econintersect.com
       
  

FREE NEWSLETTER: Econintersect sends a nightly newsletter highlighting news events of the day, and providing a summary of new articles posted on the website. Econintersect will not sell or pass your email address to others per our privacy policy. You can cancel this subscription at any time by selecting the unsubscribing link in the footer of each email.



posted on 20 December 2015

What Is The Biggest Star In The Universe?

from The Conversation

-- this post authored by Daniel Brown, Nottingham Trent University

Look up at the night sky and it is filled with stars. But only a microscopic fraction are visible to the naked eye. In fact, there are estimated to be 100 billion stars in 10,000 billion galaxies in the visible universe. This means that there are roughly 10 to the 24th power stars out there.

These spectacular powerhouses come in an array of different colours and sizes - and many make our own Sun look like a mere pipsqueak. But which is the true giant of the heavens?

Well, we have to start by defining what we mean by giant? Is it the one with the largest radius, for example, or the greatest mass?

There be giants... Mike Durkin/flickr, CC BY-SA

Galactic bohemoths

The star with possibly the largest radius is currently UY Scuti a variable bright red supergiant in the constellation of Scutum. Located around 9,500 light years from Earth, and composed of hydrogen, helium and other heavier elements similar to the chemical composition of our Sun, the star has a radius 1708 (±192) times larger than our Sun's.

That is nearly 1.2 billion km, resulting in a circumference of 7.5 billion km. To put that in perspective, it would take you 950 years to fly around it in a commercial airliner - even light would take six hours and 55 minutes to circumnavigate it. If it were to replace our Sun, its surface would be located somewhere between the orbits of Jupiter and Saturn - needless to say, Earth would be swallowed up.

UY Scuti, Rutherford Observatory Haktarfone [GFDL (http://www.gnu.org/copyleft/fdl.html), CC BY-SA

Given its vast size and a possible mass of 20 to 40 times that of our Sun (or 2-8×10³¹kg), UY Scuti has a probable density of 7×10⁻⁶ kg/m³. In other words, it is more than a billion times less dense than water.

In fact, if you could place this star in the biggest water bath in the Universe, it would theoretically float. Being more than a million times less dense than Earth's average atmosphere at room temperature, it would also bob around in mid-air like a balloon - if only you could find a park big enough.

But if these insane facts blow your mind, we haven't even started. UY Scuti may be vast but it's not a heavyweight. The king of the heavyweights is the star R136a1, located in the Large Magellanic Cloud, about 165,000 light years away.

Star R136a1 (far right) is in a dense cluster of stars 165,000 light years from earth NASA Blueshift/flickr, CC BY

Massive attack

This star, a sphere of hydrogen, helium and heavier elements at roughly half the amount of the Sun , is only 35 times the radius of our Sun, but a colossal 265 times more massive - impressive, especially given that it has already lost 55 solar masses during its 1.5 million year life time.

This Wolf-Rayet type star is far from stable. It would appear as a fuzzy blue sphere with no clear surface as it pushes out enormously powerful stellar winds. These winds travel at a blistering 2,600 km/s - or 65 times faster than the Juno probe, the fastest man-made object.

As a result, it loses mass at the rate of 3.21×10¹⁸kg/s, the equivalent of an Earth every 22 days.

Such a stellar rock star shines bright and dies fast. R136a1 radiates away nine million times more energy than our Sun, and would appear 94,000 times brighter to our eyes if it replaced it. In fact, it is the most luminous star ever discovered.

The Large Magellanic Cloud: full of stars Hubble Heritage/flickr, CC BY-SA

It has a surface temperature of more than 53,000K and it will only live for two million years. Its death will be a spectacular kind of mega supernova leaving behind not even a black hole.

Of course, against these giants our own Sun seems a little insignificant, but it, too, will grow in size as it ages. In around seven-and-a-half billion years, it will reach its maximum size as a red giant, expanding so far that the Earth's current orbit will just be inside it and spiral into the Sun even before that.

But all stars are only tiny parts of larger galaxies, themselves pin pricks in a truly vast Universe. And Earth? Well, best not dwell on that.

The ConversationDaniel Brown, Lecturer in Astronomy, Nottingham Trent University

This article was originally published on The Conversation. Read the original article.

>>>>> Scroll down to view and make comments <<<<<<

Click here for Historical News Post Listing










Make a Comment

Econintersect wants your comments, data and opinion on the articles posted.  As the internet is a "war zone" of trolls, hackers and spammers - Econintersect must balance its defences against ease of commenting.  We have joined with Livefyre to manage our comment streams.

To comment, using Livefyre just click the "Sign In" button at the top-left corner of the comment box below. You can create a commenting account using your favorite social network such as Twitter, Facebook, Google+, LinkedIn or Open ID - or open a Livefyre account using your email address.



You can also comment using Facebook directly using he comment block below.





Econintersect Contributors


search_box

Print this page or create a PDF file of this page
Print Friendly and PDF


The growing use of ad blocking software is creating a shortfall in covering our fixed expenses. Please consider a donation to Econintersect to allow continuing output of quality and balanced financial and economic news and analysis.


Take a look at what is going on inside of Econintersect.com
Main Home
Analysis Blog
Energy and Falling Productivity
Reinhard Selten: Pioneering Analyst of Rationality and Human Behaviour
News Blog
Americans Wary Of Drone Delivery
Britain's Wealthiest Households
What Next In The South China Sea
The Dollar - Gold Relationship
Almost Half Of Rape Cases End Without A Conviction
People With 'Obesity Gene' Can Still Lose Weight
The World's Most Generous Countries In 2016
What We Read Today 24 September 2016
Is The Butterfly Effect Real
August 2016 Philly Fed Coincident Index Shows Continuing Slowing Of Economic Rate of Growth
Global Bonds: Why Our Analyst Says Things Just Got "Monumental"
Trends In Expenditures By US Colleges And Universities, 1987-2013
Why Firms In Developing Nations Don't Grow As Fast
Investing Blog
The Week Ahead: How Will Election News Impact The Market?
How To Protect Your Money Against Negative Interest Rates
Opinion Blog
There's No Wall Between The Fed And Banco De Mexico
The Setting Sun: Japan Faces Monetary Exhaustion
Precious Metals Blog
War On Cash Turns To $20, $50, And $100 Bills
Live Markets
23Sep2016 Market Close: US Indexes Close Lower As Crude Prices Slip, Fed Lowers Economic Growth Prospects, Indicators Melting Into Bearish Territory
Amazon Books & More






.... and keep up with economic news using our dynamic economic newspapers with the largest international coverage on the internet
Asia / Pacific
Europe
Middle East / Africa
Americas
USA Government



Crowdfunding ....






























 navigate econintersect.com

Blogs

Analysis Blog
News Blog
Investing Blog
Opinion Blog
Precious Metals Blog
Markets Blog
Video of the Day
Weather

Newspapers

Asia / Pacific
Europe
Middle East / Africa
Americas
USA Government
     

RSS Feeds / Social Media

Combined Econintersect Feed
Google+
Facebook
Twitter
Digg

Free Newsletter

Marketplace - Books & More

Economic Forecast

Content Contribution

Contact

About

  Top Economics Site

Investing.com Contributor TalkMarkets Contributor Finance Blogs Free PageRank Checker Active Search Results Google+

This Web Page by Steven Hansen ---- Copyright 2010 - 2016 Econintersect LLC - all rights reserved