By Ted Grussing
… after an exchange with my friend Rich at Lowell Observatory this morning it was a given that the image tonight would be an astro composite and the topic would deal with forever … perhaps also a discussion of the word immediate. It all started with an exchange about how we humans seem to be hardwired to find images in the inanimate or organic such as the photo of the iris I sent out yesterday. Rich sent me an image of a nebula which someone had seen another image in but neither he nor I could locate or see what the other person did. He referenced a star forming region within the image and I asked the question how do the stars form and does the formation region wander around a galaxy, does it change and what happens after it has produced the stars. I have always had a love for whatever it is that is out there, have done a little study and much wonderment. The following is an explanation that Rich sent me which is concise and answers many questions I have had for a long time … some people have a unique ability to explain the complex in simple terms and he has that gift, So here it is …
“Most stars do form in regions like this. Gas and dust within the Galaxy move along with its majestic rotation, and as they do so they collapse and concentrate under the force of Gravity. When they reach a critical concentration areas of gas and dust collapse into a disc with a central concentration which gets hotter as the collapse continues, and eventually conditions in the center reach the point that hydrogen atoms naturally fuse into Helium. This puts the heating on overdrive and a star is born. The massive ones blow up as Supernovae almost immediately (a million years or so) and seed the cloud with the heavier elements (up to but not much beyond iron on the Periodic Table) they produced in their short lives. They also send shock waves through the cloud and so trigger more star formation. Smaller stars survive and continue with the motion of the cloud where they formed, slowly drifting apart as they go on their long orbit of the Galaxy. Early in the trip they are clumped together and we see them as “open” clusters of stars. The nearest of these is the “Hyades” cluster, which forms the head of Taurus, the bull. A more distant one appears to be dimmer and more tightly packed, and the best example is the “Pleiades”, also in Taurus as the body of the bull.
As a clusters age and the stars continue to drift apart they spread apart enough that they are not obviously related, but we can still spot them because the stars continue to move through the Galaxy with the same speed in the same direction. Such a group of stars is called a “Moving Cluster”, and the best example is Ursa Major, or the “Big Dipper”. All but two of the bright stars in it formed together and travel together.
Our Sun does have some siblings from its own formation. Since we are still fairly close to them (we have only been drifting apart for about 4,000,000,000 years) we can identify some really faint “Red Dwarfs” (like the Sun) that spawned in the same cloud that produced us. The moving cluster that includes our nearest kin is, as you would expect, all over the sky. Fortunately the Sun is a third-generation star, meaning that we reap the benefit of two generations of heavy element production.”
I like that the massive stars blow up almost immediately (a million years or so) … we have sibling stars that are traveling relatively close to us because we have only been drifting apart for about 4 billion years … and we think trends of a few decades are significant! Thank you Rich!
The image tonight is a view of the San Francisco Peaks in a composite with the Pleiades Reflection Nebula blending with strong rotor clouds whipping off the lee side of the peaks. Lowell Observatory Mars Hill campus is at the bottom of the image right of center … maybe just below the image … hard to tell. Also I was reading on the NASA site that it appears that our galaxy the Milky Way may very well collide with the Andromeda Galaxy sometime in the future … that will probably have an enormous effect on earth … wonder how we will save ourselves from that one … time to start planning and worrying :+)
What a magnificent life we have … enjoy the moment … smile and share your joy and zest for life with others.
Four and a half hours to the first five shots of espresso in a SF Vanilla latte …
For life holds cheers as well as tears,
Take this old toast from me:
This world a riddle hard you call …
A mess from which you fain would shrink?
Perhaps ’tis wisdom, all in all.
To learn to laugh as well as think.
— Max Ehrmann