Last updated: 3 July 2001

Autostar, NexStar comparison

Subject:	Objective comparison of ETX Autostar vs. Celestron Nexstar
Sent:	Friday, June 29, 2001 8:33:36
From:	dstone@w3health.com (Dave Stone)
Recently I bought a Celestron Nexstar 8 to complement my Meade ETX 90/EC
and I have been doing a (reasonably) objective comparison of the
Autostar and Nexstar computer control capabilities. My attention has
been focused on ease-of-use and feature sets. I am not including a
comparison of the mechanical or optical components and there's a big
difference between the Nexstar 8 and the ETX 90/EC.

The results can be summarized as follows:

Autostar:	Upgradeable over the internet; 3rd party patches available.
Nexstar:	NA

Autostar:	Can add satellite tracking data and track satellites.
Nexstar:	NA

Autostar:	Can download custom tours.
Nexstar:	NA

Autostar:	Large number of objects in database. The Autostar now has
over 30,000 objects in its database.  Can enter SAO number for locating
stars.  The database has:
13,235 deep-sky objects sorted by named objects; galaxies; diffuse
nebulae; planetary nebulae; and star clusters; and including the
complete Messier, Caldwell, IC, and NGC catalogs;
16,888 stars sorted by name, SAO catalog numbers, double and variable
stars; plus the centroids of the 88 constellations;
50 objects in the solar system: 8 major planets from Mercury to Pluto;
the Moon; 26 asteroids; 15 comets;
50 Earth satellites, including the International Space Station, Hubble
plus 200 memory locations for user-defined objects.
Nexstar:	Large number of objects in database but fewer named objects
than Autostar (e.g. Nexstar doesn't list Alkaid as a named object). The
Nexstar has approx. 18,000 objects. There are 10385 SAO stars, of which
there are 41 named stars, 45 named doubles, and 21 named variable stars.
In order to reference any of the other stars, you must enter an internal
ID which maps to the appropriate SAO number. This is the weakest part
(IMHO) of the Nexstar. The rest of the database breaks down as follows:
Revised NGC Catalog             7840
Messier Catalog         110
Caldwell                        109
Solar System Objects            9
Asterisms                       20
User defined objects            25

Total Objects                   18,498

Autostar:	Feature rich tool set (display moon phases, eclipse dates,
meteor shower dates, glossary, timers,eyepiece calculations, etc.)
Nexstar:	No tools.

Autostar:	Generally verbose information provided by Identify.
Nexstar:	Generally terse information provided.

Autostar:	Must scroll through levels of menus to switch between
objects and types of objects.
Nexstar:	Most object selections available with one-touch buttons on keypad.

Autostar:	User programmable backlash compensation ("percentages").
Nexstar:	User programmable backlash compensation.

Autostar:	LX200 compatible command set for use with astronomy
software; feature rich command set.
Nexstar:	Only 2 effective commands; Goto RA-Dec /Alt-AZ and Get

Autostar:	No AutoGuider port but some guiders claim to be able to use
LX200 commands for autoguiding.
Nexstar:	No AutoGuider port; can't be controlled by any guider
currently available.

Autostar:	3 tracking rates; Sidereal, Lunar, and custom.
Nexstar:	4 tracking rates; Sidereal, Lunar, King, Solar.

The Autostar has a lot more features than the Nexstar. That being said,
for general viewing the Nexstar is a little easier to use. Also it's a
lot faster to set up the Nexstar. There's no Home position for the tube
and no hard stops to worry about.

Both Nexstar and Autostar work as advertised, and if all you need is a
handbox for selecting an object and pressing GO, then either system is
adequate. The Nexstar might actually be a bit better if you're going to
be performing manual guiding for Astrophotography due to the inclusion
of the programmable anti-backlash feature. However, there is no
possibility of using an AutoGuider. If you want to try and look at the
International Space station or the shuttle in orbit, then you have to
use an ETX (or the LX90) and the Autostar.

Subject:	re: Nextstar vs. Autostar
Sent:	Sunday, July 1, 2001 20:44:22
From:	rseymour@wolfenet.com (richard seymour)
Nice comparison...

one quibble (well, two): 

The Nexstar offers the *Sun* as a goto object.
We can fudge it with the Autostar, but it's a fudge.

You quote the Autostar ads by saying:
> 50 objects in the solar system: 8 major planets from Mercury to Pluto;
> the Moon; 26 asteroids; 15 comets; 50 Earth satellites, including the
> International Space Station, Hubble telescope;
> plus 200 memory locations for user-defined objects.

There are actually 63 Kbytes of user-space in the Autostar.
You can fill that any way you'd like: 1000 satellites would fit.
(at 51 bytes each, that'd still leave 10K for a couple of Tours).
I've put in over 150 (and scrolling thru them is a real pain)

The list you cite is just what (may) come within the Autostar on
delivery... and that satellite data would be too old to be of any
 reasonable use.  Updates are required for those objects.

I don't -think- there are individual object-count limits for the
various classes... i believe they all draw from the common pool.

It -is- nice to see a by-owner comparison...
Mike here: Dave put the NexStar numbers in. I added the counts from Meade's site. I should have made that clear.

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Copyright ©1999-2001 Michael L. Weasner / etx@me.com
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URL = http://www.weasner.com/etx/autostar/as_comparison.html