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. DR AMALENDU. DR AMALENDU BANDYOPADHYAYBANDYOPADHYAY
GOURAV BANERJEE GOURAV BANERJEE 1414
PHOTOGRAPHY SECTION PHOTOGRAPHY SECTION 1919
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THE SOLAR SYSTEM THE SOLAR SYSTEM ALEXANDRA ALBANI ALEXANDRA ALBANI
3131
OUR ACTIVITY OUR ACTIVITY 3737
CONTENTSCONTENTS
[email protected]
@BhabanaBijnan
02
Co-editor :Co-editor : Puja Adhikary
President :President : Dipak Dey
SOME IMPORTANT MEMBER OF OUR ORGANIZATION “BIJÑNA BHBANBIJÑNA
BHBAN” : PRESIDENT : PRESIDENT : DIPAK DEYDIPAK DEY
VICE PRESIDENT : VICE PRESIDENT : PANKAJ SARKAR PANKAJ SARKAR
GENERAL SECRETARY : GENERAL SECRETARY : SANTU CHAKRABORTYSANTU
CHAKRABORTY
TREASURER : TREASURER : SUMITA ROY SUMITA ROY
IT & SOCIAL NETWORK HEAD : IT & SOCIAL NETWORK HEAD : SUMAN
SARKAR
COORDINATOR : COORDINATOR : ROHIT SHAWROHIT SHAW CO-COORDINATOR :
CO-COORDINATOR : BIDHAN HALDERBIDHAN HALDER MAGAZINE MAGAZINE HEAD
:HEAD : ABHIRUP DAS
OTHERS IMPORTANT MEMBER : Sagarika Banerjee, Tarun Banerjee, Subham
Das, Susanto Ranjit,John Dutta etc.
EDITORIAL BORDEDITORIAL BORD ofof
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Let us come to know about a great man of India – Dr. Amalendu
Bandyopadhyay, the Founder Director of the Positional Astronomy
Centre, Kolkata and the person who literally started astronomy
popularization in India. Dr. Amalendu Bandyopadhyay passed away at
around 20:30 pm on June 22, 2020 at his home at Kolkata at an age
of 90. Being a researcher in astrophysics myself, a future
astronomer and a close acquaintance of Dr.
Dr. Amalendu BandyopadhyayDr. Amalendu Bandyopadhyay [The story of
a Star Warrior]
By : Gourav BanerjeeBy : Gourav Banerjee [Research scholar
(astrophysics),[Research scholar (astrophysics),
CHRIST, Bangalore.]CHRIST, Bangalore.]
14
Amalendu Bandyopadhyay, I feel it is my moral duty to introduce
this great person to anyone who loves astronomy.
Born on February 1, 1930 in the Mugkalyan village of Howrah
district, West Bengal, Dr. Amalendu Bandyopadhyay completed his
school education from his village. Then he moved to Varanasi and
completed MSc. in Applied Mathematics from the esteemed Banaras
Hindu University (BHU). It was here where he received the company
of the eminent mathematician, Dr. V.V. Narlikar – father of the
world renowned Indian cosmologist Dr. Jayanta Vishnu Narlikar
(Founder of the Inter University Centre for Astronomy and
Astrophysics, Pune). Dr. V.V. Narlikar was the mathematics teacher
of Dr. Bandyopadhyay, and it was he who inspired Dr. Bandyopadhyay
to pursue astronomy in future. After MSc., Amalendu Bandyopadhyay
started his career as a lecturer of a college at Varanasi with a
monthly salary of 192/-.
Then in 1956, with untiring efforts of another legendary Indian
physicist Dr. Meghnad Saha, an unit for research in positional
astronomy – the Nautical Almanac Unit - was established at Kolkata.
The primary objective of this unit was to precisely compute the
position of planets, stars and other heavenly objects and dates of
different celestial phenomenon for each day of every year. This
branch of astronomy, known as ‘Positional Astronomy’ is extremely
important. Every astronomical observatory, each observational
astronomer, calendar maker, festival setter needs these data to
accurately perform astronomical observations and even different
festivals all over India. But Positional Astronomy was in its
infancy in India during those days. As a result, India had to
purchase these data from USA, France spending huge costs. These
calculations were meticulously done by those countries and the
results were published in the form of a book, termed as
‘Astronomical Ephimeries’.
Dr. Bandyopadhyay joined the Nautical Almanac Unit, Kolkata in 1956
and remained here as an Assistant Scientist till 1962. For the next
six years he was involved in atmospheric sciences research
necessary for flying of airplanes. Later in 1968, he took over as
the Director of the Nautical Almanac Unit. And then began his
historic two-way fights – the relentless efforts which turned him
into a legend.
15
It was during 1960s only when Amalendu Bandyopadhyay realized that
India needs to prepare its own Astronomical Ephimeries. Why will we
spend dollars to buy data from other countries? During those days,
the Nautical Almanac Unit was a small unit under the Department of
Meteorology, Govt. of India. Hence, in 1968, after taking over the
complete responsibility of the Unit, he started a tireless campaign
to establish a separate department for positional astronomy
directly under the Government of India. He was also clear about
another objective – this new department has to be established in
Kolkata. This was because during that period Kolkata was the centre
for education in India. Skilled workers, researchers,
infrastructure – everything were readily available. His request for
establishing such a separate department, that too in Kolkata, was
opposed by the Indian Government. Mrs. Indira Gandhi – the iron
lady of India- clearly mentioned that if such a department will be
established, that will be in Bangalore.
An unstoppable fight for 12 years continued. Dr. Bandyopadhyay had
only two weapons – his in-depth knowledge in positional astronomy
and indomitable personality. Ultimately on April 26, 1980, his
dream turned into immense success. Positional Astronomy Centre
(PAC), a separate centre for positional astronomy calculations
under the Government of India was established in Kolkata. He was
elected as the Founder Director of PAC. Then, within another year,
under the able leadership of Amalendu Bandyopadhyay, India
published its own Ephimeries – now known as the Indian Astronomical
Ephimeries. India is presently one among eight nations in the world
which can produce their own Astronomical Ephimeries. More than 200
observatories from over 40 countries currently buy the data from
India. It was a paradigm shift – once we had to buy such data from
abroad, now India earns foreign exchange by selling these data. The
credit for such a historical achievement goes to this simple,
humble Bengali astronomer - Dr. Amalendu Bandyopadhyay.
He retired from PAC on February 1, 1988 and then joined the M.P.
Birla Planetarium, Kolkata in 1993 as a Senior Scientist. Dr.
Bandyopadhyay took an instrumental role in providing a solid
structure to the academic stature of the Institute. Till his last
day, he remained as an active member of the Institute. In the
meantime, since 1970, Dr. Bandyopadhyay started another relentless
effort – popularization of astronomy among common
16
public and students in the remotest parts of Bengal and East India.
Within few years, he became a pioneer of science communication
movement in West Bengal and India.
Dr. Amalendu was a crusader of sorts. Since 1970s, he travelled to
remotest corners of Bengal and delivered popular talks on astronomy
with two visions – popularizing the subject among the masses and
enlighten them with true knowledge so that the burden of
superstitions can go down. His talks were mesmerizing, blended with
stories and truth in such a way that through such talks he used to
break apart the very foundation of astrology – a false subject
practiced by numerous astrologers till now in India. After his
retirement from the PAC, he spent his life’s savings to purchase a
four-inch telescope, three German slide projectors, two screen
projectors and a voltage stabilizer to make his talks more
interesting.
But the battle to promote astronomy and debunking astrology – a
menace of the society was not easy. This is because there are
numerous business houses and unscrupulous persons who feed on
peoples’ belief on superstitions. Dr. Bandyopadhyay received
numerous life threatenings from various astrologers (who show them
as the healers of all pain of common man!!!) and business houses in
his lifetime. He never compromised and stood high always with his
inborn fighting spirit against astrology.
Awards and Honours: 1995: Recipient of National Award from the
Govt. of India for best popularization of astronomy in India. He
was the first Indian to receive a National award for popularization
of astronomy.
2001: Recipient of the prestigious Gopal Chandra Bhattacharya
Memorial Award under the Govt. of West Bengal for best
popularization of astronomy in West Bengal.
2003: Recipient of honorary DSc. From the University of Burdwan,
West Bengal for best popularization of astronomy in India. He is
the only Indian to receive an honorary DSc. for popularization of
astronomy.
17
2012: Recipient of the prestigious Jagattarini Gold Medal from the
University of Calcutta for best popularization of astronomy in
Bengali language.
2013: Recipient of the prestigious G.P.Chatterjee Memorial Award
from the Indian Science Congress Association for best contribution
in positional astronomy study in India.
Apart from these, Dr. Amalendu Bandyopadhyay was elected as the
Life Member of the International Astronomical Union, Astronomical
Society of India, British Astronomical Association and an elected
Fellow of the prestigious Royal Astronomical Society and Academy of
Science and Technology, West Bengal.
He has passed away, but his contributions will remain eternal in
the minds of countless people whom he inspired. I was also one
among those innumerable people. Now, it is our duty to carry
forward his visions – to turn India into a nation full of astro -
‘nomy’, not ‘logy’.
18
PHOTOGRAPHY SECTIONPHOTOGRAPHY SECTION
THE WEARY TRAVELER IS LYING ON THE ROAD AS HE WALKS, AND THE TREES
ON THE ROAD ARE PEEKING AT HIM.
PHOTOGRAPHY BY : AKASH DEY
19
A GLIMPSE OF THE CITY OF JOY PHOTOGRAPHY BY : SUMIT BASAK
FIND THE PEACE PHOTOGRAPHY BY : SUMIT BASAK
20
SIR JOHN ANDERSON ROCK GARDEN, DARJEELING PHOTOGRAPHY BY : PUJA
ADHIKARY
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The solar system is made up of Mercury, Venus, Earth, Mars,
Jupiter, Saturn, Uranus and Neptune. The study of the data relating
to each planet has allowed us to divide them into two groups: the
terrestrial planets, or similar to Earth, (Mercury, Venus, Earth
and Mars) and the jovian planets similar to Jupiter, (Jupiter,
Saturn, Uranus and Neptune). The biggest difference that
distinguishes these two groups is the size: the Jupiter planets are
in fact larger and are also called giant planets. Due to the
presence of the asteroid belt between Mars and Jupiter, the planets
between the belt and the Sun are called inner planets, while those
beyond the belt are called outer planets. Other differences between
the planets are the composition, density and speed of rotation.
While the density of terrestrial planets is about 5 times that of
water, that of the Jupiter planets is around one and a half times.
The materials that make up the various planets are of three types:
gases, such as hydrogen and helium,
The solar systemThe solar system ( Bergamo, Italy )
By : Alexandra AlbaniBy : Alexandra Albani
31
rock-like materials such as silicate minerals and metallic iron,
and ices which include ammonia, methane, carbon dioxide and water.
The escape velocity is the velocity that a body must acquire in
order to leave the atmosphere and therefore move away from the
planet. The origin of the Solar System. Regarding the origin of the
Solar System with the passage of time, a hypothesis called the
nebular hypothesis has been formulated, according to which all the
planets originated from a huge cloud of dust and gas, called the
primordial nebula, formed by all those materials that we can find
today on the planet of the system. Around 5 billion years ago this
cloud of gas and heavy grains began to contract due to
gravitational interactions and as this contraction took place, it
kept increasing the speed of rotation according to the angular
momentum principle. A moment came when the centrifugal force
balanced the gravitational thrust towards the interior and the
cloud turned into a flattened disk with a concentration of
materials in the center that made up the protosole. Following the
formation of this protosole, the phase of gravitational heating
began, during which the temperature in the area of the inner
planets began to decrease, favoring the aggregation of materials
and the condensation of others, to give rise to planetesimals.
Following the various collisions, the proto planets originated,
which increased more and more to form what today are the 4 inner
planets. Those aggregates of matter that did not form the planets
remained in orbit between Mars and Jupiter and form what is now
called the asteroid belt. Simultaneously with the formation of the
inner planets there was that of the outer planets, which having
lower temperature due to the greater distance from the sun, became
an agglomeration of ices. Several satellites also formed around
these outer planets.
The "dome" that surrounds us is called the celestial vault and has
an apparent motion.Until 1600 it was thought
32
that there were 600 stars.From 1609, thanks to Galileo Galilei, the
telescope began to be used.
LIGHT: it is an electromagnetic radiation that propagates with a
wave motion. Electromagnetic waves have a crest and a belly, and
are characterized by a wavelength (the distance between two crests
or between two bellies) and a frequency.The shorter the wavelength,
the higher the frequency.The information that comes from space
travels in the form of electromagnetic waves and propagates both
through the vacuum and through means transparent to them. To reach
us, the light takes a time proportional to the distance at which
the light source is located. The sunlight takes 8 minutes to arrive
on our planet. In astronomy, to express the distances of celestial
bodies, the light-year is used (the distance traveled in a year by
light in a vacuum (9460 km). Stars and galaxies. Stars are
celestial bodies within which a huge amount of energy that
propagates in the universe.In the nucleus of the stars hydrogen is
transformed into helium (4 hydrogen nuclei form 1 helium nucleus).
The stars are very far away and hold their positions fixed. At the
poles, all stars are circumpolar, meaning they make a complete
rotation around the polar star. If a star rises and sets it is
called occidua. The stars group together to form galaxies. Earth is
part of the Milky Way (or Galaxy). It has a disc shape in which
spiral arms can be seen, in one of which the Sun is located.
Andromeda and the Magellanic Clouds are visible to the naked eye.
Constellations are groupings of stars. There are 88 and they allow
us to divide the universe into sectors. 12 are of the zodiac, and
are on the plane of the earth's orbit.
33
The stars in a constellation are at enormous distances from each
other. The brightest star in a constellation is called Alpha.The
mass: from 0.02 to 200 times the mass of the sun. The dimensions:
they vary from 0.1 to 1000 times the radius of the sun. The
density: it can also be different The measurement of the surface
temperature (on which the color of the star depends). The hottest
stars are blue-blue-white, the coldest (3000-8000 ° C) red-
orange-yellow. Brightness is measured by apparent magnitude. It
depends on the amount of light emitted and the distance from the
Earth. Sirius, for example, is brighter than the Sun, but further
away. The solar system is a planetary system consisting of a
variety of celestial bodies kept in orbit by the gravitational
force of the Sun, which also includes the Earth: with a diameter of
about 120-130 AU (if understood as the area of space that is
subjected to the solar wind, leaving out the immense area subjected
to solar gravity alone) is located in the Orion arm of the Milky
Way, orbiting around the galactic center at a distance of 30000 al
and a speed of 230 km / s; it is estimated that the solar system
takes about 230 million years to complete one revolution around the
galactic center.
Consisting of the Sun, which alone possesses 99.86% of the power of
the entire system, and eight planets (four inner rocky planets and
four outer gas giants) and five dwarf planets, their respective
natural satellites, and many other bodies minor, the latter
category includes asteroids, largely divided between two asteroid
belts (the main belt and the Kuiper belt), comets (mainly located
in the hypothetical Oort cloud), meteoroids and interplanetary
dust.
34
In order of distance from the Sun, the eight planets are: Mercury,
Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune; the five
dwarf planets are: Ceres, located in the main asteroid belt, Pluto,
Haumea, Makemake, and Eris. The solar wind, a flow of plasma
generated by the continuous expansion of the solar corona,
permeates the entire solar system, creating a bubble in the
interstellar medium known as the heliosphere, which extends beyond
half of the diffuse disk. celestials of the solar system were
already known since ancient times, the concept itself was ignored
as there was mostly an idea of a geocentric system with the Earth
at the center of the universe. One of the first to imagine a
heliocentric system was Aristarchus of Samo, but his ideas did not
take hold in the community of philosophers and thinkers of the
time.
It was only in the sixteenth century that Nicolaus Copernicus
proposed the modern vision of the solar system, with the Sun at the
center and the planets known at the time to orbit around. The only
known bodies in the solar system, however, were only the four
terrestrial planets, Jupiter, Saturn, the Sun and the Moon. In the
following century, with the invention of Galileo Galilei's
telescope, other minor bodies were discovered, such as the Medici
satellites, the rings of Saturn and some comets and for about 200
years it was not thought that there could be other objects in the
solar system, in particular was the firm belief that the planets
were only those then known. In 1781, the discovery of Uranus by
William Hersche questioned the preconceptions that the scientific
community had, generating doubts regarding the possibility that
transuranic planets existed.
A few years later, in 1801, Giuseppe Piazzi declared that he had
discovered a new planet, between the orbits of Mars and Jupiter; it
was actually Ceres. The conclusion came by excluding that it could
be a comet and not
35
knowing other objects other than planets and comets, completely
unaware that he had discovered a new type of object, the asteroid.
Since then the discoveries of new objects multiplied, in particular
many new asteroids were discovered. In 1846 a planet was discovered
in a completely revolutionary way: before direct observation, the
perturbations of the orbit of Uranus were calculated and it was
deduced that a planet had to exist at a precise point in space to
justify the discrepancies observed. A few days later, Johann
Gottfried Galle and Heinrich Louis d'Arrest confirmed the presence
of Neptune less than one degree away from the calculated
point.
In 1930, the discovery of Pluto increased the number of known
planets to nine, which was then believed to be an object of much
greater mass than it actually is. In the 1950s Jan Oort
hypothesized the existence of a nursery of comets far beyond the
orbits of known planets, located tens of thousands of AU from the
Sun, the Oort cloud, which when disturbed significantly changed
their orbit up to to arrive in the internal area of the system. In
1992, the discovery of Albion restarted the search for trans-
Neptunian objects. The advent of automatic search systems allowed
the discovery of thousands of objects with a diameter between 50
and 2500 km. The discovery of Eris, similar in size to Pluto, in
2005 challenged the very definition of planet, which was changed
and formalized in 2006 by the International Astronomical Union,
downgrading Pluto to a dwarf planet and bringing the total number
of planets back to eight. The most accredited theories on the
formation of the solar system describe its birth 4.6 billion years
ago starting from the fragmentation and gravitational collapse of a
gigantic molecular cloud with a diameter of 65 light years.One of
these fragments, with an initial size of 2000-20000 astronomical
units, collapsed into what is known as the protoplanetary disk. The
main components of this primordial forge were 98% primo.
36
37