NGC 1532 lies in the constellation of Eridanus at a distance of 57.8 Mly.  At an apparent magnitude of 10.7 and a size of 12.3' x 3.63', it is a popular target for imagers with access to the Southern sky.  Known as Haley's Coronet, it was discovered by James Dunlop in 1826.  It is thought to be a barred spiral that possess several dwarf companion galaxies.  The dwarf satellite galaxy, NGC 1531 is interacting to create out-of-plane distortion in NGC 1532.  Hints of this interaction can be seen in the stray blue clump of stars and gas located between the two galaxies.  The total mass of NGC 1532 is estimated to be similar to the Milky Way.

I started imaging this galaxy (and one other) shortly after commissioning my telescope.  During that period (over the last month), I've been taking note of the seeing at the El Sauce site and I've noticed that the seeing fluctuates quite a bit; however, it's not at all uncommon to see the seeing approach 1".  So I was pretty happy to see that the yield for this data set was about 50%.  The real bonus is that the sky is clear nearly every night so it doesn't take long to accumulate a lot of data in a short period of time.

I had intended to take another 10-15 hours of data and to add some Ha data but I ran into a serious snag.  As I started my system each night, my ATIK Horizon II guide camera began to have intermittent problems connecting to the PC.  This behavior grew worse over a period of three days until I could no longer connect the camera at all.  The guys at the observatory helped me by running a new, short cable directly from the camera to the PC to see if that made any difference.  With the new cable, I could get the camera to connect but it wouldn't stay connected and I couldn't transfer any image data.  We fooled with it every which way and eventually concluded that the cable wasn't the problem.  So, the scope has been dead since just after Christmas.  I jumped right on it and quickly ordered a new camera from a vendor who was going to try to have a new one shipped directly from the factory in Portugal straight to Chile.  Unfortunately, I was told that ATIK balked at that idea.  That whole effort turned into a time waster and I lost about two weeks pursuing that idea.  Yesterday, I ordered a new camera myself and it will be here in two days.  I'm going to try to FedX it to Chile as soon as I get it.  Hopefully, I can have it at the observatory and installed within 10 days or so--probably just in time for the full moon!

Hindsight is always 20:20 and I've realized that selecting the Horizon II was a mistake.  Externally it is really well made.  I don't know if this failure is a one in a million problem with this camera model but I could have used a ZWO ASI1600 uncooled camera with the exact same sensor.  Those are half the price of the Horizon II and I could have sent two of them with the scope for the same price!  For guiding, I never need a cooler.  I could change to the ASI1600 now but that involves a new adapter and I don't want to go through a complete switch unless I can travel to the observatory to do it myself.  So, for now, I'm invested in the ATIK camera.  I'll try to return the failed unit for repair so that I can have a backup.  Live and learn.

After the camera failed, there was a rare cloudy night and I was able to take a complete set of bias, flats, and dark data. The good news is that the calibrated results for this data set looked absolutely perfect!  

While the guider is down, I've also experimented a bit with running the scope unguided.  It works pretty well up to 300s exposures.  The big problem (for me anyway) is getting V-curve focusing to work very well.  I've tried with both SGP and MDL and I can get it to work but the curves are often so full of noise that I don't really believe the results.  I've fooled with all the parameters and exposure times but I concluded that I need a better multi-star software to make it work more reliably.  In my experience, astigmatic focusing is 100x more reliable and 10x easier!

For this image I selected Lum data that had FWHM below 2.0".  The RGB data was selected below 2.2".  As usual, it took two runs to get the color calibration to fall into the right range.  I may have done something bone-headed on the first run because it came out WAY too blue.  The second run worked perfectly.  Near the end of my processing effort, I found a very faint residual satellite trail that I had to clone stamp out.  I think that with StarLink, that's what we all may be doing more and more often.

As always, C&C is welcome so let me know if I missed anything.

John