Simeis 147 by Davide De Martin
Written by Tammy Plotner
If you think we're looking straight down the maul of the "Doomsday Machine", you'd be pretty much correct. While the fictionalized Star Trek account had the planet killer slowly destroying a distant solar system, this particular "star eater" is very real and still exists along the Auriga-Taurus border…
Named Simeis 147, this ancient supernova remnant has expanded so much that it's barely visible to larger telescopes. Why? Mostly because the diameter of the nebula is about 3-1/2 degrees, or about 7 times the size of the Moon – and the fact it's one of the faintest objects in the night sky. Like many nebulous "sky scraps", it is simply too large to be seen in its entirety – or beauty – except through the magic of astrophotograhy.
In this week's image by Davide De Martin, we take an up close and personal look at Simeis 147. The intricate filaments of this faint supernova remnant spans over 160 light years of interstellar space and is around 3900 light years away. With an apparent age of about 100,000 years, this awesome explosion occurred around the time of Peking Man, and like our distant ancestor left more than one artifact behind. In this case, the expanding remnant is not all. Deep within the folds and rifts lay a spinning neutron star. This pulsar is all that's left of the original star's core.
Unlike many things unexplored, more study was indicated and newer estimated gauge Semeis 147's age at about 30,000 years. The pulsar itself has recently been detected and has been cataloged as PSR J0538+2817. Imagine something that rotates completely on its axis seven times per second! And think about what happened… The outer layers of this exploding star initially carried outward at speeds of 10,000-20,000 km/s–a tremendous amount of energy released in a blast wave.
Supernovae are divided into classes based upon the appearance of their spectra: hydrogen lines are prominent in Type II supernovae; while hydrogen lines are absent in Type Ia supernovae. Put simply, this means the progenitor stars either had hydrogen in their outer envelopes or did not have hydrogen in their outer envelopes. Type II supernovae are the territory of massive stars while Type Ia supernovae more than likely originated with white dwarf binary star systems – a place where the accreting white dwarf is driven above the Chandrasekhar Mass Limit, collapses and explodes.
So how often do events like the Simeis 147 type happen? According to Rudolph Minkowski; "As regards the supernovae frequency, there are two types of supernovae. The Supernovae I seem to occur about every 400 or 500 years per galaxy and the Supernovae II about every 50 years per galaxy, with considerable leeway. But, the Supernovae II are certainly much more frequent than Supernova I." In recent studies done the 610.5 MHz Contour Maps of the Supernova Simeis 147, by Dickel and McKinley, the integrated flux densities show that the radiation is probably non-thermal and incredibly old.
As old as the Star Trek "Doomsday Machine"? Its origins were also unknown and it produced mass destruction. Maybe Simeis 147 isn't quite the same as the neutronium hulled, antiproton beam firing planet killer of Gene Roddenberry's fictionalized story… But it is definitely as intriguing to the imagination!
This week's awesome image was done by Davide De Martin.
Filed under: Astronomy, Astrophotos
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June 16th, 2008 at 11:28 am
Doomsday Machine is from Dr. Strangelove
June 16th, 2008 at 12:36 pm
How close could a solar system like ours be to a supernova such as this and be OK?
I guess you couldn't kill it by flying a starship down its maw like Kirk did.
I will also say that connecting the two (Simeis 147 and the Doomsday Machine) is an awesome display of free-association. I really mean that, its a gift, I say.
And now that I'm thinking of it, it also kind of reminds me of the Romulan Plasma Torpedo, but without the awesome power!
June 16th, 2008 at 1:01 pm
Hi, RL!
Thanks for recognizing the Star Trek episode, "The Doomsday Machine". Your kind comments make me smile!
As for supernova? Well, the "accepted safe distance" is from 160 to 200 light years away. The reality check is that we just really don't know what IS a safe distance and what isn't. The more we learn, the more it seems we tend to realign our thinking. Have we found every supernova remnant out there? And do we know exactly how far they can expand?
Until that day, we'll probably never know how far away "safe" truly is.
Live long and prosper….
June 16th, 2008 at 2:19 pm
It might be a Doomsday Machine now, but I'd point out that supernovae are essential for the formation of life, because they carry heavy elements to star-forming areas that wouldn't otherwise have them (and therefore wouldn't form terrestrial planets otherwise).
June 16th, 2008 at 2:25 pm
We'll know how far away we need to be when we get blasted good once. We should really start working on what we want to do in that event, as a preventative measure. Any ideas?
June 16th, 2008 at 5:06 pm
Tammy, Thanks for the answer and the article!
And Tyler is right. The "circle of life" extends into the cosmos.
June 16th, 2008 at 5:11 pm
Hi, Tyler! I'm glad you're knowledgeable on supernovae – because they are genuinely the "stuff" we are made of. Fusion stops at iron, so an element with more protons than iron were created in supernovae events. Even we wouldn't be here without them!
Jon? We may very well have been blasted once. According to Brian Fields:
"Recent experiments have uncovered evidence that a star exploded near the Earth about 3 million years ago. Radioactive iron atoms have been found in ancient samples of of deep-ocean material, and are likely to be debris from this explosion. Newly published, high-quality data spectacularly confirm this radioactive signal, and for the first time allow sea sediments to be used as a telescope, probing the nuclear fires that power exploding stars. Furthermore, an explosion so close to to Earth was probably a "near-miss," which emitted intense and possibly harmful radiation. The resulting environmental damage may even have led to extinction of species which were the most vulnerable to this radiation."
Once bitten… Twice shy? Somehow I have a feeling that not even SPF6000 would help.
June 17th, 2008 at 3:24 am
"Mostly because the diameter of the nebula is about 3-1/2 degrees, or about 7 times the size of the Moon."
This boggles the mind. Could someone, perhaps create an artist's impression of this with a night time picture of perhaps a house on a barren plain with the moon low in the sky…then this structure behind it (with its brightness increased of course.) I just want to picture it's size.
Thank you. It would also amaze others how something so distant could look this big from this part of the Galaxy.
June 17th, 2008 at 8:58 am
Too bad it can't be seen by backyard telescopes; especially considering how large it is. Amazing how long you can sit and just stare at supernova remnants.
June 17th, 2008 at 5:44 pm
Believe it or not, like Barnard's Loop and the Veil, some small portions can be capture with a backyard scope… a BIG backyard scope!
For those who have aperture, try your luck around 5h 43m +28 25’. There's a little "haze" that says: "Hey. I'm here!"
And Aodhhan? Man, I just got lost in this image… It's pretty incredible! Take a look at this:
Photo
It isn't as beautiful, but it's a lot more realistic as to what you can see visually.