Posts Made By: Dennis Persyk

C/2005 P3 (SWAN)

The new comet is in UMa. Magnitude about 10.0.

This was a tough one for me because it was already low in the sky at sunset. I imaged it down to 16 degrees elevation and quit before I even reached astronomical darkness.

Images and supporting information at
http://home.att.net/~dpersyk/new.htm

Thank you for visiting my site.

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL

http://home.att.net/~dpersyk/new.htm

The image was taken with a Takahashi E-160 (f/3.3) astrograph aboard an AP-1200GTO. The camera was an SXV-H9, and the exposure was 5 x 20 minutes via a 6 nm FWHM H-a filter. Guiding with an MX-716 and NP-101. There was a moon, but light pollution has no affect whatsoever on a narrow-band H-a filter.

Thank you for visiting my site.

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL

M16 Eagle in H-a

http://home.att.net/~dpersyk/new.htm

The image was taken with a Takahashi E-160 (f/3.3) astrograph aboard an AP-1200GTO. The camera was an SXV-H9, and the exposure was 8 x 15 minutes via a 6 nm FWHM H-a filter. Guiding with an MX-716 and NP-101. There was a full moon and considerable glow from sunset, but light pollution has no affect whatsoever on a narrow-band H-a filter.

I’ve posted both a straight gray-scale image and a colorized version. I gretly appreciate your comments on which you like and why.

Thank you for visiting my site.

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL

For you comet connoisseurs, this is the brightest comet in the sky now at magnitude 13.1. I managed to capture a 13 arc minute tail.

Takahashi E-160, 3 x 4 minutes unguided, SXV-H9 camera, AP1200GTO mount.

Images and supporting information at
http://home.att.net/~dpersyk/new.htm

Thank you for visiting my site.

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL

I have written a paper treating the fundamentals of steel pier design. It treats the case of a steel pipe embedded in a concrete plug. You can download the Word document from
http://home.att.net/~dpersyk/Pier_Design.htm

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL

New Images http://home.att.net/~dpersyk/new.htm

I have revised my paper treating the fundamentals of steel pier design by adding a caution about GEM clearance. You can download the revised Word document from
http://home.att.net/~dpersyk/Pier_Design.htm

Piers of 8-inch and larger diameters may present clearance problems with some GEMs. Larger diameter piers may require a short reducing section at the top to provide clearance. Check this out with a model or by contacting your mount manufacturer before constructing the pier. Thanks to John Moore (Fleet, Hants, England) for pointing out the potential for interference.

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL

New Images http://home.att.net/~dpersyk/new.htm

The lesser known Barnard dark nebulae (unlike the well-known B33 – the Horsehead) seem to be imaged very infrequently. I could find no images of B60 in my search on Google.

My image and accompanying planetarium program finder diagrams are at
http://home.att.net/~dpersyk/new.htm

The image was taken with a Takahashi E-160 (f/3.3) astrograph aboard an AP-1200GTO. The camera was an SXV-H9, and the exposure was 4 x 25 minutes. Guiding with an MX-716 and NP-101.

Thank you for visiting my site.

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL

Here is a 140 minute H-a image of the Tulip Nebula.

My image and accompanying planetarium program finder diagram are at
http://home.att.net/~dpersyk/new.htm

Seeing was incredibly steady, about Pickering 5. That is extraordinary for my Northern Illinois site!

The image was taken with a Takahashi E-160 (f/3.3) astrograph aboard an AP-1200GTO. The camera was an SXV-H9, and the exposure was 14 x 10 minutes. Guiding with an MX-716 and NP-101. Astrodon 6 nm FWHM H-a filter. Acquisition AA 3.0, processing in ImagesPlus.

Thank you for visiting my site.

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL

I have colorized my 140 minute H-a image of the Tulip Nebula, a/k/a Sharpless 2-101. I have decided that some emission nebulae H-a images respond well to colorization, whereas others look much better in monochrome. I think that the Tulip nebula looks better colorized.

I somehow feel the need to defend H-a colorization: The H-a filter passes only red light, so the colorization merely depicts what the camera would have seen if it were not colorblind. I concede that the fainter stars were mistakenly colorized in my image, and hope in the future to learn how to avoid that.

Colorized and monochrome versions viewable at
http://home.att.net/~dpersyk/new.htm

The image was taken with a Takahashi E-160 (f/3.3) astrograph aboard an AP-1200GTO. The camera was an SXV-H9, and the exposure was 14 x 10 minutes. Guiding with an MX-716 and NP-101. Astrodon 6 nm FWHM H-a filter. Acquisition AA 3.0, processing in ImagesPlus, colorization with Noel Carboni’s Astronomy Tools actions.

Thank you for visiting my site.

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL

Here is another emission nebula. I am continuing my quest for emission nebulae to image because they level the playing field for me from my light-polluted site 40 miles west of Chicago. No matter how bad the light pollution, it has virtually no effect on a narrowband H-a filter. Thus my H-a images from my VLM 3.5 site are just as good as if I had traveled many hours to a mag 6.5 site – and I only had to walk a few hundred paces instead of driving several hundred miles. Those of you who are plagued by light pollution might want to consider H-a imaging.

That is primarily why I am an imager rather than a visual observer. There is no way to mitigate light pollution with the eye as the detector. The imager has many options to alleviate the effects of light pollution.

The Cave nebula has some interesting dark lanes.

Colorized and monochrome versions viewable at
http://home.att.net/~dpersyk/new.htm

I also illustrate the power of binning with a 6x6 binned ten-second centering image. I am always amazed at what I can grab with just five or ten seconds at f/3.2 binned 6x6!

The image was taken with a Takahashi E-160 (f/3.3) astrograph aboard an AP-1200GTO. The camera was an SXV-H9, and the exposure was 12 x 10 minutes, binned 2x2. Guided with an MX-716 and NP-101. Astrodon 6 nm FWHM H-a filter. Acquisition AA 3.0, processing in ImagesPlus, colorization with Noel Carboni’s Astronomy Tools actions.

Thank you for visiting my site.

Clear skies,

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL