February 29, 2016

Cone Area in H-Alpha (Feb. 2016)


 Larger size image here.

These images are of the Cone Nebula area.  Of course, you can also see the Fox Fur Nebula near NGC2264 (also called the Christmas Tree Cluster), B39 (the darkest nebula near the bottom), and NGC2259 (the star cluster on the lower right).  It's a busy area in the Winter Milky Way.  The bright star to the left that seems to be in the middle of everything is S Monocerotis, a type O7V star 4x wider than our sun and hundreds of times brighter.  See info about S Mon here.
The total time for this image is 9 hours of h-alpha with DSW's FSQ.

February 26, 2016

NGC2419, the Far Away Globular Cluster (Feb. 2016)

 Larger image here.

This image is second light with the CFF CC290 f/13.5 at effective f/7.93, guided on the NJP.  This image is 8x720" with the SXVF-H9 and Astronomik CLS filter.  NGC2419 is one of my favorite targets.  At this longer focal length with this size scope, images show the cluster's true nature as a globular.  It's amazing to think of this thing floating 270,000 light years from our galaxy, almost not gravitationally bound to us.  The skies there must look very different from ours!

The bright star above the cluster is HD60771, a magnitude 7.19 A-type star.  There are several small galaxies in the image.

As before, the NJP guided like a champ.  Here is a screen shot of PHD2 (with a misleading equipment name, as I missed one of my spacers when I first figured the effective focal ratio):

February 25, 2016

LDN 1622 - The Spook Nebula (Feb. 2016)

Larger version here.

This ghostly apparition haunts eastern Orion, chasing behind the Horsehead Nebula.  The Spook is very dim.  The image is shrunken to 50% of its original to cover noise that appears even in the H-alpha frames.  I've always wanted to shoot this area, but only from skies in New Mexico.  This is an HaRGB composition: 21x1800"; 17.16.16x900" with DSW's FSQ.

February 15, 2016

First Light with the CFF Telescopes CC290 f/13.5

This past week I celebrated first light with the CC290, a classical cassegrain built by CFF Telescopes.  The scope arrived last week.  I've had two great nights of visual viewing and a great night of imaging with it.  I hope to write a full review later.  Just two comments for now.

First, some notes from the visual.  I set the scope out and ran the fans for a while.  On the visual nights, the temp was around 41F, so the scope took a bit to cool.  Once it cooled down, images were stunning!

One highlight of the first night was IC 418.  IC 418's central star was obvious, and the oval ring around the star was obvious, too, at 157x with a 25mm TV Plossl.

The showpiece of the first night was the Trapezium.  The E and F stars shown out like searchlights!  I've never seen them so bright and clear!  Clear, empty space between the F and D stars and between A and E.  It was an awesome sight!  The nebula was bright, too, and I could begin to see some color in it, mostly green, even from my suburban location.

The second night was just as cold, so the scope took a while to cool off.  This night was also first light with a Baader Zeiss 2" prism diagonal.  I used several eyepieces.  One was a Meade 28mm.  This eyepiece yields 140x, an exit pupil of 2.07, and a true field of .486 degrees.  For greater magnification, I used the Televue 25mm plossl (very sharp, 157x, 1.85 exit pupil, and 0.318 degree field) and the Orion 15mm expanse (261x, an exit pupil of 1.11, and a true field of 0.261).  Here are notes on some objects observed:

NGC 2438 in M46 - a ghostly round glow, gray and uniform as far as I could tell, visible only in the 28mm.

Eskimo Nebula: a bulbous shape and two levels of brightness (inner and outer), central star obvious.  Very bright!  Nicely studied in the 28mm and the 25mm plossl.

NGC 2371 - I can see two gray lobes clearly.  Best in the 28mm.

M65, M66, M96, M95, M105, NGC 2903, NGC 3626 - all good but just faint fuzzies of varying shapes.

NGC 2419 -very dim in the 25mm, not a real showcase.

Sirius B - tougher than I thought it would be in the 15mm, but there is that little star.

A few nights later, the sky was clear, and I set up for imaging.  The real test was whether the scope would guide at f/10.  I have an Astro-Physics CCDT67 reducer.  Set up to reduce at about 0.5873x, the reducer yields round stars across my smaller ccd chip.  That gives me an effective focal length of 2299mm.  Could the NJP guide at that length?  This is an effective focal ratio of f/7.93.

I thought since the Eskimo Nebula was so bright that it would be a good target.  I slewed over and, yes, there it was on my computer screen.  But . . . no guide star in my off-axis guider.  But the nebula was so bright.  I decided to catch 300 five-second subs and stack them just for fun, so here's the result.

This is not a real attempt, just fun with the camera and scope.  The subs were unguided, and there was some smearing from seeing and perhaps from the mount's movement, though the mount tracks extremely well.  Anyway, someday I'd like to go back and get the nebula with narrowband filters.

After that, I slewed to a couple of galaxies in M44, where I knew I would have guide stars.  Sure enough, I did, and I tried guiding.  I'm still dancing around (metaphorically) from the result!  Can this scope guide on the NJP at 2300mm?  Absolutely!  Actually, seeing was good, and guiding was under one arc second, peak to peak.  How's that for fun?!?  I took four 500-second images of some very distant galaxies behind M44, then slewed over to NGC 2903 and took a quick five-minute sub.  Should I post it?  Here it is. It's just a single sub at nearly f/8, and no flats because I did not have time (which explains the donut in the upper right).  Contrast is poor, and the image is kind of grainy, but look at the size of that thing.

All kinds of detail in that galaxy.  I'm still a bit shocked and thrilled that the scope will guide at that focal length.  Ah, this is going to be great!  Of course, auto-guiding at that focal length would be impossible if the scope were not extremely well made, very stiff.  The scope also handles temperature changes very well.  Kudos and thanks to CFF!  Here are some images of the scope.




February 4, 2016

NGC 1333 (Winter 2016)

Higher resolution image here.

This fascinating part of the Perseus molecular cloud shows such variety that one could spend weeks studying it.  In fact, many have.  This study in particular was very helpful in understanding what is going on there.

Distances to the NGC 1333 area---the nebula and cluster---come from two sets of studies. One set holds that the distance is around 760 light years, the other set around 1140 light years.

The bright star lighting up the bright nebula on the left is called BD +30°549.  It is spectral type B8, hot and blue, which is why the nebulosity around it is blue.

Just below the nebula are two distinctly redder knots of nebulosity.  The upper right one is HH 12, and the lower left one is HH 7-11, meaning there are actually five Herbig-Haro catalog objects here, though we are probably seeing only the outflow from one source, an infrared young stellar object known as SVS 13.

Over on the right, near the top, is HD 21110, enveloped in whitish waves of nebulosity.  The star is a type K4 and appears to be passing through the nebulosity, according to this source.  The source also suggests that the variability sometimes observed in the star in the past may result from its passing behind dust clouds of varying opacity.  Really fascinating.

The bluish star on the center right surrounded by bluish nebulosity is SAO 56444 of BD +30°540.  It is type B8V, which explains the blue reflection nebula around it.

This image is a combination LRGB  28:16:16:16 x 900" with the FSQ setup at DSW.