An interesting group of three interacting galaxies at about 150 million light years. Left to right they are NGC 3995, NGC 3994 and NGC 3991. The latter reminds me of a glow worm with a blue light at its ... is that a head or a tail?

While it is obvious that NGC 3995 and NGC 3991 are highly distorted NGC 3994 appears mostly normal but if you look close you see a faint tidal disk about it.

14" LX200R, L=4x10' binned 2x2, RGB=2x10' binned 3x3, STL-11000XM, Paramount ME

Version using slightly less compression is at:
http://www.spacebanter.com/attachmen...3&d=1209070487

Rick

Attached Images

NGC3995L4X10RGB2X10X3-7.jpg (116.3 KB, 41 views)

Rick,

Beautiful as usual. You pick and present some really lovely off-the-beaten-track galaxies. Thanks!

Are you guiding with the internal chip or using an external guide scope?

--Andy

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Observatorio de la Ballona

Short answer:
Normally I don't guide at all. This shot was unguided for instance.

Long answer:
If I do it is the internal chip though if need be I can press the ST7 at the photometric port into service as it can pick off off axis stars if need be. That's extremely rare. Think I've done it only twice and then just to see if it worked. The Paramount easily guides for 10 minutes without a problem on its own without need for a guider. I will run it to keep tabs on focus if I'm working early in the evening before the scope has cooled fully. The temp compensating can get hit with thermal lag during this interval. But then I usually turn off the guiding by setting it's max movement to 0. When seeing is poor I get better stars not guiding as even with 10 second integration I sometimes chase seeing. I do use an 800 position T-Point map that greatly improves tracking accuracy. Without it I'd be limited to about 5 minutes at 3560mm focal length. Especially when somewhat low in the sky where atmospheric refraction alters the tracking rate considerably.

Rick

Hi Rick, Another awesome group of galaxies of all sorts sizes and shapes. Great processing beautiful colors also thanks for the info. Clear Skies

Nice shot!

Tom

A lovely little group. Yes the tidal halo is quite evident. Especially nice considering the bright field star so nearby. What is a T-Point map?

__________________
Kind regards
Matt
LXD75 SN 8" f/4, DSI II pro

The most exciting phrase to hear in science, the one that heralds new discoveries, is not Eureka! (I found it!) but rather, "hmm.... that's funny...."
Issac Asimov

TPoint is a program that works with The Sky. Each map point contains two pieces of data. One is where the mount thinks it is pointed and the other where it is really pointed when looking at that specific alt azimuth location in the sky. I have about 800 of these points in my map covering the area of sky I image in. It allows the drives (both axes) to compensate for all sorts of errors in gears and flex as it tracks an object across the sky. It also increases pointing accuracy for finding an object. In my case it is only a few seconds of arc off if the data is right and I remembered to set the clock. Usually when I miss by more than that I find a catalog data error is the cause. Means I can easily script a whole night and leave the scope for 12 or more hours in winter to collect data without me having to do a thing. When I get up in the morning I find out how the sky was that night. Note that with most mounts TPoint only helps with pointing accuracy. With the Paramount (comes with the mount) and The Sky6 it can be used for tracking as well. I'm not sure if any other mount supports this without patches. Somewhere I heard of a patch for Meade's GPS mounts that could support asteroid tracking which uses much the same capabilities needed to use the TPoint map for tracking. Don't try to use the tracking option AND guide. The two will fight each other as TPoint moves the mount to where it wants it then the guider moves it to where it wants it! I learned that one the hard way! Obvious if you think about it but wasn't in the manual that I could find.
http://www.bisque.com/help/TPointInf...tm#welcome.htm

After decades of slaving over a guiding eyepiece manually guiding film shots this is too darned easy!

Rick

Thanks Rick. I am just looking forward to a simple guider. After that many years of hard work you have earned a bit of luxury.

__________________
Kind regards
Matt
LXD75 SN 8" f/4, DSI II pro

The most exciting phrase to hear in science, the one that heralds new discoveries, is not Eureka! (I found it!) but rather, "hmm.... that's funny...."
Issac Asimov