Astronomy Resolutions for 2010

Here are my personal astronomy goals for the coming year:

- Complete the Herschel 400 list (I have about 300 objects to go)

- Complete the Master level of the Outreach club of the Astronomical League (about 70 more hours of star party fun)

- Learn how to do more sketching at the eyepiece (Maybe this means the open cluster club, Asteroid club, or the Lunar II club?)

- Attend the Texas Star Party for the second time.

- Find at least 3 more dark sky sites I can easily access within 2 hours of San Antonio including one with low horizons.

Dark Skies to all

Risk

Sunspots are back

Several times this December, I have taken a look at the sun with my 10 inch scope and a Baader filter. The filter works fairly well in seeing sunspots and other white light features of the sun.

Yesterday, I tried taking a few photos with my phone camera through the eyepiece. Most of the images were not very good. A few were worth looking at. The image attached to this post was taken through a 10mm Radian eyepiece at a magnification of about 120X. The cropped area is about 1/20 of the original photo. It clearly shows the two pairs of spots which I saw visually.

I have read that sunspots always appear in pairs, that the spots are the two points where a local magnetic field line crosses the visible surface of the sun. In this photo, there are two nearly equal pairs. There is an inner pair of small spots and an outer pair of larger spots. Also, spots appear in pairs that are parallel to the sun's rotation, which is approximately parallel with our rotation around the sun. These pairs did move leftward in my reflector, so the west is to the left and the east is to the right. South is up and north is down in these views.

Dark Skies, Good People

We had nice weather in San Antonio over the weekend too. Saturday evening was a club outing to a dark sky site. The weather and the company were great. I was able to finish off the December portion of the Herschel list, as O'Meara has it programmed. I am now up to date, having finished up September to December. There were some long star hops in the December list.

I spent the rest of the time in my binocular chair, doing a mini Messier Marathon of the available objects.

By morning, what had been a moderate dew, had frozen solid on my dew covers.

All in all, a nice observing night.

Cleaning a Primary Mirror

After a summer/fall of frequent observation and two major rebuilds of the furniture for my 16 inch Lightbridge optics, there was a fair amount of earthy dust and even more saw dust coating my primary mirror.

I had a good long conversation with the owner of a 24 inch StarMaster scope at the Texas Star Party about cleaning mirrors. Before forgetting all his advice, I decided to do a full baptism of my mirror last weekend.

I removed the mirror cell from the base box like I have a number of times in my building project. Taking it out is never a problem. (Putting it back in is not quite so simple. It takes a steady hand, carefully placing the mirror cell on three springs without knocking the springs over. )

Next, I removed the three mirror clamps from the periphery of the cell. That does not release the mirror, because there are four places on the periphery where black RTV calk was used to further hold the mirror in the cell. I took a sharp knife and cut through each bead of calk next to the mirror. (Marking the mirror to know what rotation angle it was in the cell is a really good idea.)

I then was able to slide the mirror out of the main cell casting. It came out with the rear-of-the-cell spider pieces attached. There are three independent supports that make up this “spider”. Each support consists of two three cornered plates on a balance beam. Each three corner plate had one sticky pad attached to the mirror with double sided paper tape. After fiddling with these tape pieces unsuccessfully for a few minutes, I just pulled the triangles off the mirror, leaving a paper spot on the mirror in 6 places.

I then took the mirror to the back porch, placed it mostly vertical against the house, and hosed the mirror off. That took most of the contamination off the mirror, I am quite sure. But I wanted to go a little further.

I filled up a roll under the bed Tupperware container about half way. This was a new container I bought for this purpose and hosed out. These containers have a bottom which is just a little more than 16 inches by about 27 inches. I put a couple drops of dish washing detergent in the water and used the hose to spread that out.

I put the mirror in the water bath with about an inch of water over the top of the mirror.

I had previously obtained some cotton balls that were 100 percent cotton. There was no way to verify that they did not have any softener in them, like surgical cotton. But they were called 100 percent cotton and did not list any other ingredients.

I used a cotton ball and gently ran it from the center of the mirror to the edge. I threw that cotton ball away and did the same with another ball just a half inch or so from the first one. I continued in this manner around the mirror – one pass of each new cotton ball from the center to the edge. My intent was to have the smallest risk of collecting a scratching grain and scratching the mirror over and over with it.

After this cleansing, I took the mirror out of the bath. I put it vertically next to the house again, and rinsed it with a quart or so of distilled water.

Almost all the water drained off the mirror leaving it without drops. There were a few drops and I collected them with the corner of a piece of toilet paper.

After the mirror had finished drying, I saw that I had missed a few places on the mirror where I had evidently not used a cotton ball. There were some small streaks of dusty appearance between my radial strokes - but there were not many. Evidently, using the cotton balls had removed a layer of dust that had remained adherent during the spray cleaning and the immersion.

After the mirror dried, I was able to put the rear support beams with triangular plates in place, and then to slide the mirror back into the cell so that the cut surfaces of the RTV calk exactly matched. I put the three mirror clamps back on. (Remember not to do this tightly.) Then The mirror cell was bolted back in the bottom box of the scope.

It was all pretty simple and the mirror was obviously much cleaner after the operation. Even just a spraying with a hose would clean the mirror a lot the next time round.

I don’t think I would do this more than every year or so, but it is nice to have a clean mirror again.

Failed Astronomy

Some nights, things just don’t work out. I had one of those nights on Sunday.

After a long week of cloudy skies, Sunday daylight broke with hints of sunshine on the top of a fog bank. As Diane and I sat in Starbucks having coffee and coffee cake, my spirits began to rise with the glucose and caffeine levels in my blood stream.

Confidently, I said that the clouds would burn off by noon and we had the potential of a clear sky for the evening. That was a nice thought because we were very close to new moon and the Geminid meteor shower was scheduled to peak before midnight.

I set about to cautiously think about an observing evening. Maybe the night would turn out well.

As I worked around the house during the afternoon, I was overjoyed to see that the sky was bright blue. The recent rain had pushed out haze and left the sky cloudless.

I looked up Hill Country State Natural Area on the internet and saw that a public hunt was scheduled to start on Monday. The park would be closed at 10 PM. That was good enough for a nice night of Herschel observing, but it was a little disappointing that the park would not be open for the peak of the meteor shower.

I called the park office, intending to let them know that I would be at our observing site that evening, and that I would be out by the 10 PM closing time. The nice ranger on the phone told me that the park would actually be closed beginning at sunset, not 10PM. Not wanting to argue, I thanked the ranger and started to think of other options.

“Oh well”, I said to myself. “I have observed from a pull off on the park road before”, and I decided that I could do it again. Yes, I knew that I could expect to have 15-20 cars with bright headlights come by, but the rest of the time I would have 5.5 magnitude stars visible. It could be a nice night of Herschel observing (maybe I could finish the December list in O’Meara’s book) and then I could settle down to watch meteors toward 10 or 11 PM. The drive home would be 10 minutes shorter as well!

I arrived at my observing spot about 6:30 PM. Diane begged out because she had some work to do as Santa’s Elf. No one else answered my email on the San Antonio Astronomy Yahoo group when I posted that I would be out near the park. I planned on being by myself. I was.

When the sky turned dark enough to see the “faint fuzzys” on the Herschel list, I pulled out the O’Meara book and reached for my trusty digital recorder. But that recorder was back in my house in Helotes, 40 minutes away. Oh Well! I looked at a couple of the objects, but lost interest fairly quickly, knowing that I was not set up to record my observations. I looked at a number of Messier objects with my 16 inch scope. But I was a bit bummed out.

About that time, I realized that the rising Orion constellation was dimming noticeably. I looked straight up. The Milky Way had disappeared too. I looked further west, and Jupiter was shining brightly and those constellations were all present.

So it was just a local cloud.

Except that about 15 minutes after the sky cleared, there was a general dimming of all the stars and then they all winked out. They stayed that way. It was 8:45 PM. I never saw another star.

On this little trip, I had experienced loss of an observing field to a “hunt” on the State Natural Area park lands. I had to set up where bright car lights spoiled my night vision every 10 minutes or so. I forgot to bring a little recorder which spoiled my ability to run the list I had intended on. And finally I was shut out by a thick bank of clouds that suddenly formed from a perfectly clear sky. The sky has stubbornly remained cloudy all week long, ever since.

I just thought I would post this, to remind me how special it is when everything works out splendidly! Surprisingly often, the weather, the moon, the place, and the gathering of friends are all perfect. As I sit here today, I am planning on that all working out for this Saturday evening.

Wishing you Dark Skies and a Merry Christmas,
Eternally the optimist,

Risk

Simple dew shields from "Fun Foam"

I went to Hobby Lobby last week to buy a few sheets of 2mm thick black foam rubber. I found them in the children's education part of the store. I bought the foam to make a backdrop for my secondary on the ring structure of my new Looking Glass.

While I was there, I bought a couple more sheets to play with. Nearly simultaneously, Matt R. was there and working with the foam. He kindly made me a pair of dew shields for the Eyes of Texas, my 80mm binocular. He also cut a sheet for my Telrad.

From my scraps of Fun Foam, I built a simple wrap-around dew shield for my 50mm finder. I built it so that I could put a hand warmer packet inside the ring if I desired.

Last night, in my observing session at Hill Country State Natural Area, the dew was pretty heavy and early. (On the way home, there were blankets of radiation fog in every valley.) I had put the finder scope dew cover on and it kept that objective clear of dew all evening. I ended up needing to wrap a hand warmer around the eyepiece of the finder with a rubber band. that worked, but I was late in choosing to do this and had to deal with occasional dew on the eyepiece.

The Telrad cover was attached by wrapping rubber band around the long axis of the Telrad base. The cover was held nicely in place by the rubber band. This kept the Telrad remarkably free of dew without sacrificing the utility of the finder.

I was finally done in for the night at about 830 PM, two hours after I began to observe, by dew forming on my secondary. I forgot to bring my hair dryer for that. With a hair dryer, I would have been able to continue for a while longer, until fog formed in the observing area.

For just a couple bucks, these "throw-away" dew covers are extremely easy to make and work very well. Their outer surfaces were *covered* with dew by the time I packed up, but the optics were nice and clear.

Best telescope for Christmas

It seems to be the time of year to help out folks that are thinking about a Christmas telescope. Let me help out some more. This is going to be simple.

If you are part of a family or a single person who thinks that looking at stars would be fun and that you want a telescope to do so, then read this blog post.

If you have read other folks say that it really would be wise to get a planisphere and you *have* to have a scope for Christmas, then read this blog post.

If you have considered a pair of 10x50 binoculars and still *must* get a scope for Christmas, then read on.

Don't go to a department store to get your scope. You still have time to get one in the mail from an internet sales place. Unless you really know what you are doing, don't go to Craig's list - and if you really knew what you are doing, why would you be reading this blog post??

What you want is the Orion XT6. It is a six inch dobsonian scope with no bells and no whistles. It comes with one eyepiece and a red dot finder. That should be all you need to find hundreds of objects in the Texas sky. It will fit in the back seat of almost any car.

If you search well on the internet, you should be able to buy it for less than $300 and get most of the shipping for under that number too.

After placing your order, the most important thing you should do is to find an astronomy club to help you find out how to use the scope. In San Antonio, do a search for the San Antonio Astronomical Association. We will help you. You will have fun.

Next most important: buy a copy of the Sky and Telescope Pocket Sky Atlas. It will be your map to the sky. A planisphere will also help. So will a pair of binoculars.

Dark skies to all, and to all a good night!

Risk

Comet Sweeper

I just finished a very nice book about Caroline Herschel by Claire Brock. The Comet Sweeper follows Caroline's rise to fame in the late 18th century. First as an assistant to Wm Herschel and later to her nephew John, Caroline had a large number of her own accomplishments of her own. The NGC catalog was mostly her organization of the o servations that the siblings made.

As a finder of comets, Caroline ranked in the upper tier of discoverers of her time. Entirely self taught, Caroline taught herself math, singing, and astronomy. When she was provided a yearly stipend by king George III she may have been the first professional female scientist and was certainly the first female professional astronomer.

For readers in the San Antonio Astronomy club, I will be making the book available at a meeting soon.

Best of the Best

As I was sitting in the back yard the other night hoping for clear
skies, I started to think about what would be on my list of the best of
the best objects in the night sky. I thought that a list of 5 might be
harder to come up with than a list of 10.

The list I came up with was:

Moon
Milky Way
Saturn
Jupiter
M42 - Orion Nebula

Next on my list might be:

M45 - Pleiades
M31 - Andromeda Galaxy
M13 - Hercules Globular Cluster
M9 - Lagoon Nebula
M57 - Ring Nebula

My 11th would be the Crab Nebula, M1.

What would be on *your* list of the 5 and 10 top night-time sky objects?

Next question I have for myself is how much do I know about these
objects? What class of object are they? What has been their history?
How far away are they? What was going on in history when the light from
them started this way? For the deep space objects, who discovered them,
and when?