Planetary – Page 56 – Astronomy Sketch of the Day

Shadow on the cloudtops

Jupiter/Io Shadow Transit

With its large apparent diameter, turbulent belts and zones, and Great Red Spot,
Jupiter is a fascinating object to observe. This fascination goes up another notch
when one of the four Galilean moons makes a transit across the Jovian disk.

A transit occurs when the orbit of one of Jupiter’s moons takes it across the face
of the planet as seen from our vantage point here on Earth. The moon itself can be
hard to detect, but the inky black shadow that it casts on the planet’s cloud tops
is easily seen with most telescopes.

In the hour of time recorded in the sketch, Jupiter is rotating from left
(following) to right (preceding). Because the Great Red Spot happened to be visible
during the transit, the observer can get a sense of the incredible rotational speed
of this giant planet–one complete rotation about every ten hours!

The sketch was done at the eyepiece with 2B, HB, and 9B pencils on Strathmore 400
series 80 lb. paper.

Michael Rosolina

Observational Data:

Time: 23 May 2006 0300-0400 UT
Telescope: 8″ (20cm) SCT f/10
Magnification: 254x & 200x
Filters: Wratten #11, #56, #80A, & IL
Seeing: 4-5/10 (Pickering)
Transparency: 4/6
System II: 102° & 138°
Altitude: 35°
Diameter: 44.2″
Magnitude: -2.5

Colorful Red Planet

These are sketches created by hand and processed with Photoshop CS after being
scanned. I use graphite pencil and colored pencil on white paper.

Naturally some of these are based on looking at astrophotography, for more details.
Here are two sketches. The one is by hand and the other after being scanned and
processed with Photoshop.

With this method, I’ve created sketches of the Sun Prominences, and other objects of
the Deep Sky..

Basic equipment used: My Telescopes, ETX-125 5″/ LX 200R 8″/ and my
PST/Coronado/SolarMax 40/TMax Filter- Double Stacked.(For the Sun Sketches)

Scanner, EPSON PERFECTION 3490 PHOTO. ToUcam PRO
II-DSI-c..and my SBIG (recently) ST-2000XM.!!

All the Best from Athens

22 March, 2007

Peter Desypris

To a southern exposure

Comet C/2006 P1 (McNaught)
10 January 2007 2255 UT
10×50 Binoculars
Cold Knob, WV USA
Altitude: ~3°
Conte’ Crayon on textured pastel paper

For me, getting a look at the famous Comet McNaught was not easy. I had tried and failed two days earlier at sunset when trees and houses blocked the view and it was rapidly sinking lower each evening–in a couple more days it would be gone for observers in the Northern Hemisphere.

Determined to see this comet before it disappeared, I trekked to the top of a nearby mountain to get a clear view of the western horizon and set up my binoculars. It had snowed 6 inches the night before, but now it was clear. Before the end of civil twilight, the comet popped into view. As the orange winter twilight progressed, McNaught took on the appearance of a burning ember just above the horizon.

The sketch is taken from a graphite pencil sketch I did in the field. The most notable features at 10x were the bifurcated tail extending about 30 arcminutes to the northeast and the very bright coma. The comet against the orange background of sunset was unforgettable. I have seen many images of McNaught in magazines and online that were taken on the evening of January 10th and they all show that orange winter sunset.

Of course, Comet McNaught went on south to become the brightest comet in 41 years, visible during daylight, and with a tail so long that it extended back to the northern hemisphere. But I saw it before it became famous.

Michael Rosolina