[Chaos-l] Observing Report From Medoc Mountain

[Mark South]

Thanks for the heads up on this nice observing spot.  You guys rock!

Sent from my cell

On Jan 25, 2009, at 8:55 PM, Robert Nielsen <robertnielsen at nc.rr.com>  
wrote:

> Well, you might not believe this ... but there was a useful  
> observing session at Medoc Mountain State Park last night.  I was  
> there, along with Mark Lerch (from CHAOS) as well as Allen Davis  
> (camped next to us at MASP) and two of Allen's friends - Tim and  
> Don.   I got there a little early to setup my Mewlon in the  
> daylight ... and yes, the skies were completely covered in clouds at  
> the time (although during the drive over from Astronomy Days I could  
> see breaks in the clouds).   Allen setup his 20" Obsession, Tim had  
> some binoculars on a parallelogram mount, and Mark had his  
> "minimalist" astrophotography setup with the AstroTrac.
>
> It was a little odd setting up under the clouds, and taking on faith  
> that the Clear Sky Clock was correct and that things would clear  
> up ... but they did indeed ... actually an hour earlier than  
> expected.   So we all got in some early observing starting around  
> 7PM.   Then the wind changed and some clouds rolled in from the  
> east.   While things clouded over, we sat under a picnic pavilion  
> and enjoyed a fire provided by Allen.   In some ways, Medoc Mountain  
> is a *more comfortable" place to observe since it has (heated)  
> restrooms, a fireplace, etc. than other places we have gone.  Too  
> bad it is 1.5 hours away!
>
> Before the clouds rolled in, I had polar aligned my telescope, and  
> took a quick look at M42 (to see how the skies were).  As predicted  
> by the Clear Sky Clock, the transparency was very good ... although  
> the seeing was not the best (more on that later).  I could pretty  
> easily make out the fifth Trapezium star ... and the sixth flickered  
> in and out.  But since the transparency was good, I decided to focus  
> on the galaxies that I had chosen for the nights targets.
>
> First up was NGC2403 ... a spiral galaxy in Camelopardalis that  
> looks a lot like a miniature M33 (faint, face-on, with bright area  
> that I think are star-forming regions).   It was faintly visible  
> with the bright spots looking like little diamonds in the area of  
> the galaxy.  It is framed nicely by two brighter stars on the two  
> sides of the galaxy.   I was impressed by how much detail was  
> visible with direct (not averted) vision.   I was also impressed  
> with the skies at Medoc Mountain ... since I stayed almost the  
> entire night at 225X while looking at all the galaxies in the  
> northern sky.
>
> I also checked out NGC2655, which was listed in some observation  
> lists as "the western member of a pair of galaxies".  Well, 2655 was  
> easily visible, but it's partner was much much fainter.   It was a  
> nice galaxy viewed from the side (not really edge on) but it's  
> partner was just a smudge.  I then moved to NGC1501, which is a  
> planetary nebula also in Camelopardalis.   Very nice, with a easily  
> visible central star.  That was the last thing I was viewing when  
> the clouds rolled in ... and when the clouds cleared 40 minutes  
> later, I could tell the mount was well aligned ... it hadn't moved  
> at all in the field of view.
>
> One of the nice things last night was that I could compare views  
> through my scope with views through Allen's Obsession.   The first  
> object we compared was NGC2403, and that started Allen on a tour of  
> (as he put it) "10th magnitude galaxies in the northern sky".  By  
> the fire, we discussed how amazing it was that his scope, built of  
> wood and assembled with struts and collimated earlier, was able to  
> locate objects (using the Argo Navis) and provide views that were  
> that amazing.   It is amazing when you think about it.
>
> After the clouds cleared, we branched out.   Actually, at this  
> point, I think I should publicly thank Mark Lerch for appeasing the  
> astronomy gods and providing the clear skies because during the  
> cloud cover, he decided it looked bad and had packed up his gear (a  
> sure way to cause the skies to clear).   I guess that's a side- 
> effect of the difference in our gear.  His is so light and easy to  
> setup (and take down) that you can make decisions quickly.  I, on  
> the other hand, didn't want to take my gear apart and I waited (and  
> hoped) things would get better.   But I'm glad to know that Mark got  
> at least one good shot during the night.
>
> But under the new clear skies, I borrowed Allen's hydrogen-beta  
> filter and tried once again to see the Horsehead Nebula through my  
> scope.  Some of you may remember from MASP that Allen let Michael  
> Hrivnak and I borrow the filter, and we both tried to see the  
> Horsehead ... Michael with immediate success ... but nothing but  
> frustration for me.   Admittedly, I have 12-inches of aperature,  
> compared to Michael's 18 and Allen's 20 ... but Allen thought I  
> would be able to see it in my scope.   Well, after MASP I researched  
> Hb filters and found some interesting articles on the filter and  
> *exit pupils*.   The summary of the articles I read was that because  
> the Horsehead is so faint, you need an exit pupil of at least 5mm to  
> see it optimally.   Well, the exit pupil is calculated by dividing  
> the eyepiece focal length by the telescope's focal ratio.   Allen's  
> and Michael's telescopes?  Both around f/4 or f/5.  Mine?  f/ 
> 11.9!!!!  So to get to that point, you need a long eyepiece.   I  
> hadn't tried that at MASP (since I didn't know ... sorry to Jim  
> Pressley who explained this to us once at a CHAOS meeting) since I  
> didn't own an eyepiece long enough.  Now I have a 55mm Plossl.   The  
> exit pupil for this eyepiece in my scope?   55/11.9 or 4.62.   Not  
> optimal ... but close.
>
> And yes, it was close.   Both Allen and I could ... when your eyes  
> were dark adapted ... and you stared long enough to get good  
> conditions ... just barely see it.  In Allen's Obsession ... no  
> problem.   I guess I'm just not going to be able to see that object  
> well in my Mewlon.   But galaxies and planetary nebulae ... it is  
> really great!
>
> Which is why I switched to the Eskimo Nebula next.   My scope does a  
> really, really good job of viewing it.  You could definitely see the  
> radial spikes in the "fur".   And the skies allowed me to push the  
> magnification to 400X.   About that time, Allen had the Rosette  
> Nebula in his obsession, with a very nice German widefield  
> eyepiece.   Again, the skies allowed the nebula itself to be  
> wonderfully bright, with lots of structure.   Couldn't get it all in  
> one field of view ... but it was great shifting the view and looking  
> at all the complexity of that nebula.
>
> While Allen and I were hunting galaxies and nebulae, Tim was  
> searching the skies around Canis Major for clusters, including M46  
> (the open cluster with the embedded planetary).   I tried looking at  
> the Perseus A Galaxy Cluster (which was amazing at MASP) and I could  
> see NGC1725 clearly ... but the other galaxies were a little dim.  I  
> probably waited a little too long ... and Perseus was getting low in  
> the sky.   With Perseus low, Leo was getting higher in the sky, and  
> that meant Saturn was visible.   I was really looking forward to  
> seeing Saturn in my scope, which is supposed to be good for planets,  
> but I had forgotten about the seeing conditions ... and sure enough,  
> Saturn was wobbly.   It was an interesting sight ... with just  
> *lines* sticking out of each side (since the rings are almost edge- 
> on) but it never settled down.  In fact, at 2 AM when Allen and I  
> were getting ready to leave, we took one last look at it higher in  
> the sky.  Still wobbly.   I need to wait for a better night, with  
> better seeing.
>
> Before it set, we looked at Hind's Crimson Star (R Leporis) which  
> was bright orange.   And before we left, Allen looked at a couple of  
> objects rising in the east.   M51 (Whirlpool) was about the best I  
> had seen it in a long while.  With direct vision, you could see the  
> arms clearly in the larger galaxy of the pair, and definitely some  
> structure even in the smaller galaxy.   Allen got NGC4565 (a nice  
> edge-on in Coma Berenices) in his scope, and it was beautiful.   And  
> we looked at M3, one of my favorites.  It was a little low in the  
> sky, but still beautiful.   Can you tell I was having fun?
>
> I was debating whether to stay after Allen left, but decided I  
> needed to get back ... which was a good thing since I started seeing  
> more and more clouds as I drove back to Chapel Hill.  So it was just  
> a matter of time before it got to Medoc Mountain.   But still, it  
> was an amazing night, especially considering the clouds and rain and  
> such that has been happening recently.   I hope next time that  
> everyone can join us over there!
>
> Sorry for the long post, but a lot happened.   I'm really happy I  
> went!   Moral of the story: trust the Clear Sky Clock!
>
> Robert
>
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