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Milky Way Galaxy Facts with Pictures

milky way galaxy

milky way galaxy

The Milky Way Galaxy is the name of the Galaxy where our own solar system is located. In shape Milky is kind of a spiral and it is the building block of our universe. That means our universe is nothing but the conglomeration of numerous galaxies. The name Milky Way came from a Latin word called Via Lactea, which has a root in Greek, means a pale band of light.

The Size of Milky Way Galaxy

In 1917, Harlow Shapley made an estimation of the size of Milky Way and it is still valid. He determined that our galaxy will be around 100,000 light years in diameter and our Sun is almost 30,000 light years from the center of the center of this galaxy. The most distant stars of the galaxy found to be almost 72,000 light years from the galactic center (center of milky way), which means if you start our journey at the speed of light from the center of milky way towards its most distant stars, that will take us 72,000 light years and it we start our journey from the our planet towards, at the same speed, toward the center of Milky way that would take approximately 30,000 light years.

milky way in google earth

milky way in google earth

The Mass of Milky Way

Estimating the total mass of a galaxy is extremely complicated matter, which takes into account of the velocity and position of hydrogen gas, its distance from the center, gravitational pull etc. the mass is found by constructing a mathematical model of the galaxy considering all the components within it. In 1960 an estimate predicted that value of total mass of our galaxy is 200,000,000,000 times the mass of the Sun. however, in 1980, another estimate was made, which included the mass of invisible matter like dark matter, and the prediction was that the total mass of milky way is around 1,000,000,000,000 times the mass of our Sun, which is almost 10 times higher than the previous estimation of Milky Way Mass.

Actually the nature of undetected matters like dark matter, sub-atomatic particles still remains the matter of questions and this contributed significant change is the 1980’s estimation of our galaxy. It will be extremely difficult to identify the mass of the total nondirective matters in our universe, which might change the latest predicted mass of Milky Way.

Mass of the Sun- 1.98892 × 1030 kilograms

Major components of Milky Way

A galaxy is mainly composed of numerous Stars and stellar populations. All stars are not of the same character tics and values, just like Hollywood stars of our planet, they mainly differ by masses, luminosities and orbiting characteristics. That is why not all stars become black holes, when they die. Only the stars having 1.44 times of the mass of Sun can turn into black holes-this critical mass of becoming black hole is also known as Chandrasekhar limit. Though most of the stars in our Milky Way exists as either a single star (the Sun), but there are a number of well defined groups and clusters of stars, which has thousands of member stars. This type of formation of stars in a galaxy can be subdivided into three main categories-globular, open and stellar associations-age and numbers are the main distinguished parts of star sub division system. Apart from grouping of stars, there are some other important objects like emission nebulas, planetary nebulas act. More or less, the followings are the major components of Milky Way galaxy

  • Star clusters and stellar associations
  • Emission nebulas
  • Planetary nebulas
  • Supernova remnants
  • Dust clouds
  • Interstellar medium
milky way  courtesy-www2.lns.mit.edu

milky way courtesy-www2.lns.mit.edu

1 Star clusters and stellar associations

Though most of the stars in our Milky Way exists as either a single star (the Sun), but there are a number of well defined groups and clusters of stars, which has thousands of member stars. This type of formation of stars in a galaxy can be subdivided into three main categories-globular, open and stellar associations, moving groups-age and numbers are the main distinguished parts of star sub division system.

1.1 Globular clusters

They are the largest star clusters with the most massive size stars. There are 130 globular clusters in Milky Way, mostly are spherically spread around the Milky Way. This 'type of clusters are the most luminous too, globular clusters brightness is comparable to around 25,000 suns. The masses of these objects are roughly 1,000,000 of the mass of Sun. almost all the clusters are extremely dense at the center and having radius of 10 to 300 light years.

1.2 Open clusters

They are smaller in numbers and less massive to globular type clusters. They are called open clusters because they have loose appearance in comparison to globular clusters. They are very concentrated at the center and gradually decrease at the edge from their center. They are less luminous than globular clusters; the most brightest open cluster is equivalent to 5000 times greater than the luminosity of the Sun. the average mass of an open clusters can be around 50 solar mass and the number of starts can be anywhere between tens to thousands. About 20 light years an average open clusters diameter. Most of open clusters are at the age of 1,000,000 or 2,000,000 years and only a few percentages have reached over 1,000,000,000 of age. So, far only 1,000 open clusters have been found in our galaxy.

1.3 Stellar associations

In terms of age, they are younger than open clusters and consist of very loosely grouped stars. They appear in the region of the galaxy where start formation take place, mostly at the spiral arms of the Milky Way. They very luminous objects, even brighter than the globular clusters. Their luminosity is about 1,000,000 times the Sun. but the lifetime of stars in stellar associations of clusters is very short-only a few million years. The size of stellar association is very high, their average diameter is over 700 light years and. Only a several hundred solar mass can be the mass of an average stellar body. All stellar associations are so loosely structured that their gravitational pull is not enough to hold them together, most of them after a few million years get disperse in the galaxy and become like unconnected stars of Milky Way.

carina nebula

carina nebula

Supermassive Black Hole in the Milky Way Galaxy

2. Emission Nebulous

Emission Nebulous are mainly a kind of cloud-like objects consists or bright and diffusive gases and stars. In a nebula gas exists in the form of ionized gas- this state of gas is due to the emission of ultra violet lights by hot stars inside a nebula. Since emission type nebulas are mostly of ionized hydrogen- they are also known as H II regions. Many of the emission nebulas are located 10,000 light years away from the center of Milky Way.

3. Planetary nebulas

Planetary nebulas are gaseous clouds. They are so called because they almost resemble disk shaped planets when you look at them with telescope. This type of nebula represents the end stage of stellar life cycle. So, far over 1,000 planetary nebulas have been identified in our Galaxy.

4. Supernova Remnants

They are another form of nebulous objects found in our galaxy, in the form of gas. The main reason of their existence is because of the forming of super massive stars or supernova. Though they almost look like planetary nebulas, but they have three distinguished characteristics that make them differ from other types of nebulas-they have larger mass, higher velocity, short life-time. Example of an observed supernova remnant is AD 1054. Inside these types of stellar objects particles move in spiral direction with the speed of light and their emitted radiation patterns form flat spectrum of radio waves-this pattern of radiation also know as synchrotron radiation.

5. Dust clouds

They are located, mainly, to the Milky Way Plane and they are very conspicuous in the region of spiral arms of our galaxy. Dust clouds over 2000 light years distant from our Sun are not detectable with any optical telescope. Dust clouds can have masses over several hundred of solar masses and their maximum size can be about 200 light years.

Milky Way in 3D

Structure of Milky Way

If we look at our Milky Way with 3D view, it can be considered as a large spiral system with 6 separate parts.

  1. Nucleus
  2. Central bulge
  3. Disk
  4. Spiral arms
  5. Spherical component
  6. Massive hallow

What is in the center of Milky Way

At the center point of our galaxy, there is a super massive black hole, which is only detectable by radio waves only. Near the center of this black hole, the activities like infrared radiation, X-ray emission, rapidly moving gases can be observed if you ever have the opportunity to visit this place. All the radio evidence gathered indicates that this black hole pulling material outside the nucleus of the Milky Way. When gases clouds near this black hole, its gravitational force turn it into a fast moving rotating disk, which extends 5-30 light years! And can you guess about the


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pari kapoor on February 16, 2013:

these are good but not soo. much

Zain Pak on December 08, 2012:

Great info. Helps me a lot to understand the complicated nature of universe. Plz write more about it

Angela Kane from Las Vegas, Nevada on February 27, 2012:

Very good hub, I voted it up and useful. I am very interested in space exploration and your article is every good.

syras mamun (author) on February 13, 2012:

@Bob:Glad to know that Bob.

bob on February 13, 2012:

it sux

syras mamun (author) on February 03, 2012:

@cheesecake:Glad to know that you liked my hub.Hope to write more about galaxies :)

cheesecake on February 03, 2012:

you should write more hub pages. this one really helped me a lot for my project! :)

cheesecake on February 03, 2012:

wow, you helped me with my science project!! thanks a bunch

Aurogra on January 20, 2012:

Fascinating, great images I am always taken aback by how much information we have gathered over the recent years and how we know what is out there. P.s. The video blew me away..



leta on January 11, 2012:

i think this is asom

IM SO STUPID on December 23, 2011:



SHAKIRA on December 23, 2011:


doc117 on December 11, 2011:

Thanks for the thought stimulating topic. After all as Jim Kirk so eloquently puts it.." Space..the Final Frontier."

syras mamun (author) on December 09, 2011:

@lily-I am glad that you like it.Thank you so much for your series of comments :)

lily on December 08, 2011:

this video is so cool and full of facts and so creativey and naturey like and its so so ..........so awsome i cant even tell any more ............................................................by the way its so amazingly cool that's all and so spacie like ...well its space like any way

lily on December 07, 2011:

iam so facinated with your video case it it so full of facts and so natury like and i showed almost evry body in the house

rebecca on December 07, 2011:

this video was so epic i almost exsloded and it was soooooooooooooo cool i ran screaming it was awsome jkkkkkkkkkkkkkk

lily on December 07, 2011:

this video is so awsome because it tells you facts about outer space stuff and the milkyway so watch this video and learn about space !!!!

syras mamun (author) on November 16, 2011:

@Felixedet2000-Thank you so much for your feedback.

Felixedet2000 from The Universe on November 16, 2011:

Well written and laid out, i flow along with the revealing information with passion. Thanks for making my day.

bob on October 13, 2011:

the milky way is so cool man dude!

Wooded on March 29, 2011:

I really enjoyed this hub. I love staring at the stars whenever I have the opportunity! Thanks

syras mamun (author) on December 10, 2010:

@larryprices-I always love astronomy and physics.I agree with you that people who do not take a look at astronomy certainly missing one of the most fascinating subject of modern science.And astronomy also helps to broaden the horizon of human mind. thank you so much :)

@Vandana-thank you so much :)

vandana on December 09, 2010:

Nice job.lines are well written.most of the people remains unoticed 4m d galaxy news, bt dis z a nice way to make dem mark d facts.

Larry Wade Price from Long Beach, California on December 09, 2010:

Good work here. Very interesting and well written.

Keep up the great work. Astronomy and Astrophotography are wonderful hobbies, and most people don't realize what they are missing.

A family hobby option here will never be seen as a mistake. It is a lifelong hobby pursuit.


Tom Ware from Sydney, Australia on August 17, 2010:

This is an amazingly detailed and well researched Hub. Still, on reading it one cannot help wondering if this visual universe is only as we human beings see it through the very narrow slit of the visual spectrum our eye sight allows. Maybe there is no such thing as space; no such thing as 'no thing,' or 'nothing.' And that the illimitable universe is illimitable in infinite direction.

syras mamun (author) on July 30, 2010:

Elena, you can imagine our galaxy as a kind of chocolate,which is gradually stretching outwards. I am quite familiar with "milky way" chocolate, I won't mind if you send a box of "milky way" :)

syras mamun (author) on July 30, 2010:

Elena, you can imagine our galaxy as a kind of chocolate,which is gradually stretching outwards. I am quite familiar with "milky way" chocolate, I won't mind if you send a box of "milky way" :)

Elena from London, UK on July 29, 2010:

Great Hub Andromida - I opened this Hub because I thought it was about Chocolate. Trust me. lol. There is a chocolate called "milky way" and another one called "galaxy" in UK. Anyway... I'm not disappointed, I enjoyed reading it and have learnt a few things. Its amazing and thanks for including photos.

Best Wishes. :)

syras mamun (author) on July 28, 2010:

@vydyulashashi-I just read a news that maybe our solar system has not its origin in Milky Way.Thank you for your feedback :)

@Coolmon- Astronomy is always a fascinating subject to me. Glad to have your comment.Thank you so much :)

Coolmon2009 from Texas, USA on July 28, 2010:

Good information, I have always been fascinated by astronomy.I enjoyed reading your article.

vydyulashashi from Hyderabad,India on July 28, 2010:

in this ever expanding universe milky way stands as one of the major galaxy..it is one of the largest galaxy!!

nice hub

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