DENVER MUSEUM OF NATURE AND SCIENCE

Lunt Solar Telescopes

Training Manual

DMNS Telescope Team

6/10/2015

Introduction

This guide is designed for you to use as a reference in conjunction with your training on

these telescopes. Please strive to keep a watchful eye on the telescope(s) at all times.

These telescopes are wonderful, expensive (approximately $4000/each) and delicate

instruments. Following the steps below will help ensure that everyone can enjoy using

these amazing instruments for years to come. If you have any questions about these

instructions or the use of the Lunt telescopes, ask any of the telescope team members.

Thank you for being a part of the telescope team at DMNS!

Equipment Descriptions

Lunt LS100THa H-alpha Solar Telescope

The Lunt Solar Systems LS100THa is a 100mm aperture, dedicated hydrogen-alpha solar

telescope. This is a high precision refractor-based system that allows for fully corrected

clear, crisp, flat-field images of the sun. The focal length is 714 mm, for an f/ratio of 7.

Course focus adjustment is via a slide tube. More fine-tuned focusing is achieved with a

high precision 2″ Starlight Feather Touch focuser with 10:1 reduction. Inside the

telescope is an energy rejection filter (ERF) and etalon which make the telescope safe for

solar viewing. The ERF removes unwanted heat and UV light from the system. The

etalon is adjustable and allows for a <0.7 Angstrom bandpass. This means that the

wavelength of light we observe through the telescope can be adjusted to bring out

different features on the sun, such as surface detail or prominences. The tuning is

achieved with a “pressure tuner” located on the side of the telescope. This controls the air

pressure inside of the etalon in the telescope. Varying the air pressure changes the

refractive index, and thus moves the wavelength of light you see slightly to the blue or

red, allowing you to see different features in greater detail. True Doppler Tuning allows

for a shift into and away from the user, adding a 3-D like component to the viewing

experience. While it has minimal effect on prominences due to their location at the edge

of the disk, it does have an effect on filaments and active regions on the surface. While

looking at a filament at the center of the Sun, the user has the ability to Doppler shift

from the base of the filament to the tip, following the filament through its structure

toward you and away from you, allowing for enhanced visual and imaging capability for

the observer. The pressure tuning system provides an order of magnitude more precision

to the tuning of the desired features.

Lunt ED Doublet Optical Tube Assembly (White Light Telescope)

We use this 102 mm aperture telescope primarily for white light solar viewing but it can

also be used for night sky work with the addition of the proper accessories. This telescope

utilizes a white light solar wedge to make viewing the sun safe, see below.

Lunt White Light Wedge Information

For solar white light imaging and white light visual observing using the 102 mm

telescope, we’ve installed the 2” Lunt White Light Herschel Wedge which comes with a

built in ND3 filter which allows perfectly safe imaging or visual observing of the Sun.

Herschel wedges work by refracting most of the light out of the optical path, allowing for

safe visual observation. The Neutral Density filter further darkens the image. For more

comfortable visual observing, we’ve dimmed the image with a Polarizing Filter. You can

adjust the brightness to your comfort by rotating the eyepiece.

Initial Set-up Instructions

1. Place the three telescope signs, table, ladder and a chair or two in the Sky Terrace

viewing area. The eyepiece storage case should be on one of the roller tables along with

the handbook and business cards with solar web sites. When setting up, please move the

peripheral equipment before the telescope(s).

2. Plug-in a fresh battery to the controller(s) from the battery charger station located in the

storage cage (see Fig. 7 thru 11) every time you start a session. To increase the lifespan

of these batteries, please keep them as shaded as possible both while in use, and when

being stored. This should help to prevent overheating, which may contribute to rapid

battery drain. Please monitor battery power by looking at the light in the center of the

hand controller (see Fig. 3) to make sure you have enough power to ensure accurate

tracking.

3. Before leaving the storage area, make sure to disengage the telescope mount clutches by

turning them counter-clockwise (see Fig. 4). This will prevent stripping of the worm

gears during movement.

4. When bringing the telescope(s) out of the storage area, use caution when going over any

bumps as the tube may sway because the weights only counter-act movement along one

axis.

5. Facilitate only as many telescopes as you’re comfortable handling. So if you just want to

use one telescope, that’s fine. Better to be more cautious than to risk equipment damage

or being stressed out.

Aligning the Telescopes

1. Align the telescopes pointing north (see Fig. 1). To orient the telescope to North, point

the shaft six tiles down and one over. We call this the “six tile method.” Figure 2 shows

the telescope properly aligned using this method.

2. Figure 3 shows the controller. Push the slider from 0 to N which tells the tracker the

telescopes are being used in the northern hemisphere. Make sure that the middle slider is

set to the image of the sun (top image). This will ensure the telescope tracks at the proper

speed to keep the sun centered. The 0.5X, 2X and 16X speeds allow you to center the sun

in the eyepiece. Keep in mind, however, that this feature uses more power than just

tracking and will drain the batteries more quickly.

3. Loosen the clutches by turning them counter-clockwise (one of which is shown in Fig. 4).

Then, using the shadow cast by the telescope tube, point the telescopes at the sun. To get

a rough alignment, try to get the shadow of the telescope as small as possible. Then look

at the sun spotter (“Sol Searcher” in Figure 5) When you see the sun cast onto the sun

spotter, tighten the clutches by turning them clockwise (Fig. 4). Make sure that the

clutches are locked snugly, or tracking will not be accurate. There is a different style of

sun spotter to fine tune the centering activity.

4. Once the telescope is aligned properly, engage the telescope cart caster brakes by

pressing down with your foot on the silver tab located just above the caster wheel.

5. Using the 40mm eyepiece will make it easier to find the sun in the eyepiece. After

centering, you can switch to a higher-powered eyepiece based on your preference.

NOTE: The white light telescope image is very bright, so use the moon filter to make it

easier on your eyes. Just screw it in and out of your eyepiece of choice as well as the

40mm when centering the sun (see Figure 6)

Facilitation Suggestions

Whether you’re using one or two telescopes, it’s a good idea to instruct visitors to form a

line several feet away from the telescopes to avoid crowding.

It is advisable to use two operators when facilitating both Lunt telescopes. It is possible

with one operator if care is taken to control the lines by instructing each visitor when they

can approach each telescope. If you’re by yourself, feel free to use only one telescope if

that’s more comfortable for you.

Before allowing guests to approach the telescope, please explain what they are about to

see and the differences in each telescope.

Let each person know when you want them to approach the telescope(s). Explain that this

is for their protection as well as to protect the equipment.

Instruct guests to use the “cover one eye and shade the other” method and ask them to

make every effort to not touch the telescope or the eyepiece.

Monitor and check the eyepiece view often to ensure the image is centered.

And last but not least, have fun!

Storing the Equipment

1. Turn off the power on the controller(s).

2. Remove the eyepieces, put the eyepiece caps and lens caps on.

3. Put on the front cover and back cover of telescope.

4. Loosen telescope clutches and move telescopes to rest position.

5. Release brake on telescope cart casters. (Instructions continue on next page...)

6. Move the telescope(s) into the storage cage. If necessary, let any guests in the area know

what you’re doing. Be careful of the telescopes while moving them to ensure that they do

not bump into anything or move inappropriately.

7. Double-check that you have turned-off the power on the controller(s).

8. Unplug and remove the battery pack and plug it into the charging unit.

9. Store all signage, tables, stools etc. after telescope(s) is stowed securely as shown in

Figure 12.

Cleaning Eyepieces:

It is very important not the drag any dirt or debris across the surface of the eyepiece

because it might scratch the lens. So, first use compressed air (stored with the telescopes)

to blow off any dirt, dust or debris. Next moisten the lens with the moisture from your

breath. Use a Q-Tip and gently circle from the middle to the edges. Only use one side of a

Q-Tip once to minimize dragging debris and scratching the lens. Repeat as necessary.

For really stubborn debris, apply a small amount of cleaning fluid to the Q-Tip and gently

wipe in circles from the inside out. Then, use the moisture from your breath and a clean

Q-Tip to clean the surface one more time.

Thanks for reviewing these instructions and have fun facilitating telescopes at DMNS!

Questions? Let us know…

Naomi Pequette: Naomi.Pequette@dmns.org

Dave Martinez: galaxy_guide@comcast.net

Dan Neafus: Dan.Neafus@dmns.org

Dr. Dimitri Klebe: Dimitri.Klebe@dmns.org

Dave Blumenstock: Dave.Blumenstock@dmns.org

See the following pages for illustrations…

Figure 1 showing the “six-tile alignment” method.

Figure 2 shows telescope aligned properly.

Figure 3 showing the controller turned on. Note the indicator light in the center will

glow red when powered on.

Figure 4 shows one of the clutches.

Figure 5 showing the Sol-Searcher used in aligning the telescope.

Figure 6 showing the two filters in the correct order needed for the white light

telescope to dim the image of the sun.

Figure 7 showing the battery charging station in the storage cage.

Figure 8 shows a battery pack plugged into the charger. The white-colored plug

connects it to the charger. The silver-colored plug will go to the controller.

Figure 9 showing the where to plug in the battery pack to the hand controller

Figure 10 shows how to insert the battery pack into the pouch.

Figure 11 showing the battery pouch on the telescope after plugging the battery

pack into the controller.

Figure 12 illustrates how equipment should be stored after use.