What's New at Sierra Stars Observatory
November 29,
2007
SSO Featured as the Cover Story of the December Issue of
Astronomy Technology Today Magazine!
Rich Williams wrote the cover story for Astronomy Technology Today magazine. In
addition Dave Snay was asked by the editor of the magazine to use SSO for a few
weeks and write an independent story about his experience in the same issue! You
can read the articles before the magazine is delivered to your door by clicking
on the links below:
We thank Stuart and Gary Parkerson of Astronomy Technology Today for letting us
post these articles on our web site!
November 6, 2007
SSO Latest Images of Comet Holmes Show Increase in Size and Detail!
Below
are two images of Comet Holmes I took last night. (Click on the thumbnail
images to see the full resolution images.) The seeing and transparency
were good so I wanted to see how much detail I could image of the potential dust
in the tail and in the coma. The images are 30 minute LRGB total exposures were
the Luminance data comes from an Infrared filter. Exposure times were:
I = 30
x 30 seconds
B, V,
R = 10 x 30 seconds each filter
Experimenting
with the various filters I found that I could get most detail using IR for the Luminance
than a straight full spectrum Luminance. You can make out subtle detail in the image.
One of the images has no image processing other than combining the color composite
while I used an FFT high band pass filter the other image to try to bring out detail
using that technique. I tracked on the comet and stacked the images on the nucleus
therefore you can see some separation in the field stars. It seems that the comet
is slowly turning from coming almost straight on (or away) from our point of view.
This is quite an amazing serendipitous event and a lot of fun to follow!
Rich Williams
Comet Holmes
11/5/07
Comet
Holmes 11/5/07 w/ FFT High Band Pass
October 26, 2007
SSO Takes Deep, Detailed Image of Comet Holmes
Rich Williams imaged comet 17/P Holmes On the morning of
October 26. The moon was full (100%) and not exactly prime for taking pretty pictures
of deep sky objects. However, comet 17P-Holmes brightened a million fold and he
decided to image a chance of a lifetime. To see how much detail he could get of
the coma area nearer the nucleus he took a series of very short exposure to not
overexpose the area closest to the nucleus and show any potential detail of a developing
tail. Rich used an Infrared filter for the Luminace frames to better highlight details
from dust in the comet. Normally Luminance frames are taken witl Clear (no) filters.
Here are the details of the L(I)RGB image:
B filter- 50 x 4 seconds
V filter- 50 x 4 seconds
R filter- 50 x 4 seconds
I filter- 100 x 4 seconds
Total exposures: 250
Total exposure time: 1,000 seconds (16.7 minutes)
Other than calibration file corrections and
combining the images to create a color composite, no other image processing was
done to the image.
You can see what looks like a start of a tail at a very oblique angle and the colors
around the comet/tail indicate some interesting activity almost like a pseudo color
enhancement (It's all pseudo color anyway when you come right down to it. . .) Click
on the image and zoom in on it a lot to see the detail.
October 17, 2007
SSO Customer Images Dawn Spacecraft
Blinking of Two 14-Minute Exposures of the Dawn
Spacecraft
Images taken by Bill Dillon
Bill Dillon used the Sierra Stars Observatory telescope to image the Dawn spacecraft
earlier this month when it was almost 600,000 miles from Earth on its way to visiting
the asteroids
Vesta and Ceres! Bill submmited his astrometry observations to the
Minor Planet Center (MPC) and his images (static and animated GIF) will be featured
in the Image Gallery of the Dawn Mission web site
(www.dawn.jpl.nasa.gov).
Bill scheduled 30 60-second images to get the data for the Dawn images. The spacecraft
was only 20th magnitude and moving fast -- and he took the images during a bright
gibbous moon. Dawn was in a fairly crowded star field at the time, but fortunately
the spacecraft was not hidden behind stars dudring the time that Bill scheduled his
images. This is quite an extraordinary achievement.
Bill is a regular advanced user of SSO always doing challenging imaging of objects
near the limit of SSO's capabilities. He has been an avid member of the American Association of Variable Star Observers (AAVSO) for over 10 years.
We expect that you will be reading more about Bill's accomplishments here in our
news section in the near future.
Congratulations Bill!
October 4, 2007
Autoguider to be Installed in October!
We are developing an autoguider system that will soon be installed on our telescope.
Installation and testing begins the week of October 7. We anticipate testing and
integration to take about two weeks. As soon as this new feature is ready, we will
send out a notice to everyone who registered at SSO and make an announcement here
in our news section.
Sierra Star Observatory's OMI telescope has a friction-drive system (no gears of
bands) and has the smoothest, most precise tracking system of any commercially available
mount. Also our tracking (as well as pointing) is monitored using optical encoders
with 0.3- arc second resolution. Even so we limit our exposures to 300 seconds (5
minutes) to ensure that you will get tracking results with good aspect ratios (no
elongation). No matter how precise a system is, there is a limit to what tracking
results you can achieve for long periods of time without some active correction.
For most of our users exposure times of 30 to 300 seconds provide the signal to
noise ratio (SNR) and/or saturation they need and can achieve longer total integration
(exposure) times by stacking multiple images using one of the many available image
processing software. Our FLI camera with a KAF09000 CCD chip has remarkably low
noise and stacking images adds very little noise compared to the overall increase
in SNR. And if there happens to be a bright object in a field of view, stacking
shorter exposure images mitigates the overexposure of those objects.
Once our new autoguider system is installed you can schedule exposures for any length
of time you choose. It will also enhance the precision of shorter exposures as well.
We are excited about offering this new feature to our customers!