APOD: NGC 2683: Spiral Edge On (2010 Oct 11)

[APOD Robot]

NGC 2683: Spiral Edge On

Explanation: Does spiral galaxy NGC 2683 have a bar across its center? Being so nearly like our own barred Milky Way Galaxy, one might guess it has. Being so nearly edge-on, however, it is hard to tell. Either way, this gorgeous island universe, cataloged as NGC 2683, lies a mere 20 million light-years distant in the northern constellation of the Cat (Lynx). NGC 2683 is seen nearly edge-on in this cosmic vista, with more distant galaxies scattered in the background. Blended light from a large population of old yellowish stars forms the remarkably bright galactic core. Starlight silhouettes the dust lanes along winding spiral arms, dotted with the telltale blue glow of young star clusters in this galaxy's star forming regions.

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[Ann]

I groaned when I saw the colors of this galaxy, which I myself find so very unappealing (even though I realize that others may find them extremely beautiful), so I tried to find out what filters had been used to acquire the image. I was unable to find any information that I could use. I clicked on Hubble Legacy Archive, the first link given to this image. What I found was a site that I had to enter, and as I entered it and searched for "NGC 2683", I got this:

http://hla.stsci.edu/hlaview.html#Inven ... 2CGHRS&ds=

I don't understand the information here. So could anyone tell me what filters were used to produce the Hubble picture of NGC 2683?

Ann

[owlice]

"ugly colors"???

Wow.

I think this is gorgeous.

[Chris Peterson]

I groanded when I saw the ugly colors of this galaxy, so I tried to find out what filters had been used to make the image. I was unable to find any information that I could use. I clicked on Hubble Legacy Archive, the first link given to this image. What I found was a site that I had to enter, and as I entered it and searched for "NGC 2683", I got this...

The search shows that there were four or five separate imaging projects for NGC 2683, using many different filters. There's no easy way to tell which images were used by the creator of today's APOD, and how he assigned them to specific colors. If you want more information, you need to contact him.

[owlice]

He has posted here, so perhaps he'll read this thread and respond.

[Chris Peterson]

He has posted here, so perhaps he'll read this thread and respond.

The credits for the APOD link his website, which has his email address listed. So it is easy enough to contact him directly.

[bystander]

If it was me, I probably would have nothing good to say to her.

[supamario]

If it was me, I probably would have nothing good to say to her.

Agreed. Ann appears to only appreciates pretty colors so I suspect she would also dislike black and white or gray-scale photos. That particular post has a tone of lack of respect.

[mexhunter]

Hi Ann:
Unless you contact the Author of the photo process, to tell us that use filters, it appears that the LRGB filters are embedded in the photo. Galaxies do not favor the use of narrow filters, except to highlight the concentrations of gas (nebulae) of these other galaxies.
Greetings
César

[nstahl]

It's kind of grouchy here today. Ann made a perfectly reasonable comment about her reaction to the colors (not so different from mine) and said she realizes others may differ. For that she got jumped on.

In the past she's displayed knowledge of astronomy and astrophotography which has added value to discussions here I've seen. I take it there have been some disagreements but this will be a more pleasant place if we show each other more respect, and especially to those who have earned it.

And while we should definitely appreciate the effort and skill that's gone into many of the APODS, and into maintaining this site, whenever you put your stuff before the public it can be criticized.

[owlice]

Ann's comment was edited after several comments following it were made, and her post is considerably softer now (yay! for that) than it was initially.

[Charlie]

Which edge is toward us? The bright one or the one covered by clouds? It's the standard problem of a 3D object reduced to 2D, but I never noticed it in a photo of a galaxy before.

[LLacertae]

Hallo everyone!

I am the creator of this image.

I used the Hubble 814W (for red) and 435W (for cyan) filters. My aim at this images was NOT to create a scientific "correct" rendering of the galaxy. The reason why there are no filteres to find is that I developed a process, in which two filters (435W/814W) can be combined to create (for some people) beautiful RGB pictures (with pure colors). Otherwise the colors would look something like this: http://www.spacetelescope.org/static/ar ... w1025a.jpg
Standardised -> most times boring (in my opinion)

And please do not forget, that the 814W filter is in the near infrared and thus invisible -- there is no color in the spectrum for infrared.

Many thanks to everybody who enjoyed my picture of the day!!

[orin stepanek]

I; for one, liked today's photo. I had to click on it to get it to fit on my computer screen though. I wish the pictures were screen sized to begin with; or maybe I need a bigger screen.

[biddie67]

Excellent work, LLacertae!!! Thanks for adding some comments - I think all the authors should be invited/encouraged to add their personal comments to their photo on APOD - it adds a lot to our appreciation of their efforts.

On a more subjective level, the effect of the photograph is to make me feel like I'm on a space craft, approaching this galaxy after a long journey - magnificent view of my destination ....

[bystander]

I; for one, liked today's photo. I had to click on it to get it to fit on my computer screen though. I wish the pictures were screen sized to begin with; or maybe I need a bigger screen.

Strange, mine comes up window size by default, I have to click to zoom.

I, too, enjoyed today's apod. There is another rendition of NGC 2683 from Hubble data by Robert Gendler here. I have no idea if it's the same data or filters, though.

Excellent work, LLacertae!!! Thanks for adding some comments - I think all the authors should be invited/encouraged to add their personal comments to their photo on APOD - it adds a lot to our appreciation of their efforts.

Agreed, hearing from the originator is a definite plus.

Good work, LLacertae, and congratulations.

[rstevenson]

I find these three (so far) different renditions of the colours of the galaxy to be very interesting. Presumably each would yield different information to a knowledgeable viewer, so each is valuable in its own right. As to preferences, I prefer the one the original artist refers to as "most times boring".

Obviously we all have different preferences when we're just appreciating these astronomical photographs as art. Just as obviously, scientists have different needs and prefer different filter sets for their own purposes.

I always find Ann's comments illuminating, if sometimes a little too, um, colourful.

Rob (500!)

[PatQ]

This is probably common knowledge to other board contributors, but when distances are mentioned to a galaxy, are they from our little blue marble to the center of the imaged galaxy, or to its edge?

[Chris Peterson]

This is probably common knowledge to other board contributors, but when distances are mentioned to a galaxy, are they from our little blue marble to the center of the imaged galaxy, or to its edge?

Within the uncertainty on the measurements, it makes no difference. Galaxy sizes are on the order of tens of thousands of light years; galaxy distances on on the order of millions of light years, with the values usually only known to a few percent or worse.

It's kind of like my telling you it's 3000 miles from Los Angeles to New York, and they being asked "do you mean to the edge of New York, or the center?"

[sajaki]

... a mere 20 million light-years ...

i always chuckle when astronomers use the words "a mere" when the subject is about lightyears..

I mean, it's just a hop over the pond, right ?

[PatQ]

All very true for the majority of the universe, but I was considering the neighboring Magellanic cloud galaxies a mere ~ 200k light years distant. Since out Milky way is 100k LY in diameter the scale makes the question somewhat relevant. Now I must get back to my space pod and await your answer so I can program the coordinates for my vacation.