Astrophilia

Theoretically , the Sun’s solar energy can be used at  infinitely large distances  from it provided we have  infinitely large collector plates  for gathering the light. However there are obvious problems like space dust which largely obscure and scatter this light. So let us look into more practical ways to use solar energy. The  total luminosity  of the Sun is about  3.8 X 10 ^ 26 watts . It radiates this energy outwards into space, and apparently, places nearer to it receive more energy per unit area than places far from it, according to the  inverse square rule . But the total energy radiated in a unit of time is constant and so the energy generated in one second can be divided by the surface area of the theoretical sphere that we seek to find its power in. At Earth the value per m^2 is about  1400 Watts . This is enough to run about  23  60-watt bulbs at the same time. If we were to move to  Jupiter , which is...

As far as I know,  the Internet  is a great place to learn stuff about the Universe in general. There are a great many of websites and YouTube channels that make regular updates on latest research happening about out Solar System and beyond. However, since the question was about books in specific, I’ll try to answer that. These are some great books that I have read and feel that they are accurate enough. Universe  by Geller, Freedman and Kaufmann This book is really good if you’re a beginner starting out with learning astronomy in general. It is pretty descriptive, with cool pictures here and there.  Universe: Roger Freedman, Robert Geller, William J. Kaufmann: 9781429231534: Amazon.com: Books 2. Astronomy Demystified  by Stan Gibilisco This book is slightly more detailed than the previous ones but is definitely a good read.  Astronomy Demystified: Stan Gibilisco: 9780071384278: Amazon.com: Books However books have a limited scope tha...

The stages of evolution of a star largely depend on its  initial mass , the mass which it started with. Based on this stars are divided into 3 categories : the  low mass stars, the medium mass stars and the heavy ones . Low mass stars  have a mass of about  less than 0.8 times the mass of the Sun.  Since they are less massive, the gravitational pressure at their cores is low, making their fusion really slow. So such stars can undergo fusion for a really long time, which is estimated at around  10 trillion years . These stars are commonly referred to as red dwarf stars and have a low surface temperature, due to low fusion. Medium massed stars , like our Sun, have a mass from  0.8 to 10 times the mass of the Sun . These stars have a higher fusion rate as compared to low mass stars. When these stars run out of hydrogen to fuse, they look for the next best thing to fuse, Helium. Helium fusion occurs in the following steps Calculating the energy...

A less likely possibility. An upper limit of distance between two binary stars is around o.25 light years. Considering that and the fact that we are able to observe stars and celestial objects with apparent magnitudes up to 32, we get using the expression… (where m = apparent magnitude i.e., 32 in this case, M = absolute magnitude, r is distance in parsecs ) M ≈ 42.57 This value is so high ( meaning that the star is too dim ). In fact the dimmest red dwarfs ever observed, are only about 15 - 20 in absolute magnitude. If we still want to theoretically prove it wrong, we can go ahead and use the Stefan- Boltzmann Law to make an attempt to find its surface temperature. Assuming a Sun sized binary star, with an area of 6.09 * 10 ^18 m^2, plugging in some values we get T, the surface temperature of the binary star to be a mere 1.02 Kelvin. If we try to make the size of the binary star even smaller, ( in an attempt to increase the surface temperature) by pushing it ...

Discovered by the Pan-Starrs telescope in October 2017, this rocky body has been claimed to be the  first interstellar body  to enter the solar system. It is interstellar in the sense it came from a different star system. This was determined by studying its orbit, and its chemical composition. It was found to have a higher velocity ( around 320,000 kilometres per hour ) than it would have if it orbited the Sun, hence it must have been from somewhere else. ( Of course, the below image is a piece of an artist’s imagination of how it would look like ). The asteroid was also weirdly shaped like an elongated cigar, which drew media attention, who hypothesised that it could be an alien spaceship. After some debate, a paper was published in March 2018 which said that Oumuamua was in fact, a comet and not an interstellar asteroid as it was previously claimed. This was established with some evidence relating to its trajectory through the Solar System. It was expected to go ...

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Elliptical galaxies, like the name suggests have an elliptical shape with no specific axis of rotation. Elliptical galaxies are classified on the basis of their eccentricity, ie how much they deviate from a circle. The class starts from E0 which are the most circular galaxies to E7 which are the most elliptical in shape. Elliptical galaxies are also divided into stages. Compact elliptical galaxies are denoted by cE, normal ellipses just by E and late elliptical galaxies by E+. For example the galaxy M32, located in the constellation Andromeda is denoted cE2. It looks like this. It is clearly seen that it is only slightly elliptical and hence denoted by 2. Another elliptical galaxy is M59 which is more elliptical than M32 and hence designated as E5. It looks like this.