Sunday, August 27, 2006

Black Holes & Mira, the Wonderful Star

Ever since I heard what a Black Holes is I wanted to see one! Ever see that cheesy Disney movie from the 70's Blackhole? It fascinated me.

Since the creation of the Hubble Telescope it was only a matter of time before we got to see one. Buts whats that I hear you say? You cant see a blackhole because light cant esacpe from it? Well that is true; you might not be able to see the blackhole, but you can certainly see its passing!!

When a Blackhole passes close to a star, it starts to suck it in. The matter from the star streams towards the BH. As BH's are rotating the matter from the star starts to swirl around the event horizon of the BH just like a whirlpool. The gravity is so strong that the matter rotates close to the speed of light. They call this an accretion disc. You certainly can see those.

In fact the gravity is so strong that the BH sucks in far more matter than it can swallow. It ends up throwing out billions of tons of stellar matter from either pole. It throws them thousands of light years into space in two continuous jets.

Its not just BH's that create accretion disks. White Dwarf and Neutron stars do also. Both are the remains of collapsed stars that werent quite big enough to make a BH. The gravity they immit is still huge. A neutron star can have a diameter of 25k kilometres but have the gravity of a million Suns!!!

The last pictures are of Mira, the Wonderful Star, so called for its unusual fluctuations of brightness. Scientists now know Mira is a binary star system, with Mira A, a nice normal bright star, and Mira B, a White Dwarf star that is pulling huge amounts of solar matter from Mira A towards itself. The matter is spinning around Mira B at a huge speed kicking out emense amounts of radiaition. Radiaion is the main give-away for a BH.

The final picture is an artists recreation of what the Mira system might look like.



Kasia said...

Black Holes have always fascinated me too. When I was a child i often wondered how would it feel to be sucked into one?? What is there inside?

Where do you take your photos from???

Alexander said...

Ah "The Black Hole" with Maximillian.

We named one of our early cats "Max" after that maroon robot with the spinning blades.

Martin said...

I check every day NASA's Astronomy Picture of the Day or APOD on

I then get inspired and see what I can find on the web. Does this mean that you wont be suprised when I post me new photos? :(

I remember those robots fondly, Alexander. Also Maxamillian rocks!!blol

Kasia said...

Sure I will be surprised:))))I just thought that maybe you are sitting on the roof somewhere with a huge telescope and a camera. :D