Argo Navis User Manual

Figure 1 (Argo Navis^TM Model 102B shown)

This section describes the various interfaces of the Argo Navis^TM.

Types of interface

The Argo Navis^TM has 3 interfaces:

the user interface;
the encoder interface;
the serial interface.

Each type of interface is described below.

The user interface

The user interface is the front panel and consists of five elements as shown in Figure 1.

the ON/OFF switch;
the liquid crystal display (LCD));
the DIAL;
the ENTER button;
the EXIT button.

The ON/OFF switch is located at the top, left-hand of the front panel - ON is marked with “I”; OFF is marked with “O”.

The LCD is the horizontal window located near the top of the front panel. When the power is off the LCD will appear to be a blue colour. When the power is on the display will appear to be a red colour. Argo Navis^TM uses a red display because this colour is less likely to impact upon your night vision, which is important when you want to view faint celestial objects. The brightness of the display can also be altered to suit your current viewing conditions (see page setup brightness).

“Firmware” is the term used to describe the software in an electronic appliance. The Argo Navis^TM firmware is organized as a set of menus which you can navigate by using the DIAL and the ENTER and EXIT buttons.

The DIAL is located in the centre of the front panel. It is used to scroll through the menus, to alter an item within a menu and to manually scroll long text messages. The DIAL has what are known as “detent clicks” (see Glossary). Sometimes you will need to move the DIAL one detent “click” at a time.

The ENTER button is located on the right-hand side of the front panel. It is used to enter a particular menu you have selected with the DIAL and to select a particular item within a menu.

The EXIT button is located on the left-hand side of the front panel. It is used to exit from menu selections.

The encoder interface

Figure 2 (Argo Navis^TM Model 102B shown)

The encoder interface is the receptacle found on top of the unit and marked by the label “ENCODERS”. See Figure 2. If you study your encoder cable, you will find one end has an 8-way RJ-45 plug from which two 4-way cables split. Insert this plug into the encoder interface receptacle.

If you have an encoder cable assembly supplied by Wildcard Innovations, the 4-way cable that has a white sleeve near the encoder end will go to the Altitude axis encoder. The other 4-way cable will go to the Azimuth axis encoder.

The Argo Navis^TM Digital Telescope Computer (DTC) encoder interface was designed to be pin and electrically compatible with that used on the older JMI NGC-MAX^TM, Celestron Advanced Astromaster^TM, Lumicom Sky Vector^TM, SkyComm Engineering Sky Commander^TM and similar Digital Setting Circle (DSC) units. Therefore, if you are upgrading to an Argo Navis^TM from one of these older units, you can retain your existing encoders and cable. Note, however, that the Argo Navis^TM supports a higher encoder sampling rate than these older units and therefore will reliably support higher resolution encoders. Though Argo Navis^TM will work with lower resolution encoders, Wildcard Innovations recommends that you consider upgrading to 10,000 step encoders if you would like to achieve potentially finer pointing accuracy.

The serial interface

Argo Navis^TM has two RS-232 serial ports on top of the unit marked SERIAL1 and SERIAL2. See Figure 2. Argo Navis^TM can be used completely standalone. However, it is also possible to interface it to a PC, Macintosh^TM or Linux computer assuming your PC/Mac has an RS-232 serial port or a USB port.

To interface to a computer with an RS-232 serial port use the Argo Navis^TM serial port cable (Wildcard Innovations Part No. pn-ser-cbl).

If your PC/Mac does not have a RS-232 serial port but is equipped with a USB port, Wildcard Innovations have available a USB to RS-232 Serial Port Adaptor (Wildcard Innovations Part No. pn-usb) which works in conjunction with the optional RS-232 serial cable (pn-ser-cbl).

By communicating with your PC/Mac, you can perform the following tasks:

Download firmware & in-built catalog upgrades to the unit. See the page on Transferring firmware files for details.
Download asteroid, comet and satellite orbital elements. See the page on Where to obtain Asteroid, Comet or Satellite Orbital Element Files for details.
Download your own user objects. See the page on How to create your own User catalog files for details.
Save and restore your Argo Navis^TM setups.
Communicate with all known popular star charting, planning & ephemeris programs such as Sky Safari^TM, Star-Atlas PRO^TM, The Sky^TM, SkyMap Pro^TM, Astroplanner™, Deepsky™, KStars™, Starry Night Pro™, Cartes du Ciel™, SkyTools™, MegaStar™, SkySafari™, Stellarium™, Xephem^TM, any ASCOM compliant planetarium program and many more, to have a “tracking cursor” display. See the setup serial page for details.

Argo Navis^TM can communicate to an Android™ tablet or iPad™ or to a smartphone/iPhone™ by interfacing the Argo Navis^TM serial port cable (Wildcard Innovations Part No. pn-ser-cbl) to third party serial to WiFi adapters such as the Microchip/Roving Networks RN-340 and RN-370 or third party serial to Bluetooth adapters such as the Microchip/Roving Networks RN-270M. It can then be used with apps such as Sky Safari^TM.

Argo Navis^TM serial ports can be interfaced to ServoCAT™ servo controllers, Starmaster Star Tracker™ GOTO controllers and Sidereal Technology SiTech™ GOTO controllers. In each instance, a special serial cable, distinct from the Argo Navis^TM serial port cable (Wildcard Innovations Part No. pn-ser-cbl), needs to be used. Contact Wildcard Innovations for details as to the correct cable to use.

The two serial ports operate completely independently. Their Baud rates (communications speeds) can be set from the Argo Navis^TM front panel. See the setup serial page.

For all operations, except downloading new firmware, either serial port can be used. For downloading firmware, SERIAL1 is special and is the only port that can be used for this purpose.

WARNING: The pin assignment on the Argo Navis^TM serial ports is not compatible with those of the SkyComm Engineering Sky Commander^TM. However, they are compatible with those on the JMI NGC-MAX^TM, Celestron Advanced Astromaster^TM, Lumicom Sky Vector^TM and similar Digital Setting Circle (DSC) units. (See Port pin descriptions). To avoid possible damage to your Argo Navis^TM or PC, we recommend you use only a genuine Argo Navis^TM optional serial interface cable (Wildcard Innovations Part No. pn-ser-cbl).

WARNING: When interfacing your Argo Navis^TM to a PC, you should be aware of the possibility of electrostatic discharge that could result in damage to your Argo Navis^TM, PC and associated peripherals. Be sure to ground yourself adequately prior to interfacing any two pieces of equipment. Be particularly careful in static prone environments, especially in low humidity conditions or while walking on carpets. Wildcard Innovations bears no liability for loss or damage caused to your equipment from static discharge.

WARNING: It is your responsibility to ensure that any cables connected to your Argo Navis^TM do not pose a hazard to yourself and others. Ensure that it is not possible for yourself or others to trip over your cabling. You should be aware that cabling could be a hazard to persons especially at night-time and when outdoors. Wildcard Innovations bears no liability for loss, damage or injury caused by persons tripping over your cabling.

Figure 3 (Argo Navis^TM Model 102B shown)

This section describes the once-only requirements for setting-up the Argo Navis^TM to suit your scope and your individual requirements. This includes:

setting up the power sources;
setting your initial mount type;
setting your encoder resolution;
setting your encoder senses;

· setting your final mount type;

· setting the local time zone, date and time;

· setting your location;

· enabling refraction modelling;

Power sources

There are two types of power source:

internal battery power; and,

· external battery power.

Internal Battery Power

4 “AA”, 1.5V batteries provide the internal battery power. These should be alkaline, lithium or rechargeable NiMH batteries. Since NiMH batteries have reduced capacity below 20C (68F), their use is not recommended in cool or cold climates. Do not use NiCd or regular/ heavy-duty zinc-oxide batteries.

To install batteries, refer to Figure 3. Using a coin, remove & retain the battery hatch thumbscrew on the battery housing (the raised section at the top of the back) of the Argo Navis^TM. Gently slide the battery cover slightly toward the top of the unit by about 1cm and then lift it off.

To place the batteries in, refer to Figure 4. Observe the polarity indicators inside the battery housing (+ on the battery should be placed at the same end as the + on the markings inside the battery housing). Replace the battery hatch cover and thumbscrew.

· Ensure batteries are removed from the Argo Navis^TM if it is to be stored or not used for prolonged periods in case of battery leakage.

· Do not charge rechargeable batteries whilst in battery housing.

· Do not connect any other form of power supply to battery terminals.

Fresh alkaline batteries with the display fully dimmed can provide from 12 to 40 hours usage of the unit depending on several additional factors including what type of encoders are installed.

External battery power

The optional external DC power cable allows you the convenience to power the Argo Navis^TM from an external battery source such as a 12V car battery. The external power receptacle is found on the top of the unit and is marked DC IN. The external battery voltage should be in the range of 8V to 16V DC. An incorrect power voltage source or polarity could cause damage to your unit and void your warranty. Use only the optional external DC power cable supplied by Wildcard Innovations (Part No. pn-pwr-cbl) for supplying external power to your unit. Though Argo Navis^TM provides in-built reverse polarity and short circuit protection, the optional cable contains a 350mA fuse for additional safety.

WARNING: Never use a cable with an incorrect fuse (we recommend 315mA) and never bypass the fuse protection. Observe all safety procedures when working with external batteries. Many contain dangerous acids that can be spilt and some batteries are capable of delivering very large currents that can destroy equipment or cause a fire if they are short-circuited.

WARNING: Be careful not to trip or allow others to trip over the external power cable or any other cables from your unit.

Figure 4 (Argo Navis^TM Model 102B shown)

Setting the initial mount type

Argo Navis^TM requires you to specify what style of mount your telescope is on.

However, for the purpose of this once-only initial setup procedure, you will be asked to set your mount type to the fork exact align setting, irrespective of what type of mount you really have.

Later, you will be asked to set the mount type to match the type of mount you are using.

Power the unit on. Turn the DIAL clockwise until you see -

MODE SETUP

Press ENTER. Now turn the DIAL clockwise until you see -

SETUP MOUNT

Notice how Argo Navis^TM orders its various menus alphabetically so you can find a particular one logically and quickly.

Now press ENTER. The display might then show -

ALTAZ/DOBSONIAN

where the whole line will be flashing. Spin the DIAL until the display shows –

FORK EXACT ALIGN

Then press EXIT or ENTER. Argo Navis^TM will briefly display the words

SAVING ….

while it saves your settings into its memory (EEROM device) and then display the message –

SETUP MOUNT

Setting encoder steps (resolution)

Before you can perform an alignment, you need to set up in Argo Navis^TMthe resolution and “direction senses” of your altitude and azimuth encoders.

Encoder operation background

Most optical encoders will have a printed label specifying either their part number or their resolution. For example, if you have an encoder marked with the part number S2-2500, this is a 10,000-step encoder (10,000 is 4 times 2500 - this style of encoder is technically known as a Quadrature Encoder).

When an encoder rotates, it transmits electrical pulses or ‘steps’. A 10,000-step encoder will produce 10,000 steps when it is rotated 360°. Therefore, one ‘step’ on such an encoder corresponds to an angle of rotation of about 2.16 arc minutes.

Encoders can be geared to produce a higher or lower number of ‘steps’ when the telescope mount bearing they are attached to rotates through 360°.

In any case, you need to establish how many steps your encoders produce when the bearing they are attached to is rotated through 360°. In many cases, bearings, particularly altitude (declination) bearings, may be incapable of being rotated through a full 360°. Nonetheless, you will still need to establish how many steps the encoder would produce if the bearing could be rotated through a full 360°.

If the shaft of your encoder is attached directly to the axis of rotation of the bearing and is not geared, then the number of steps for that particular encoder is simply its rated number of steps.

Setting altitude steps

Having established how many steps each encoder is, spin the DIAL within the setup menu-level until you see -

SETUP ALT STEPS

Press ENTER and the display might show something like this -

ALT=+0010000

where the ‘+’ sign will be flashing. Leave the sign as a ‘+‘ for now and press ENTER and edit the fields as need be by using the DIAL to change a value and ENTER to advance to the next field. When the correct number of steps is displayed, press either ENTER or EXIT and if the value has changed from what it originally was, Argo Navis^TM will briefly display the words -

SAVING ….

while it saves your settings into its memory (EEROM device) and then display the message –

SETUP ALT STEPS

You have now set your altitude encoder step setting. However, as will be explained later, you may need to come back and change the encoder ‘direction sense’ (the ‘+’ sign or ‘-’ sign) depending upon your circumstances.

Setting azimuth steps

Using the DIAL, go to -

SETUP AZ STEPS

Press ENTER again and the display might show something like this -

AZ=+0010000

SAVING ….

while it saves your settings into its memory (EEROM device) and then display the message –

SETUP AZ STEPS

You have now set your azimuth encoder step setting. However, as will be explained later, you may need to come back and change the encoder ‘direction sense’ (the ‘+’ sign or ‘-’ sign) depending upon your circumstances.

Testing encoder communication

Power Argo Navis^TMoff. Make sure that your encoders are installed on your mount and that your encoder cable is connected both to them and into the ENCODERS port of the Argo Navis^TM. (See Figure 2.)

Power Argo Navis^TMon and use the DIAL to go to -

MODE ENCODER

Press ENTER. The display should show something like this –

AZ/ALT ENC ANGLE

000.00° +000.00°

The display is showing the angle of the azimuth encoder on the bottom left of the display and that of the altitude encoder on the bottom right.

Move the scope in azimuth (Right Ascension). Make sure that the AZ angle on the display changes. Now move the scope in altitude (Declination). Make sure that the ALT angle changes. If the ALT reading changes when you move the scope in azimuth and vice versa, you have the encoder cables swapped around. On most encoder cables supplied by Wildcard Innovations, the cable that has the white sleeve near its encoder end should go to the altitude encoder.

If neither or only one angle changes on the display check that the connections to the encoders are correct, in particular making sure that the plug that connects to the encoder pin header is inserted the right way up. On encoders and cables supplied by Wildcard Innovations, the correct orientation can be ascertained by matching the small circular sticker on the plug with the same type of sticker on top of the encoder (the side opposite that from which the shaft protrudes). Also, ensure that any set-screw holding the encoder shaft in place is firm and is not allowing the encoder shaft to slip. Finally, check the batteries in your Argo Navis^TMand replace them if necessary.

If you are performing the above test without having installed the encoders on your mount and you are simply turning the encoder shafts with your fingers, you may see one of the following messages on the display –

· AZ ENCODER ERROR

· ALT ENCODER ERR

· BOTH ENCODER ERR

This simply means that you have turned the encoders too quickly and have exceeded their sampling rate, thus missing counts. Argo Navis^TMtypically samples the encoders at a very high rate (much higher than older Digital Setting Circle, or ‘DSC’, units) and when the encoders are installed on your mount, you should not see these errors during normal operation. If the encoders are installed on your mount and you do see these errors, check the batteries in Argo Navis^TM and the connections on your encoders. Otherwise see the Troubleshooting guide.

Once you have established that your Argo Navis^TMcan reliably communicate with your encoders, you are ready to proceed.

Determining encoder direction senses

When you were initially setting your encoder resolution with setup alt steps and setup az steps, you were asked to ignore the flashing ‘+’ sign. Using the DIAL, the sign can be made to be either a ‘+’ or a ‘-’. It determines the way that Argo Navis^TM interprets the ‘direction sense’ of the applicable encoder.

Setting the correct direction senses of your encoders is very important. Many factors influence the setting of encoder direction senses. For example, in the case of an altitude encoder, whether it is mounted on the left or right-hand side of the mount and whether it has been geared an even or odd number of times are just two of the factors. The section named Factors affecting encoder direction sense details these. For this reason, determining the correct direction senses of your encoders may not be simply intuitive. Fortunately, you can perform a test with your scope that will tell you what the correct senses are. Once you have patiently worked through the test and have determined the correct settings for the encoders on your mount, you should never need to change them again.

To determine the direction senses of your encoders, follow these instructions.

Power off your Argo Navis^TM, and then power it back on. After it initializes, you should see –

MODE ALIGN STAR

then press ENTER. The display should show something like -

ALIGN ACHERNAR

If your scope is on a Fork Mount, roughly polar align it. Orient the tube so that it is the “way-up” you normally observe, thus –

Figure 5

If your scope is on a German Equatorial Mount (GEM), roughly polar align it. If you are in the Northern Hemisphere, place the tube on the West side of the mount. If you are in the Southern Hemisphere, place the tube on the East side of the mount.

If your scope is on an Alt/Az Mount, such as a Dobsonian, just continue reading. If your Alt/Az mount is mounted on top of an equatorial table, accurately polar align the table, move the table to the start position and switch it off for now.

Look up at the sky and pick a familiar bright star not far from the Celestial Equator (the imaginary line in the sky where Declination = 0°.) Spin the DIAL and look for that star’s name. There are 35 to choose from. The mode align star reference page lists the alignment stars. If you cannot find the star you have chosen in the list, pick another that is in the list that is not too far from the Celestial Equator. For example, say you have chosen Sirius. Spin the DIAL until you
see -

ALIGN SIRIUS

Centre Sirius in the eyepiece, then press ENTER. The display will briefly show something like this –

ALIGN SIRIUS

WARP= +0.00

Now press EXIT and spin the DIAL until the display shows –

MODE RA DEC

then press ENTER. The display should show the approximate Right Ascension and Declination of the last star you aligned on. In the example of Sirius, the display might show something like this -

06:45.3 -16°43’

CANIS MAJOR

While watching the RA reading on the display, rotate the scope slowly in an Easterly direction. The RA value should increase. If instead it decreases, take note of that fact and continue for now.

While watching the Dec reading on the display, rotate the scope slowly in a Northerly direction. The Dec value should increase (a negative Dec value that becomes more and more negative is in fact decreasing). If the Dec value is decreasing, take note of that fact and continue.

If the Right Ascension and Declination directions were consistent with the above procedure, you do not need to alter the setup alt steps or setup az steps direction senses.

If the Right Ascension reading decreased as the scope was moved towards the East, then go back to setup az steps and change the direction sense sign.

If the Declination reading decreased as the scope was moved towards the North, then go back to setup alt steps and change the direction sense sign.

If you changed either or both signs, power the unit off and then on and repeat the procedure to verify that the new encoder direction senses are correct.

Setting the final mount type

During the initial once-only setup procedure, you were asked to set the mount type to fork exact align. You will now need to set your mount type to match your actual mount. If you have a Fork mount that is exactly polar aligned, you obviously do not need to change the setting.

Otherwise, power the unit off, then on. Turn the DIAL clockwise until you see -

MODE SETUP

Press ENTER. Now turn the DIAL clockwise until you see -

SETUP MOUNT

Now press ENTER. The display should show -

FORK EXACT ALIGN

where the whole line will be flashing. Spin the DIAL and select your mount type. The various mount types are tabled below.

Menu selection	When to use	Number of alignment stars required
ALTAZ/DOBSONIAN	For altitude/azimuth mounts such as Dobsonians (but not on equatorial tables);	fix alt ref step plus 2 alignment stars
EQ TABLE EXACT	For altitude/azimuth mounts mounted on top of an accurately polar aligned equatorial table	fix alt ref step plus 2 alignment stars
FORK EXACT ALIGNED	For any accurately aligned equatorial mount, such as a fork mount, but not a German equatorial or an equatorial table.	One alignment star
FORK ROUGH ALIGN	For any roughly aligned equatorial mount, such as a fork mount, but not a German equatorial or an equatorial table.	fix alt ref step plus 2 alignment stars
GEM EXACT ALIGN	For an accurately polar aligned German equatorial.	One alignment star
GEM ROUGH ALIGN	For a roughly aligned German equatorial.	fix alt ref step plus 2 alignment stars

Once you have selected your mount type, press either EXIT or ENTER. Argo Navis^TM will briefly display the words

SAVING ….

while it saves your settings into its memory (EEROM device) and then display the message –

SETUP MOUNT

Setting the local time zone, date and time

Argo Navis^TM contains an in-built battery-backed time of day clock. An internal lithium coin cell battery powers the clock even when the power is switched off or the main batteries are removed.

Though Argo Navis^TM does not require you to set the time or your location to operate, doing so provides the following additional features and benefits:

The local time and date, the UTC (Greenwich) time and date and the current Julian date (see Glossary) will be available to you from the mode time menu.

· The Local Apparent Sidereal Time (LAST) will be available to you in mode sidereal if you have also specified your location.

· The topocentric azimuth and altitude (see Glossary) will be available to you in mode az alt assuming you have also specified your location and have performed a valid star alignment.

· The horizon mask filtering option will be applied correctly in mode identify and mode tour assuming that you have also specified your location.

· If in setup guide mode the guide below horz setting has been set to h indicator on, then an ‘H’ symbol will appear on the guide mode display whenever an object is computed to be below the computed horizon, which in turn also assumes that you have specified your location.

· Correction for atmospheric refraction (see Glossary) will be made while you point your scope assuming you have also specified your location and assuming you have turned refraction correction on in the setup refraction sub-menu.

· Objects will be precessed and nutated (see Glossary) from their internally stored J2000.0 epoch positions to their actual position at the time you observe them.

· The positions of planets can be accurately determined.

· The positions of asteroids and comets can be computed from their orbital elements.

· The position of earth orbiting satellites can be computed assuming you have also specified your location.

· If you have a ServoCAT^TM slew and track system, Argo Navis^TM will provide horizon limit checking when running the “servocat” startup command on the Argo Navis^TM serial port. Horizon limit checking also assumes you have specified your location.

For these reasons it is worthwhile setting your local time zone, date and time. Since Argo Navis^TM retains the time even when it is powered off, you only need do it once and then possibly occasionally to correct for normal clock drift.

To set the local time zone, date and time, perform the following. Power the unit on. Turn the DIAL clockwise until you see

MODE SETUP

Press ENTER. Now turn the DIAL clockwise until you see

SETUP DATE/TIME

Notice how Argo Navis^TM orders its various menus alphabetically so you can find a particular one logically and quickly.

Press ENTER. Argo Navis^TM will display something like

TIMEZONE=+00:00

Where the ‘+’ (or possibly ‘-‘) sign will be flashing.

To understand the concept of time zone, it is important to know that Argo Navis^TM always internally keeps track of time in terms of Universal Co-ordinated Time (UTC), which was previously referred to as Greenwich Mean Time (GMT). The time zone is the number of hours that your local time differs from UTC. For example, in New York when Daylight Savings Time (Summer time) is not in effect, the time zone setting is
-05:00 hours. When Daylight Savings (summer time) is in effect, the time zone is –4:00. In Sydney, when Daylight Savings time is not in effect, the time zone setting is +10:00 hours and when Daylight Savings is in effect +11:00. In New Delhi the time zone is +05:30.

Use the World timezones section of this manual to determine your local time zone. If you are in a time zone that is west of Greenwich, you will set the sign to a ‘-‘. If you are in a time zone that is east of Greenwich, you will set the sign to a ‘+’.

By turning the DIAL you can change the sign alternately between a ‘+’ and a ‘-‘. When you have selected the correct sign, hit ENTER, which advances the flashing ‘cursor’ to the first numeric field. You can change the value in that field by turning the DIAL. When you have selected the correct value, advance the cursor to the right by hitting the ENTER button again and so on. When you have finished editing the last field (most people will live in a time zone that is only a whole number of hours offset from UTC), pressing the ENTER button again will result in a display something like

DATE=24 APR 2015

TIME=15:30:45

where the first digit will be flashing. Again, as in editing the time zone, edit the correct local date and time by using the DIAL and pressing the ENTER button to advance over fields. If you make a mistake, press EXIT and start over again. Keep in mind that you are entering your local date and time here, not the UTC time. Argo Navis^TM will perform the appropriate arithmetic to convert the date and time you enter to internal UTC time by taking into account the time zone you entered.

When you have edited the last field, you may like to synchronize the pressing of the ENTER button against some correct time reference. Argo Navis^TM will then briefly display the words

SAVING ….

and then the words

INITIALIZING ….

in the lower half of the display before returning to the setup sub-menu with the message

SETUP DATE/TIME

You have now successfully set your local time zone and your local date and time.

While the SAVING… message appeared, Argo Navis^TM saved your time zone setting into its memory (EEROM device) and the date and time into the battery backed time-of-day clock. While the INITIALIZING … message appeared, Argo Navis^TM re-initialized such things as the positions of planets, asteroids and comets and recalculated the amount of precession and nutation to account for since the J2000.0 epoch.

It is handy to remember that whenever Daylight Savings comes into or out of force in your locality, simply edit the time zone by adding or subtracting an hour from it as necessary. There is no need to change the local time as changing the time zone will automatically perform the correct arithmetic.

Normally the lithium coin cell battery used by the time of day clock should last for several years. If for any reason it should run flat, when Argo Navis^TM is powered on, it will display briefly this message

RTC BATTERY FLAT

Followed by this message -

SETTING DATE TO

12:00 1 JAN 2000

See the section How to replace the lithium coin cell battery for details.

Setting the location

As was discussed in the section on setting the time zone, date and time, Argo Navis^TM does not require you to set your location to operate, however, doing so brings about other features and benefits.

While in mode setup, turn the DIAL until you see -

SETUP LOCATION

Then press ENTER, where you will then see a location name such as this

NOWHERE,ATLANTIC

If you turn the DIAL you will then see the names of 10 locations in the world. If you happen to live in one of them, simply hit EXIT while its name appears in the display and you are done.

Chances are, however, that you do not live in any of the locations indicated. This is not a problem, since you can edit the locations to places that you observe from. For example, say you are unlikely to do any observing from Mawson Base in Antarctica. Let us edit the ‘mawson base’ location to ‘home’.

While in setup location, Turn the DIAL until

MAWSON BASE

appears on the display The whole line will be flashing.

Now press the ENTER button. You have now entered location name edit mode. The ‘M’ character will be flashing indicating that the cursor is at that location. Turn the DIAL anti-clockwise until the letter ‘H’ appears, then press ENTER to advance to the next letter, which is an ‘A’. Turn the DIAL in either direction to make it a ‘O’, press ENTER, and so on until you have spelt out the word ‘HOME’. Continue to erase the rest of the characters in the old mawson base name by turning them into SPACES. The SPACE character is found just after the letter ‘Z’ if you are turning the DIAL clockwise. When you have erased the last character, press ENTER multiple times until the display shows this

LAT=67:35:59 S

This is the latitude of Mawson Base which you will now change to your local latitude. To determine your local latitude, consult an atlas or one of the many location databases (such as www.heavens-above.com) available on the Internet. Unless you plan on observing satellites, or accurately knowing your Local Apparent Sidereal Time (LAST), don’t be too concerned if you cannot determine the exact co-ordinates of your location. Within a degree or so should be fine for most situations.

Using the DIAL and ENTER button, edit the latitude fields to values appropriate for your observing location. Latitude is displayed in terms of degrees:minutes:seconds either North or South of the Earth’s equator. Change the ‘S’ to an ‘N’ depending upon whether your location is in the Northern or Southern Hemisphere.

After editing the North/South field, pressing ENTER again will result in the display showing this

LONG=062:53:00 W

This is the longitude of Mawson Base. Edit it as you did the Latitude, replacing the fields with values appropriate to your observing location. Longitude is displayed in terms of degrees:minutes:seconds either East or West of Greenwich. Change the ‘W’ to an ‘E’ depending upon whether your location is East or West of the Greenwich Meridian. For example, if you live in the United States or Canada, your location will be West of Greenwich so you will enter a ‘W’. If you live in Australia, for example, your location will be East of Greenwich so you will enter an ‘E’.

When you have edited the last longitude field, press ENTER. The display will then show

HOME

where the word home will be flashing. Press EXIT to set home as your observing location. The display will briefly show

SAVING ….

And then the words

INITIALIZING ….

In the lower half of the display before returning to the setup sub-menu with the message

SETUP LOCATION

You have now successfully set your location.

While the SAVING… message appeared, Argo Navis^TM saved your location settings into its memory (EEROM device). While the INITIALIZING … message appeared, Argo Navis^TM re-initialized such things as the current Local Apparent Sidereal Time (LAST).

You can edit as many of the locations in the setup location menu as you desire. Whenever you change observing location, simply enter the
setup location menu, turn the DIAL until the name of the location you are observing from appears, then hit EXIT.

Remember, in order to perform an alignment and to use most of the features of Argo Navis^TMyou don’t need to set your time zone, date, time or location unless you also decide to turn on refraction modelling correction or would like some of the other features or benefits discussed earlier.

Setting refraction modelling

Due to the phenomenon of atmospheric refraction, celestial objects close to an observer’s horizon will appear to be higher in altitude than what they actually are. Argo Navis^TM can compensate for the effects of atmospheric refraction. However, to do so, Argo Navis^TM must have had the time zone, date, time and location set reasonably accurately. It uses these parameters in conjunction with information it will obtain once you perform an alignment, to determine where the observer’s local horizon is. Having determined that, it then can correct for refraction.

If you do not plan to observe objects close to the horizon, you may decide to leave refraction modelling off. However, if you are confident you have set your time zone, date, time and location correctly, it is a good idea to turn it on to improve your pointing accuracy.

To turn refraction modelling on, go to the

SETUP REFRACTION

sub-menu and press ENTER. The display might then show -

REFRACTION=OFF

where the word ‘OFF’ is flashing. Use the DIAL to change the setting to either ‘ON’ or ‘OFF’ as you desire. Then press either EXIT or ENTER to save that selection into memory (EEROM device) and to specify it as your current setting.

This section gives a quick introduction to the alignment procedure for Argo Navis^TM. Variations and possible refinements to the alignment procedure are discussed in -

and

After reading this section, you are encouraged to read the sections just referenced to provide you with a fuller understanding of the alignment procedure. They are worth reading as the alignment procedures described here are simply meant to help you get started. A fuller understanding of the alignment procedure will help you improve your pointing accuracy.

Purpose of alignment

Whenever you power on Argo Navis^TM you will need to carry out an alignment procedure in order for it to locate objects.

The alignment procedure depends on the type of mount you have and whether it is accurately polar-aligned or not. You should have already set your mount type in setup mount.

Fork Exact Align and German Equatorial Exact Align Mounts

The possible polar-aligned mount settings are fork exact align and gem exact align (for German Equatorials). The following procedure assumes that the mount has been accurately polar-aligned. If that is so, only one alignment star is required.

When Argo Navis^TM is first powered on, after initializing, it will prompt you
with –

MODE ALIGN STAR

Press ENTER. The display should show something like -

ALIGN ACHERNAR

If you have a German Equatorial Mount, and are in the Northern Hemisphere, position the tube on the West side of the mount.

If you have a German Equatorial Mount and are in the Southern Hemisphere, position the tube on the East side of the mount.

If you have a Fork mounted scope, orient the tube the “normal” way up that you observe with it.

Look up at the sky and pick a familiar bright star. Spin the DIAL and look for that star’s name. There are 35 to choose from. The mode align star reference page lists the alignment stars. If you cannot find the star you have chosen in the list, pick another that is in the list.

Figure 6

Sight the star. If you have a German Equatorial mount and would like to sight the star with the tube on the opposite side of the mount, go to setup alt steps and change the direction sense sign. Whenever you wish to re-align using the scope on the original side of the mount, be sure to change the sign back.

Centre the star as accurately as possible in the centre of the eyepiece, not just the finder-scope. When the star is perfectly centred, press ENTER. For example, say you have chosen Sirius. The display will briefly show –

ALIGN SIRIUS

WARP= +0.00

This completes the alignment procedure. Now go on to read An introductory run.

Alt/Az Dobsonian Mounts including on Equatorial Tables

If you have set your mount type to be alt/az dobsonian or eq table exact then use the following procedure. You will be required to perform an operation called fix alt ref and two star alignments.

If you are using an equatorial table, park the table to its start position and switch it off for now.

When Argo Navis^TM is first powered on, after initializing, it will prompt you
with –

FIX ALT REF

Press ENTER. Turn the DIAL until you see -

ALT REF=90°

AUTO ADJUST OFF

Now move your telescope to a position in altitude so that the tube is pointing at right angles with respect to the base like thus-

The scope does not have to be level on the ground. Only the orientation of the tube to the base is important. If the telescope is sitting on an equatorial table, it is the orientation of the tube to the plane of the table that is important. Due to mechanical constraints in your mount, you may not be able to get the scope at exactly right angles. Try to get it as close as possible for now. Later on you can review the mode fix alt ref reference page that discusses the auto adjust on feature that can assist you with this procedure. It’s worth reading as this is a very important step that can dramatically improve your pointing accuracy.

When your tube is in this position, press ENTER. The display will briefly show -

ALT REF=90°

WARP=ALT FIX OK

Press EXIT. In the top-level menu, spin the DIAL until you see –

MODE ALIGN STAR

then press ENTER. The display should show something like -

ALIGN ACHERNAR

Look up at the sky and pick a familiar bright star. Spin the DIAL and look for that star’s name. There are 35 to choose from. Section mode align star lists the alignment stars. If you cannot find the star you have chosen in the list, pick another that is in the list. For example, say you have chosen Sirius. Spin the DIAL until you see -

ALIGN SIRIUS

Centre Sirius in the eyepiece, then press ENTER. The display will briefly show something like this –

ALIGN SIRIUS

WARP= -4.75 (1)

Your “WARP” number will probably be different, but don’t worry. Now pick a second bright alignment star. Preferably choose one approximately 30° to 90° away from the first and which will involve having to move the scope in both axes. For example, say you have chosen Capella. Spin the DIAL until you see –

ALIGN CAPELLA

Centre Capella in the eyepiece, then press ENTER. The display will briefly show something like this –

ALIGN CAPELLA

WARP= +0.12

Your “WARP” number should ideally be as close to 0.00 as possible. A number in the range of –0.5 to +0.5 will probably give you reasonable pointing accuracy depending upon the accuracy of your initial fix alt ref step and how far you move from the initial alignment stars.

If your WARP number was much larger you may want to check that you identified the correct stars and repeat the alignment procedure if need be. Otherwise see the Troubleshooting guide.

Only if you are using an equatorial table and you have set your mount type to be eq table exact, then perform the following steps to begin tracking –

Press EXIT to go to the top-level menu and then spin the DIAL until you see –

MODE EQ TABLE

then press ENTER. The display should show this -

EQ TBL ELAPSED
00:00:00.0 STOP

Simultaneously start the table and press ENTER which will start the Argo Navis^TM equatorial table timer. Refer to the section entitled mode eq table in order to learn more about how to successfully use your Argo Navis^TM with an equatorial table.

This completes the alignment procedure. Be sure to take the time to read the section on mode fix alt ref. In particular you may want to come back and attempt to use the auto adjust on mode. It may well dramatically improve your alignment. Now go on to read An introductory run.

Fork Rough Align Mounts

Sometimes you may not want to align your Fork mount accurately but would still like to find objects. If you have set your mount type to be fork rough align, then use the following procedure. You will be required to perform an operation called fix alt ref and two star alignments.

When Argo Navis^TM is first powered on, after initializing, it will prompt you
with –

FIX ALT REF

Press ENTER. Turn the DIAL until you see -

ALT REF=0°

AUTO ADJUST OFF

Roughly polar align your scope. Orient the tube as accurately as possible so that it is 90° with respect to the forks and the “way-up” you normally observe, thus –

Figure 7

When your tube is in this position, press ENTER. The display will briefly show -

ALT REF=0°

WARP=ALT FIX OK

Press EXIT. In the top-level menu, spin the DIAL until you see –

MODE ALIGN STAR

then press ENTER. The display should show something like -

ALIGN ACHERNAR

ALIGN SIRIUS

Centre Sirius in the eyepiece, then press ENTER. The display will briefly show something like this –

ALIGN SIRIUS

WARP= -1.75 (1)

ALIGN CAPELLA

Centre Capella in the eyepiece, then press ENTER. The display will briefly show something like this –

ALIGN CAPELLA

WARP= +0.20

If your WARP number was much larger you may want to check that you identified the correct stars and repeat the alignment procedure if need be. Otherwise see the Troubleshooting guide.

GEM Rough Align

Sometimes you may not want to align your German Equatorial Mount accurately but would still like to find objects. If you have set your mount type to be gem rough align, then use the following procedure. You will be required to perform an operation called fix alt ref and two star alignments.

When Argo Navis^TM is first powered on, after initializing, it will prompt you
with –

FIX ALT REF

Press ENTER. Turn the DIAL until you see -

ALT REF=0°

AUTO ADJUST OFF

Roughly polar align your scope.

If you are in the Northern Hemisphere, place the tube on the West side of the mount.

If you are in the Southern Hemisphere, place the tube on the East side of the mount.

If you are going to do the first star alignment with the tube on the opposite side of the mount, go to setup alt steps and change the direction sense sign. Be sure to change it back when you want to do a first-star alignment on the original side of the mount.

Set the tube so that the scope’s Optical Axis is at 90° with respect to the Polar Axis. Try to do this as accurately as possible.

When your tube is in this position, press ENTER. The display will briefly show -

ALT REF=0°

WARP=ALT FIX OK

Press EXIT. In the top-level menu, spin the DIAL until you see –

MODE ALIGN STAR

then press ENTER. The display should show something like -

ALIGN ACHERNAR

Look up at the sky and pick a familiar bright star. Sight the star in the scope without moving more than 90° in declination. That infers that you should not cross the North or South Celestial Pole in order to sight the first star. Spin the DIAL and look for that star’s name. There are 35 from which to choose. The mode align star reference page lists the alignment stars. If you cannot find the star you have chosen in the list, pick another that is in the list. For example, say you have chosen Sirius. Spin the DIAL until you see -

ALIGN SIRIUS

Centre Sirius in the eyepiece, then press ENTER. The display will briefly show something like this –

ALIGN SIRIUS

WARP= -1.75 (1)

Your “WARP” number will probably be different, but don’t worry. Now pick a second bright alignment star. You can now move the telescope in any direction to sight it. Preferably choose one approximately 30° to 90° away from the first and which will involve having to move the scope in both axes. For example, say you have chosen Capella. Spin the DIAL until you see –

ALIGN CAPELLA

Centre Capella in the eyepiece, then press ENTER. The display will briefly show something like this –

ALIGN CAPELLA

WARP= +0.20

If your WARP number was much larger you may want to check that you identified the correct stars and repeat the alignment procedure if need be. Otherwise, read the Troubleshooting Guide and the introductory sections of setup mnt errors.

This completes the alignment procedure. Be sure to take the time to read the section on mode fix alt ref. Improving the accuracy by which you perform the fix alt ref operation will dramatically improve your pointing accuracy. In particular your attention is drawn to the auto adjust on feature of mode fix alt ref.

Now go on to read An introductory run.

This section gives a quick introduction as to some of the ways you might locate objects using your Argo Navis^TM. It does so by way of examples. It assumes that you have successfully aligned the unit by following the instructions in Alignment procedures. It purposely doesn’t give a lot of detail as to how things work (that is covered in detail in the Operating modes section). However, by following the directions, you should quickly learn by this ‘hands-on’ experience. Each example builds on the previous example, so it is best to follow them in order. The objects in the examples may not be viewable from your site, or when you perform a search you may not find the same ones, but you should still be able to grasp the basic ideas.

Argo Navis^TM provides a great deal of flexibility and power in the many ways it can help you locate or identify objects. For a more detailed discussion of these methods, it is recommended you read the following reference pages –

Examples

Example 1 – You want to locate the Messier object M53, assuming it is above the horizon.

You have already aligned your scope. Enter mode catalog by spinning the DIAL in the top-level menu and pressing ENTER when you see –

MODE CATALOG

appear on the display. You will be prompted by a message such as –

BRIGHT STARS

where those words will be flashing.

The catalogs are listed in alphabetical order. Spin the DIAL clockwise and cycle through the list of available catalogs until you see –

MESSIER

then press ENTER. Spin the DIAL clockwise until the display shows -

then press ENTER. Spin the DIAL clockwise until the display shows –

M53

then press ENTER again. The display might show something like this –

M53

GUIDE 45® 25¯

Now move the scope in Azimuth (Right Ascension on a polar aligned scope) and try to make the first set of digits as close to 0.0 as possible. For example –

M53

GUIDE 0.0 25¯

Now move the scope in Altitude (Declination on a polar-aligned scope) and try to make the second set of digits as close to 0.0 as possible. For example –

M53

GUIDE 0.0 0.0

Now look through the eyepiece and hopefully there is your object!

Now press ENTER again. You will see a scrolling description of the object -

M53 ALSO KNOWN AS NGC 5024 GLOBULAR CLUSTER IN COMA BERENICES SIZE=12.6’ MAG=7.6 RA=13:12:56 DEC=+18°10’08” 2000.0 ABOVE HORIZON HB=C29

While the message is being displayed, you can grab the DIAL and scroll the text back and forth if you so desire. When you have finished reading it, press ENTER or EXIT and the display will return to guide mode.

M53

GUIDE 0.0 0.0

Now press EXIT again and return to –

MODE CATALOG

Example 2 – You want to locate the Sombrero Galaxy, assuming it is above the horizon. You know it has both a Messier and NGC number, but you have forgotten both.

Enter mode catalog and spin the DIAL until you see –

POPULAR DEEP SKY

Then press ENTER. Spin the DIAL to make the first character an ‘S’, then press ENTER. Now spin the DIAL and make the second character an ‘O’, then press ENTER. Now make the third character an ‘M’, then press ENTER. You should now have a display similar to this –

SOMBRERO GALAXY

GUIDE 5®0 73

You can then guide to it as you did in the previous example.

You may have noticed while you were spelling out the name of SOMBRERO GALAXY using the DIAL and the ENTER button, that Argo Navis^TMprompted you with the names of other objects that matched your partial input at each point along the way. Once enough characters had been entered to uniquely match the object name you were after, you were guided to it straight away without requiring any more input. This is known as the Intelligent Editing System^TM.

If you press ENTER, you will get the scrolling description.

SOMBRERO GALAXY ALSO KNOWN AS M104 ALSO KNOWN AS NGC 4594 GALAXY IN VIRGO SIZE=8.7’x5.3’ MAG=7.6 SB=12.1 MORPH=SA(s)a sp SOMBRERO GALAXY RA=12:40:00 DEC=-11°37’21” J2000.0 ABOVE HORIZON HB=D31,C48

Therefore you could have also retrieved the object as M104 in the MESSIER catalog or as NGC 4594 in the NGC catalog.

When the display returns to guide mode, press EXIT.

Example 3 – You want to locate the nearest Globular Cluster in Ophiuchus of Magnitude 15 or brighter. Assume the constellation is viewable.

Spin the DIAL in the top -level menu until you see -

MODE IDENTIFY

then press ENTER. Now spin the DIAL until you see -

FIND GLOBULAR CL

then press ENTER. Now spin the DIAL anti-clockwise until you see –

FAINTEST MAG +15

then press ENTER. Now spin the DIAL and make the first flashing character an ‘O’, then press ENTER. Now spin the DIAL and make the second character a ‘P’. The display should now show –

IN OPHIUCHUS

Press ENTER. The display should now show –

HORIZON MASK OFF

Press ENTER. Argo Navis^TMthen will briefly display the message -

SEARCHING

before showing you the name of the closest object. The object you find will probably be different, but by way of example, you might see –

TERZAN 5

FOUND

Pressing ENTER or spinning the DIAL one ‘click’ will put the unit into guide mode.

For example -

TERZAN 5

GUIDE 76® 25¯

After guiding to the object, press EXIT or spin the DIAL one ‘click’. Then press EXIT again.

Example 4 – You want to move the scope around and let Argo Navis^TM tell you in ‘real-time’ what the closest object is.

Enter mode identify and spin the DIAL until you see -

FIND ANY OBJECT

then press ENTER. Now spin the DIAL until you see –

FAINTEST MAG ANY

then press ENTER. Now spin the DIAL and make the first flashing character an ‘A’, then press ENTER. Make the second character an ‘N’ then press ENTER. Now make the third character a ‘Y’. The display should now show –

IN ANY CONSTEL

Press ENTER. Now spin the DIAL and make the first flashing digit a ‘3’ then press ENTER. Make the second digit a ‘6’ then press ENTER. Now make the third digit a ‘0’. The display should now show –

WITHIN 360°

Press ENTER. The display should now show –

HORIZON MASK OFF

Press ENTER. Argo Navis^TMthen will briefly display the message -

SEARCHING

before showing you the name of the closest object.

Now move your scope across the sky. Notice how quickly Argo Navis^TM provides you with the name of the closest object. It is searching its entire database of tens of thousands of objects several times every second. The speed by which it does this should be testimony to its powerful processing ability.

Whenever the name of an object that looks interesting appears on the display, stop moving the scope. By pressing ENTER or spinning the DIAL one ‘click’ you can ‘lock-on’ to it as Argo Navis^TM enters guide mode. Pressing EXIT or spinning the DIAL one ‘click’ will return you to the continual search mode.

Remember that while in guide mode you can press ENTER to get a scrolling description of the object.

Example 5 – You would like to tour every Galaxy of 13^th Magnitude or brighter in Fornax.

Point your scope to the part of the sky from which you would like to begin the tour. The scope does not necessarily have to be pointed at Fornax.

Return to the top-level menu and spin the DIAL until you see -

MODE TOUR

then press ENTER. Now spin the DIAL until you see –

FIND GALAXY

then press ENTER. Now spin the dial until you see –

FAINTEST MAG 13

then press ENTER. Now spin the DIAL and make the first flashing character an ‘F’. The display should now show –

IN FORNAX

Press ENTER. The display should now show –

HORIZON MASK OFF

Press ENTER. Argo Navis^TMthen will briefly display the message -

SEARCHING

before showing you the name of the closest Galaxy in Fornax of 13^th Magnitude or brighter. Notice that you have automatically been put into guide mode. For example –

NGC 1049

GUIDE 14® 35¯

You can then move the scope and guide to the object. While in guide mode, if you spin the DIAL one ‘click’ clockwise, Argo Navis^TMwill find you the next closest object, and so forth. When you reach the end of the tour, you will see the message –

NO MORE OBJECTS

You can even spin the DIAL anti-clockwise at any time and go backwards through the tour. While it is searching backwards, you will briefly see the message –

BACKTRACKING

At any time while in guide mode you can press ENTER to get a scrolling description. Remember by grabbing the DIAL you can stop the automatic scrolling and instead scroll manually.

That concludes this brief introductory run. Hopefully by now you might have got some feel for how the unit operates. Argo Navis^TMhas many more features than are mentioned here. As suggested earlier, you are encouraged to read the various reference pages in the Operating modes section of this manual to help give you further insight into its various capabilities.

Name	Constellation	Greek	RA J2000.0	Dec J2000.0	Mag
ACHERNAR	ERI	ALPHA	01:37:43	-57:14	0.5
ACRUX	CRU	ALPHA	12:26:36	-63:06	1.3
AL NAIR	GRU	ALPHA	22:08:15	-46:57	1.7
ALBIREO	CYG	BETA	19:30:43	+27:51	3.1
ALDEBARAN	TAU	ALPHA	04:35:55	+16:30	0.9
ALPHARD	HYA	ALPHA	09:27:35	-08:27	2.0
ALPHERATZ	AND	ALPHA	00:00:58	+29:05	2.1
ALTAIR	AQL	ALPHA	19:50:47	+08:44	0.8
ANTARES	SCO	ALPHA	16:29:24	-26:25	1.0
ARCTURUS	BOO	ALPHA	14:15:40	+19:14	0.0
BETELGEUSE	ORI	ALPHA	05:55:10	+07:24	0.4
CANOPUS	CAR	ALPHA	06:23:57	-52:42	-0.7
CAPELLA	AUR	ALPHA	05:16:41	+46:00	0.1
CASTOR	GEM	ALPHA	07:34:36	+31:53	1.6
DENEB	CYG	ALPHA	20:41:26	+45:17	1.3
DENEBOLA	LEO	BETA	11:49:03	+14:51	2.1
DUBHE	UMA	ALPHA	11:03:43	+61:45	1.8
FOMALHAUT	PSA	ALPHA	22:57:39	-29:37	1.2
HADAR	CEN	BETA	14:03:48	-60:22	0.6
KAUS AUSTRALIS	SGR	EPSILON	18:24:11	-34:22	1.9
MIMOSA	CRU	BETA	12:47:43	-59:41	1.3
MIRFAK	PER	ALPHA	03:34:19	+49:52	1.8
MIZAR	UMA	ZETA	13:23:55	+54:56	2.3
NAVI	CAS	GAMMA	00:56:42	+60:43	2.5
POLARIS	UMI	ALPHA	02:31:50	+89:16	2.0
POLLUX	GEM	BETA	07:45:20	+28:01	1.1
PROCYON	CMI	ALPHA	07:39:18	+05:21	0.4
RASALHAGUE	OPH	ALPHA	17:34:56	+12:34	2.1
REGULUS	LEO	ALPHA	10:08:22	+12:13	1.4
RIGEL	ORI	BETA	05:14:32	-08:12	0.1
RIGEL KENT	CEN	ALPHA	14:39:37	-60:38	0.0
SIRIUS	CMA	ALPHA	06:45:09	-16:43	-1.5
SPICA	VIR	ALPHA	13:25:11	-11:10	1.0
SUHAIL	VEL	LAMBDA	09:08:00	-43:26	2.2
VEGA	LYR	ALPHA	18:36:56	+38:47	0.0

Function

mode catalog allows you to look-up an object by name then to optionally guide to it and to also optionally retrieve more information about it. When an object is accessed in mode catalog it automatically becomes the Current Object. That means that it will appear as the alignment object when entering mode align.

Objects in the Argo Navis^TM are grouped in a number of catalogs.
mode catalog allows you to browse the available catalogs and to either access a particular object in a particular catalog or to browse objects within the catalog.

Using MODE CATALOG

Enter mode catalog by spinning the DIAL in the top-level menu and pressing ENTER when you see –

MODE CATALOG

appear on the display. You will be prompted by a message such as –

BRIGHT STARS

where the words BRIGHT STARS

will be flashing.

By spinning the DIAL, you can cycle through the list of available catalogs. The catalogs are listed in alphabetical order.

The current catalogs are –

· ASTEROIDS (assuming your Argo Navis^TM has an asteroid catalog currently loaded)

· BRIGHT STARS (a selection of stars to magnitude 6.5, particularly those with well-known historical names, such as BETELGEUSE and those with Bayer Greek alphabet or Flamsteed numbers. Names have constellation abbreviation first, then Bayer or Flamsteed identifier. For example, FOR ZETA for Zeta Fornax. They are ordered this way to make the catalog easier to browse)

· COMETS (assuming your Argo Navis^TM has a comet catalog currently loaded)

· FROM PLANETARIUM (consists of the single “FROM PLANETARIUM” object. When Argo Navis^TM is interfaced via a serial port to an appropriate planetarium program and a GOTO command is issued from that program, the RA/Dec co-ordinates corresponding to that GOTO position and optionally the name of some associated object are transmitted to the “FROM PLANETARIUM” object. This then allows you to guide to the position that was sent from the planetarium program)

· IC (non-stellar selections from the Index Catalogue)

· MESSIER (the complete Messier Catalogue)

· MISC BRIGHT NEB (miscellaneous bright nebulae, such as emission and reflection nebulae, that do not appear in the messier, ngc or ic catalogs)

· MISC DARK NEBULA (miscellaneous dark nebulae)

· MISC DOUBLE STAR (miscellaneous double stars that do not appear in the bright star catalog)

· MISC GALAXIES (miscellaneous galaxies that do not appear in the messier, ngc or ic catalog, such as ESO, MCG, UGC and Local Group galaxies)

· MISC GALAXY CLUS (miscellaneous galaxy clusters such as the Abell and Hickson clusters)

· MISC GLOBULARS (miscellaneous globular clusters that do not appear in the messier, ngc or ic catalogs)

· MISC OPEN CLUST (miscellaneous open clusters that do not appear in the messier, ngc or ic catalogs)

· MISC PLANETARIES (miscellaneous planetary nebulae that do not appear in the messier, ngc or ic catalogs)

· MISC VARIABLE ST (miscellaneous variable stars that do not appear in the bright star catalog)

· NGC (the complete New General Catalogue, including all non-stellar, stellar and non-existent objects. Also includes ‘letter suffixed’ objects such as NGC 554A and NGC 554B and all objects that are also Messier objects)

· PLANETS/MOON/SUN (in our solar system)

· POPULAR DEEP SKY (a convenient cross reference to objects in the messier, ngc or ic catalogs that have popular names, such as ANDROMEDA GALAXY, GHOST OF JUPITER and TARANTULA NEBULA)

· SATELLITES (artificial earth orbiting satellites - assuming your Argo Navis^TM has a satellite catalog currently loaded)

· SCRATCH (see setup scratch)

· USER OBJECTS (assuming your Argo Navis^TM has user defined objects currently loaded)

By way of example, say you are interested in the planetary nebula popularly known as the ‘Ghost of Jupiter’. Spin the DIAL and press ENTER when you see -

POPULAR DEEP SKY

You might be then presented with the message in the top line that reads -

47 TUCANAE

where the ‘4' will be flashing. By spinning the DIAL and pressing the ENTER button, you can use the Intelligent Editing System^TM to enter the name of the object in which you are interested, in this example, Ghost of Jupiter. By spinning the DIAL clockwise (+), the symbol at the flashing cursor position will alphabetically increase. By spinning the DIAL anti-clockwise (-), the symbol will decrease. 'Wrapping' occurs when the 'maximum' symbol is displayed and the DIAL is turned clockwise or when the 'minimum' symbol is displayed and the DIAL is turned anti-clockwise.

Note: A symbol might be a number or letter or even a special character such as a '/', a '-' or even a space ' '. In general, Argo Navis^TM treats special characters as alphabetically before numbers and numbers as alphabetically before letters. See the section on How Argo Navis orders its symbols for a reference table.

Spell out the name of the object by spinning the DIAL and pressing ENTER to select a character and advance the cursor to the next editable field. The Intelligent Editing System^TM will only prompt you with valid names. A tip is to concentrate just on one letter at a time. In this example, spin the DIAL clockwise until the letter 'G' appears at the flashing cursor position.

The display might show something like

GEM CLUSTER

Now press ENTER to advance the cursor to the next editable field. In this case the display might continue to show

GEM CLUSTER

but now the 'E' in GEM will be flashing. Spin the DIAL clockwise until an 'H' appears at that place. The display might then show -

GHOST OF JUPITER

with the 'H" still flashing. Now press ENTER again. If a valid alignment has not been performed, you will see the following warning message -

GHOST OF JUPITER

NOT ALIGNED

In this case pressing ENTER again will give a further alignment warning message. If a valid alignment has been previously performed, Argo Navis^TM will enter guide mode.

Note : As a special feature, if you select the PLANETS catalog, the planet of interest can be found by rotating the DIAL. The planets are listed in Solar System order and are spelt out in full. When the name of the planet of interest appears on the display, simply press ENTER to go to guide mode.

Continuing with our example, the display might read -

GHOST OF JUPITER

GUIDE 101®25¯

This means the telescope should be moved 101° in azimuth and 25° in altitude to locate The Ghost of Jupiter. The arrows represent a relative movement. For example, if the ® arrow is displayed, even though the arrow points to the right, whether one moves the telescope to the right or to the left is dependent on several factors according to your setup. If you wish to change the default direction sense of one or both arrows, you can do so by changing the settings in setup guide mode.

In any case, you should move the telescope in the direction that causes the angle to become smaller. As the telescope is moved, the display continually updates the angles and changes the direction arrows if the object is passed. When an angle less than 10° is displayed, the arrow will move to double as a decimal point. For example, 5¯3 means 5.3°.

Generally you might find it is easier to move the telescope in one axis at a time. When the telescope is at the correct position, you will see -

GHOST OF JUPITER

GUIDE 0.0 0.0

If a proper alignment has been performed, the object should appear within the field of view of a moderate power eyepiece (for example, one that gives a field of view of about 30 arc minutes). If objects do not appear consistently within the field of view, you might want to perform a re-alignment or review the section Factors that affect pointing accuracy.

Detailed object description

At any time during guide mode, if you press ENTER, a scrolling description of the object is given. Typical descriptions include the full name of the object, other popular names the object might be known by, what constellation the object is in, the size of the object, the visual magnitude of the object, its surface brightness, in the case of stars its spectral luminosity class, in the case of galaxies its abbreviated Hubble morphology, the object's Right Ascension and Declination, whether it is currently above or below the horizon and what volume and page of the default atlas the object would appear on (See setup atlas). For the Moon, you can determine its current phase and the local date and time of the next phases.

While the description is scrolling (to change the default scroll rate, see setup scroll), you can press EXIT or ENTER to have Argo Navis^TM go back to guide mode or wait until the description has completed scrolling and Argo Navis^TM will automatically return to guide mode. If you move the DIAL while the description is scrolling, manual scroll mode is entered.

Turning the DIAL clockwise scrolls the message forward for convenient reading at your leisure while turning the DIAL anti-clockwise scrolls the message in reverse. By pressing EXIT or ENTER while in manual scroll mode, Argo Navis^TM will return to guide mode

Sequentially stepping through a catalog

While in guide mode, if you spin the DIAL clockwise (+), you can browse the next object in the currently selected catalog. Similarly if you rotate the DIAL anti-clockwise, you can browse the previous object.

Below horizon indication

Whenever you are about to locate an object you may want to automatically determine if it is below your local horizon or not.

To do so, ensure that your time zone, date and local time is correctly set in setup date/time, that your latitude and longitude are correctly set in setup location and that in setup guide mode you have set guide below horz to h indicator=on.

For example, if the display showed -

GRUS QUARTET

GUIDE 19®132¯H

the h symbol at the end of the second line indicates that the grus quartet is currently beneath your local horizon.

Examples

Example 1 - You want to observe the Ghost of Jupiter.

Spin the DIAL until you see -

MODE CATALOG

then press ENTER. Spin the DIAL until you see -

POPULAR DEEP SKY

then press ENTER.

Use the Intelligent Editing System^TM to enter the name of GHOST OF JUPITER and then press ENTER.

The display might then show -

GHOST OF JUPITER
GUIDE 5®0 7¯3

Move the telescope in both axes until the display reads -

GHOST OF JUPITER
GUIDE 0.0 0.0

Pressing ENTER again will display the following scrolling information about the object.

GHOST OF JUPITER ALSO KNOWN AS NGC 3242 PLANETARY NEBULA IN HYDRA SIZE=25" MAG=7.8 GHOST OF JUPITER. BLUE GREEN. BRIGHT INNER DISK & FAINT HALO RA=10:24:46 DEC=-18°38'34" J2000.0 ABOVE HORIZON MSA=VOL II 851

While the text is scrolling, you can enter manual scroll mode by moving the DIAL.

Note: Had you known that the Ghost of Jupiter is also known as NGC 3242, you might well have accessed it via the NGC catalog.

Note that when sample mode is on, in the setup mnt err/acquire data submenu, rather than a scrolling description immediately appearing, a new submenu appears.

In this case, by spinning the DIAL a detent ‘click’ at a time, the bottom line of the display can be alternated as follows –

· DESCRIPTION

· SAMPLE MNT ERROR

If you want to view the description of the object, spin the DIAL until the word DESCRIPTION appears and then press ENTER. If you want to sample the position of an object as part of a pointing test, spin the DIAL until the words SAMPLE MNT ERROR appears and then press ENTER (See setup mnt errors for details).

Pressing EXIT will return you to guide mode -

GHOST OF JUPITER
GUIDE 0.0 0.0

Pressing EXIT again will return you to the top-level menu -

MODE CATALOG

Example 2 - You want to align on MARS.

Spin the DIAL until you see –

MODE CATALOG

then press ENTER. Spin the DIAL until you see -

PLANETS/SUN

then press ENTER.

Spin the DIAL until you see -

MARS

Press EXIT. Mars is now the Current Object.

Spin the DIAL counter-clockwise until the display reads –

MODE ALIGN

then press ENTER.

The display should show -

ALIGN MARS

Centre Mars in the eyepiece and press ENTER to perform the alignment.

Example 3 - You want to determine the current Moon phase and when the next New Moon will be.

Spin the DIAL until you see -

MODE CATALOG

then press ENTER. Spin the DIAL until you see -

PLANETS/MOON/SUN

then press ENTER.

Spin the DIAL until you see –

MOON

Press ENTER and then press ENTER again. A scrolling description will appear. Whilst the text is scrolling, you can enter manual scroll mode by moving the DIAL.

MOON CURRENTLY IN VIRGO MAG=-11.7 DIA=30.4’ ILLUM=38.6% PHASE=LAST QUARTER NEXT LAST QTR=10-DEC-2017 18:51 LOCAL NEXT NEW MOON=18-DEC-2017 17:31 LOCAL NEXT FIRST QUARTER=26-DEC-2017 20:20 LOCAL NEXT FULL MOON=2-JAN-2018 13:24 LOCAL DIST=392462KM RA=12:16:55 DEC=+02°48’00” J2000.0 BELOW HORIZON HB=E12,C48

From the description the Moon phase is currently close to Last Quarter and the next New Moon will be on 18 DEC 2017 at 17:31 local time.

Example 4 – Whenever you are about to locate an object, you want to automatically determine if it is below your local horizon or not.

Ensure your time zone, date and local time is correctly set in setup date/time, that your latitude and longitude are correctly set in setup location and that in setup guide mode you have set guide below horz to h indicator=on.

For example, if the display showed -

TARANTULA NEBULA

GUIDE 169®108¯H

the h symbol at the end of the second line indicates that the tarantula nebula is currently beneath your local horizon.

See also

How Argo Navis orders its symbols