When I first started using a telescope about 8
years ago I
got lost every time I looked for something in the sky. This was
particularly
true if I did so from my light polluted back yard in suburban San Jose.Sure I recognized the bright star patterns I
learned as a cub scout like the Big Dipper, but the rest was a mystery.In frustration I got a GOTO scope, but having
it do all the work gave me an experience like watching TV. What I need
was a good chart and some instruction of how to use it.
This video is the result of my own journey. The material began as
a chapter in the internet book
I produced on the Messier Marathon. Using the medium of video I have
been able to greatly expand that brief explanation making it both more
entertaining and more informative.
The total run
time is 30 minutes. If you want
to just get a flavor of what I have done then I suggest you start with
section
In this section I discuss the types of finders, introduce the choices
for charts, and describe the symbols used in charts
Section 2
A Sample Star Hop
This section introduces the process of star hopping in detail. I
use animation to show how each step should be done and what you will
experience.
This example is also provided in text version below
Section 3
Astronomical Coordinates
Using Paper Charts
Optical Rotations
This defines the coordinate system used in astronomical charts. I
also discuss how optical rotations in Newtonian telescopes and straight
finders affect what you will see. I include a brief repeat of
section 2 to show the difference.
Section 4 -
Scopes with Diagonal Mirrors
Working Efficiently
Selecting a Dark Site
The final section continues the discussion on optical rotations by
showing how a diagonal prism or mirror affects what you will see.
I provide some suggestions on how to work efficiently, finally I stress
that star hopping is easier if you can see the stars.
To find your way around in the sky you need the
right kind of finders
and a good set of charts. I use paper charts (Pocket Sky
Atlas, Bright Star Atlas, and Uranometria), but most of the time I use a laptop running SkyMap Pro and more recently SkyTools V 3.
The trick to Star Hopping is first getting your
bearings.Experience has told me that
before I get behind the telescope you first have to sit with a visual
star
chart and acquaint yourself with the stars.In this example we will find M38 in a November sky.In November M 38 will be in the east. Click on
the picture for a full size view.
We have to first locate the area of interest in the sky. Using
the Naked Eye chart (or high level charts in paper atlases) we can see
that the target area is just to the left and above the constellation
Orion.
Looking at the more detailed view we can see that M38 is in the middle
of the pentagon of Auriga (which actually borrows a star from another
constellation).
To star hop we have to pick an obvious starting point and then navigate
using easy to recognize patterns. Anything that is distinctive
will do in this case there is a row of stars part way from iota ( ι)
Auriga and M38. We place our red dot finder on iota.
We need to then verify we are really on the right star and determine
how the image is rotated. The fastest way to do this is by star
patterns.
Look for patterns of stars around the suspected start point. The
green pattern is fairly bright and should survive even city
lights. The red pattern is distinctive, but dimmer. We may
not be able to see it in all skies.
One this is done we rotate
the chart to agree with the sky. As you get more experienced you
may be able to skip this step, but I strongly recommend beginners
always do it.
We now can see we have to move the field of view to the right.
Let's do so until we see the row of stars.
Move that group to the left of the field of view as shown in the chart
Now move the field of view in the 5 o'clock direction until the group
just disappears. We should now be on M38.
Remember that what you will actually see will depend on your time,
location, and optics. The technique will work as shown for all
Newtonian telescopes and finders. See Section 4 above for scopes
with diagonals.
