19
Telescopes and What to Do?
iTelescope.net
offers rentals of robotic telescopes of all sizes. Currently there
are 9 telescopes in Australia, 3 in Spain, 6 telescopes in New
Mexico, and one in California. To use them, all you need is an
account and a web browser.
by
Greg Crinklaw, developer of SkyTools
A
few months ago I was surfing the web and I stumbled across
something that rocked my world: iTelescope.net. Like others, I
have long dreamed of having my own observatory with a state of the
art imaging system. I've looked at land in the mountain area of
New Mexico where I live and I've watched for deals on everything
from domes to cameras. People talk about how expensive astronomy
is as a hobby, but the cost of a plot of land, utilities, dome,
24-inch astrograph, and top of the line CCD camera are in a whole
different league. Oh, but think of the projects I could do! Well,
maybe someday.
So
there I was looking at a web site and being faced with
the realization that I could have all of that now, and so much more.
I signed up and suddenly had 19 telescopes available to me all
over the world, but I didn't know where to start. There were so
many telescopes in so many configurations! So I did what anyone
would do--I started playing around. I was the proverbial kid in a
candy store. But after my first month of observing I realized that
I had spent over $150 and I only had a few fuzzy images to show
for it.
 |
My
first image of a comet over the internet. It is a stack of
4x120 second exposures of C/2014 Q2 (Lovejoy). I used a
150mm APO refractor with an SBIG ST-8300C One Shot
Color CCD, located at New Mexico Skies, ironically just a
few miles from my home. This is a great starter system. It
is inexpensive and very easy to use.
I know it's not very
impressive, but it was a start. This is the sort of image
that anyone can get with very little effort. |
Planning
is the Key
Not
only did I now have all of these telescopes available, with
different capabilities and fields of view, but I also had access
to all of the astronomical objects in the southern hemisphere.
Planning had never been more important. The basic questions are
similar to using a telescope in your back yard or garden: what can
I observe? When should I observe an object for the best results?
Only now there were more dimensions, and things were turned around
a bit: I picked a target, but which telescope in which hemisphere
is best?
I
naturally turn to SkyTools to answer questions like these. When I
wanted to image a comet I opened the observing list of observable
comets and picked one that looked good. It was only a matter of
switching between observatories to find the one with the best
view. It was a large comet, so I previewed it in the
telescopes with larger fields of view until I settled on one.
Finally, with the location and telescope decided, I used the
Nightly Planner to determine which night would be good and what
local time I should start imaging. It only took a few minutes.
Getting
Off to a Good Start
Robotic
telescopes have been in development for 30 years, but they are
only now coming into their own. The hardware has been around for
some time, but what makes them practical is the pipeline of
impressive automation software, including the basic control
system, autofocus, and pointing corrections via star field
recognition. At the far end of that pipeline is image processing,
where the raw images are transformed into astrometry, photometry,
or works of art. But I am always surprised by how little thought
and attention is given to the front end of that same pipeline.
There are books and websites devoted to processing your images,
but observers are left on their own when it comes to choosing
suitable targets and deciding when to observe. Planetarium
programs display the sky, but they were not designed for planning.
The result is that many people fall into the familiar trap of
observing the same bright Messiers again and again and even then
their own images are not nearly as spectacular as today's APOD.
 I
recently started a special project to observe Planetary Nebulae. I needed objects with high
surface brightness within a narrow range
of diameters. Naturally I again turned to SkyTools, where I used
the Database Power Search to make a list of potential targets that
met my criteria. I put these in an observing list and downloaded a DSS image for each one. I made my final selections
based on their appearance, culling the list down to a reasonable
size. Each month I load the final list into the Nightly Planner to
determine which objects I should observe and assign an appropriate
telescope. Finally, I reserve time on each telescope when the
objects will achieve the maximum SNR for each filter. The
processing will come later. For now I want to ensure that I get
the best data I can.
It's
all about Blood, Sweat, and SNR
Once
you spend any time doing astro-imaging you discover that it is all
about the SNR (Signal to Noise Ratio) and hours spent processing.
To make your image of M42 look better, you need to spend more time
observing so that you can stack more images to beat down the noise
(get a higher total SNR). But if you are going to be paying for
your observing time by the minute, it is more important than ever
to maximize the SNR in each individual image. You can do this by
paying more attention to the airmass of your object, the
brightness of the sky during the night, and choosing
your filter order more appropriately--things SkyTools is designed
to help you with.
I
have seen it suggested that planning your astrophotography is as
simple as plotting how high your target is in the sky in
your favorite planetarium program. To my way of thinking, if you
are going to spend hours slaving over the processing to get your
final image just right, then you should start by putting some
effort into getting the most SNR possible out of your observations
to begin with.
It's
been said that a great astrophoto is 50% SNR and 50% processing;
SkyTools will get you half way there.
It
all starts with SkyTools 3.
Read
more about SkyTools 3
Download
the complete iTelescope data for SkyTools 3 Pro
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