Two of the Leo Trio

After I got a glimpse of Pan-STARRS, it looked like it would be clear enough to open the Hut.  I wanted to run some more v-curves (calibration runs) in FocusMax, but apparently I had the steps set too small and the center focus position set too far off.  So the run took forever and didn’t give a good curve.  Meanwhile I went inside and was working remotely and the network was uncharacteristically slow, in fact excruciating, so I went back out to the hut and worked from there.  TeamViewer was running at 90% CPU, which is not normal.  Anyway to salvage the evening, I chose an easy target that was far enough from the meridian to avoid mirror flop issues.  The “Leo Trio” consists of M 105, NGC 3384 and NGC 3389, a pretty tight grouping of obvious galaxies.  My camera field at 17 x 11.5 arc-minutes is a bit tight for all three, so I framed  3384 and 3389 and set up for 10 – 300 second exposures.

Two of the Leo Trio, NGC 3371 and NGC 3389.  8 x 300 seconds.

Two of the Leo Trio, NGC 3384 (left) and NGC 3389 (right). 8 x 300 seconds.

The stars in the subs are a bit oval in the  East-West direction, so something is not optimal with guiding, will work on that later.  I didn’t shoot RGB because the sky started murking up, and ended up with 8 ok luminance frames to work with.

After processing the image, mainly with Maxim’s DDP (“digital development”) utility, you can see what looks like the remnant of a central bar or disk not exactly perpendicular to the axis of the ellipse.  I was expecting an elliptical galaxy, but it looks like NGC 3384 hasn’t evolved quite that far yet.  NGC 3384Elliptical galaxies are considered to be the end state of possibly numerous galaxy mergers and are mostly found in crowded galactic neighborhoods, in this case the M96 group.  When I selected NGC 3384 from TheSky, it was identified as NGC 3371, and guess what, it’s both!  NGC 3371 was discovered Mar 11, 1784 by William Herschel and eventually listed as NGC 3384, then recorded Mar 23, 1830 by John Herschel and listed as NGC 3371. Apparently this is one of the ways that errors cropped up in the NGC catalog; the accepted name seems to now be 3384.  Depending on the source, it’s identified as an E07 elliptical, or occasionally as an SB0 (which is to say a lenticular galaxy with no apparent spiral structure but with a bar), which looks to be more accurate.  NGC 3389 looks like a beat-up spiral that has been distorted by a close encounter, and would be fun to add some RGB data.  It’s blue and has active star formation going on; from it’s motion and distance, it’s not considered to be part of the the M96 Group.

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