Re: How often do you need to polar align a permanent mount?

Mike Shade

In SE Arizona at 5000' elevation, where we can have a pretty good heat cycle from day to night, I check and adjust polar alignment if needed once a year.  If there are any adjustments needed, they are small.  But remember metal can sag, fatigue, heat cycle, bolts can loosen up, fasteners can back off and so on.  I also go over all the fasteners on the OTA and make sure they are snug.  Generally in September after monsoon is over and prior to starting the new season.


Mike J. Shade

Mike J. Shade Photography:


In War: Resolution

In Defeat: Defiance

In Victory: Magnanimity

In Peace: Goodwill

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Already, in the gathering dusk, a few of the stars are turning on their lights.

Vega, the brightest one, is now dropping towards the west.  Can it be half

a year since I watched her April rising in the east?  Low in the southwest

Antares blinks a sad farwell to fall...

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International Dark Sky Association:


From: [] On Behalf Of CurtisC via
Sent: Wednesday, November 04, 2020 9:14 PM
Subject: Re: [ap-gto] How often do you need to polar align a permanent mount?


Picking up from Mr. Erickson's post -- Palomar Mountain is bounded by major faults on both the northeastern and southwestern sides of the block, and it is, of course, pretty close to the San Andreas and San Jacinto Fault Zones.  The foundation of the 200-inch has adjustments for polar alignment, but -- to my knowledge -- it has never been readjusted due to effects from an earthquake.  Nobody currently on staff remembers any such realignment.  The mm 7.2 Cucapah Earthquake in Baja Calif. in 2010 was strong enough to slosh water in the observatory's water tanks, but it didn't affect any of the telescopes.

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