Actually, a supernova went off in 2005 (2005cs). I got a picture of it entirely by accident; I was just showing some friends how to use the university’s CCD camera to make a color image. A few weeks later I heard about the supernova, checked the image, and there it was!

Supernova 2005cs is the bright dot directly above the core of M51 in my picture (link in name). You can see it’s on (actually, in) a galactic arm, while none of the stars in the Hubble image are, not even the yellow one that’s almost in the right place.

As for why we don’t see tons of them going off, I think it has to do with how incredibly rare those bright blue stars are. Mathematically speaking, if they last five million years, you’ll need five million of them to get approximately one going off every year.

There are about 6,250 star systems expected within 25 parsecs of the Sun, none of them contains a star capable of core-collapse supernova (I’m ignoring type 1a white dwarf supernovae). That means the fraction of stars that CAN is something much less than, say 1 in 10,000. If there are 100 billion stars in M51, there will only be 10 million supernova-producing stars, tops. That would seem to work, but I’m betting my 1 in 10,000 is far, far too high.

As a bickering twit, I am offended, sir, by your demand.

We each have our personal cyberspace tolerance threshold. (I, for one, will never, under any circumstances, waste my time reading youtube comments.) You simply have to ask whether the signal to noise ratio on this blog is high enough to make you want to tolerate the noise floor. For me it is, more often than not. But not always (e.g. global warming troll posts).

If you still think your pointless quibbles about ontology are important enough to spew them all over my monitor, please quit typing and look at the picture of the galaxy, because it has not yet humbled you sufficiently.

No, no retorts. Yes, you. Yes. I know you’re just aching to tell me how very serious the problem of your political opponents actually is. Shut up. Look at the picture.

It is not a picture of you being right.

Because this is evidence that the earth may just be a little older than 6000 years? Just saying.

Shouldn’t that be ‘like?’

The Lancet retracted Wakefield’s 1998 antivax article.

http://tinyurl.com/ykjcdd3

It is truly humbling to think that we are capable of viewing the cosmos from our tiny speck of a rock. Thank you for sharing this image.

I wish I could have that M51 Whirlpool galaxy photo displayed as a giant mural on my house.

The Whirlpool surely has to be the beautiful spiral galaxy of all with NCG 2997 in Antlia being its closest rival or possibly tying with it. (http://en.wikipedia.org/wiki/NGC_2997 )

Of course, as seen in the sky the Large Magellanic Cloud looks better or at least so much bigger! But a) the LMC has the unfair advantage of being so much closer and b) its not a spiral but a messy and loose *barred* spiral & so gets disqualified on that technicality.

galactify.

Another neolgism (spelling?) to your credit BA?

It may look blurry and fuzzy through a small telescope, but our brains are big enough to encompass all those light years, and to understand what it is we’re seeing.

You know I sorta agree with you there but also sorta wonder if we really do fully understand what we’re seeing in the deeper sense.

“I used to be a creationist until I saw the light. I can tell you firsthand, those poor people deserve pity, not derision.”

That’s a very humane way to see it.

@#1:

I used to be a creationist until I saw the light. I can tell you firsthand, those poor people deserve pity, not derision.

Decades ago, it was not known with certainty whether the companion galaxy NGC 5195 was a true companion, or another galaxy passing at a distance. The advent of radio astronomy and subsequent radio images of M51 unequivocally demonstrated the reality of the interaction.

Recent simulations bear out that M51′s spiral structure was caused by NGC 5195 passing through the main disk of M51 about 500 to 600 million years ago. In this model, NGC 5195 came from behind M51 through the disk towards the observer and made another disk crossing as recently as 50 to 100 Myrs ago until it is where we observe it to be now, slightly behind M51.

Source: Wikipedia — Whirlpool Galaxy; Companion.