Saturn Sketch and Observation using Pastels
Posted 15 July 2013 - 08:25 AM
I observed and made a sketch of Saturn back in late May but did not get the opportunity to scan it in and add it to my web page until recently.
In addition I went to an arts supply store and picked up some pastel pencils to see how they would work for my sketches of the planets.
I found that pastel pencils do allow me to record the color of the planetary features but in a more subtle way than colored pencils.
I would be interested to hear what others have found in using pastels.
Here are my observing notes and link to the sketch.
TMB 130mm (5.1") f/9.25 refractor on a alt-az mount. Magnification mostly 255x with Baader binoviewer. Filters used: none and Baader Moon & Skyglow filter.
In the sketch the preceding limb is on the left, the following limb is on the right, south is at the top, and north is at the bottom. The North Polar region is now tilted towards the Earth.
The South Polar Region appeared blue in color.
The North Equatorial Zone appeared light yellow in color.
The North Equatorial Belt appeared brown in color.
The North Tropical Belt appeared green in color.
The North Tropical Zone appeared white in color.
The North Polar Region appeared green in color and a small round cap was noted.
The shadow of the globe was visible on the preceding (left hand side) of the rings, giving the planet a 3-D look to it. The rings cast a shadow on the front of the globe.
The Cassini Division was noticeable on both ring ansa.
Nearby the moons Titan, Tethys, Dione, and Rhea were visible.
Posted 15 July 2013 - 09:32 AM
Great sketch. I always like the detail in your observations.
Posted 15 July 2013 - 03:29 PM
Posted 17 July 2013 - 09:42 AM
I like your pastel sketch of Saturn. I generally don't detect much color on Saturn but I do find that the Baader Moon & Skyglow filter improves the contrast on subtle features. For my eye it works well on Saturn and Mars but not with the Moon or other planets.
Posted 17 July 2013 - 08:37 PM
Posted 18 July 2013 - 04:56 PM
So, I thought I would provide a very different palette for the colors seen on Saturn. I am not certain that Emily really saw those colors in my scope, I certainly did not.
Posted 20 July 2013 - 02:41 AM
Posted 20 July 2013 - 07:46 AM
Thanks for the kind words. I was fortunate to have some good seeing during the observing session.
Posted 20 July 2013 - 08:12 AM
Sorry to hear that the Moon & Skyglow (Neodymium) Filter does not work for you.
I had read back in 2006 that they helped to enhance planetary detail and had a chance to test it as well as other Baader filters using my TMB apo's refractors. This included:
Baader Planetarium's Premium Color Filters
Baader Planetarium's Moon & Skyglow (Neodymium) Filter
Baader Planetarium's Semi-APO Filter
Baader Planetarium's Contrast-Booster Filter
and the Baader Planetarium's UH-S Filter (for deep-sky objects).
Here is a link to the reviews:
For me it did help to enhance detail for Mars, Jupiter, and Saturn.
In your sketches you always pick up a lot of detail so perhaps you don't need the Moon & Skyglow filter
Posted 20 July 2013 - 08:17 AM
For me I find that the filter does help to bring out detail on Mars, Jupiter, and Saturn but have not tried it for the Moon, Uranus, or Neptune.
Posted 20 July 2013 - 08:37 AM
Also making color sketches has helped me to learn more about Saturn's atmosphere.
For example, as seen from Earth the rings vary from 0 degrees to -27 degrees when the southern portion of the globe is visible, then from 0 degrees to +27 when the northern portion of the globe is visible. There is evidence to suggest that this change in ring angle causes seasonal color changes of Saturn's atmosphere.
For example, when one hemisphere has been in eclipse by the rings for a number of years, the color of that hemisphere has more of a gray, gray-green, or blue-gray color to it.
If you look at the first two sketches on my Saturn Nomenclature page:
you will note that the color had changed over time in the South Polar Region from green to yellow.
In my first sketch above the color of the southern portion of the globe, after it was coming out of eclipse for a number of years, had more of a gray-green color to it.
In the second sketch, made after the southern hemisphere had been exposed to the sun for a longer period of time, the colors appear more yellow and yellow-brown in appearance.
In my most recent sketch the southern hemisphere has more of a blue color to it.
So it has been neat to watch as the color changes over the decades.
Posted 20 July 2013 - 08:59 AM
Nice to hear from you again. I do recall the Compuserve AstroForum. The late Tom Back was on it and suggested that I join it.
That's a nice sketch that Emily made. It is interesting that you mention the colors that she saw.
There have been times I have observed with my daughter and she can sometimes see colors that are more enhanced than I could. Perhaps because as we age our pupils cannot dilate (or open) as much as when we were younger.
I can recall back in the 1980's when I was observing M42 late when night with an AP 6" f/9 and the seeing and transparency was quite good.
At low to medium power using 2" eyepieces the bottom of the nebula had a pronounced red color to it. As I have gotten older I have not seen the color as pronounced using similar aperture telescopes and magnifications.