APOD: Deep Auriga (2010 Mar 05)

[APOD Robot]

Deep Auriga

Explanation: The plane of our Milky Way Galaxy runs right through Auriga, the Charioteer. A good part of the ancient northern constellation's rich collection of nebulae and star clusters is featured in this expansive, 10 degree wide skyscape. Bright star Elnath lies near the bottom right, linking Auriga to another constellation, Taurus, the Bull. Three open star clusters, Charles Messier's M36, M37, and M38 line up in the dense star field above and left of Elnath, familiar to many binocular-equiped skygazers. But the deep exposure also brings out the reddish emission nebulae of star-forming regions IC 405, IC 410, and IC 417. E. E. Barnard's dark nebulae B34 and B226 just stand out against a brighter background. For help identifying even more of Auriga's deep sky highlights, put your cursor over the image.

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[EmisMcC]

What do the symbols represent in this field? I have seen the planetary symbols before, and they are relatively easy to associate with their corresponding planet. However, I have never seen these ones before. It could be that they are very common, but I am relatively new to night time skygazing, so they are new to me.

[Chris Peterson]

What do the symbols represent in this field? I have seen the planetary symbols before, and they are relatively easy to associate with their corresponding planet. However, I have never seen these ones before. It could be that they are very common, but I am relatively new to night time skygazing, so they are new to me.

The objects are labeled with catalog references. Several different catalogs are involved. For instance, NGC=New General Catalog, IC=Index Catalog (an NGC supplement), M=Messier Catalog, Sh2=Sharpless Catalog (emission nebulas), B=Barnard Catalog (dark nebulas). Single numbers, letter pairs, and Greek letters are references to individual stars that are part of Auriga (Bayer or Flamsteed designations).

[WallyWeet]

This Deep Auriga Starfield looks like it is jammed with stars. Two questions: 1. When they move are they so close they might bump into each other? 2. Is our sun as close as these, is it in a starfield as jammed with stars as these? Wally Weet

[Chris Peterson]

This Deep Auriga Starfield looks like it is jammed with stars. Two questions: 1. When they move are they so close they might bump into each other? 2. Is our sun as close as these, is it in a starfield as jammed with stars as these?

It isn't as jammed as it looks. The view is in the plane of the galaxy, so you are seeing a hugh volume of space which contains stars. Being two dimensional, the image doesn't let us easily tell which stars are near and which are far. Certainly there are regions of high density, such as the visible clusters, and regions of average density- most of what we see. Most of the stars are probably separated from others by similar distances of the Sun to its neighbors.

Even in the densest of areas, such as globular clusters, stars don't bump into each other. They are simply too small compared with the distances between them.

[biddie67]

....... NGC=New General Catalog, IC=Index Catalog (an NGC supplement), M=Messier Catalog, Sh2=Sharpless Catalog (emission nebulas), B=Barnard Catalog (dark nebulas). Single numbers, letter pairs, and Greek letters are references to individual stars that are part of Auriga (Bayer or Flamsteed designations).

Thanks for this information - I have been wondering what all the different designations were.

[Eye in the North]

So...is it Elnath or Alnath?

[bystander]

I've seen both used. How about β Tauri.

[Chris Peterson]

So...is it Elnath or Alnath?

Take your pick. A lot of star names are from the Arabic, and start with the definite article. In Arabic, that is al... or el, or ul. The uncertainty is because vowel sounds tend to vary within a language due to accents and other regional effects. Therefore, the transliteration of vowels in particular is pretty loose. That's why you see star names with variant spellings. Beta Taurus may even be written as two words- Al Nath or El Nath.

[Eye in the North]

Can be really confusing for the newby...not that I'm a newby...which suggests that it can also be confusing for non-newbys. Is there not a standard approach within the astronomical society / professionals that would alleviate this confusion? I would hope that this would be the case, but I am also very aware of our inability to agree.

[Chris Peterson]

Can be really confusing for the newby...not that I'm a newby...which suggests that it can also be confusing for non-newbys. Is there not a standard approach within the astronomical society / professionals that would alleviate this confusion? I would hope that this would be the case, but I am also very aware of our inability to agree.

There is a standard approach used by pros (and many amateurs): don't use star names at all. Only a few have names in any case, and there's no official source for those names. But the stars are uniquely identified by catalogs, eliminating most opportunities for confusion. Alnath is Beta Taurus (or Tauri, if you prefer), any astronomer would recognize this designation, and it's almost certainly what you would find used in any paper or professional discussion.