Goto Nixed for Club by AAVSO Oldtimer

"This club doesnt need go to".

"They should learn astronomy the way I had to _ the hard way".

"We already invested $1500 in a conventional scope and Go To
wasn't in the plan ............. in 1986".

"Screw ___________ and those other trouble makers who want
the easy way."


AAVSO Oldtimer

On Oct 2, 11:53 pm, Goto is Bunk wrote:
"This club doesnt need go to".

"They should learn astronomy the way I had to _ the hard way".

"We already invested $1500 in a conventional scope and Go To
wasn't in the plan ............. in 1986".

"Screw ___________ and those other trouble makers who want
the easy way."

AAVSO Oldtimer

"I remember when...cough, cough." Old people are KILLING the hobby.
Being exclusionary is a hallmark of the breed. Read anything written
by a club, you'll find all sorts of sad pop-culture references having
their origin in the 1960s and 1970s. No wonder young people avoid the
hobby.

"Rich" wrote in message
ups.com...
On Oct 2, 11:53 pm, Goto is Bunk
wrote:
"Screw ___________ and those other trouble makers who want
the easy way."

AAVSO Oldtimer

"I remember when...cough, cough." Old people are KILLING the
hobby.

DAMN! All this time I thought it was light pollution.
Guess I need to refocus my attention on getting old
people to take up other interests.
--

Rick Evans
---------------------------------------------------------------
Lon -71° 04' 35.3"
Lat +42° 11' 06.7"

WELL, when I was a boy, all WE had were big rocks set in circles, and we
were THANKFUL for it.
whippersnappers...

Marty

Hello, everyone.

As someone who got interested in amateur astronomy during
the Sputnik era, I'd say that we can have a happy balance
of the old and new without excluding anyone.

The fact that I like starhopping in light-polluted skies,
and using sidereal time as a navigating aid to help
determine what I am likely to see through a rather
constrained observing window, doesn't mean that you
can't use a go-to or computerized push-to arrangement,
or manual setting circles for that matter.

Mutual appreciation isn't the worst approach. Thus the
fact that I have a commercial scope doesn't stop me from
appreciating all the ATM folks who indeed have an
understanding of the craft in ways I do not, and helped
to pave way for all the commercial Dobsonians (i.e.
Newtonian reflectors on Dobsonian mounts) including mine.

Club newsletters should ideally reflect the mix of
readers, young and old. Please let say that what we
older folks have to share can be a treasure; but
there needs to be space for young people, and newcomers
to our pursuit of all ages, to have their say.

There's a lot of humor on Usenet about passionate
allegiances that people have to a given computer
operating system or programming style, and I guess
that amateur astronomy can be similar. This kind of
enthusiasm can have great charm when exhibited by the
right person in the right way, like our SCT maven
Unk Rod.

However, a lot of choices can be by circumstance and
happenstance. I wonder if I would be so happy with
"navigation by meridian and sidereal time" if my
observing site had an orientation other than
southerly, or if I were viewing a larger portion
of the sky at any one time.

Why not state it positively: listening to young
people, and newcomers of all ages, and explaining
the range of options so that they can make their
own informed choices (not necessarily the same as
ours) and then share their own adventures, is a
key to success.

A good newsgroup or club is an open system, open
to experience, beginner's enthusiasm, and a lot
of mutual learning.

Most appreciatively,

Margo Schulter

On Wed, 3 Oct 2007 16:45:01 -0500, Marty wrote:

WELL, when I was a boy, all WE had were big rocks set in circles, and we
were THANKFUL for it.
whippersnappers...

Marty

When I were a lad, we 'ad to carve our own lenses out of wood.

Margo Schulter wrote:
The fact that I like starhopping in light-polluted skies,
and using sidereal time as a navigating aid to help
determine what I am likely to see through a rather
constrained observing window, doesn't mean that you
can't use a go-to or computerized push-to arrangement,
or manual setting circles for that matter.

That's quite true - manual setting circles let you point your properly
polar-aligned telescope at a piece of sky by R.A. and declination.
Which basically means that if you can find north, and know what your
latitude is, you can get pretty close to places in the sky without
knowing the constellations and without star-hopping... even without a
computer.

When computerized go-to was a very expensive feature on telescopes, I
suppose people could have been concerned about the tension caused by
people buying their way in to astronomy. However, if one is concerned
about astronomy clubs being riven by the divide between rich and poor
- today one should worry about *light pollution*, since deep-sky
observing seems to be what is all the rage, for which one needs a
*car* to drive out in the country even before one needs a 17-inch
Dobsonian.

In a way, this reminds me of the debate over Morse Code in ham radio.
Learning the constellations can be seen as a way to keep the riff-raff
out... because it is more convenient to deal with fellow members who
share a serious commitment to observing. The trouble is, of course,
that the existence of go to - and the light pollution that renders the
constellations less recognizable on any given night, with fewer stars
visible - is, to an extent, turning this skill into an obsolete skill.

So if attitudes turn learning the constellations into a precondition
for advancement, the result is going to be fewer members.

My telescope has manual setting circles, not go to, and I'm afraid the
only constellations I can recognize without a star atlas are the Big
Dipper and Orion. But with a well-collimated finder, I can certainly
find the planets from my light-polluted backyard. As I have an
interest in astrophotography, and go to scopes tend to be altazimuth
(yes, the smaller ones can often be tilted up...) I'm waiting until
they start adding computer controlled image rotators... or they start
selling beginning amateurs telescopes with horseshoe mounts, which
avoid the problem of hitting your head on the telescope mounting when
trying to observe by using the Nasmyth focus.

I think I'll have a long wait for any of those... but perhaps other
ingenious solutions to the problem of equatorial mounting will be
forthcoming!

John Savard

Quadibloc wrote:

When computerized go-to was a very expensive feature on telescopes, I
suppose people could have been concerned about the tension caused by
people buying their way in to astronomy. However, if one is concerned
about astronomy clubs being riven by the divide between rich and poor
- today one should worry about *light pollution*, since deep-sky
observing seems to be what is all the rage, for which one needs a
*car* to drive out in the country even before one needs a 17-inch
Dobsonian.

Hi, John.

Certainly I'd agree that for _optimal_ deep-sky observing, a dark sky
and therefore from most locations a car (your own or a very helpful
friend's who has similar inclinations) are bigger essentials than
aperture fever grin.

However, as a beginning urban DSO observer, I would emphasize that
it can be done without a car from an urban area, albeit with some
obvious compromises. Something like M24 or M25, which can come
through nicely even in nautical twilight, is beautiful in
these bright skies (say limiting magnitude of 3.5 at the relevant
distance from the horizon). Finding something like M22 is harder,
and the view a lot less spectacular, than in darker skies -- but
the pleasure of finding that "faint fuzzy" is something else again.

The problem, of course, is especially with lower surface brightness
objects. Looking through a list, I ask myself if a few galaxies in
the Fornax Group might have enough surface brightness to compete
with an urban skyglow maybe around magnitude 17.0 per arc-second^2.
Will my Astronomik CLS filter help -- broadband LPR filters can
make some difference, but often a modest one? Maybe it gives a
new meaning to "extreme DSO" observing: seeing with a 200mm Dob
what you could easily see with a small scope or even binoculars
in darker skies.

In a way, this reminds me of the debate over Morse Code in ham radio.
Learning the constellations can be seen as a way to keep the riff-raff
out... because it is more convenient to deal with fellow members who
share a serious commitment to observing. The trouble is, of course,
that the existence of go to - and the light pollution that renders the
constellations less recognizable on any given night, with fewer stars
visible - is, to an extent, turning this skill into an obsolete skill.

Maybe your striking analogy points to one asymmetry: in ham radio, Morse
Code transmitted by CW can be a viable mode of communication when the
noise level or "radio pollution" would make voice difficult to decipher,
while in amateur astronomy light pollution makes the skill of starhopping
more difficult to apply.

For me, maybe the light pollution makes starhopping a "deeper" skill: using
binoculars, or even starhopping through the eyepiece, where someone
in the country could use a Telrad. The "deep" part also means relying
on more detailed charts or atlases to match the aperture and magnification
for starhopping which can partially(!) compensate for brighter skies.

So if attitudes turn learning the constellations into a precondition
for advancement, the result is going to be fewer members.

Agreed the in urban conditions, I'm not sure how many people are
crazy enough to adopt my methods, and especially to do so and enjoy
it grin. That might be a rather strange initiation rite if we're
trying to attract a substantial number of people.

My telescope has manual setting circles, not go to, and I'm afraid the
only constellations I can recognize without a star atlas are the Big
Dipper and Orion. But with a well-collimated finder, I can certainly
find the planets from my light-polluted backyard. As I have an
interest in astrophotography, and go to scopes tend to be altazimuth
(yes, the smaller ones can often be tilted up...) I'm waiting until
they start adding computer controlled image rotators... or they start
selling beginning amateurs telescopes with horseshoe mounts, which
avoid the problem of hitting your head on the telescope mounting when
trying to observe by using the Nasmyth focus.

While my Dob doesn't have altaz setting circles, I can use my observing
window as something of a guide, since I'd estimate that the range around
the meridian is between hour angles of roughly -1h15m and +0h35m, and
the range of declinations from about -7 degrees to maybe -35 degrees
(I need to test this more). Knowing the sidereal time, I can make a
good guess on the right star atlas page(s) to consult. With an eyepiece
field of about 2 degrees, my window at any one time might be 15 fields
or so in either dimension.

As for navigating by constellations, I can recognize naked-eye landmarks
like the _Chaynik_ (Yiddish for "tea kettle") of Sagittarius, or Scorpio
with its prime attraction of Antares. Even at mag 3.5 or so, these provide
some guidance. However, it's often binocular/finder or even eyepiece
asterisms that help me with my navigation.

For example, there's the "Antares-Rho Ophiuchi pentagon" right above M80;
a "Flipped Radical Sign" around 17h30m preceding M20-M21 and M8; and a kind
of trapezoid formed by four bright stars of the Chaynik or Sagittarius
around 19h00m. There's also a graceful "Semicircle" of stars in Capricornus
not too far from M30; and a "Z" asterism in Sculptor from which one can
sweep down a bit to NGC 253 (which I hope I can see with enough patience,
more experience, and the CLS filter).

To me, "urban starhopping" means a touch of celestial mechanics plus lots
of binocular or telescopic asterisms and some detailed charts or atlases
to help keep them in order.


I think I'll have a long wait for any of those... but perhaps other
ingenious solutions to the problem of equatorial mounting will be
forthcoming!

One thing I need to learn, as your informative discussion makes me
realize, is what a "Nasmyth focus" is, and also a horseshoe mount --
time for some Googling and also a look at the library astronomy
section.

John Savard


Most appreciatively,

Margo Schulter

Lat. 38.566 Long. -121.430

Margo Schulter wrote:
One thing I need to learn, as your informative discussion makes me
realize, is what a "Nasmyth focus" is, and also a horseshoe mount --
time for some Googling and also a look at the library astronomy
section.

My website illustrates a horseshoe mount, but while it shows what a
Coude focus is, it doesn't discuss the Nasmyth focus. For those too
lazy to Google, here are the explanations...

The most common way of providing an equatorial mount for an amateur
telescope used to be - and is again - the German equatorial mounting,
invented by Fraunhofer.

This is the one that's a bit awkward, and requires a counterweight.
Used for f/8 and f/6 reflectors, used for refractors.

The Schmidt-Cassegrain telescopes tend to use fork mounts. These need
to be sturdy, since the telescope is at the far end of the mount.

The English mounting is a fork pivoted at both ends, so the telescope
is in a box. That means you can't point it at the North Pole.

A horseshoe mount tries to compromise between the fork and the English
by having a fork at the bottom, extending the tines upwards to a disk
with an opening in it, so the telescope can point to the North Pole,
the disk resting on a bearing to support the telescope from above as
well as below. The 200-inch Hale telescope at Mount Palomar uses this
style of mounting.

The coude focus is what telescopes use to bring starlight to big,
heavy spectrometers.

Main mirror reflects light to Cassegrain secondary. Secondary reflects
light to a diagonal which goes just where the telescope is pivoted for
declination. Mirrors in the mounting take the light through the pivot
in the base of the mounting that turns the telescope for R.A. - in
this way, the spectroscope can stay still and observe! No craning your
neck on a telescope with the coude focus.

The Nasmyth focus is based on the principle that going from the
declination pivot to the R.A. pivot involves lots of mirrors and relay
lenses - so it quits, and just leaves in the diagonal close to the
mirror - one looks through the declination pivot. This is a reasonable
compromise that keeps the observer's head out of a horseshoe mount.

John Savard

Quadibloc wrote:
My website illustrates a horseshoe mount, but while it shows what a
Coude focus is, it doesn't discuss the Nasmyth focus.

I've remedied that omission:
http://www.quadibloc.com/science/opt03.htm

John Savard