Saturday, 19 December 2020

Tuesday, 5 July 2016

Galaxy

Galaxy

A galaxy is gravitationally bound structure of stellar remnants, interstellar gas, stars, dark matter, and dust. On the basis of quantity of stars, It’s size ranging from dwarf to huge. Dwarf galaxies are contains few thousands of stars whereas huge galaxies are containing trillions of stars.
pink galaxy

Stars are orbiting around galaxies center of mass. Galaxies are also categories on the basis of their visual appearance or morphology. They are normally three types, elliptical, spiral and irregular. Many galaxies have black holes at their active center. Our milky way’s galaxies also have a black hole at their center. The milky way’s galaxy black hole is known as Sagittarius A*.
Sagittarius A* is four million times greater than sun in mass. On the basis of March 2016, 32 billion light year away from earth a most distant and oldest galaxy observed known as GN-z11. There are approx 170-200 billions of galaxies exist in our observable universe. They are 1000 to 100,000 parsecs in diameter, separated by distance of millions of parsecs. The space between them is filled with tenuous gas of density one atom/cubic meter. Galaxies are associates together because of galaxies in galaxy groups, cluster and super clusters. Overview they are arranged as sheets and filament surrounded by immense voids.
Types of morphology:
Galaxies are normally three main types spirals, ellipticals, irregulars. More types are given by Hubble sequence on the basis of their visual appearances.
types of morphology

Ø  elliptical galaxy
on the basis of their Ellipticity Hubble classification system ranging elliptical galaxies. They are ranging from E0 to E7, where it became nearly spherical. They are classified according to their ellipsoid profile regardless of their viewing angle.
Elliptical galaxies are believed as they form due to interaction of galaxies. Due to their interaction they collide and merge. Giant elliptical are larger galaxies, they found near the larger galaxies clusters. Grow to enormous size, larger than spiral.
Ø  Shell galaxy
The shell galaxies are also a type of elliptical galaxy. Stars in this galaxies halo are arranged in concentric shells. One tenth of elliptical galaxies are shell like structure. They are not observed in spiral galaxies. They thought to form when larger galaxies are absorbs smaller one. As their center approach and stars vibrate at their center. due to this gravitational ripples are form which arrange stars like shells. NGC 3923 galaxy have 20 shells.
NGC 3923

Ø  Spiral galaxy
Spiral galaxies resemble huge spiraling pinwheels. The Mass of galaxies are exist in roughly spherical halo of dark matter. Which extends beyond the visual appearance and the constituent are arrange in nearly flat disc.
Spiral galaxies have a rotating disc which contains stars and interstellar material. they have central bulge contains normally older stars. The arms are extending outward from centre bulge and they are relatively brighter. On the basis of Hubble classification scheme, “spiral galaxies” are listed as type “S” followed by letter (a, b or c). which indicates size of central bulge and degree of tightness of spiral arms.

Reference:

Wikipedia

Wednesday, 29 June 2016

Our Universe

Our Universe

Our universe is everything that we can touch, sense, feel, observe, measure and detect. it includes all of us, living things, stars, planets, galaxies, dust clouds, light and even time. before the birth of our universe space, time, matter, nothing exist.
our universe
Our universe containing billions of galaxies, each of galaxies contains millions or billions of stars. but the spaces between these stars and galaxies are largely empty. however this spaces are not fully empty they contains scattered particles, dust or few hydrogen atom per cubic meter. Space is also contains radiation, magnetic fields and high energy particles(eg. light, heat, cosmic rays).
The size of universe is incredibly huge. If we want to go to our nearest star then it take more than millions of year from our fighter jet. To cross our milky way it would take 100,000 years at travelling with the speed of 3oo,ooo km per second.
Our visible universe is more than 93 billion light years in size. Where, one light year is the distance that light travels in one year and it’s nearly about 9 trillion km. we can’t no the exact size of our universe because no one se the edge of universe if they exist.
The size of our universe has not always been same .our universe is began with big bang before 14 billion years ago. Since then, at very high speed our universe has been expanding in outward direction. So  the area of space is expanding billions of time grater than it was when our universe was young. Galaxies and stars are moving apart and so the space between them has expands.
shape of universe


Our universe is made from spacetime fabric. Shape of space and time is define by general relativity. it says how spacetime curved and it’s bent by mass and energy. because of space time is curved we can’t see the whole universe. The section of universe which is observable is backward light cone. They delimits on cosmological horizon. Horizon represents the boundary between the observable and non observable universe.
Astronomers calculate the age of universe by lambda-CDM model. Assuming that it accurately describe the evolution of universe from hot, dense primordial state to present state. Measurements of parameter by variety of techniques and numerous experiments we find the best age of the universe which is about 13.799 billion year raging from 0.021 billion year more or less.

daily universe

Daily universe



 Hey brothers this blog is for enhancing your ideas about our universe. here we can find a daily ideas updates about our universe. we also provide you a lots of amazing picture of universe, solar system, our space and it's objects.
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our universe