New Observing Site

Today was clear after several days of rain so I headed down to the park at dusk to look for a key. Nobody around except the border patrol so I explored for a place to observe instead. The courtyards just outside the A/V room look ok and are certainly convenient. Even with the trees I had a good view down to about 15-20° with no visible street lights. As Venus dipped into the trees I noticed Vega appearing and Jupiter high in the East. Deneb and Altair made their appearance and I started looking for the coathanger (Cr399). It wasn't quite dark enough so I waited for ISS to show at 6:50. I was afraid I had been 'had' again and it was 6:50am instead of pm. Nope, I had it right and ISS showed up right on time, rising to about 5° above Altair and traveling about 5° every 12s. It rose to about 1° above Deneb before decending slowly toward the North. It was visible in binocs just to the east of north and about 20° altitude. By then it was plenty dark and I was able to spot Sagitta in my 7x50's and nearby was Cr399, the fabled coathanger asterism. In the east, Aldeberan was rising, pointing out the Hyades, above and to the left was 'Subaru' the Seven Sisters (visible unaided), and of course, Jupiter. I was able to see 5 stars in Cassiopeia unaided and 6 stars in Cygnus. I was even able to convince myself that I was able to spot M31 the Andromeda Galaxy, unaided. It was nice in 7x50's.
All in all, while it would be nice to have a view of the western horizon, the courtyard is convenient and should work just fine for star parties.

Power Supply Mod

I've been wanting to replace the battery clip style connector on my ETX's 9v supply. Today I picked up a type N bayonet style jack from Radio Shack on Trenton and 10th. Two others on 83X and N Conway were unable to help. Radio Shack seems to be dropping their parts merchandise gradually. Type N is 5.5mm OD and 2.1mm ID. They didn't have the matching plug in stock so I'll either have to use something from the junkbox or wait until the weekend. In the meantime, I can install the jack on the ETX and either switch to the portable power station or keep using the wall wart supply. Tomorrow is partly clear, so maybe I'll get a quick peek at the moon or the sun then.

Train Drives

Rainy today so it was a good day to Calibrate and Train my ETX70 drives. Calibrate is simple and automatic and needs to be done when power supply changes are made. Training was done with my 10x eyepiece and a slow slew rate. I need to redo this when I can train using Polaris. My new focus extender worked well, for awhile. As I was finishing up it broke! I re-glued the knob and will see if that fixes it. The ETX site says that training is indicated by 'rubberbanding' or when the drives slew away from a target that has been manually positioned. Mine does this a lot at higher power. Hopefully this will cure the problem.

Park telescope checkout

I spent about 4 hours today checking out three of the Park's telescopes: Celestron 5", Orion 3", and Meade 4". The Celestron continues to look good. The optics are in pretty good collimation. The targets were all in alignment although it could be a bit better. The tripod is a little bit wobbly but otherwise seems serviceable. It is missing a locking bold on one leg. This tripod is similar to the one's on the Orions and one of those bolds may work temporarily. I plugged the drive into my 12v portable power station (Chicago Electric from Harbor Freight, $90) and everything fired up. Movement is smooth and handbox buttons all work fine. I tried pointing at a distant tree and verified that the 'save land object' and 'goto land object' functions work. If the scope is in the near vertical position there is some interference between the OTA and the tripod. This may be normal but needs to be checked out and if normal, watch out for it. There doesn't appear to be any protection and the gears might be stripped. The view through either 25mm or 10mm eyepieces seems good and I could tell no difference between the available ep's and my Plöessls. Some of the eyepieces are marked KE and others are Orion Explorer II. They all look similar. Tristan Schwartz at Cloudy Nights gives them high marks. They are basically either Kellners (25mm) or Plöessls (10mm). The Celestron's red dot finder needs a 3v battery.

The Orion 3" Spaceprobe needed a bit of tightening and it is now steady as a rock. The tripod seems sturdy enough although I did not extend the legs. The optics were in perfect collimation. The red dot finder also needs a battery. There are three more boxes in the storage room that may also be Orion 3" scopes. These also need to be taken down and checked for missing/damaged parts.

The Meade 4" tripod is pretty much unusable when the legs are fully extended. They flex quite a bit. The azimuth bearing is very wobbly and the altitude bearing a bit so. The most serious problem is that there are no eyepieces. The focuser is a 2" barrel but it was fitted with a .965" adapter. There is a 2" bushing but no threaded ring to hold it on. It needs a 1.25" adapter before the existing eyepieces can be used. I was able to install the second motor. The power supply is 12v but my bayonet connector would not fit so I was not able to check out the drive operation. The Autostar handbox appears to be unused as the protective cover on the screen was still in place!

Here are the magnification firgures for the three scopes. The 3" is a 700mm FL, the 4" is 910, and the 5" is 650mm. Magnification available for the 3" is: 700/25 = 28x, and 700/10=70x. With a 2x shorty barlow this gives magnifications of: 28x, 56x, 70x, and 140x.
Magnification for the 5" is:
650/25 = 26x, and 650/10 = 65x. With a 2x barlow, that gives 26x, 52x, 65x, and 130x.
If the 4" is ever usable, it's 910mm focal length will result in magnifications of: 910/25 = 36.4x, 9210/10 = 91x or 36.4x, 72.8x, 91x, and 182x.
The next step is to try star testing the optics. It'll be interesting to see what sort of detail can be seen on Jupiter and how well the two scopes can split close doubles.

First day as Park Astronomer

Today was my first day on the job as Park Astronomer for Bentsen Palm State Park. First order of business was to find my 'office' and do some inventory on the park's collection of astro-scopes. They have quite a collection of some really nice optics used for their birding outreach but not so much for astronomy outreach. I went in with the expectation that I would either be driven to the depths of despair with junk or completely elated with some fine optics. Actuality was something in between. Definitely not junk though. There are a number of Orion Spaceprobe 3 AltAz newtonians, and a couple of goto newts. All are altaz tripod mounts so alignment will be straightforward and the little Spaceprobes have red dot finders at least. One goto is a Celestron Starseeker and the other is a Meade Telestar DS-114. The Orion mounts are lightweight wiggly-looking altaz tripods. It might be better to try to mount these on a dobsonian base of some sort, either commercial or homemade. All have 10 and 25mm eyepieces. The goto's appear to both be 12v AA driven. One battery box is slightly damaged. One eyepiece appears to be missing. All equipment is in the Audio Visual room which stays locked. I am to contact Javier (off friday and saturdays), Roy, or Melissa to gain access. Observing can be done in the office courtyards (dark with power), or the middle loop in the park (power available near restrooms), or out in the yard. Green laser pointers abound as do binoculars and 50mm spotting scopes.
The park hosts a 'night hike' on Wednesday and Saturdays as well as monthly special programs for volunteers. The Saturday night hike would be a good place to start some sort of outreach program. An astronomy program for volunteers would also be good.
First order of business is to complete checkout of the telescopes and familiarize myself with their operation. As a volunteer, this should be fun. If nothing else, I can work at my own pace!
Research results: The DS-114 gets uniformly bad reviews. The Spaceprobe 3 gets good reviews as a beginner scope, but this is for their SP3 with equatorial mount.
The Celestron is basically a NexStar GT. It remains to be seen about details like which handbox is attached but the site www.nexstarsite.com has a wealth of material on it, similar to Weasner's ETX site. I'm hopeful about this one as Orion sells it and it is essentially a current product with some support. It has a 1.25" focuser and an Orion EZFinder.