Astronomy is the study of celestial objects, their motions, their positions, and properties. It is considered as oldest science after medicine. The clear starry night has always amazed humans.

The presence of astronomy in India can be seen since prehistoric times. Earlier it was used to predict auspicious dates for special events and religious festivals.

The beginning of astronomy can be traced back to Vedas- Rigveda and Yajurveda. Earlier astronomy was called Jyotisha. The Vedangna Jyotisa is the earliest available Indian Astronomy textbook. The accepted period for this book is between 12^th and 14^th century B.C. In today’s world, the word Jyotisha is used for predictive astrology or pseudo-science. But still it must deal with Sun, moons, planets, nakshatras, etc.  Have you ever wondered, how astrology books claim to predict positions of celestial bodies?

Mathematics was always a part of Jyotisa, which calculated the positions of celestial bodies in Vedic period. But it’s over utilization for religious predictions, hindered its development as science and became obsolete to modern world.

Vedanga Jyotisa 

Vedanga Jyotisa contains the record of essential astronomical knowledge needed by the people of Ancient India for day to day life. This book has two parts-

1.   Rigveda Jyotisa- This contains 36 verses.
2.   Yajurveda Jyotisa- This contains 44 verses.

The people of that era had good knowledge of planetary systems and some other celestial bodies. The planet Jupiter is mentioned as Brihaspati, Venus as Sukra or Vena in Rigveda. Apart from this, the sidereal period of moon, 27.3 days was well known during those days.

This book contains details of Nakshatras (Stars) and its groups (constellations). The brightest star in its group ware called as Nakshatras. The Rigveda Samhita mentions five Nakshatras and the Taittiriya Samhita mentions all 28 Nakshatras including Abhijit (Vega).

In vedanga Jyotisa, the calendarial items like seasons, solstices, the visuvas (equinoxes), the revolution of Sun and Moon as observed from earth, the length of longest day and the shortest night, etc is mentioned in detail.

Later on, Siddhantas or established theories were developed which were used for astronomical studies. At this time period, decimal system was introduced in Mathematics which helped astronomers to make precise calculations of celestial phenomenon.

In India, there were 18 well established Siddhantas- Surya, Paitamaha, Vyasa, Vasistha, Atri, Parasara, Kasyapa, Narada, Gargyan, Marici, Manu, Angira, Lomasa, Paulisa, Cyavana, Yavana, Bhrgu and Saunaka.

Asia’s Largest Reflector

 Telescope- DOT

The Aryabhatta Research Institute of Observational Sciences (ARIES) built a 3.6-meter reflector telescope (Devashtal Optical Telescope), is the largest reflector telescope in Asia. It is located at Devasthal site 30 Km from Nanital India. Its construction was completed in 2015 and was activated remotely on 31^st March 2016 by Indian Prime minister Mr. Narendra Modi and Belgian Prime minister Mr. Charles Michal.

This telescope is first of its kind in India with three features-

• High resolution Steller Spectro polarimeter
• Charged Coupled device (CCD) Imager
• Near Infra-red Spectrograph

It has active optic system, a wave front sensor, and pneumatic actuators for compensating micro distortions. This is controlled remotely from Bangalore for observing-

1. Magnetic Field Structure of stars
2. Search for planets
3. Chemical composition of Milky way galaxy
4. NIR Spectroscopy and narrow band imaging of galactic nuclei and debris around stars.
5. Optical spectroscopy and high resolved imaging of Binary systems.

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AstroSat was launched on September 28, 2015 using PSLV launch vehicle by Indian Space Research Organization (ISRO). It is first Indian Astronomical satellite dedicated for studying deep sky celestial objects using multi wavelength analysis simultaneously. It can observe X-Ray (like Chandra X-Ray Observatory), Optical (like Hubble Telescope) and UV bands simultaneously.

Its primary objective is to observe high energy processes in binary star systems, estimate magnetic fields of neuron star, detect new briefly bright X-Rays and perform deep sky observations in Ultraviolet region.

The minimum useful life of AstroSat is of 5 Years. During this lifespan it is controlled by a ground-based control station of ISRO located at Bangalore.

In recent update from ISRO about AstroSat Mission is that it discovered a deepest galaxy which was named as AUDFs01.It is estimated to be 9.30 billion light-years away. This discovery was made by observing Extreme Ultraviolet Light coming from other galaxy by scientist at Inter-University Center for Astronomy and Astrophysics (IUCAA), Pune.

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In simple terms, GDP is the estimated value of Goods and services produced in a country for a particular time frame. We can say that the economic growth of a country directly depends on its GDP. Higher the GDP, higher is its economic growth.

In this COVID-19 pandemic time GDP of this country is continuously decreasing. This leads to slow economic growth & decreased per ca pita income. So, we must understand how GDP is related to Economic growth contribution of common man in it. Let me explain with an example.

I am a private sector employee. Before pandemic, my overall monthly expenditure was Rs 25000. This was my indirect investment in the market. My expenditure was in form of paying rent, bills, outdoor dining, movie theater, snacks & tea shops, regular consumable goods, vehicle fuel, outdoor hangout with friends, etc. But now I am leaving in this pandemic time. My overall expenditure was cut short to around Rs 18000. Now this is my indirect investment in the market. As we all are aware of the reason. Due to pandemic I must close my outdoor activities like outdoor dining, hangout with friends, movie theater, vehicle fuel, etc. This leads to no investment on these activities. In a way I saved Rs 7000 but in other way, market lost Rs 7000. This is loss of 28 percent of my expenditure for market.

Taking consideration of the entire population of this country, the loss for market is too huge. The less investment by people leads to low demand of goods which in result depreciates the production.

Now a company with low production will require lower number of employees. Thus, few or more employees will be fired leading to no source of stable income for some of them. This on exponential condition will lead to recession.

A common man contribution to market has huge impact on GDP and economic growth of a country.

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