A Cool Night with a NexStar

DS022604 RECENT OBSERVATIONS
by David Knisely

DATE: February 26th, 2004, 0130 to 0445 hrs UTC.
LOCATION: Beatrice, Nebraska, USA, 40.283N, 96.735W, (402m elevation)
INSTRUMENTS: Celestron NexStar 9.25GPS SCT, 78x, 195x, 297x, 388x, 479x,
CONDITIONS: Partly Cloudy, Temp. 30 deg. F. (-1.1 deg. C), wind calm.
UNAIDED-EYE ZENITH LIMITING MAGNITUDE: 5.0
SEEING (above 45 deg. altitude): 1.5 to 0.5 arc seconds (Antoniadi II)

OBJECTS OBSERVED: Venus, Mars, Moon, Saturn, Jupiter, Struve 872, Rigel
Sirius, M42.

OBSERVATIONS: I finally got a night when it wasn't near or below zero and the
snow cover wasn't covering up the driveway. I had the new NexStar 9.25GPS
that I am reviewing out for cooldown while I went on a quick trip out to
Arbys for a sandwich. By the time I got back, all was ready, and unlike
previous outings with the 9.25, the seeing was quite good. After watching
the NexStar go though its alignment gymnastics (and doing some tweaking of
the alignment) my first target was brilliant Venus. Even at 78x, it showed
its gibbous form well, with a pure-white color. From there, it was a short
slew to the moon, but one problem with Go-To operation is that the moon is
a very big target. I ended up looking at the area illuminated by only
Earthshine, so it took a little slewing to get back onto the illuminated
portion. The view, despite a little high cirrus, was spectacular, with a high
level of fine detail visible. The sun was just rising on the central peak of
Theophilus, so it was fun to watch more and more of the peak emerge from the
darkness. The area around and south of Madler showed numerous tiny pits in a
fine field on the west edge of Mare Nectaris. It was fun to slew around all
over the surface, rather than having to reach up and nudge the scope
repeatedly to get things where I wanted them.
I could have just manually slewed the scope to Mars since it wasn't very
far away from the moon, but since I had a high power eyepiece in the scope, I
decided to let the scope do the work and see just how close it would come.
The slew didn't put Mars quite in the center, but it wasn't far away. At
297x and up, the planet was still quite tiny (5.76" arc), but surprisingly
showed a vague dark patch (probably Mare Erythraeum) across the middle of the
disk, along with a hint of a bluish patch around the south polar region.
From Mars, it was on to Rigel, and even at 78x, the star's tiny faint
companion was nicely shown, with jet-black sky between them. At 297x, the
companion was easier to see and occasionally showed a diffraction disk when
the seeing settled down. With seeing this good, I decided to try for the E
and F stars in the Trapezium, so with a couple of keystrokes, I sent the
scope slewing to M42. Sure enough, both E and F were visible through some
of the high haze which was passing through that region, along with the very
mottled nebulosity of the central core of the Orion nebula. With these
successes, I decided to try for the "pup" white dwarf companion to Sirius.
Unfortunately, I didn't get more than a hint of it, as the seeing at that
bright star (located over a nearby home with a heat vent) made the area
around it mottled with "false" companions.
I had seen in Richard Digon-Smith's book STARLIST 2000 that he noted
the faint double star Struve 872 as one of the more colorful binaries. The
book indicated that it was a gold-blue pair, so I was off to try and find
it. While the database of the NexStar has a number of the most prominent
double stars in its double-star list, Struve 872 wasn't one of them (and from
the view I got, I can see why it didn't make the list). Digon-Smith's book
doesn't give the coordinates for the double, so I had to go to Megastar to
find out where it was. I dutifully input the coordinates to the NexStar, and
it obligingly slewed to the double. As I have seen with other colorful
claims in Digon-Smith's book, this one also wasn't all that accurate. It
consists of a magnitude 6.9 star and a mag. 7.5 star about 11.3 arc seconds
apart, with very little difference in color between them. The primary was
perhaps a pale yellowish-white, and the companion was maybe a bit more yellow
but fainter, so it was difficult to see much of a color contrast here.
I had had enough of doubles for a while, so it was on to Saturn. My
first look brought out an immediate "WOW!" as seeing was rock-steady. The
contrast provided by the StarBright XLT coatings put a lot of black sky
between the inner moons of Dione, Rhea, and Tethys and the edges of the
rings. I had to search around for a while, but I finally did locate faint
Hyperion amongst the numerous field stars of Gemini. Titan showed its disk,
and I did occasionally glimpse Enceladus, but Saturn was simply stunning! It
was one of those "Mack Truck through the Cassini Division" nights, with the
planet taking all the power I could muster. The Crepe ring showed its dark
gray form well, hugging the inside of the B-ring, while the B-ring showed
its "step" variations in brightness across its span. I didn't see the true
Encke Division, but the rings still showed a lot of detail. The planet
itself showed the narrow fine belt that sits right on the equator, along with
the broad main orangish band. That large band almost appeared to contain two
distinct components, although the poleward side was rather diffuse. I could
also see two other very fine belts, one north of the dark polar cap and one
hugging the cap's northern edge. The dark southern cap itself looked a bit
darker towards its center.
For a final target, Jupiter was finally getting out of the heated air
above the house, so it was time to see what it showed. I wasn't disappointed
as the view was nearly as good as it had been at Saturn. I counted 7 or 8
belts with lots of fine detail, including a rather prominent white oval in
one of the temperate belts. The moons also showed some interesting color
variations at high power, although at low power, they seemed almost
colorless. I identified Io fairly easily, as its pale yellowish-orange
coloration made it stand out. Europa looked nearly white, while Ganymede
showed its larger and more greyish disk well. Callisto had a very pale
almost reddish-brown cast, although the color was quite subtle to say the
least. At this point, I noticed some frost forming on the side of the tube
and the corrector plate was showing dewing as well, so it was time to break
things down and get back inside to warm up a bit.

Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

Great review as always David. Now this begs the question: If you keep the
N9.25GPS what will you do with your beloved 10" Newt? And which will get
more use?

Just curious,
Jeff


"David Knisely" wrote in message
...
DS022604 RECENT OBSERVATIONS
by David Knisely

DATE: February 26th, 2004, 0130 to 0445 hrs UTC.
LOCATION: Beatrice, Nebraska, USA, 40.283N, 96.735W, (402m elevation)
INSTRUMENTS: Celestron NexStar 9.25GPS SCT, 78x, 195x, 297x, 388x, 479x,
CONDITIONS: Partly Cloudy, Temp. 30 deg. F. (-1.1 deg. C), wind calm.
UNAIDED-EYE ZENITH LIMITING MAGNITUDE: 5.0
SEEING (above 45 deg. altitude): 1.5 to 0.5 arc seconds (Antoniadi II)

OBJECTS OBSERVED: Venus, Mars, Moon, Saturn, Jupiter, Struve 872, Rigel
Sirius, M42.

OBSERVATIONS: I finally got a night when it wasn't near or below zero and
the
snow cover wasn't covering up the driveway. I had the new NexStar 9.25GPS
that I am reviewing out for cooldown while I went on a quick trip out to
Arbys for a sandwich. By the time I got back, all was ready, and unlike
previous outings with the 9.25, the seeing was quite good. After watching
the NexStar go though its alignment gymnastics (and doing some tweaking of
the alignment) my first target was brilliant Venus. Even at 78x, it
showed
its gibbous form well, with a pure-white color. From there, it was a
short
slew to the moon, but one problem with Go-To operation is that the moon is
a very big target. I ended up looking at the area illuminated by only
Earthshine, so it took a little slewing to get back onto the illuminated
portion. The view, despite a little high cirrus, was spectacular, with a
high
level of fine detail visible. The sun was just rising on the central peak
of
Theophilus, so it was fun to watch more and more of the peak emerge from
the
darkness. The area around and south of Madler showed numerous tiny pits
in a
fine field on the west edge of Mare Nectaris. It was fun to slew around
all
over the surface, rather than having to reach up and nudge the scope
repeatedly to get things where I wanted them.
I could have just manually slewed the scope to Mars since it wasn't
very
far away from the moon, but since I had a high power eyepiece in the
scope, I
decided to let the scope do the work and see just how close it would come.
The slew didn't put Mars quite in the center, but it wasn't far away. At
297x and up, the planet was still quite tiny (5.76" arc), but surprisingly
showed a vague dark patch (probably Mare Erythraeum) across the middle of
the
disk, along with a hint of a bluish patch around the south polar region.
From Mars, it was on to Rigel, and even at 78x, the star's tiny
faint
companion was nicely shown, with jet-black sky between them. At 297x, the
companion was easier to see and occasionally showed a diffraction disk
when
the seeing settled down. With seeing this good, I decided to try for the
E
and F stars in the Trapezium, so with a couple of keystrokes, I sent the
scope slewing to M42. Sure enough, both E and F were visible through some
of the high haze which was passing through that region, along with the
very
mottled nebulosity of the central core of the Orion nebula. With these
successes, I decided to try for the "pup" white dwarf companion to Sirius.
Unfortunately, I didn't get more than a hint of it, as the seeing at that
bright star (located over a nearby home with a heat vent) made the area
around it mottled with "false" companions.
I had seen in Richard Digon-Smith's book STARLIST 2000 that he noted
the faint double star Struve 872 as one of the more colorful binaries.
The
book indicated that it was a gold-blue pair, so I was off to try and find
it. While the database of the NexStar has a number of the most prominent
double stars in its double-star list, Struve 872 wasn't one of them (and
from
the view I got, I can see why it didn't make the list). Digon-Smith's
book
doesn't give the coordinates for the double, so I had to go to Megastar to
find out where it was. I dutifully input the coordinates to the NexStar,
and
it obligingly slewed to the double. As I have seen with other colorful
claims in Digon-Smith's book, this one also wasn't all that accurate. It
consists of a magnitude 6.9 star and a mag. 7.5 star about 11.3 arc
seconds
apart, with very little difference in color between them. The primary was
perhaps a pale yellowish-white, and the companion was maybe a bit more
yellow
but fainter, so it was difficult to see much of a color contrast here.
I had had enough of doubles for a while, so it was on to Saturn. My
first look brought out an immediate "WOW!" as seeing was rock-steady. The
contrast provided by the StarBright XLT coatings put a lot of black sky
between the inner moons of Dione, Rhea, and Tethys and the edges of the
rings. I had to search around for a while, but I finally did locate faint
Hyperion amongst the numerous field stars of Gemini. Titan showed its
disk,
and I did occasionally glimpse Enceladus, but Saturn was simply stunning!
It
was one of those "Mack Truck through the Cassini Division" nights, with
the
planet taking all the power I could muster. The Crepe ring showed its
dark
gray form well, hugging the inside of the B-ring, while the B-ring showed
its "step" variations in brightness across its span. I didn't see the
true
Encke Division, but the rings still showed a lot of detail. The planet
itself showed the narrow fine belt that sits right on the equator, along
with
the broad main orangish band. That large band almost appeared to contain
two
distinct components, although the poleward side was rather diffuse. I
could
also see two other very fine belts, one north of the dark polar cap and
one
hugging the cap's northern edge. The dark southern cap itself looked a
bit
darker towards its center.
For a final target, Jupiter was finally getting out of the heated
air
above the house, so it was time to see what it showed. I wasn't
disappointed
as the view was nearly as good as it had been at Saturn. I counted 7 or 8
belts with lots of fine detail, including a rather prominent white oval in
one of the temperate belts. The moons also showed some interesting color
variations at high power, although at low power, they seemed almost
colorless. I identified Io fairly easily, as its pale yellowish-orange
coloration made it stand out. Europa looked nearly white, while Ganymede
showed its larger and more greyish disk well. Callisto had a very pale
almost reddish-brown cast, although the color was quite subtle to say the
least. At this point, I noticed some frost forming on the side of the
tube
and the corrector plate was showing dewing as well, so it was time to
break
things down and get back inside to warm up a bit.

Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

Jeff Richards wrote:

Great review as always David. Now this begs the question: If you keep the
N9.25GPS what will you do with your beloved 10" Newt? And which will get
more use?

Keep them both??


"David Knisely" wrote in message
...
DS022604 RECENT OBSERVATIONS
by David Knisely

DATE: February 26th, 2004, 0130 to 0445 hrs UTC.
LOCATION: Beatrice, Nebraska, USA, 40.283N, 96.735W, (402m elevation)
INSTRUMENTS: Celestron NexStar 9.25GPS SCT, 78x, 195x, 297x, 388x, 479x,
CONDITIONS: Partly Cloudy, Temp. 30 deg. F. (-1.1 deg. C), wind calm.
UNAIDED-EYE ZENITH LIMITING MAGNITUDE: 5.0
SEEING (above 45 deg. altitude): 1.5 to 0.5 arc seconds (Antoniadi II)

OBJECTS OBSERVED: Venus, Mars, Moon, Saturn, Jupiter, Struve 872, Rigel
Sirius, M42.

OBSERVATIONS: I finally got a night when it wasn't near or below zero and
the
snow cover wasn't covering up the driveway. I had the new NexStar 9.25GPS
that I am reviewing out for cooldown while I went on a quick trip out to
Arbys for a sandwich. By the time I got back, all was ready, and unlike
previous outings with the 9.25, the seeing was quite good. After watching
the NexStar go though its alignment gymnastics (and doing some tweaking of
the alignment) my first target was brilliant Venus. Even at 78x, it

[rest of a good evening snipped]...

For a final target, Jupiter was finally getting out of the heated
air
above the house, so it was time to see what it showed. I wasn't
disappointed
as the view was nearly as good as it had been at Saturn. I counted 7 or 8
belts with lots of fine detail, including a rather prominent white oval in
one of the temperate belts. The moons also showed some interesting color
variations at high power, although at low power, they seemed almost
colorless. I identified Io fairly easily, as its pale yellowish-orange
coloration made it stand out. Europa looked nearly white, while Ganymede
showed its larger and more greyish disk well. Callisto had a very pale
almost reddish-brown cast, although the color was quite subtle to say the
least. At this point, I noticed some frost forming on the side of the
tube
and the corrector plate was showing dewing as well, so it was time to
break
things down and get back inside to warm up a bit.

If you decide to buy the scope, sounds like you will need a dew heater
where you live...

There exists a Nexstar discussion group at:

http://groups.yahoo.com/group/nexstar/

and an associated Website at:

http://www.nexstarsite.com/index.html

--
Pat O'Connell
Nexstar 114GT
which shows far more than I ever thought I'd see in a 114 mm telescope.

Great report, Thanks!
I am looking forward to owning the 9.25 OTA. It seems like a great
performer.
Cleardarkskies!
Orion

"David Knisely" wrote in message
...
DS022604 RECENT OBSERVATIONS
by David Knisely

DATE: February 26th, 2004, 0130 to 0445 hrs UTC.
LOCATION: Beatrice, Nebraska, USA, 40.283N, 96.735W, (402m elevation)
INSTRUMENTS: Celestron NexStar 9.25GPS SCT, 78x, 195x, 297x, 388x, 479x,
CONDITIONS: Partly Cloudy, Temp. 30 deg. F. (-1.1 deg. C), wind calm.
UNAIDED-EYE ZENITH LIMITING MAGNITUDE: 5.0
SEEING (above 45 deg. altitude): 1.5 to 0.5 arc seconds (Antoniadi II)

OBJECTS OBSERVED: Venus, Mars, Moon, Saturn, Jupiter, Struve 872, Rigel
Sirius, M42.

OBSERVATIONS: I finally got a night when it wasn't near or below zero and
the
snow cover wasn't covering up the driveway. I had the new NexStar 9.25GPS
that I am reviewing out for cooldown while I went on a quick trip out to
Arbys for a sandwich. By the time I got back, all was ready, and unlike
previous outings with the 9.25, the seeing was quite good. After watching
the NexStar go though its alignment gymnastics (and doing some tweaking of
the alignment) my first target was brilliant Venus. Even at 78x, it
showed
its gibbous form well, with a pure-white color. From there, it was a
short
slew to the moon, but one problem with Go-To operation is that the moon is
a very big target. I ended up looking at the area illuminated by only
Earthshine, so it took a little slewing to get back onto the illuminated
portion. The view, despite a little high cirrus, was spectacular, with a
high
level of fine detail visible. The sun was just rising on the central peak
of
Theophilus, so it was fun to watch more and more of the peak emerge from
the
darkness. The area around and south of Madler showed numerous tiny pits
in a
fine field on the west edge of Mare Nectaris. It was fun to slew around
all
over the surface, rather than having to reach up and nudge the scope
repeatedly to get things where I wanted them.
I could have just manually slewed the scope to Mars since it wasn't
very
far away from the moon, but since I had a high power eyepiece in the
scope, I
decided to let the scope do the work and see just how close it would come.
The slew didn't put Mars quite in the center, but it wasn't far away. At
297x and up, the planet was still quite tiny (5.76" arc), but surprisingly
showed a vague dark patch (probably Mare Erythraeum) across the middle of
the
disk, along with a hint of a bluish patch around the south polar region.
From Mars, it was on to Rigel, and even at 78x, the star's tiny
faint
companion was nicely shown, with jet-black sky between them. At 297x, the
companion was easier to see and occasionally showed a diffraction disk
when
the seeing settled down. With seeing this good, I decided to try for the
E
and F stars in the Trapezium, so with a couple of keystrokes, I sent the
scope slewing to M42. Sure enough, both E and F were visible through some
of the high haze which was passing through that region, along with the
very
mottled nebulosity of the central core of the Orion nebula. With these
successes, I decided to try for the "pup" white dwarf companion to Sirius.
Unfortunately, I didn't get more than a hint of it, as the seeing at that
bright star (located over a nearby home with a heat vent) made the area
around it mottled with "false" companions.
I had seen in Richard Digon-Smith's book STARLIST 2000 that he noted
the faint double star Struve 872 as one of the more colorful binaries.
The
book indicated that it was a gold-blue pair, so I was off to try and find
it. While the database of the NexStar has a number of the most prominent
double stars in its double-star list, Struve 872 wasn't one of them (and
from
the view I got, I can see why it didn't make the list). Digon-Smith's
book
doesn't give the coordinates for the double, so I had to go to Megastar to
find out where it was. I dutifully input the coordinates to the NexStar,
and
it obligingly slewed to the double. As I have seen with other colorful
claims in Digon-Smith's book, this one also wasn't all that accurate. It
consists of a magnitude 6.9 star and a mag. 7.5 star about 11.3 arc
seconds
apart, with very little difference in color between them. The primary was
perhaps a pale yellowish-white, and the companion was maybe a bit more
yellow
but fainter, so it was difficult to see much of a color contrast here.
I had had enough of doubles for a while, so it was on to Saturn. My
first look brought out an immediate "WOW!" as seeing was rock-steady. The
contrast provided by the StarBright XLT coatings put a lot of black sky
between the inner moons of Dione, Rhea, and Tethys and the edges of the
rings. I had to search around for a while, but I finally did locate faint
Hyperion amongst the numerous field stars of Gemini. Titan showed its
disk,
and I did occasionally glimpse Enceladus, but Saturn was simply stunning!
It
was one of those "Mack Truck through the Cassini Division" nights, with
the
planet taking all the power I could muster. The Crepe ring showed its
dark
gray form well, hugging the inside of the B-ring, while the B-ring showed
its "step" variations in brightness across its span. I didn't see the
true
Encke Division, but the rings still showed a lot of detail. The planet
itself showed the narrow fine belt that sits right on the equator, along
with
the broad main orangish band. That large band almost appeared to contain
two
distinct components, although the poleward side was rather diffuse. I
could
also see two other very fine belts, one north of the dark polar cap and
one
hugging the cap's northern edge. The dark southern cap itself looked a
bit
darker towards its center.
For a final target, Jupiter was finally getting out of the heated
air
above the house, so it was time to see what it showed. I wasn't
disappointed
as the view was nearly as good as it had been at Saturn. I counted 7 or 8
belts with lots of fine detail, including a rather prominent white oval in
one of the temperate belts. The moons also showed some interesting color
variations at high power, although at low power, they seemed almost
colorless. I identified Io fairly easily, as its pale yellowish-orange
coloration made it stand out. Europa looked nearly white, while Ganymede
showed its larger and more greyish disk well. Callisto had a very pale
almost reddish-brown cast, although the color was quite subtle to say the
least. At this point, I noticed some frost forming on the side of the
tube
and the corrector plate was showing dewing as well, so it was time to
break
things down and get back inside to warm up a bit.

Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************




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Pat O'Connel wrote:

Jeff Richards wrote:

Great review as always David. Now this begs the question: If you keep the
N9.25GPS what will you do with your beloved 10" Newt? And which will get
more use?

Keep them both??

Yup, I may indeed keep them both, as their optical difference isn't huge
(visible, but not not enormous), and the SCT is something I have been looking
for as I get closer to CCD imaging in the near future. The 9.25GPS review
will be on the Cloudynights web page in the near future. Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

From there, it was a short
slew to the moon, but one problem with Go-To operation is that the moon is
a very big target. I ended up looking at the area illuminated by only
Earthshine, so it took a little slewing to get back onto the illuminated
portion.

That was a tough break, having to slew from the center all the way
over to the
illuminated part of the moon! A beginner could get completely lost in
this operation
and miss the moon entirely... ;-)) Actually, I am surprised that
some GO TO scope
maker has not yet incorporated libration tables and crater coordinates
into the
scope computer. Wouldn't be that big of a job

I had had enough of doubles for a while, so it was on to Saturn. My
first look brought out an immediate "WOW!" as seeing was rock-steady. The
contrast provided by the StarBright XLT coatings put a lot of black sky
between the inner moons of Dione, Rhea, and Tethys and the edges of the
rings. I had to search around for a while, but I finally did locate faint
Hyperion amongst the numerous field stars of Gemini. Titan showed its disk,
and I did occasionally glimpse Enceladus, but Saturn was simply stunning! It
was one of those "Mack Truck through the Cassini Division" nights, with the
planet taking all the power I could muster. The Crepe ring showed its dark
gray form well, hugging the inside of the B-ring, while the B-ring showed
its "step" variations in brightness across its span. I didn't see the true
Encke Division, but the rings still showed a lot of detail. The planet
itself showed the narrow fine belt that sits right on the equator, along with
the broad main orangish band. That large band almost appeared to contain two
distinct components, although the poleward side was rather diffuse. I could
also see two other very fine belts, one north of the dark polar cap and one
hugging the cap's northern edge. The dark southern cap itself looked a bit
darker towards its center.
For a final target, Jupiter was finally getting out of the heated air
above the house, so it was time to see what it showed. I wasn't disappointed
as the view was nearly as good as it had been at Saturn. I counted 7 or 8
belts with lots of fine detail, including a rather prominent white oval in
one of the temperate belts. The moons also showed some interesting color
variations at high power, although at low power, they seemed almost
colorless. I identified Io fairly easily, as its pale yellowish-orange
coloration made it stand out. Europa looked nearly white, while Ganymede
showed its larger and more greyish disk well. Callisto had a very pale
almost reddish-brown cast, although the color was quite subtle to say the
least. At this point, I noticed some frost forming on the side of the tube
and the corrector plate was showing dewing as well, so it was time to break
things down and get back inside to warm up a bit.

I think I have to move west, the seeing in New Jersey never gets like
this! I don't get
to see detail like that until after a lot of computer crunching with
Registax-II.
Clif Ashcraft

Hello, David,
Great report!
Some questions:
How helpful was Go-To for you? You know the sky very well indeed,
and you have a very dark site. I am sure you can find things very very easily
yourself. Is it important that Go-To is faster than finding it yourself? Or is
the tracking aspect of Go-To what is important?
Let me ask your advice about my own situation. I live in a light polluted
urban area. I use a Starmaster 11 ELT f/4.55 Shorty, with Sky Commander digital
setting circles from my driveway w hen I am unable to journey to a dark sky
site.. I find the Sky Commander DSCs enormously helpful because in an urban area
there are not enough stars to star hop With the DSC's I can find just about
anything. I know the skies fairly well but I can't put that into play owing to
light pollution.
Now Starmaster has announced that GoTo is available for the 11 inch models,
and can be retrofitted to my scope. It reputedly works great but it is not
inexpensive. I am primarily an observer of DSOs rather than of planets so I don't
use very high magnification, say over 200 or so, very often. How helpful would
Go-To plus tracking be in my situation if I already have DSCs?
Thanks for any thoughts you may have on this subject.
Clear skies,
Bill Meyers

David Knisely wrote:

DS022604 RECENT OBSERVATIONS
by David Knisely

DATE: February 26th, 2004, 0130 to 0445 hrs UTC.
LOCATION: Beatrice, Nebraska, USA, 40.283N, 96.735W, (402m elevation)
INSTRUMENTS: Celestron NexStar 9.25GPS SCT, 78x, 195x, 297x, 388x, 479x,
CONDITIONS: Partly Cloudy, Temp. 30 deg. F. (-1.1 deg. C), wind calm.
UNAIDED-EYE ZENITH LIMITING MAGNITUDE: 5.0
SEEING (above 45 deg. altitude): 1.5 to 0.5 arc seconds (Antoniadi II)

OBJECTS OBSERVED: Venus, Mars, Moon, Saturn, Jupiter, Struve 872, Rigel
Sirius, M42.

OBSERVATIONS: I finally got a night when it wasn't near or below zero and the
snow cover wasn't covering up the driveway. I had the new NexStar 9.25GPS
that I am reviewing out for cooldown while I went on a quick trip out to
Arbys for a sandwich. By the time I got back, all was ready, and unlike
previous outings with the 9.25, the seeing was quite good. After watching
the NexStar go though its alignment gymnastics (and doing some tweaking of
the alignment) my first target was brilliant Venus. Even at 78x, it showed
its gibbous form well, with a pure-white color. From there, it was a short
slew to the moon, but one problem with Go-To operation is that the moon is
a very big target. I ended up looking at the area illuminated by only
Earthshine, so it took a little slewing to get back onto the illuminated
portion. The view, despite a little high cirrus, was spectacular, with a high
level of fine detail visible. The sun was just rising on the central peak of
Theophilus, so it was fun to watch more and more of the peak emerge from the
darkness. The area around and south of Madler showed numerous tiny pits in a
fine field on the west edge of Mare Nectaris. It was fun to slew around all
over the surface, rather than having to reach up and nudge the scope
repeatedly to get things where I wanted them.
I could have just manually slewed the scope to Mars since it wasn't very
far away from the moon, but since I had a high power eyepiece in the scope, I
decided to let the scope do the work and see just how close it would come.
The slew didn't put Mars quite in the center, but it wasn't far away. At
297x and up, the planet was still quite tiny (5.76" arc), but surprisingly
showed a vague dark patch (probably Mare Erythraeum) across the middle of the
disk, along with a hint of a bluish patch around the south polar region.
From Mars, it was on to Rigel, and even at 78x, the star's tiny faint
companion was nicely shown, with jet-black sky between them. At 297x, the
companion was easier to see and occasionally showed a diffraction disk when
the seeing settled down. With seeing this good, I decided to try for the E
and F stars in the Trapezium, so with a couple of keystrokes, I sent the
scope slewing to M42. Sure enough, both E and F were visible through some
of the high haze which was passing through that region, along with the very
mottled nebulosity of the central core of the Orion nebula. With these
successes, I decided to try for the "pup" white dwarf companion to Sirius.
Unfortunately, I didn't get more than a hint of it, as the seeing at that
bright star (located over a nearby home with a heat vent) made the area
around it mottled with "false" companions.
I had seen in Richard Digon-Smith's book STARLIST 2000 that he noted
the faint double star Struve 872 as one of the more colorful binaries. The
book indicated that it was a gold-blue pair, so I was off to try and find
it. While the database of the NexStar has a number of the most prominent
double stars in its double-star list, Struve 872 wasn't one of them (and from
the view I got, I can see why it didn't make the list). Digon-Smith's book
doesn't give the coordinates for the double, so I had to go to Megastar to
find out where it was. I dutifully input the coordinates to the NexStar, and
it obligingly slewed to the double. As I have seen with other colorful
claims in Digon-Smith's book, this one also wasn't all that accurate. It
consists of a magnitude 6.9 star and a mag. 7.5 star about 11.3 arc seconds
apart, with very little difference in color between them. The primary was
perhaps a pale yellowish-white, and the companion was maybe a bit more yellow
but fainter, so it was difficult to see much of a color contrast here.
I had had enough of doubles for a while, so it was on to Saturn. My
first look brought out an immediate "WOW!" as seeing was rock-steady. The
contrast provided by the StarBright XLT coatings put a lot of black sky
between the inner moons of Dione, Rhea, and Tethys and the edges of the
rings. I had to search around for a while, but I finally did locate faint
Hyperion amongst the numerous field stars of Gemini. Titan showed its disk,
and I did occasionally glimpse Enceladus, but Saturn was simply stunning! It
was one of those "Mack Truck through the Cassini Division" nights, with the
planet taking all the power I could muster. The Crepe ring showed its dark
gray form well, hugging the inside of the B-ring, while the B-ring showed
its "step" variations in brightness across its span. I didn't see the true
Encke Division, but the rings still showed a lot of detail. The planet
itself showed the narrow fine belt that sits right on the equator, along with
the broad main orangish band. That large band almost appeared to contain two
distinct components, although the poleward side was rather diffuse. I could
also see two other very fine belts, one north of the dark polar cap and one
hugging the cap's northern edge. The dark southern cap itself looked a bit
darker towards its center.
For a final target, Jupiter was finally getting out of the heated air
above the house, so it was time to see what it showed. I wasn't disappointed
as the view was nearly as good as it had been at Saturn. I counted 7 or 8
belts with lots of fine detail, including a rather prominent white oval in
one of the temperate belts. The moons also showed some interesting color
variations at high power, although at low power, they seemed almost
colorless. I identified Io fairly easily, as its pale yellowish-orange
coloration made it stand out. Europa looked nearly white, while Ganymede
showed its larger and more greyish disk well. Callisto had a very pale
almost reddish-brown cast, although the color was quite subtle to say the
least. At this point, I noticed some frost forming on the side of the tube
and the corrector plate was showing dewing as well, so it was time to break
things down and get back inside to warm up a bit.

Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

Bill Meyers wrote:

How helpful was Go-To for you?

Well, it was far from necessary, as I could easily see all the targets I
looked at with the unaided eye (except for the 6th magnitude double star
Struve 872, which would have required an extended star hop). I am reviewing
the instrument, so a lot of my using the Go-To under cold conditions was
continuing testing (I learned the hand controller goes blank at temperatures
below zero). The NexStar's Go-To was a real convenience (and kind of fun to
use, at least for a while), so under light-polluted conditions, I could easily
see using it more often (and I may, since I may buy the instrument I am
reviewing).
Where it might really help me more is with certain variable stars I would
like to monitor, as getting to the fields around the fainter ones in rather
hazy or light-polluted skies might be a bit trying at times. The Go-To could
help me do measurements on more stars per night, since I would not have to
spend as much time finding the right spot on the sky and getting the scope on
it. I did use the Go-To one dark night on deep-sky, but many of the objects I
used it on I could have moved the scope to faster than the computer's Go-To
slewed to them, but it was still amusing for a bit to "shoot fish in a
barrel". However, after a while, it was less fun, as part of the enjoyment I
get is in tracking down a faint fuzzy using only a star chart, my finder, and
a low-power eyepiece.

Now Starmaster has announced that GoTo is available for the 11 inch models,
and can be retrofitted to my scope. It reputedly works great but it is not
inexpensive. I am primarily an observer of DSOs rather than of planets so I don't
use very high magnification, say over 200 or so, very often. How helpful would
Go-To plus tracking be in my situation if I already have DSCs?

It may be a little more convenient to use the Go-To, although again, the
DSCs should be enough if you want to use them. In many cases, the Go-To's
pointing accuracy isn't quite good enough to put an object square in the
middle of a high-power field of view each time you slew (especially in the
altazimuth mode). Locating such objects using Go-To requires using a low
power wide-field eyepiece so that you can get an object somewhere in the field
before you increase the power. You still have to know the sky to do the
alignments, as well as knowing it well enough to recognize when the scope's
computer is confused due to some mechanical problem (tripod gets kicked, scope
settles, grease gets too stiff and something doesn't move right). You can
also get some wierd things happening due to "operator error", as happened to
me a couple of times when I pushed a *really* wrong button while looking in
the eyepiece. These electro-mechanical gadgets aren't perfect, and will
sometimes do a few strange things, so you have to be on your guard. Clear
skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

Thanks, David, this gives me a really good picture of what the pros and cons of
Go-To might be in my particular case.
Since I am using a Starmaster scope, which is really custom crafted and
individually tested before being sold rather than mass produced like and SCT, I have
good confidence that the Go-To will work fine, or Rick wouldn't sell it. And Rick does
great after-sale service so if anything did go wrong it would be remedied. The
usefulness for a Dob as small as 11 inches is what I was wondering about. Go-To costs
very much more than Sky Commander alone but of course Go-To includes trackkng..
I am very struck by your feeling that after a while the Go-To seems to leave you
out of the finding process. I myself enjoy zeroing in on an object with the Sky
Commander I feel I am participating in finding the object.. It's more impressive to
bystanders if I just point the Telrad at it and there it is in the eyepiece, but this
doesn't work for me in light polluted skies.
I could find the DSOs in a dark sky without Go-To, but in a hazy or light polluted
sky, I need the Sky Commander for many of the DSOs. Buying and having installed Sky
Commander was a great decision in my case.
I also notice that you find Go-To requires that you first use of a low power wide
field eyepiece to acquire the object, just as the Sky Commander does, at least as I use
it. Some people say they can use Sky Commander to put the object in the field of a
medium or even high power eyepiece but I can't do that..
For the larger Dobs, the focal length is longer and so the maximum true field
of view is smaller, and there is more attention paid usually to very faint objects,
so Go-To might be more valuable for that kind of scope. From what I can tell from
people's postings, Go-To has already proved itself valuable for the larger Dobs, but it
is the smaller ones that concern me.
After reading your response, I think what I will do is wait until I see instances
of Go-To on one of the smaller Starmasters, say the 11 or the 12.5, at a star party,
and talk to the users. Until then, I will hold off on the purchase, I think.
Thanks again for your help.
Clear skies,
Bill Meyers


David Knisely wrote:

Bill Meyers wrote:

How helpful was Go-To for you?

Well, it was far from necessary, as I could easily see all the targets I
looked at with the unaided eye (except for the 6th magnitude double star
Struve 872, which would have required an extended star hop). I am reviewing
the instrument, so a lot of my using the Go-To under cold conditions was
continuing testing (I learned the hand controller goes blank at temperatures
below zero). The NexStar's Go-To was a real convenience (and kind of fun to
use, at least for a while), so under light-polluted conditions, I could easily
see using it more often (and I may, since I may buy the instrument I am
reviewing).
Where it might really help me more is with certain variable stars I would
like to monitor, as getting to the fields around the fainter ones in rather
hazy or light-polluted skies might be a bit trying at times. The Go-To could
help me do measurements on more stars per night, since I would not have to
spend as much time finding the right spot on the sky and getting the scope on
it. I did use the Go-To one dark night on deep-sky, but many of the objects I
used it on I could have moved the scope to faster than the computer's Go-To
slewed to them, but it was still amusing for a bit to "shoot fish in a
barrel". However, after a while, it was less fun, as part of the enjoyment I
get is in tracking down a faint fuzzy using only a star chart, my finder, and
a low-power eyepiece.

Now Starmaster has announced that GoTo is available for the 11 inch models,
and can be retrofitted to my scope. It reputedly works great but it is not
inexpensive. I am primarily an observer of DSOs rather than of planets so I don't
use very high magnification, say over 200 or so, very often. How helpful would
Go-To plus tracking be in my situation if I already have DSCs?

It may be a little more convenient to use the Go-To, although again, the
DSCs should be enough if you want to use them. In many cases, the Go-To's
pointing accuracy isn't quite good enough to put an object square in the
middle of a high-power field of view each time you slew (especially in the
altazimuth mode). Locating such objects using Go-To requires using a low
power wide-field eyepiece so that you can get an object somewhere in the field
before you increase the power. You still have to know the sky to do the
alignments, as well as knowing it well enough to recognize when the scope's
computer is confused due to some mechanical problem (tripod gets kicked, scope
settles, grease gets too stiff and something doesn't move right). You can
also get some wierd things happening due to "operator error", as happened to
me a couple of times when I pushed a *really* wrong button while looking in
the eyepiece. These electro-mechanical gadgets aren't perfect, and will
sometimes do a few strange things, so you have to be on your guard. Clear
skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************