How to Set up your Telescope Mount

Congratulations on getting your new telescope!   Or maybe you are about to get a new telescope?   You are about to discover and explore the hidden treasures in the night sky up close.

You probably have a few questions like how do I set up a telescope?     In this blog update, lets review some basic terms that you need to know, and some general steps on how to to set up a telescope.    My name is Erik, and I am an amateur astrophotographer.

Before we get started, a good place to start is with the manufacture's instruction manual or any videos they may provide online.   

ALTITUDE AND AZIMUTH

So let's start first with some general terms.   Altitude and Azimuth.  

ALTITUDE and AZIMUTH are part of a local coordinate system on how we find the apparent location of celestial objects in the night sky.   All measurements are expressed in degrees.

ALTITUDE, or ALT for short, stands for the altitude or elevation axis.    On the horizon is the zero degrees altitude or elevation on the axis.     Directly overhead is the zenith at 90 degrees altitude.    Halfway in-between is 45 degrees.

AZIMUTH is "the direction of a celestial object from the observer, expressed as the angular distance from the north (Oxford Dictionary)."  

In the northern hemisphere, we use Polaris to help find the celestial north pole, denoted as zero degrees north.     Go clockwise 90 degrees from the celestial north, you will reach the 90 degree point, or East.   Another 90 degrees clockwise is south at 180 degrees.  Another 90 degrees clockwise is 270 degrees or West.  

This coordinate system works best with Alt-Azimuth mounts.    After initializing and star-aligning your mount, armed with your local position and time, you are able to slew your telescope to the apparent location of celestial objects that are potentially viewable from your location that is above the horizon.

For example, if the Moon is halfway up the horizon, by telling your APP or hand-controller to find the moon, its apparent position may be 210 degrees in azimuth and 45 degrees in altitude.  

DEGREES

Before we move on, lets talk about degrees.   It is helpful to know that degrees are further divided into arc-minutes.   There are 60 arc-minutes to a degree.   

And there are 60 arc seconds to a 1 arc-minute.     So the apparent location of a celestial objects have a precise location that is always moving, due to the rotation of the Earth, or their own movement in space.      So going back to our moon location, its apparent azimuth position tonight at this very moment might be 210 degrees, 30 minutes, and 29.5 seconds.  

We also express the apparent width of objects in the night sky in degrees as well - like the Sun, Moon, planets, galaxies, nebulas, constellations, etc..

So far example, the Sun is approximately 1/2 degree apparent width or 32 arc minutes.    

The moon has an apparent width of 29.4 and 33.5 arcminutes depending on its orbit, similarly at 1/2 a degree wide.   As we just recently witnessed across North America, the moon was at the right spot in its orbit to give us a total eclipse on April 8th.

MORE ON CELESTRIAL NORTH

It is important to note that celestial north is not the same as true north or magnetic north.    Celestial north is around 1 degree off of true north.    However, magnetic north varies greatly due to your location on Earth due to magnetic declination.     Magnetic declination is the angular difference between true north and magnetic north.    Here just south of Atlanta, magnetic north is over 5 degrees west of true north.  

CELESTRIAL SPHERE

Lets talk about another coordinate system that is used by astronomers and equatorial mounts.   Let's start with the coordinate system we use here on Earth, Latitude and Longitude.   

Latitude measures the distance north or south of the equator.   It is expressed in degrees.   0 degrees latitude is equal to the equator.  90 degrees North is equal to the true north pole.  90 degrees South equals to the true South pole.   The poles are where the Earth spins on it's axis.

Longitude measures distance east or west from the prime meridian.   The prime meridian is an imaginary line from Greenwich, England, dividing the Earth into two hemispheres - West and East.   It is measured in degrees, minutes, and seconds.  

For astronomy, the sky has a similar coordinate system.   There is a celestial north pole and a celestial south pole.   Halfway in-between the north and south poles is the celestial equator.  

DECLINATION

To help find objects in the night sky with this system,  we describe celestial objects either north or south of the celestial equator in degrees.   If the object is south, we use negative degrees.   So for example,  Antares is negative 26 degrees and 29 minutes, south of the celestial equator.

RIGHT ASCENSION

Right ascension is similar to longitude on Earth and the prime meridian and Greenwich, England.    The "meridian" on the celestial sphere is determined on where the Sun falls on the celestial equator at the Spring equinox.     The 360 degrees circle around the sphere is subdivided into 24 parts called hours.   So as each hour passes, one hour advances on the celestial sphere.    Actually slightly a little less at 10 seconds each hour.   One solar days is 24 hours where one sidereal day is short 4 minutes of that.   This is why the constellations are just a little further west at the same time each night, unless you live at the true north or south poles.

Equatorial mounts are polar aligned with the celestial poles.    One the telescope has slewed to its declination location and right ascension location, the mount can track the object on one axis, adjusting for the rotation of the Earth.

So in astronomy, we use altitude (ALT) and azimuth to find objects in the sky.  Based on your exact location and time, this coordinate system is used by your telescope mount to find objects in the night sky.     

TELESCOPE MOUNTS

Telescope mounts fall in two categories.  Alt-Azimuth (Alt-Azi) and Equatorial mounts (EQ). 

ALT-AZIMUTH MOUNTS

Alt-Azimuth mounts are great for observation and planetary imaging.   They are perfect for beginners.    Some companies sell their telescopes that are attached with these types of mounts - like the Celestron Nexstar series.    Some alt-azimuth mounts come with a hand controller.   Others utilize an app from your mobile device.   And still others like my  Sky-Watcher SolarQuest alt-azimuth Solar Mount use both GPS and a HelioFind solar finder to locate and track the sun during the day.   And more basic mounts are moved manually by adjusting knobs or through cables.

Setup is generally easy with an alt-azimuth mount.   When setting up your equipment, ensure it is on stable ground.   I normally get my equipment away from streetlights or the road.   Next you want to extend the individual legs on your tripod to ensure your mount is level.   

After providing power to your mount, go through the set-up process on your hand-controller or app.    After performing a basic star alignment process, you are ready to go and explore the night sky.    

If you are getting into this hobby, I recommend alt-azimuth mounts.  They are mostly affordable and easy to setup.   Strain-wave mounts like the ZWO AM3, AM5, the new Sky-Watcher Wave 100i and 150i and many others can operate in both alt-azimuth and equatorial modes.

EQUITORIAL MOUNTS

Equatorial mounts (and strain wave mounts operating in equatorial modes) are for both astronomers and astrophotographers.    Once polar aligned, these mounts are able to track objects in the night sky for an extended period of time with higher accuracy.    Depending on the mounts,  they can also be moved through a app, hand-controller, or manually through knobs and/or cables.  

I'd like to review my setup for my Skywatcher HEQ5 Pro Computerized Equatorial Mount.    This equatorial mount has a 30 point payload capacity, hand-controller with a 42,900 object database, a built-in polar scope with an illuminator, two 11-pound counterweights, dovetail saddle.  

Setting up these mounts have some common steps.   However, your setup may vary.  Please reference your instruction manual.   

I normally set up my equipment one the sun is no longer shining on the spot where my telescope is going to be setup, but prior to complete darkness.

1.    Find a good spot.   Once again, look for dry, stable ground.   Select an area that has a good view of the night sky while avoiding any unwanted lights.  

2.  Start with magnetic north (northern hemisphere).   I use a compass to help me locate the approximate location of magnetic north.   Since I know that my magnetic declination in my location is about 5 degrees to the west of true north, I'll point my mount and telescope about 5 degrees to the right (clockwise) to approximately true north.    This is a great starting point.

3.  Level the mount.   My HEQ5 features a bubble level.    I carefully extend or retract the tripod legs until the bubble is in the middle of the inner marked circle.

4.  Assemble your support equipment.   Since I am home, I run an electrical extension cord to my equipment.   Otherwise, I would use a portable power supply.   At this point, I usually set up a portable table and place my accessories there, like eyepieces, filters, covers, etc..   

5.  Attach your telescope.    Be sure that all knobs are tightened, especially on the mount prior to placing your telescope on the saddle.   You could not want your telescope optical tube coming lose or flopping unexpectedly.

6.  Attached counterweights (if needed).  If your telescope and attached accessories is going to strain the motors on the mount, or be unbalanced when moved, attach your counterweights.   Be sure to tighten any screws so those weights do not move.

7.  Balance your telescope.   This is a two-step process.    It involves positioning your telescope and counterweight rods horizontal the ground.    You want to move your counterweights so that your rig is balanced.    By releasing the RA lock lever, you can test to see if your rig is balanced.   

The other test is whether your telescope is balanced in the saddle attachment.   Carefully release the declination lock lever.  If your telescope rig sags to one side of the other, relock the declination lock lever.  Move your telescope forward or backwards and check the balance again.

8.  Focus your telescope.   If your eyepieces or imaging cameras have never been focused, I normally take this opportunity before complete darkness to focus my telescope.   I'll try to find a radio antenna or other object in the distance to focus my telescope on.     In my area, there is a communications antenna several miles away.   I'll normally point the telescope at the top of the antenna on the red light.     Once that is centered and focus, I'll ensure that any attached guidescopes, finderscopes, or starfinders are centered as well.   Adjustments are normally made through screws and/or with hex wrenches.

WAIT FOR DARKNESS

Now I wait for darkness.   Since my equipment was inside the house earlier, I like to my equipment some time to get acclimatized to the ambient air temperature.    Once the night has hit nautical twilight, the brightest stars should be apparent in the night sky.     

1.  Focus.    If my telescope needs to be focused, I'll take this opportunity to point the telescope to a bright star and focus.    I'll cover Bahtinov mask and electronic focusers in another video.

2.   Find Polaris (northern hemisphere).    You can find the Polaris star in the northern hemisphere by using the end of the cup on the "Big Dipper".      You are looking for the "Little Dipper" in Ursa Minor.   Polaris is at a altitude that equals your latitude in the northern hemisphere.     Atlanta is approximately 34° North in Latitude.   Polaris for me is 34° in altitude near magnetic north.   Using my hands, that is three fists and a half up the sky from level ground.

Photo Credit:  NASA

3.  Polar Align your Telescope.    With my mount, I can utilize a polar scope reticule in the mount.    By using the included hand-controller or any APP on my mobile phone, I will make manual adjustments to the mount by hand cranking both the Altitude Adjustment T-bolts and Azimuth Adjustment Knob to place Polaris in the exact location in the reticule.  

When you have the ZWO ASIAIR Plus WiFi Camera Controller, polar alignment is even easier.     Select the polar alignment (PA) tool in the app.   The app plate solves the sky using your main imaging camera.   Then it commands the mount to rotate and repeats the plate solving process.  Once it is done, the app will tell you where Polaris.   By manually adjusting the altitude and azimuth adjustment bolts and/or knobs, you can reach polar alignment.   Never been easier to polar align.

Now that my equipment is setup, I am ready for the exciting part - observing and imaging the night sky.     It takes some time to get used to this process.    You may have challenges along the way.  I know I did!    Have patience.   With repeated practice, it will get easier.

I hope this episode was helpful.   If your interested in learning more about astronomy and astrophotography, be sure to subscribe to my YouTube channel.   Be sure to check out my video on this very topic.

Also, if your like me, there are no telescopes stores my area, not even in my state.  I purchase all my astronomy gear and solar viewing gear from High Point Scientific.   They have a huge inventory of astrophotography cameras, solar telescopes, solar eclipse viewing glasses, and more.    By using the High Point Scientific link below in the description, you can help this  channel.   Thank you for your support.

High Point Scientific
https://www.highpointscientific.com/?rfsn=7755489.66ed8e

 "Astronomy compels the soul to look upwards and leads us from this world to another".   Until next time, take care.

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