Using the Ground Telescopes

You can find the manual for the Celestron Nexstar 8 GPS with some simple googling. It is practically identical to the 11 version. Although it is a discontinued model and could be difficult to find in the future.

These instructions are for general use during public nights at the observatory (assuming it is already dark; you may have to wait some time for a public night), but these scopes have been used for astrophotography by Dylan Mankel, Joey Seitz, and Megan Davis (Class of 2019) to great success. If you have any questions that are not covered by these instructions, feel free to reach out to them! We made at least one dew shield out of foam from Michaels (?) that works perfectly, and the plastic screws and rubber o-rings that held the finder scope in place were replaced with metal screws and new o-rings from Ace Hardware. Be careful not to tighten too much with the metal screws, as the pressure may break the metal bracket that they are in (has happened before).

## General Operation

1) Use an extension cord to plug in the telescope with the DC power block (you may also use a battery pack that can be strapped to one of the legs of the telescope. They can plug in using the appropriate cords that came with them)

2) Align the guide scope with the main telescope. This can be done by pointing the telescope to an object far away and centering it in the eyepiece. The telescope slews using the arrow buttons; **If the telescope is moving slow, you can adjust it by pressing RATE then an appropriate number i.e. 1 is the slowest and 10 is the fastest.** Focus the target using the knob directly adjacent to the eyepiece. Then, using the three screws, maneuver the guide scope such that the cross bar is centered on said object. **THIS STEP IS CRUCIAL FOR 2-STAR ALIGNMENT.**

3) **Follow the instructions displayed on the control paddle to begin 2-Star Alignment** (I believe you press ENTER or ALIGN, but it should be very obvious as it is the first thing to pop up). The telescope should begin moving as it aligns itself by GPS.

*NOTE: If the telescope does not stop facing North or close to it, see the instructions for how to fix that below. You may have the same issues if it points downwards at any point during this initial alignment.*

 4) Upon successful alignment towards North (usually points a little left of North, but results may vary), it will display the time and date. Make sure this is correct. (this is what causes the issues stated above)

5) After a few seconds after it has aligned by GPS, The telescope will then start slewing to the first guide star. If you are unsure of the stars location, scroll through the list of stars by pressing the UNDO button until you find one that you know of. (again, if it faces downward i.e. a star below the horizon, then you will have to fix it using the steps below).

6) Once the telescope has come to a stop, center the star in the finder scope using the cross bar as a guide. Then press ENTER.

7) Then, center the star in the eyepiece, and press ALIGN. This does not have to be perfect. **If your stars look like donuts, then it's out of focus. Adjust the focus using the knob directly adjacent to the eyepiece.**

8) Repeat steps 5-7 for the second star. Generally, you can pick two stars that are relatively close to each other in the sky, but you will have better results if you pick two stars that are far apart.

9) The control paddle should say ALIGNMENT SUCCESSFUL. If it does not, turn off and back on and restart the procedure. This will happen if there is a large gap of time between aligning your first and second guide stars.

You can navigate some of the menus to try and find a target, or you can enter in a target by it's Messier or NGC number (useful for public nights), or it's RA and Dec

## Good Targets to use for Public Nights (time and location vary)

Here is a list of good targets to look at for public nights:

Alberio - double star - 19h 30m 43.3s, +27 57' 38.8"

M13 - "the Great Globular Cluster in Hercules" - globular cluster

M17 - "the Omega Nebula" - HII region in Sagittarius

M42 - "the Orion Nebula" - star forming region (really bright!)

M27 - "the Dumbell Nebula" - planetary nebula (first planetary nebula discovered)

M11 - "the Wild Duck Cluster" - open cluster

M33 - "Triangulum Galaxy" - spiral galaxy (haven't tried it myself, but should be bright enough)

M45 - "Pleiades" - open cluster

M44 - "Beehive cluster" - open cluster

M22 - "Sagittarius Cluster" - globular cluster

M4 - "" - globular cluster

M8 - "Lagoon Nebula" - Nebula with cluster (on the edge of what were able to see)

M5 - globular cluster

Feel free to add to this list, or when they're usually up in the sky. Depending on the object, I wouldn't go much dimmer than 6 magnitude. You can stretch that if it's a star cluster, but it may be hard for visitors to make it out with their untrained eyes. (I've had people struggle with M13, 5.8 magnitude, and it's in the top 10 for brightest globular clusters in the Milky Way, just to put that into perspective).

## Troubleshooting

The Main Issue with Aligning:

1) So from my experience (have not tested this theory), when you shut of the telescope while it is still tracking, it might not know that you've shut it off. Therefore, the next time you turn it back on, the date and time and even location may be completely wrong. To fix this, go to MENU and look through the options (maybe UTILITIES or SCOPE SETUP) and find FACTORY RESET. Press enter and follow the instructions. Then go to SCOPE SETUP and go to something like SET TIME AND LOCATION. Enter in the time, date, indicate the time zone and whether or not it's daylight savings. Then enter the location of 42o 42' 23" N and 05h 37m 56s W for the MSU observatory (it's been a while, but that should be the correct stuff you need). You may need to turn it off then back on again, but after that go back to the first screen by pressing UNDO then try aligning again. It should display the correct time, but if it's off you can press either UNDO or ENTER (it will tell you) to redo it. It could be the daylight savings stuff.

2) Another issue that comes up is the telescope won't move in either the Alt or Az directions. This is an easy fix, as one of the locks is open, allowing for free movement by hand. They can be found on the top of the telescope (metal lever) and underneath the motor carriage (sorta where the telescope plugs in with the DC adapter). Make sure these are both secure so that the telescope cannot be moved by pushing it around.