Hubblecasts from ESA

[MargaritaMc]

Hubblecast 64: It all ends with a bang!
Most stars in the Universe are small and insignificant, and they will -- eventually -- fizzle out without much drama. But a few light up the sky when they die, and in the process, they don’t just tell us about the lives of stars: they create the building blocks of life, and help us to unravel the whole history of the Universe. These are the stars that end their lives as supernovae, explosions that are among the most violent events in the Universe.

http://www.spacetelescope.org/videos/hubblecast64a/
I found this latest Hubblecast video, on supernovae, really informative - though it might be a little bit basic for advanced Asteriskeans.

It needs Flash Player and is just under ten minutes long.

Margarita

[bystander]

Click to play embedded YouTube video.

All the Hubblecasts are on YouTube

[MargaritaMc]

Marvellous - you are such a mine of information, bystander. Thank you.

Here is another Hubble cast

Click to play embedded YouTube video.

Hubblecast 62: A spiral galaxy with a secret

This will delight Ann, as it features stunning images by Rob Gendler of Messier 106!

Also animations showing the jets from the super massive black hole and how they affect the unusual galactic 'dust arms'.

Margarita

[Ann]

Thanks, Margarita!

My complete amateur take on how those glowing red "gas arms" form is... no, I have no idea of the actual mechanism. However, there is one huge difference between M106 and M87, another galaxy with a jet emanating from its center.The jet of M87 is clearly much more powerful than the jet of M106, so that the jet of M87 "upsets" practically all of the gas and dust in that galaxy, whereas the jet in M106 only upsets the gas that is located close to the black hole.

NGC 4051. Image Credit: George Seitz/Adam Block/NOAO/AURA/NSF

Of course that still doesn't explain why we don't see such extra "ghost arms" in other spirals with active nuclei. NGC 4051 is a spiral galaxy with a supermassive black hole in its active nucleus, but it doesn't have any glowing "ghost arms". Perhaps the black hole isn't feeding so much right now.

http://en.wikipedia.org/wiki/NGC_4051 wrote:
NGC 4051 is a spiral galaxy. It contains a supermassive black hole inside the center.

This galaxy was studied by the Multicolor Active Galactic Nuclei Monitoring 2m telescope. [1]

The galaxy is a Seyfert galaxy that emits bright X-rays. However in early 1998 the X-ray emission ceased as observed in by the Beppo-SAX satellite.

Ann

[stephen63]

I noticed the jets from the black hole in M 106 weren't perpendicular to the galactic plane. That allows for more interaction with dust and gases