Category Archives: evolution of galaxies

astronomy news, cassini, cassini mission, evolution of galaxies, galaxies, globular clusters, omega centauri

Cassini Catches a Cluster

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Omega Centauri as Ring Backdrop

Well, this is kind of cool. The Cassini Mission out at Saturn happened to be studying the planet’s F ring and during the course of the observations caught view of the globular cluster Omega Centauri as it passed through the camera’s field of view.

The movie above is actually 13 images taken three minutes apart and then surgically joined together by the Cassini team to make the animation.  It clearly shows the cluster moving through the background.

Omega Centauri is really a spectacular naked-eye sight. It’s visible from throughout the southern hemisphere and lucky folks in more southerly parts of the northern hemisphere closer to the equator have a good vantage point for it, too. It has several millions stars packed into an area less than 90 light-years across.

The cluster lies about 15,800 light-years away from us, and is the largest of the globular clusters that are associated with the Milky Way Galaxy.  Omega Centauri may have played an interesting role in the evolution of our galaxy. Some astronomers suspect that it could have been part of a dwarf galaxy that was consumed by the Milky Way billions of years ago.  If this is true, then the cluster is what’s left of that galaxy’s core.  It’s an intriguing idea and one that astronomers are still researching.

On an unrelated note, if you’re a fan of the Carnival of Space, check out this week’s Carnival, written by Emily Lakdawalla.  Great stuff in there, including one of my own entries.

astronomy, evolution of galaxies, galaxies, galaxy interactions, galaxy shapes

View from a Distance

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Galaxy Beauty

What if you could move anywhere in the cosmos just to get a good view? Where would you go? The view from our own planet takes in the interior of our own galaxy, plus a healthy look out to intergalactic space. We can see, literally, for billions of  light-years, provided we use the right instruments.  But, what if you could live on a world at the rim of a distant galaxy that was overlooking a pair of interacting galaxies?  What you like this to be your view?

NGC 1532/1 as seen by ESOs 1.5-meter Danish Telescope. (Click to embiggen.)
NGC 1532/1 as seen by ESO's 1.5-meter Danish Telescope. (Click to embiggen.)

This is a pair of galaxies called NGC 1531/2 and they lie about 70 million light-years away from Earth. From this point of view, we can tell they are interacting in a sort of spirited galactic waltz. The spiral galaxy in the foreground is being warped by its dance with the smaller galaxy just above it. The cosmic dance leads to another dramatic effect: a whole new generation of massive stars that were created in the chaos of collision during the dance.  They are visible as the purple objects in the spiral arms.

This view from your living room window on that distant planet I mentioned above is really an exquisite image from the European Southern Observatory. It was made by R. Gendler and J.-E. Ovaldsen who used the 1.5-meter Danish telescope to capture the image.

I often wish we had dramatic views like this from our own back yards here on Earth rather than the skies we do have. On the other hand, using telescopes like the ones at ESO, we really kinda do.  So, enjoy!!