17 August 2005

Observing Location	Parkchester #6 Subway Station, Bronx, NY
Observational Period	0545-0600 EDT
Atmospheric Conditions	Clear Sky Clock says it is supposed to be clear with good transparency and it appears to be so, but I was not able to locate Mars even at 61° of elevation and well away from the Sun. There was heavy haze on the eastern horizon and no stars were visible there at all. Transparency Good Seeing Unknown
Instruments	Canon 15x50 Image Stabilized binocular - Charlie
Observing Party	Charlie Ridgway

Target	Mercury-Saturn Conjunction
Constellation	Cnc
Category	Planets
Time	17Aug05; 0545 EDT
Comments	Not Seen I received an alarm on my PDA this morning about a conjunction between Mercury and Saturn. I looked it up in Planetarium and calling it a conjuction is generous since the two planets are not in my binocular field of view. But they are both close to Praesepe, M44 (the Beehive Cluster) and either should make a nice sight with the beehive so I got dressed quickly and rushed down to the train station where I can get a good view to near the eastern horizon. But all that was there was clouds. On arriving home I checked my calendar to see what I had said about the event and couldn't find it so checked tomorrow and see that the alarm today was an early warning for the actual event tomorrow morning. But it still isn't a conjunction although the planets will be a little closer together. But the weather tomorrow is not supposed to be as good as today's. Had I been able to see them, they would have made a nice view forming a triangle with M44 to their left and a mush larger triangle with Sirius to their right. Saturn is on top and Mercury below. And the big ball on the horizon is the Sun. Images from Cartes du Ciel Even nicer would have been to see them at night since they are in a very nice area of the sky right now. And here is a view of the event from another free software package called Stellarium.

Target	Mars
Constellation	Ari
Category	Planet
Time	17Aug05; 0555 EDT
Comments	Not Seen As long as I was out and Mars was too I looked for it but was not able to see it. If the sky had been a little darker I should have been able to have located it.

As long as I am up I guess I will put the mirror in my telescope since it looks like tonight might be the night to meet Ben and Peter to test it out with their eyepieces.

I got the mirror installed and checked out by 0715 EDT.

I don't know how but somewhere between the kitchen sink and the top of the refrigerator it got a fingerprint on the edge. And all that crud I thought had disappeared is visible in this light. It is going to have to be cleaned again. I think using the colloidion on it would work best since soap and water didn't do the trick last time. But for the time being I am going to leave it in the scope and see how things look through an eyepiece.

When I installed the mirror I wore latex medical exam gloves so there was no chance of getting any more fingerprints on the mirror. To get it into the cell and align the screw holes I had to touch the edges of the front of the mirror.

I started reading through the hack on collimation and looked down the drawtube of my scope without my home built collimation tool and it looks to me like the secondary mirror is not well aligned and there are no adjustment screws to correct that. The mirror circles that are supposed to be concentric within the drawtube hole both look to me like they are shifted off to one side. Since I can't make any changes to the secondary alignment I am going to skip down to the section of the hack about aligning the primary.

Some Assembly Required Requires More Assembly

I just got back from my somewhat local Home Depot where my mission was to buy a new eyepiece retaining screw to replace the one I got last week which was too large, and to buy a set of drill bits to use with my Dremel tool to finish making my collimation toll.

It took forever but I eventually found the screws and the drawer had a bunch of loose screws in it so I started trying them to make sure the size I thought I needed would indeed fit. My guess was right and #8-32 easily screwed into the hole. But then it stopped screwing about half way through. I tried other sizes but they either wouldn't fit into the hole or slipped right through. I thought maybe I needed a different thread count but they didn't have any others. So I gave up and planned to go back to the Manhattan store which is newer and has better organized inventory,

I searched around for a while and finally found where power tools were hidden and got my drill bits and a few other interesting Dremel accessories. The stuff there is so dusty it must not have been moved since the store opened.

I figured I should at least see what it would cost me to re-tap the threads so headed back over to screws, which I had trouble finding again, to look for taps. I couldn't find them so asked a stock guy for assistance. He checked the scope with an assortment of screws and agrees that #8-32 is the right size and that it appears my threads are damaged. So where ate the taps? They aren't next to threaded things where I would be if I were a thread tapping tool. They are back in power tools even though you turn them slowly by hand. So I bought a pair of #8-32 screws, a tap and drill bit(which I don't need since I already have a hole), and a T-handle ratcheting tap wrench for another $16.42.

After a quick lunch I will see if I can clean up my threads and then proceed with the collimation tool which was the original task for today.

---

This is like roller coaster. You start off with a long uphill climb and then go into a long glide when things are going great. Then you bottom out at another unresolved opportunity and start climbing another hill. Now I am in coast mode again.

Cleaning out the screw hole and building the collimation tool were both easy tasks. It took me longer to get the tools out of their blister packs than it did to use them.

Tapping the screw hole was a breeze. I could have done it with the tap and a pair of pliers but it is better to have bought the right tool than to have possible gotten the tap going in the wrong direction and completely messed up the threads. With the sharp knives on the tap if felt like I could have almost twisted it through with my fingers. It cut very little metal. I had speculated about just taking one of the screws I bought and forcing it through with a hex wrench which might have worked given how little effort it took with the tap, but if it hadn't I might have made the situation worse. I held a piece of paper inside of the tube against the bottom of the drawtube to keep any shavings from falling on the secondary. When I was done I turned it over over the toilet to dump them there then used canned air to blow anything out of the hole, the drawtube and off the secondary. The screw feels loose in the threads but ties up nicely against a film canister and will be fine on an eyepiece.

I had to drill two film canister lids to get one acceptable hole. The drill bit walked badly on the first hole after it punched through the plastic and it looked more like a bean than a perfect circle. The second one was a little bit off center but not too bad. But it might be too far off to use as a collimation tool.

I tried the tool on the scope and the image of the mirrors still looks like it is offset toward the primary. Twisting the tool at different angles didn't change anything so the 1/16" hole must be larger than my pupil and will be ok as a collimation tool. I tried moving the cans together to see if that changed anything and it didn't appear to. However I did notice that when a can is not centered over its thumbscrew the end of the car that it is pressing against angles up and the other end down so the mirrors will not be lined up the same depending on where the cans are relative to their respective screws. I don't know if this is something that is inherent in the design of the scope or if it is because I don't have a factory-made bar. Maybe it will tighten up a bit when I get Teflon tape to replace that which is missing. I am not going to make any mirror adjustments until Peter has a look at it and express an opinion.

While researching parfocalizing rings for eyepieces I found a place on the Web called ScopeStuff (www.scopestuff.com) that sells screws and Teflon tape in small quantities. Eventually I will get screws with more appropriate heads and Teflon tape from them.

---

Observing Location	PSC
Observational Period	1630-1645 EDT
Atmospheric Conditions	It was a very nice day. It was hot but the humidity was low so it didn't feel oppressive. There were occasional gusts of wind put primarily it was calm. There was a thin layer of uniform haze lit up around the sun but there was no atmospheric boiling at all. Transparency Very Good Seeing Excellent
Instruments	Canon 15x50 Image Stabilized binocular - Charlie
Observing Party	Charlie Ridgway

Target	Sunspots
Constellation	Cnc
Category	Solar
Time	17Aug05; 1630 EDT
Comments	There is only one spot visible and it is a very bland one. 797 SW quadrant. This is a simple sunspot with no penumbra or plage.   Groups Spots R Northern Hemisphere 0 0 0 Southern Hemisphere 1 1 11>/th> Total 1 1 11 NOAA Boulder Sunspot Number R = 10 * Groups + Spots

---

Observing Location	TotL
Observational Period	2045-0045 EDT
Atmospheric Conditions	It was a lovely evening. The temperature was mild. There was no wind. The humidity was low. There were only a few passing stripes of cloud or contrail. And the air was rock solid. Mosquitoes weren't even a problem at dusk. Transparency Very Good Seeing Excellent
Instruments	Canon 15x50 Image Stabilized binocular - Charlie Coulter CT-100 - Charlie Coulter CT-100 - Peter Tacahashi 22x60 binocular - Peter Fujinon 7x50 binocular - Peter
Observing Party	Charlie Ridgway Peter Tagatac Kin Lee

Coulter CT-100 First Light

The primary focus of the observing tonight was to assess the condition of my now assembles Coulter CT-100 coffee can telescope. I wish I had pictures of it to include here but having dropped my digital camera and rearranged something in the lens I no longer have that capability.

I'll put the bottom line up at the top. The scope, although it has some known issues, performed favorably in side by side tests with Peter's identical, and in much, much better condition scope.

My first light target was the Moon because it was easy to find. It was so bright it was uncomfortable to look at. I am going to have to get a neutral density filter for lunar observing with this scope.

I was able to find M32, the Andromeda galaxy. It has been a while since I have seen it so first found it in the hand-held binoculars to be sure I knew what I was looking for. Next I used Peter's Saran Wrap tube as a finder and got dead on. A length of PVC pipe might be a better option for a finder scope than the red dot finder I have but I will give the red dot a try once I get an eyepiece. I was able to see M32 in Peters 32mm, and 20mm, but not in the barlowed 22mm.

The 32mm eyepiece looked very sharp, but it was providing the least magnification so that is expected. It only provides 13x while my binoculars are 15x so it doesn't seem like something worth investing in unless I want to get a low power view of something dim. It would be good for wide field viewing and did accommodate the entire coathanger.

Peter has an original Coulter 20mm eyepiece with built-in helical focuser. The eyepiece is convenient, but I did not like the view. Admittedly the eyepiece has some grime on it and it might perform better once cleaned. I thought his TeleVue 20mm eyepiece provided a much nicer view and even will if the Coulter eyepiece is cleaned. I think there was more contrast and the view was very sharp.

The 8mm eyepiece provided nice views but was a little hard to focus lacking depth of field. The moon almost spills out of the field of view with this eyepiece and I should get something similar for solar observing. Magnification with it is 54x. I did not try this eyepiece with the Barlow on the moon to see if I could use it that way for detailed views of sunspots. But the focus of the scope is different at the edges than it is toward the center so maybe I don't want the sun filling so much of my FoV.

My drawtube wobbles when you touch it. I can probably tighten it up a bit with the two screws that attach it but I think they are fairly tight. Replacing that setup with some sort of low profile helical or Crayford focuser would make this scope much easier to use.

We tried finding M57 at the end of the night. Vega is at zenith and it was very hard to figure out what was in the field of view and to star hop to anything. You can crank on the geared head forever up there and not move anywhere. It is going to take a little bit of getting used to finding things wit this scope. The FoV is a bit more confining than I am used to in the binocular. I am not having much trouble translating directions to be able to describe locations I am seeing in the scope to their orientation in binoculars. If I know the star field I know which direction I want the stars to move in the FoV to get where I want to go. I get going in the wrong direction when I start adjusting the geared head but I do that with the binoculars so that is not a big problem. The view just looks very different to me and will take some getting used to.

I also need to learn to fully close my right eye. I find that when I am looking in the eyepiece I relax the eyelid muscles and see blue glare from light hitting the secondary cage and bouncing into that eye. Astronomy Hacks recommends using an eye parch to preserve night vision in your observing eye when you are not at the eyepiece. I might need one for my non-observing eye to block out stray light while I am at the eyepiece.

Peter feels the risk to my mirror in taking it out to clean it again out weigh any possible gain in image quality that I might achieve and recommends against it. A better use of my time will be in trying to improve the stability of the can to bar connections and in collimating the primary mirror.

Eyepiece	Formula	Focal Length	Magnification	Comments
32mm		32 mm	13.5x	very crisp less magnification than my binoculars
Coulter 20mm	Kellner	20 mm	21.6x	didn't seem solid
TeleVue 20mm	Plossl	20 mm	21.6x	very nice view crisp, contrasty, black sky
8mm		8 mm	54x	hard to focus, not much depth of field
2x Barlow				no image degradation with any eyepiece tested probably worked better since it only used the sweet spot in the center of the mirror

Target	Venus
Constellation	Vir
Category	Planet
Time	17Aug05; 1955 EDT
Comments	Venus was first observed naked eye then in the binoculars. It was very bright and much higher in the sky than I expected.

Target	Jupiter
Constellation	Vir
Category	Planet
Time	17Aug05; 2000 EDT
Comments	I was not able to find Jupiter hand holding the binoculars but with them on the tripod I got right on it by offsetting from Venus using the very crude setting circles on my tripod head. The planet looked big and no moons were visible. By 2015 two moons were visible to the left of the planet and one to the right. At 2020 I finally found Callisto way out to the right.

Target	Vega
Constellation	Lyr
Category	Star
Time	17Aug05; 2018 EDT
Comments	Vega is the only star visible at this time

Target	Moon
Constellation	Cap
Category	Lunar
Time	17Aug05; 2020 EDT
Comments	The moon is starting to rise from behind the trees. By leaning over the fence I can see it in the hand-held binocular. You can tell that the bottom left corner is missing, it is obviously not round.

Target	Arcturus
Constellation	Boo
Category	Star
Time	17Aug05; 2020 EDT
Comments	Arcturus is now visible

Target	Cygnus
Constellation	Cyg
Category	Stars
Time	17Aug05; 2025 EDT
Comments	It is getting dark enough for stars of the second order to start appearing. I am seeing stars in the wings of Cygnus now.

Target	Summer Triangle
Constellation
Category	Asterism
Time	17Aug05; 2030 EDT
Comments	Altair has appeared so now the whole Summer Triangle is visible overhead and to the NE.