Expert: Tom Whiting - 10/30/2005

Question
Hi Tom,
Im hoping you can help me. Im an American guy who retired here in Cebu Philippines about 5 years ago.
After my father died I inherited his small DOB (4"). My wife and I realy enjoyed lQQking at the skies with it, Mostly the moon, LOL. Anyway, I bought a 12" DOB and we realy enjoy this as well. Being amatures (not even sure we qualify for amature status)maybe I should say newbes, we have no Idea what planets we are lQQking at with the exeption of Jupiter and Saturn, only because of all the moons and the rings.
I bought some lenses 9MM, 10MM WA, 26MM WA, 32MM WA,  2x, 3x, and 5x Barlows, as well as a laser collimator. Im not sure my choices were all that great.
1 Planet we lQQk at I cant quite get a sharp view for some reason, but it has a blue line (not straight and not uniformed) going around it on the upper half. The other Planet appears to eclipsed, or only like a quarter to half moon shape. I can only see half of it with no details at all. I only have limited viewing time of the second planet as it disapears quickly (about 1 hour)out of sight right after sunset.
I have scowered all over the internet to find out what planets these are lQQKing at hubble pictures and anything else I can thing of to no avail. I have also been trying to find out what I should be able to see with a 12" DOB. The Planets I speak of are very very small when viewing no matter what lenses or combinations of Barlow and lens I use. The view is rather disapointing.
Maybe the 2 planets we are lQQking at are so far away that this is the best view i could hope for with a 12"
The only star map I have found is at http://home.astronomy.com.ph/starmaps/ right now im lQQking at map 21
but this is no help since it doesnt list the planets.
There are very very few telescopes here in the Philippines so there arent any star watching parties or anyone to help newcomers that we have found.
Any help would be greatly appreciated.
Thanx,
Craig Upton  

Answer
Hi Craig,
Sorry I didn't answer sooner, but we were down at Cherry
Springs State Park (PA) observing all weekend...just got home 2 hours ago.....

 Well, You just verify what we tell all the new people....in our great hobby, equipment (scopes) come LAST...knowledge of the naked eye night sky comes FIRST.  For,  if you can't point your finger to the Andromeda Galaxy, the Beehive star cluster, or Mars,  (all naked-eye objects),
how are you going to point a telescope --which only sees
a 1/2 degree field of view (FOV)-- at them?
Make your first task, to learn the naked-eye night sky....
otherwise, you are just 'spinning your wheels' with a scope...
and actually, a scope is useless to you, at this point.

Best thing to do is put the telescope away for a few months,
purchase a good star chart like Cambridge 2000.0 Star Atlas, or Norton's Star atlas and Reference Handbook, take 4-6 months and learn the naked-eye night sky...then you will be ready for a telescope.  (Sailors of the seas need a top-notch
charts, and so do 'sailors' of the stars.)

You can't find the Armory in Columbus Ohio until you first
know where Ohio (constellation) is, then the city of
Columbus (a guide star), then offset 10 miles to the south
to find the Armory....we do exactly the same thing in
Astronomy.  But you have to first know your "Ohio's "....
your constellations and some of the stars in those
constellations....just like the cities of Ohio.
Fortunately, it ain't that hard...if you can memorize and
learn the states PA, Ohio, Indiana, Illinois- 4 adjoining
areas, then you can also learn and memorize Scorpius,
Sagittarius, Capricornus, and Aquarius, 4 adjoining areas
(constellations) of the night sky.  NOTE -the word constellation and area of sky are the same meaning...that's
all they are...area's for identification purposes only.
But you have to know them first...just like you have to
know "Ohio" first, before locating anything in Ohio.

The super-bright planet you're viewing in the west shortly after sunset is no doubt Venus....since Mercury and Venus
are inside the Earth's orbit, both planets go thru phases
just like our own moon.  Currently Venus is at maximum
eastern elongation, thus we are viewing it as a half-moon
shape, 50% illuminated.  Over the next few months, it will become a thinner and thinner (but larger) crescent phase, as it passes betweeen the Earth and Sun, but approaches - thus a bigger crescent.
Mercury does exactly the same thing.
(This is basic stuff you should have known before even
purchasing a telescope, so you know what to look for when
you see it - an excellent example that you  need the
Knowledge" before the observing!)  There are no details
on Venus because the planet is perpetually enshrouded
with "sulfuric acid" clouds, so it's always a bland cream
white color...again very basic details that, honestly, you
should have already known in your readings of the subject
of astronomy.  BTW, ours is a knowledge hobby, not
a flashy visuals hobby....if you just want flashy visuals,
then go watch TV.  There are only about a dozen flashy
visuals in the night sky...the moon, a few planets, and a few
deep sky objects.....they grow old mighty fast....
now you are down to the dim, small fuzzies.....thus, the enjoyment comes, in part, the knowledge that the fuzzy galaxy you are viewing is 65 million lightyears distant...and not how non-flashy it looks to you...to even be able to see it at all, is remarkable to us in the hobby.  So if all you want
is the flashy visuals, then go watch a movie.

I don't know what is causing the "blue line" looking at....
what planet?  It could be an internal reflection due to using
a cheap eyepiece, a streetlight off in the distance, or
extreme poorly collimated telescope to begin with....
have you looked down the eyepiece hole with no eyepiece
in place?  What do you see? Is the primary mirror perfectly
super-imposed on a perfectly tilted (45 degrees) diagonal
mirror? Are the 3 or 4 secondary holder vanes perfectly
centered in the reflection of the diagonal?  If not, you are out of collimation.  (Your optical axis is not aligned- very
critical that it is, otherwise...your scope is nearly useless.)
You need to insert the laser collimator into the eyepiece hole,
first align the diagonal mirror so the laser light strikes exactly on the center of the primary mirror (You also have to put a
{gummy paper reinforcement ring} dead center on your
primary mirror so you can properly collimate it with a laser).
Don't worry, you can't hurt the primary mirror, as the center of the primary is in the shadow of the secondary mirror, and thus is unuseable.  It's (the center of the primary mirror) only purpose is for accurate collimation!

After the diagonal mirror is aligned, the return light of the
laser has to backtrack exactly to the center of the eyepiece
hole....you do this last, by tilting the primary mirror.
(I check collimation EVERY  time I set up to observe, and maybe even once or twice during the night)!  If  you aren't properly collimated - optical axis perfectly aligned, then high power is out of the question because your focal point isn't even hitting the back of the eyepiece....low powers will work under even the worst of collimations, but not high powers.
So I would guess your lack of focus at the higher powers
is just bad collimation, and not your optics....unless you have
a severely malformed mirror....and there is even a check for this too, once you achieve a decent collimation.
Just put scope on Polaris at high power, defocus the star
Polaris, and minutely examine the diffraction pattern around
the slightly out-of-focus Polaris....you should see perfectly
circular diffraction pattern rings on both sides of focus,
equally bright.....if you see ellipses, rounded triangles, etc,
then you have a malformed mirror, perhaps pinched optics,
perhaps zonal defects, there is a whole book on how to
interpret this star pattern test around Polaris.

(It is a very critical test, measuring defects down to one
millionth of an inch.!)

Also it would really help you if you could find an astronomy
club nearby where you live....(or start one)...that way, you
can learn from other amateurs in your area.  Surely someone
with experience with the night sky lives nearby you.

Don't depend on computer programs, courses in astronomy,
planetariums, etc...these are all good incentives, but they
don't give you what you need RIGHT NOW...right now,
you need a good star atlas, perhaps an inexpensive
pair of binoculars, and a red flashlight, and go outside
at night, and self teach yourself  --Yes, just like Abraham
Lincoln did....self teach yourself, the constellations, and
the "fuzzy" things contained therein....as explained above,
it's not that difficult....but it does take a little effort and
motivation on your part.  If you don't want to do this,
then sorry, you picked the wrong hobby to go into- if
you wish me to be honest with you.

Also I suggest you go to our club website at
http://www.velocity.net/~bwhiting
and read Tom Whiting's Sound Advice for the Novice"

Good luck and hope all this helps you,
Clear Skies,
Tom Whiting
Erie, PA
bwhiting@velocity.net
And feel free to contact me directly if you need any other
help.
PS- you didn't give me the focal length (or focal ratio)
of your 12 inch scope....so I have no idea what power your
32 mm eyepiece is giving you...but I do know that the
32 mm eyepiece is your lowest power, and that will be the
eyepiece that you use 90% of the time, to maximize the
other 3 items...
Field of View
Light
Detail
Every step up in power, you lose slightly on the 3 items listed above...
sorry, just the laws of optics.  We can do nothing about it.