A famous radio map of the sky

http://www.cv.nrao.edu/course/astr53...ioNightSky.jpg

Where in the sky is this image, i.e. name a few (two) of the constellations it encompasses (or even better, name some of the radio sources (two))?

Hint: Check out this map

http://home.xtra.co.nz/hosts/Wingmak...ns%20Maps.html

This one's a pain.

It's easy enough to find that this is the radio sky above Green Bank and the images are at 4.85 MHz. The view is 40-45 degrees across. The picture is facing south west.

But which bit?

The line of the Milky Way is easy to spot (low left to upper right). It can't be the galactic centre (not enough radio sources). There is a prominent SN remnant center left and two more further left.

If it's SW, then we can't have Cass, Ceph or the other circumpolars.

Ghz not MHz, your own deductions only leave a few possibilties

The only trouble is which one.

I'd guess that the two possibilities are Orion and Monoceros - and Cygnus and Vulpecula.

The Orion Nebula might be at the bottom right, and the Rosette in the middle.

Sorry,

Did you find the original page of the picture? The answer isn't there but a clue that would have ruled out cygnus is there. While Monoceros semi-fits this category (the clue), another part fits it better.

outer galaxy... 160-180ish ...

OK

The weird thing at the bottom is the California Nebula/ Perseus OB1 and the centre is Auriga A.

Right, although I never heard of Auriga A, Auriga the constellation is in there. Thanks for sticking it out

It's surprising just how many SNRs are in Auriga. I found references to at least 4 major ones and of course the Crab is just over the border.

Thats nothing compared to closer to the center, they almost overlap each other there are so many, I can't seem to find a picture, this reference (http://adsabs.harvard.edu/abs/2006AAS...208.6302B) says there is 35 in a 22 square degree patch.

A new easy question then...

Other than the Milky Way, what is the largest deep sky object as seen from earth (apparent angular diameter)? How old is it, how massive is it, and when is best seen from the Northern Hemisphere?

If M31 qualifies as a DSO, then:

M31 (a.k.a the Andromeda Galaxy)
Size: 178x63 arc seconds
Distance: 2.6 million LY
Mass: (It's a galaxy for cryin' out loud)
Age: 10 billion years, give or take?
Best seen: Northern Hemisphere Fall - call it early October - early December.

If you're going to say "other than the Milky Way" as if the Milky Way would be a contender, then I guess the answer is the Large Magellanic Cloud, followed in second place by the Coalsack Dark Nebula.

(Grumble grumble...) I guess that the LMC is visible from the Northern Hemisphere....on the equator...from a mountain top...on a REALLY clear night.

If we allow the microwave band, then I'll guess the local universe itself seen as the CMBR. Angular size is 41,253 sq. deg.

__________________
Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

M31 does qualify as a DSO. It's just a little bit smaller than the object I'm talking about. It does contain a similar object to the one I'm talking about though (with its own NGC number as well)

Let me clarify - I meant the Milky Way as the milky band in the sky (visual object) not the local Galaxy. The LMC is big (not big enough). The Coalsack? - which one (Northern or Southern)? The Northern Coalsack is 5 degrees across and centred on Cygnus OB7. It's not a bad guess.

The Southern Coalsack is bigger but is a worse guess....

Ingenious. But I'm not going to allow it. This is akin to saying that the entire Universe is the biggest DSO - true but meaningless.

I'm looking at a much more localised object or structure. It is in our galaxy and you probably saw it last time you got your telescope out.

hmm....

__________________
Sometimes I think we're alone. Sometimes I think we're not. In either case, the prospect is staggering!

What about the Ursa Major Moving Cluster?

__________________
- Learn a lot teaching others.