Daytime Observing/Alignment  
with the LX200 (classic)

       

Subject: LX200 Daytime Observing/Alignment --part 1

From: Allen Ginzburg <allengsco.com>

Daytime Alt-Az alignment of an LX200 Classic is quite easy:

The only thing to make sure of (possibly the night before) is that the focus is correctly set to infinity with a relatively wide field eyepiece. I use the 26mm on my 10" LX200.

1. Set up the scope so that it's facing approximately south. That is, when you are facing the control panel, you are facing south.
2. Accurately level the base. Use a torpedo level on the top of the OTA and adjust the tripod until you can rotate the OTA 360 degrees while keeping the bubble centered.
3. Set the DEC axis at zero elevation. I use the level on the OTA for this. It's more accurate than the setting circles. Use a builder's bubble-level sitting along the top of the tube. (And once you've done this the first time, loosen the lock and adjust the Dec circle so that it is dead on. Subsequent leveling jobs will then be easier since you can start close to right; but you still need to use a level.)
4. Use a compass to point the OTA as close as you can to true south. Remember to correct for the magnetic variation in your area. In California it's 17 degrees to the east of magnetic. Make sure both the DEC and RA axis are locked. It's useless to put the compass near the scope. I just hold it out in front about a meter and sight along the compass to align the OTA. This is the hardest part of the whole operation. It's also not that important to get it exactly right -- if you are very close in Dec then you can find your first object by searching in azimuth only; this is a lot easier than searching in both dimensions.
5. Power up the scope and make sure the date and time are set correctly.
6. Make sure your location is set to a known site with the correct coordinates.
7. Select some bright object like Venus, Jupiter, or the Moon. Leave all the lens covers on and do a GoTo that object. The scope will move somewhere close to the object.
8. MAKE SURE YOU ARE NOT POINTING NEAR THE SUN. Take off the lens covers from the finder scope. Your object should be visible. Center it using the keypad.
9. MAKE SURE YOU ARE NOT POINTING NEAR THE SUN. Uncover the main tube OTA and center the object using your pre-focused eyepiece. Then sync (by holding down the enter key).

After that you can GoTo any bright object. I can view any 1st magnitude star, Jupiter, Venus, Mercury, and Mars with no difficulty. In certain parts of the sky (away from the sun) even less bright stars are visible). Splitting the double star Castor is easy, even in full daylight. Whenever I do a GoTo, I put the lens cover back on the main OTA just in case it might cross the Sun. Then I verify that it's pointing somewhere at least 15 degrees from the Sun before uncovering it.

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Subject: LX200 Daytime Observing/Alignment --part 2   

From: Bill Arnett <billaznet.com>

Use the "zero star alignment procedure" (OTA level and pointed exactly due south at power up). Then slew to a bright star or planet (Venus works well now). You'll be off a little but you can probably find it in the finder scope. Center it up and sync on it by holding down the Enter key until it beeps. Now you should be able to slew to any of the alignment stars and see them in the eyepiece. Do a two star alignment as usual and you're off to the races!

The zero star alignment assumes the tripod is level so make an attempt to get it close. A magnetic compass is sufficient for finding due south if you know your local magnetic deviation.

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Subject: LX200 Daytime Observing/Alignment --part 3 of 3   

From: Mark Buettemeier <markbuemicrosoft.com>

Daytime viewing and full use of GoTo is quite possible and fairly easy with an LX200. I have done it many times and have viewed Venus, Mercury, Mars and dozens of bright stars.

The trick is that you need to properly set up the scope for a zero-star alignment. I have only attempted this in AltAz mode. I think Polar mode would be nearly impossible unless you setup the scope the night before and leave it out all night.

To set up zero-star alignment in AltAz mode, you must start with a VERY level tripod, the optical tube perfectly level and pointing directly opposite of the control panel, the control panel pointing directly to true north, not magnetic north. (Thus, the optical tube is pointing to true south and is perfectly aligned with the control panel -- the little line on the base of the RA assembly lines up with the little line on the control panel). Furthermore, the correct date and time and offset from UT must be entered into the scope and your correct Lat. & Long. information for your current location. Once you have done all these things, power up the scope.

A GoTo at this point should get you VERY close, if not dead on, to the selected object. Best alignment will be achieved if you can fine tune the alignment on a bright star, planet or the Moon and then re-sync the scope to that object. If the Moon is up try doing a STAR 903 GoTo. Fine tune the alignment using the arrow keys and then press and hold ENTER. Venus, at the right points in its orbit, is also a good fine-tune alignment target since it can sometimes be seen in the finder scope and some times even naked eye. Remember that as you GoTo further from your original alignment object you may start to loose accuracy and may need to re-sync.

WARNING: Although the LX200 software will prevent a direct GoTo to objects too near the Sun, it will not avoid slewing past the Sun on its way to a target. This means that it is possible for the image of the Sun to transit inside the eyepiece and/or finder scope. Stray sunlight from the eyepiece could be projected into your eyes or the eyes of nearby observers. For this reason, it is a good idea to cover the aperture of the scope prior to starting a GoTo in the daytime.