Placidus
12-04-2018, 03:11 PM
To our amazement, we've not looked at the Sombrero since 2012.
The sky here is expected to be cloudy throughout the rest of new moon, and perhaps even raining (very needed for the pasture) so we'll show you what we have so far. Five hours 30 mins of Luminance, in 15 minute subs, so as not to burn out the core.
Seeing was very good for us, so even in that short period of time, the number of distant background galaxies in the full uncropped image (https://photos.smugmug.com/Category/Astrophotography-at-Placidus/i-BswWHd2/0/b9beb752/O/Sombrero.jpg) is very gratifying.
A first point of interest is that the central core is really a pin-point.
The second is that the halo appears larger than is usually shown. If we increase the contrast, we can make the halo look smaller, because the faint outer regions go to black, but according to a NASA JPL Spitzer (http://www.spitzer.caltech.edu/images/1419-ssc2005-11a-Spitzer-Spies-Spectacular-Sombrero) article, the halo really is pretty big: it appears that the Sombero is a spiral galaxy that has formed inside a large elliptical, not swallowed, but formed in situ as a result of the elliptical gulping down fresh intergalactic gas and dust.
We've read elsewhere that galaxies don't really have an outer edge, but just become thinner and thinner forever. Hence the apparent size must depend on processing choices, particularly the amount of contrast used.
We certainly hope to come back to this beastie next new moon.
Very best,
Mike and Trish
The sky here is expected to be cloudy throughout the rest of new moon, and perhaps even raining (very needed for the pasture) so we'll show you what we have so far. Five hours 30 mins of Luminance, in 15 minute subs, so as not to burn out the core.
Seeing was very good for us, so even in that short period of time, the number of distant background galaxies in the full uncropped image (https://photos.smugmug.com/Category/Astrophotography-at-Placidus/i-BswWHd2/0/b9beb752/O/Sombrero.jpg) is very gratifying.
A first point of interest is that the central core is really a pin-point.
The second is that the halo appears larger than is usually shown. If we increase the contrast, we can make the halo look smaller, because the faint outer regions go to black, but according to a NASA JPL Spitzer (http://www.spitzer.caltech.edu/images/1419-ssc2005-11a-Spitzer-Spies-Spectacular-Sombrero) article, the halo really is pretty big: it appears that the Sombero is a spiral galaxy that has formed inside a large elliptical, not swallowed, but formed in situ as a result of the elliptical gulping down fresh intergalactic gas and dust.
We've read elsewhere that galaxies don't really have an outer edge, but just become thinner and thinner forever. Hence the apparent size must depend on processing choices, particularly the amount of contrast used.
We certainly hope to come back to this beastie next new moon.
Very best,
Mike and Trish