NGC 891

Object: NGC 891
Date: 21 Jan 2004
Location: Redwood City, CA, heavy light pollution
Telescope: AP Starfire 5 inch f/8 on Vixen New Atlux
Camera: ST-7ME self guided, Baader IR-blocking filter
Exposure: 900 sec
Processing: dark subtracted, some mid-range brightening,
contrast and brightness adjusted(CCDSoft)
Observer: J. Wolf

Comments and suggestions are welcome.
Thanks, Juergen

Attached Image:

Nice shot Juergen... great detail...
Your alignment seems to be pretty accurate, as your stars are nice & round...


Thanks for sharing!



Ivan

Juergen,

If you take 4-6 images like that and stack them, you will have a fabulous shot! Well guided and focused.

Jeff

That's a beauty!

-Jake

Very nice Juergen. Did you also take flat fields?

Derrick.

Hi Richard,

The Vixen New Atlux mount is not sold officially in the US. I was considering several options to purchase one: there are distributors in Europe and Australia who would sell it to the US (I assume you are in the US). If you like more detailed information on this, please let me know.

I was very lucky to find a used Atlux in the US last summer on Astromart.

I have not measured its periodic error so far; it is specified at +/- 3 arcsec. For imaging I use autoguiding with the ST-7, as for NGC891 (900sec) - which works great. I get error readings of the autoguider at typically 0.2 to 0.5 pixels in X and Y (1.8 arcsec per pixel in my setup).

The weight of the equatorial head is specified at 18kg. It is heavy, so I take it off its pillar for transporting it short distances.

I am using my AP 5inch f/8 with finder, motor focuser and ST-7 on it (about 11 kg total). That works perfectly for photography. I have put on a C11 OTA also (13 kg). Visually that works good, I have not tested photography with it - but expect it to be ok without wind. The C11 with some assessories is probably the upper limit, although the mount is rated to carry 22kg.

There has been quite some play in both the DEC and RA gear when I got the mount. Another amateur in the region had the same problem and he was able to get valuable hints how to fix that out of ORION in the UK. I did the readjustment on my mount - was pretty easy - and now I have a very steady mount. When focusing mu AP by hand it feels as stable as an AP 900 or AP 1200.

The price for a new NEW ATLUX will be around $6000.- depending on exchange rates and if you need the Sky Sensor or not. The GOTO functions of the SS2K are very precise (a few acrmin pointing accuracy mostly after a 3-star-alignment). Considering that it comes complete with a polar finder the price may be ok. From my perspective it is superior to the Losmandy G11. The AP 900 is probably a little better but more expensive - and the wait ... If the Williams Optics GT1HD would become available, that might be very comparable to the Altux.

You will find specifications at
http://www.vehrenberg.de/frmset_zubehoer.html

Let me know if you like more information or have specific questions. I will be happy to assist if I can.

- Juergen