Sloan Survey Second Data Release

TMB writes "The Sloan Digital Sky Survey, a large survey for distant galaxies and quasars that will cover 1/4 of the sky, just celebrated Data Release 2. The imaging data covers 3324 square degrees, with 88 million objects, plus spectra of 367,360 objects (mostly galaxies)."

square degrees?

[4of12]

Whatever happened to good old steradians?

Of course, I'm probably living in someone else's view of a sky that is measured in cubic degrees.

Re:square degrees?

[Merlin42]

A quick calculation shows that 3324 square degrees is almost exactly 1 sr ... hmm coincidence?

Re:square degrees?

[Tango42]

Your calculations are sound... I guess it must be a coincidence...

Re:square degrees?

[mroch]

Which sounds more impressive to someone that doesn't know what either means, 1 or 3324?

*3283* square degrees per steradian

[Anonymous Coward]

(180/Pi)^2 = 3282.8063500117437947816946079953

Mindblowing

[WTFmonkey]

88 million objects... very weird.

I just picked up a book by a guy named Rees called Before the Beginning which does a fabulous job of explaining the basics of cosmology and astronomy. I'm only about a hundred pages in, but am absolutely fascinated.

Is anyone else kept up at night thinking about the immensity and unknowability of the universe? I toss and turn, switching between two modes of thought, one being "Man, this place is huge and everything we do is pretty much inconsequential! I wish I could live long enough to hear answers to the cool questions, and this paltry 80 years we're dealt just doesn't cut it. The injustice!" And the other mode of thought being, "Yeah, but this shit's cool! I don't need to know it all, just enough to keep my brain churning. The wonder!"

What does this have to do with the article? Well, it seems pretty obvious to me that each of those 88 million objects is unique and interesting in its own way, and even though I feel like we're amoebas piggybacking on a brontosaurus (borrowed metaphor), it's cool that we're getting to know our little patch of dirt. Fun stuff, and nicely done.

Re:Mindblowing

[Pumpernickle]

There is something to what you say. In my case, however, if I'm kept up at night and I'm thinking about 88 million objects, they probably happen to be all those blasted sheep I've been counting. =/

Re:Mindblowing

[mbrother]

I'm a collaborator on the SHEEP project (that's the Search for the High Energy Extragalactic Population) and there are more like 88 of them (approximately), rather than 88 million. We write articles with cute titles like "Counting SHEEP", etc.

Is it REALLY huge?

[Cujo]

Puny Earthling, your universe is just a spacetime bubble in someone's lab. As soon as your creator defends his thesis, you're out of here.

Is anyone else annoyed...

[drox]

... at the line that indicated this is in the "tax-sink dept."?

With all the useless and/or downright dangerous and scary things are taxes are spent on, it seems very small-minded and petty to complain about the embarassing pittance that's spent on learning more about our universe.

mindboggling indeed

[Roman_(ajvvs)]

When you think a sizeable portion of our interstellar and -galactic sight is obscured by our own galaxy, to see "mostly galaxies" just boggles the mind. If there are billions of stars in each galaxy, and you're seeing more galaxies than you see stars in your own galaxy, how mindbogglingly many stars are there to eventually to look at?

*head explodes*

Re:mindboggling indeed

[TMB]

Just to clarify... in the imaging data, the stars outnumber galaxies by a lot. They purposely target likely galaxies for spectroscopy, which is why there are more galaxies than anything else in the spectroscopic data.

That's in contrast with the Hubble Ultra Deep Field [hubblesite.org], where almost every object is a galaxy, because they purposely chose a patch of sky with very few stars.

But, yes, there are an incredible number of stars in the observable universe. :)

[TMB]

I'm a slave driver...

[mbrother]

...I've put my student to work on the SDSS DR2 already! He was working on a paper characterizing a rare type of quasar, we found 3 examples in DR1, and now we'll take the extra time to see if we can add a few more before submission. Just looked at a big pile of spectra today. It was fun!