
there is no doubt that the magnetic field is responsible for this phenomenon.
This magnetic field interferes with the convection of the star's plasma (Plasma
Phase: This is the fourth phase of element where the bonds between the
electrons, protons and neutrons of the elements at a very high temperature are
completely broken). Plasma is released through this phenomenon. But this
kind of phenomenon is very normal in the young stars, but it is not seen to
happen in such an old star which makes it a very rare event. In 2019, two such
incidents were noticed again. This time the stellar flare was of ultraviolet
rays.
If
we look at the first three stellar neighbors of Barnard's Star, we see that its
nearest star is Ross-154. It is also a red dwarf star like Barnard's Star. The
distance between these two stars is 5.4 light year. There is very little
difference between the second and third place stars in terms of distance. In
the second place is our Sun and in the third place is the combination of three
stars Alpha Centauri. The distance between Barnard's Star and these second and
third stars are 5.95 light years. Here the sun occupies the second place as it
is only a few crores km away. In this context, it should be noted that if our
sun is seen from the position of Barnard's Star, then its luminosity value is
+4.83, that is, our sun is seen very bright from the Barnard's Star.
Just as we are aware of our own area through the perception of our neighbors around our habitat, so do we try to know what is happening around our solar system, and it is very important to try to know this because it will give us an accurate idea of our universe. In order to understand the cosmology of the universe, one has to understand all its elements well. Just as there are planets and satellites in our solar system, there are also exoplanets, comets, galaxies, stars, and so on. Every cosmic object is a source of information and there is a time in the future when we will be able to understand the real cosmic events little by little in the right way through combining all pieces of information together, coming from these sources.
DECLARATION: All The Images Have Been Sourced From Google.
