[AZ-Observing] Re: M101 for the month of May

  • From: "Jennifer Polakis" <m24@xxxxxxx>
  • To: <az-observing@xxxxxxxxxxxxx>
  • Date: Fri, 25 May 2007 02:17:46 -0700

Chris,

Another highly detailed photo but do you really think 10x better than your 
previous photos with your "old" camera.  Definitely 100x better than a 
Brownie!

I wonder to gravitational lensing--when there is a galaxy within the obvious 
confines of  the nearer galaxy, is it _always_ magnified by the 
gravitational lens? Would a camera still pick all of them up if they weren't 
magnified by the closer galaxy?

Jimmy,
As for the inclination of M101 it's actually 17o, and yes, all spiral 
galaxies are round. There is a set formula to determine the inclination 
based on the  length and width + a few degrees for what radio telescopes 
pick up beyond that.  It's a bit counter-intuitive in that 0 degrees is 
perfectly face on and 90 degrees is an edge on. The Andromeda galaxy for 
example is inclined 77+degrees.

Does anyone knows where to find a list of galaxy inclinations, even a small 
list like for the M's would be great for a comparison.


Chris,
...The brightest knot in the arms to the upper right of the nuclear region 
is NGC5462, an complex blue stellar association with a rim of red hydrogen 
around its energetic core. When we add the hydrogen data to this image, the 
galaxy dynamics that will become visible here will be simply out of this 
world....

Actually NGC 5462 is to the left of the nuclear region at about 9:30 with an 
even brighter NGC 5461  just below it closer to the nucleus.

Jenn.



----- Original Message ----- 
From: "Jimmy Ray" <jimmy_ray@xxxxxxx>
To: <az-observing@xxxxxxxxxxxxx>
Sent: Thursday, May 24, 2007 7:49 PM
Subject: [AZ-Observing] Re: M101 for the month of May


Hi Chris,

A great shot! I have it up as my desktop picture so I can admire it for
awhile.
Now for the questions borne of Novice ignorance and curiousity. On your
website there are a couple of statements that I'm pondering over:

"its inclination is less than 1 degree and is face on to our line of sight."

How is this actually calculated and/or figured out? Do all spiral galaxies
have a certain degree of "roundness" so any amount of "obliqueness" can be
corrolated into degrees of "tilt" or other?

"Hordes of faint background galaxies dot this image, most being a leaden
yellow color, dimmed from their great distance through intergalactic dust."

Is this dust causing the "yellowing" galactic or interstellar dust
collecting around the galaxy itself in the plane of or within the
gravitational field of that galaxy? Or an unrelated dark nebula somewhere
between here and there? And / or is this caused because of the general
"dustiness" of the Universe?
Jimmy Ray


Subject: [AZ-Observing] M101 for the month of May

HI all,
It took all month to image this one, due to clouds,
wind, and giving it lots of exposure time.  Anyway, I
think youll like the lastest image of the Pinwheel
galaxy with our newer ST10xme camera.  It does 10x
better job on galaxies than the older ST8i with the
same setup and exposures!
http://www.schursastrophotography.com/ccdimagepages/m101-3.html
Comments?
Chris
Take Care,

Chris
Astro: http://www.schursastrophotography.com
Robotics: http://www.schursastrophotography.com/roboticsmain.html





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