Celestron Travel Scope 70 (21035), Travel Scope 50 (21038) - Telescope Manual

INTRODUCTION

The Travel Scope is made of the highest quality materials to ensure stability and durability All this adds up to a telescope that gives you a lifetime of pleasure with a minimal amount of maintenance
This telescope was designed with traveling in mind offering exceptional value The Travel Scope features a compact and portable design with ample optical performance Your Travel Scope is ideal for terrestrial as well as very casual astronomical observation
The Travel Scope carries a two year limited warranty For details see our website at www.celestron.com
Some of the standard features of the Travel Scope include:

Take time to read through this manual before embarking on your journey through the Universe It may take a few observing sessions to become familiar with your telescope, so you should keep this manual handy until you have fully mastered your telescope's operation The manual gives detailed information regarding each step as well as needed reference material and helpful hints to make your observing experience simple and pleasurable as possible
Your telescope is designed to give you years of fun and rewarding observations However, there are a few things to consider before using your telescope that will ensure your safety and protect your equipment

SOLAR WARNING

WHAT'S IN THE BOX

We recommend saving your telescope box so it can be used to store the telescope when it is not in use Unpack the box carefully as some parts are small Use the parts list below to verify that all parts and accessories are present

PARTS LIST

ASSEMBLING YOUR TELESCOPE

This section covers the assembly instructions for your Travel Scope Your telescope should be set up indoor the first time so that it is easy to identify the various parts and familiarize yourself with the correct assembly procedure before attempting it outdoor
The Travel Scope 70 comes in one box
The pieces in the box are – telescope optical tube, tripod, erect image diagonal, 20 mm eyepiece, 10mm eyepiece, 5x24 finderscope with bracket (all packed in the travel backpack) and a bonus Astronomy software download
The Travel Scope 50 comes in one box All items the same as above except it has a 2x20 finderscope and 8 mm eyepiece (instead of 10 mm) In addition, the Travel Scope 50 includes a 3x Barlow Lens – 1 25"

SETTING UP THE TRIPOD

ATTACHING THE TELESCOPE TUBE TO THE TRIPOD

The telescope optical tube attaches to the tripod by using the mounting bracket on the bottom of the optical tube and the mounting platform of the tripod Before starting make sure all of the knobs on the tripod are locked.

MOVING THE TRAVEL SCOPE MANUALLY

The Travel Scope is easy to move wherever you want to point it The up and down (altitude) is controlled by the Pan Handle Control Knob (figure 1) The side-to-side (azimuth) is controlled by the Azimuth Locking Knob (top left knob in Figure 7) Both knobs are loosened when turned counterclockwise and tightened when turned clockwise When both knobs are loose you can find your objects easily (through the finderscope which is discussed shortly) and then lock the controls

INSTALLING THE DIAGONAL AND EYEPIECE

The diagonal is a prism that diverts the light at a right angle to the light path of the telescope This allows you to observe in a position that is more comfortable than if you had to look straight through The Travel Scope diagonal is an erect image model that corrects the image to be right side up and oriented correctly left-to-right which is much easier to use for terrestrial observing Also, the diagonal can be rotated to any position which is most favorable for you To install the diagonal and eyepiece:

INSTALLING THE FINDERSCOPE (TRAVEL SCOPE 70 ONLY)

ALIGNING THE FINDERSCOPE

TELESCOPE BASICS

FOCUSING

To focus your Travel Scope turn the focus knob located near the rear of the telescope (see Figure 1) Turning the knob counterclockwise allows you to focus on an object that is farther than the one you are currently observing Turning the knob clockwise from you allows you to focus on an object closer than the one you are currently observing
Note: Remove the front lens cap of the Travel Scope optical tube prior to attempting your observation
Note: If you wear corrective lenses (specifically glasses), you may want to remove them when observing with an eyepiece attached to the telescope If you have astigmatism, corrective lenses should be worn at all times

CALCULATING MAGNIFICATION

You can change the power of your telescope just by changing the eyepiece (ocular) To determine the magnification of your telescope, simply divide the focal length of the telescope by the focal length of the eyepiece used In equation format, the formula looks like this:

Let's say, for example, you are using the 20mm eyepiece that came with your Travel Scope 70 telescope To determine the magnification you divide the focal length of your telescope (the Travel Scope for this example has a focal length of 400mm) by the focal length of the eyepiece, 20mm Dividing 400 by 20 yields a magnification of 20x
Although the power is variable, every telescope under average skies has a limit to the highest useful magnification The general rule is that 60 power can be used for every inch of aperture For example, the Travel Scope 70 is 2 8" inches in diameter Multiplying 2 8 by 60 gives a maximum useful magnification of 168 power Although this is the maximum useful magnification, most of your observing will be done at low powers which generate brighter and sharper images
Note on Using High Powers– Higher powers are used mainly for lunar and sometimes planetary observing where you can greatly enlarge the image, but remember that the contrast and brightness will be very low due to the high magnification When using the 8mm eyepiece together with the 3x Barlow lens with the Travel Scope 50 gives extremely high power and can be used on rare occasions – you will achieve the power but the image will be dark with low contrast because you have magnified it to the maximum possible For the brightest images with the highest contrast levels, use lower powers
You can purchase optional eyepieces to give you a range of powers you can observe with Visit the Celestron website to see what is available

INSTALLING AND USING THE BARLOW LENS (TRAVEL SCOPE 50 ONLY)

Your telescope also comes with a 3x Barlow Lens which triples the magnifying power of each eyepiece However, the greatly magnified images should only be used under ideal conditions – see the Calculating Magnification section of this manual To use the Barlow lens remove the diagonal and insert the Barlow directly into the focuser tube You then insert an eyepiece into the Barlow lens for viewing
Note: Start by using a low power eyepiece as it will be easier to focus

DETERMINING FIELD OF VIEW

Determining the field of view is important if you want to get an idea of the angular size of the object you are observing To calculate the actual field of view, divide the apparent field of the eyepiece (supplied by the eyepiece manufacturer) by the magnification In equation format, the formula looks like this:

As you can see, before determining the field of view, you must calculate the magnification Using the example in the previous section, we can determine the field of view using the same 20 mm eyepiece that is supplied standard with the Travel Scope 70 The 20 mm eyepiece has an apparent field of view of 50° Divide the 50° by the magnification, which is 20 power This yields an actual (true) field of 2 5°
To convert degrees to feet at 1,000 yards (which is more useful for terrestrial observing) multiply by 52 5 Multiply the angular field of 2 5° by 52 5 This produces a linear field width of 131 feet at a distance of one thousand yards

GENERAL OBSERVING HINTS

When using any optical instrument, there are a few things to remember to ensure you get the best possible image

Note: Your telescope was designed for terrestrial observation Knowing how to use it for this purpose has been described already as it is quite simple and straightforward Your telescope can also be used for casual astronomical observing which will be discussed in the next sections

ASTRONOMY BASICS

Up to this point, this manual covered the assembly and basic operation of your telescope However, to understand your telescope more thoroughly, you need to know a little about the night sky This section deals with observational astronomy in general and includes information on the night sky

THE CELESTIAL COORDINATE SYSTEM

To help find objects in the sky, astronomers use a celestial coordinate system that is similar to our geographical coordinate system here on Earth The celestial coordinate system has poles, lines of longitude and latitude, and an equator For the most part, these remain fixed against the background stars
The celestial equator runs 360 degrees around the Earth and separates the northern celestial hemisphere from the southern Like the Earth's equator, it bears a reading of zero degrees On Earth this would be latitude However, in the sky this is referred to as declination, or DEC for short Lines of declination are named for their angular distance above and below the celestial equator The lines are broken down into degrees, minutes of arc, and seconds of arc Declination readings south of the equator carry a minus sign (-) in front of the coordinate and those north of the celestial equator are either blank (i e, no designation) or preceded by a plus sign (+)
The celestial equivalent of longitude is called Right Ascension or R A for short Like the Earth's lines of longitude, they run from pole to pole and are evenly spaced 15 degrees apart Although the longitude lines are separated by an angular distance, they are also a measure of time Each line of longitude is one hour apart from the next Since the Earth rotates once every 24 hours, there are 24 lines total As a result, the R A coordinates are marked off in units of time It begins with an arbitrary point in the constellation of Pisces designated as 0 hours, 0 minutes, 0 seconds All other points are designated by how far (i e, how long) they lag behind this coordinate after it passes overhead moving toward the west

MOTION OF THE STARS

The daily motion of the Sun across the sky is familiar to even the most casual observer This daily trek is not the Sun moving as early astronomers thought, but the result of the Earth's rotation The Earth's rotation also causes the stars to do the same, scribing out a large circle as the Earth completes one rotation The size of the circular path a star follows depends on where it is in the sky Stars near the celestial equator form the largest circles rising in the east and setting in the west Moving toward the north celestial pole, the point around which the stars in the northern hemisphere appear to rotate, these circles become smaller Stars in the mid-celestial latitudes rise in the northeast and set in the northwest Stars at high celestial latitudes are always above the horizon, and are said to be circumpolar because they never rise and never set You will never see the stars complete one circle because the sunlight during the day washes out the starlight However, part of this circular motion of stars in this region of the sky can be seen by setting up a camera on a tripod and opening the shutter for a couple hours The timed exposure will reveal semicircles that revolve around the pole (This description of stellar motions also applies to the southern hemisphere except all stars south of the celestial equator move around the south celestial pole )

All stars appear to rotate around the celestial poles. However, the appearance of this motion varies depending on where you are looking in the sky. Near the north celestial pole the stars scribe out recognizable circles centered on the pole (1). Stars near the celestial equator also follow circular paths around the pole. But, the complete path is interrupted by the horizon. These appear to rise in the east and set in the west (2). Looking toward the opposite pole, stars curve or arc in the opposite direction scribing a circle around the opposite pole (3).

CELESTIAL OBSERVING

With your telescope set up, you are ready to use it for observing This section covers visual observing hints for solar system and deep sky objects as well as general observing conditions which will affect your ability to observe

OBSERVING THE MOON

With your telescope set up, you are ready to use it for observing This section covers visual observing hints for solar system and deep sky objects as well as general observing conditions which will affect your ability to observe
Often, it is tempting to look at the Moon when it is full At this time, the face we see is fully illuminated and its light can be overpowering In addition, little or no contrast can be seen during this phase One of the best times to observe the Moon is during its partial phases (around the time of first or third quarter) Long shadows reveal a great amount of detail on the lunar surface At low power you will be able to see most of the lunar disk at one time Change to optional eyepieces for higher power (magnification) to focus in on a smaller area

Lunar Observing Hints
To increase contrast and bring out detail on the lunar surface, use optional filters A yellow filter works well at improving contrast while a neutral density or polarizing filter will reduce overall surface brightness and glare

OBSERVING THE PLANETS

Other fascinating targets include the five naked eye planets You can see Venus go through its lunar-like phases Mars can reveal a host of surface detail and one, if not both, of its polar caps You may be able to see the cloud belts of Jupiter and the great Red Spot (if it is visible at the time you are observing) In addition, you will also be able to see the moons of Jupiter as they orbit the giant planet Saturn, with its beautiful rings, is e visible at moderate power

Planetary Observing Hints

OBSERVING THE SUN

Although overlooked by many amateur astronomers, solar observation is both rewarding and fun However, because the Sun is so bright, special precautions must be taken when observing our star so as not to damage your eyes or your telescope
For safe solar viewing, use a proper solar filter that reduces the intensity of the Sun's light, making it safe to view With a filter you can see sunspots as they move across the solar disk and faculae, which are bright patches seen near the Sun's edge

OBSERVING DEEP-SKY OBJECTS

Deep-sky objects are simply those objects outside the boundaries of our solar system They include star clusters, planetary nebulae, diffuse nebulae, double stars and other galaxies outside our own Milky Way Most deep-sky objects have a large angular size Therefore, low-to-moderate power is all you need to see them Visually, they are too faint to reveal any of the color seen in long exposure photographs Instead, they appear black and white And, because of their low surface brightness, they should be observed from a dark-sky location Light pollution around large urban areas washes out most nebulae making them difficult, if not impossible, to observe Light Pollution Reduction filters help reduce the background sky brightness, thus increasing contrast

Star Hopping
One convenient way to find deep-sky objects is by star hopping Star hopping is done by using bright stars to "guide" you to an object For successful star hopping, it is helpful to know the field of view of you telescope If you're using the standard 20 mm eyepiece with the Travel Scope 70, your field of view is approximately 2 5º or so If you know an object is 3º away from your present location, then you just need to move a little more than one field of view If you're using another eyepiece, then consult the section on determining field of view Listed below are directions for locating two popular objects The Andromeda Galaxy (Figure 16), also known as M31, is an easy target To find M3:

1. Locate the constellation of Pegasus, a large square visible in the fall (in the eastern sky, moving toward the point overhead) and winter months (overhead, moving toward the west)
2. Start at the star in the northeast corner—Alpha (α ) Andromedae
3. Move northeast approximately 7° There you will find two stars of equal brightness—Delta (δ) and Pi (π) Andromeda—about 3° apart
4. Continue in the same direction another 8° There you will find two stars—Beta (β) and Mu (μ) Andromedae —also about 3° apart
5. Move 3° northwest—the same distance between the two stars—to the Andromeda galaxy
   Star hopping to the Andromeda Galaxy (M31) is a snap, since all the stars needed to do so are visible to the naked eye

Star hopping will take some getting used to and objects that don't have stars near them that are visible to the naked eye are challenging One such object is M57 (Figure 17), the famed Ring Nebula Here's how to find it:

These two examples should give you an idea of how to star hop to deep-sky objects To use this method on other objects, consult a star atlas, then star hop to the object of your choice using "naked eye" stars

SEEING CONDITIONS

Viewing conditions affect what you can see through your telescope during an observing session Conditions include transparency, sky illumination, and seeing Understanding viewing conditions and the effect they have on observing will help you get the most out of your telescope

Transparency
Transparency is the clarity of the atmosphere which is affected by clouds, moisture, and other airborne particles Thick cumulus clouds are completely opaque while cirrus can be thin, allowing the light from the brightest stars through Hazy skies absorb more light than clear skies making fainter objects harder to see and reducing contrast on brighter objects Aerosols ejected into the upper atmosphere from volcanic eruptions also affect transparency Ideal conditions are when the night sky is inky black

Sky Illumination
General sky brightening caused by the Moon, aurorae, natural airglow, and light pollution greatly affect transparency While not a problem for the brighter stars and planets, bright skies reduce the contrast of extended nebulae making them difficult, if not impossible to see To maximize your observing, limit deep sky viewing to moonless nights far from the light polluted skies found around major urban areas LPR filters enhance deep sky viewing from light polluted areas by blocking unwanted light while transmitting light from certain deep sky objects You can, on the other hand, observe planets and stars from light polluted areas or when the Moon is out

Seeing
Seeing conditions refers to the stability of the atmosphere and directly affects the amount of fine detail seen in extended objects The air in our atmosphere acts as a lens which bends and distorts incoming light rays The amount of bending depends on air density Varying temperature layers have different densities and, therefore, bend light differently Light rays from the same object arrive slightly displaced creating an imperfect or smeared image These atmospheric disturbances vary from time-to-time and place-to-place The size of the air parcels compared to your aperture determines the "seeing" quality Under good seeing conditions, fine detail is visible on the brighter planets like Jupiter and Mars, and stars are pinpoint images Under poor seeing conditions, images are blurred and stars appear as blobs
The conditions described here apply to both visual and photographic observations

Seeing conditions directly affect image quality. These drawings represent a point source (i.e., star) under bad seeing conditions (left) to excellent conditions (right). Most often, seeing conditions produce images that lie some where between these two extremes.

TELESCOPE MAINTENANCE

While your telescope requires little maintenance, there are a few things to remember that will ensure your telescope performs at its best

CARE AND CLEANING OF THE OPTICS

Occasionally, dust and/or moisture may build up on the objective lens of your telescope Special care should be taken when cleaning any instrument so as not to damage the optics
If dust has built up on the optics, remove it with a brush (made of camel's hair) or a can of pressurized air Spray at an angle to the glass surface for approximately two to four seconds Then, use an optical cleaning solution and white tissue paper to remove any remaining debris Apply the solution to the tissue and then apply the tissue paper to the optics Low pressure strokes should go from the center of the lens (or mirror) to the outer portion Do NOT rub in circles!
You can use a commercially made lens cleaner or mix your own A good cleaning solution is isopropyl alcohol mixed with distilled water The solution should be 60% isopropyl alcohol and 40% distilled water Or, liquid dish soap diluted with water (a couple of drops per one quart of water) can be used
Occasionally, you may experience dew build-up on the optics of your telescope during an observing session If you want to continue observing, the dew must be removed, either with a hair dryer (on low setting) or by pointing the telescope at the ground until the dew has evaporated
If moisture condenses on the inside of the optics, remove the accessories from the telescope Place the telescope in a dustfree environment and point it down This will remove the moisture from the telescope tube
To minimize the need to clean your telescope, replace all lens covers once you have finished using it Since the cells are NOT sealed, the covers should be placed over the openings when not in use This will prevent contaminants from entering the optical tube
Internal adjustments and cleaning should be done only by the Celestron repair department If your telescope is in need of internal cleaning, please call the factory for a return authorization number and price quote

Note: Specifications are subject to change without notice or obligation