Alignment, Software and Stupidity

[DronJes]

Howdy all..
I am VERY new to this game.. I have just purchased a Nexstar 114SLT with GoTo.
I have purchased the required RS Cable to connect the Scope to my Laptop.
I have updated the firmware of the device to the lasted version as well as having updated to the latest version of Nexstar Observers list.
I have entered the Lat/Lon for Perth in the Setup of Nextsar Ob List (Although I am unsure whether it should West/North/East/South for Lat/Long).
I have aligned the scope using solar system alignment using the moon. Now when I choose a object for the scope to 'slew' to IE: NGC 936. and click 'goto'
The goto handset says: 'Slew Limit Warning - Change Slew Limit in Scope Setup'.
The thing is I have not touched these settings (Min Slew is +00 Max is 65) why cant the scope accept the command to slew to this object if it has been aligned correctly?
In fact any object I choose the Goto Handset comes up and says the same error.
My apologies for the stupidity of this question.. But I am tearing my hair out! any help greatly appreciated..

David

[Dennis]

Hi David

Can't help with the warning message, but your set up should be:

Longitude = East
Latitude = South

Also, have you entered a Time Zone? Does the mount require an initialization, such as setting it up to point North and be level, so it has a reference point from which to start from?

If these values are not entered correctly, the system may return an error message believing the object to be below the horizon, or warning that an attempt to slew to it might cause a collision with the mount or tripod.

Cheers

Dennis

[MikeyB (Michael)]

The Slew Limits are automatically set by the GoTo software so as to protect the telescope from accidentally contacting the mount while slewing to a target (see page 22 of the manual):

Slew Limits – Sets the limits in altitude that the telescope can slew without displaying a warning message. The slew limits prevent the telescope tube from slewing to an object below the horizon or slewing to an object that is high enough that the tube might hit one of the tripod legs. However, the slew limits can be customized depending on your needs. For example, if you would like to slew to an object that is close to the zenith and are certain that the tube will not hit the tripod legs, you can set the slew limits to 90º in altitude. This will allow the telescope to slew to any object above the horizon without warning.

Incidentally, Solar System Alignment is a single target system that is less than optimum for night time astronomical use. Sky Align or one of the Two Star alignment methods would be preferable for better accuracy.

I think that a galaxy such as NGC 936 is too ambitious as an early target for a 114mm reflector with the moon as prominent as it is at present. You'll probably find it easier to get started by selecting objects that are naked eye visible (eg. Sirius, Orion Nebula, Saturn, Jupiter), so that you can readily confirm that your alignment is OK. When your aligned GoTo settings are finding such visible objects correctly, you can then progress to slightly harder but easily verified objects (eg. the Jewel Box - NGC 4755 or Acrux - an easy multiple star). Once your GoTo's to these are working well, you can confidently start exploring fainter objects. However, don't expect too much of your scope until the moon wanes and we get some decently dark sky again, particularly if you're observing from an area exposed to city/suburban light pollution.

Hope this helps get you started, David!

[g__day (Matthew)]

Can I also add you'll likely get much better accuracy if you align to 3-4 star (or all 6 stars)that are well spaced. Moons and planets seem to give you worse pointing accuracy then pointing to far, far more remote stars.

Also download the free Cartes du Ceil and get use to locating say the 16 brightest stars in the sky. If it wants you to align on Canapus, Antares, Acturus, Mimosa, Hadar, Proycon, Pollux, Rigel Kentarus etc - it helps you to know exactly where these stars are. If it slews to the middle of two bright stars to align, you gotta know which is the right star to select.

Also try some brighter nebulae like NGC 5139 and some Messier objects for excellent viewing. But some Messier objects like M42, M7 etc are alot easier to see in your scope than say Sombero M104.

Hope this helps and great to see you around.