APOD: M31: The Andromeda Galaxy (2013 Jun 26)

Comments and questions about the APOD on the main view screen.
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Anthony Barreiro
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Re: APOD: M31: The Andromeda Galaxy (2013 Jun 26)

Post by Anthony Barreiro » Wed Jun 26, 2013 7:08 pm

Chris Peterson wrote:... It is the ability to adjust contrast in images that makes the technique so much more valuable than visual astronomy.

They may not be cutting edge research instruments any more, but I'm still going to keep using my little telescopes and eyepieces.
And it is the often radical difference between what objects look like in images and what they look like through eyepieces that results in the common question in this forum: "How the heck did they ever come up with that name?"
The Trifid nebula, for instance, doesn't look anything like it's namesake:

Image

Image

:lol2:
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Chris Peterson
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Re: APOD: M31: The Andromeda Galaxy (2013 Jun 26)

Post by Chris Peterson » Wed Jun 26, 2013 7:18 pm

Anthony Barreiro wrote:
Chris Peterson wrote:... It is the ability to adjust contrast in images that makes the technique so much more valuable than visual astronomy.

They may not be cutting edge research instruments any more, but I'm still going to keep using my little telescopes and eyepieces.
Sure. I meant scientifically valuable.
The Trifid nebula, for instance, doesn't look anything like it's namesake:
Thank goodness for that.
Chris

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Re: APOD: M31: The Andromeda Galaxy (2013 Jun 26)

Post by neufer » Wed Jun 26, 2013 7:26 pm

Chris Peterson wrote:
freidaV wrote:
First, aren't the Milky Way and Andromeda already gravitationally interacting? Two million light years is not so far away, universally speaking...
Certainly. The two galaxies are in orbit around each other.
I prefer to say that they orbit around a common barycenter roughly half way between them. :arrow:
Chris Peterson wrote:
freidaV wrote:
Second, if the galactic arm where we're located is adjacent to Andromeda, could that interaction be a culprit in global warming?
Global warming is caused by the Earth retaining slightly more solar energy than it radiates, due to chemical changes in its atmosphere.
Man made global warming is caused by the Earth retaining slightly more solar energy than it radiates, due primarily to the annual dumping of 23 billion tons of carbon dioxide into the atmosphere. (But right after that I would blame Andromeda.)
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Re: APOD: M31: The Andromeda Galaxy (2013 Jun 26)

Post by Lorenzo Comolli » Wed Jun 26, 2013 7:35 pm

Thank you all again for the kind comments :-)

@ Chris Peterson: thank you for noting; the apod version is not flipped as I wrote, but it is rotated by 180°. The rest of my comment remains the same. I agree that the rotated version is more pleasant for aestetic purposes.
tkc wrote:Just out of curiosity, what are the two background galaxies (circled)?
Here is a "solved" image by astrometry.net: http://nova.astrometry.net/user_images/58017#annotated
Image

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Re: APOD: M31: The Andromeda Galaxy (2013 Jun 26)

Post by Chris Peterson » Wed Jun 26, 2013 7:43 pm

neufer wrote:I prefer to say that they orbit around a common barycenter roughly half way between them.
That's fine. Dynamically, the local group is basically a two-body system made up of the Milky Way and Andromeda, slightly perturbed by other members.
Man made global warming is caused by the Earth retaining slightly more solar energy than it radiates, due primarily to the annual dumping of 23 billion tons of carbon dioxide into the atmosphere. (But right after that I would blame Andromeda.)
The Earth radiates so little internal heat in comparison with solar re-radiation, that I think it's fair to say all global warming is caused by an imbalance between the solar radiation we receive and what gets re-radiated. The man-made component (which right now is virtually all of it) is, of course, caused primarily by the changes we ourselves are making to the atmosphere (which produces a cascade of secondary elements, too).
Chris

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Re: APOD: M31: The Andromeda Galaxy (2013 Jun 26)

Post by LocalColor » Wed Jun 26, 2013 7:55 pm

Congratulations Lorenzo Comolli for being selected for today's APOD. Very nice image. We went to your website, you have an impressive collections of "toys"!!!

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Re: APOD: M31: The Andromeda Galaxy (2013 Jun 26)

Post by Boomer12k » Thu Jun 27, 2013 1:12 am

Chris Peterson wrote:
Anthony Barreiro wrote:Here's another interesting complication: while on Lorenzo's beautiful long-exposure photograph M110 appears bigger and brighter than M32, when you look at Andromeda and her satellite galaxies through a telescope, M32 is much more obvious than M110. Objects that have larger apparent sizes tend to have lower surface brightnesses, and thus appear dimmer.
Indeed. It is the ability to adjust contrast in images that makes the technique so much more valuable than visual astronomy. And it is the often radical difference between what objects look like in images and what they look like through eyepieces that results in the common question in this forum: "How the heck did they ever come up with that name?"

Ah...the illusions of perception and space...huh?...even direction, and conditioning to seeing the vast majority of pictures not depicting the accurate angles and placements in the heavens...Hollywood Vs. Reality....

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