Monday, July 10, 2017

Double Feature!

Prominence and Sunspot

An enormous prominence was suspended above the Sun's eastern limb on July 8th. Nearby was a growing active sunspot. The sky, rarely clear during July, was cloudless, so I seized the opportunity to image these dramatic features. Only brief puffs of gentle breeze gave any relief from the heat with temperature at 85 degrees while I worked.

The first image below is a 14-panel mosaic made with a 5X Barlow lens. It shows the Sun's eastern side with sunspot 2665 and several prominences along the limb. (Click on the image for a more detailed view.)
The next image is a closer view of the largest prominence and sunspot 2665. White energetic emissions erupt in the middle of the sunspot group. The giant prominence is several Earth diameters high.
It's hard to work comfortably in humid July heat. My shirt was soaked with perspiration after only 35 minutes. More than three months have passed since the last time I used my solar telescope. It may be months again until conditions are right for another solar imaging session.

Tuesday, June 6, 2017

Double Shadow Transit on Jupiter

Three Moons and the Red Spot!

Orbiting Jovian moons sometimes pass in front of Jupiter and sometimes behind. When they pass in front, it's possible for their shadows to fall on Jupiter. There have been several recent opportunities to see two of these shadows on Jupiter at once! Unfortunately, it was cloudy at my location every time. Finally, on June 3rd, conditions were good enough to try observing this interesting phenomenon. Scattered clouds filled the sky as I set up my telescope. As darkness fell, clouds diminished leaving a slightly hazy sky. With no wind, and temperature at 74 degrees, it was very comfortable working outside at the telescope. Jupiter was about 1.5 degrees below the 75 percent illuminated Moon, forming an attractive pair.

I captured the image below at 10:15pm EDT, just after the first shadow entered Jupiter's disc. Two moons visible to the right of Jupiter are Ganymede and Callisto, with Ganymede above Callisto. Another moon, icy Europa, was left of Jupiter, but too dim to show in any images I took. The final Galilean moon, volcanic Io, cast the black shadow seen below. Io itself was located directly in front of Jupiter's disc to the right of the shadow. Consequently, Io is hard to distinguish from bright background planetary features in this image.
At 10:21pm EDT Ganymede's shadow can be seen making a small, black entrance notch in the upper left of Jupiter's disc.
Ten minutes later, at 10:31pm EDT, Ganymede's shadow was still entering the disc. Notice the small, pale red spot nearly centered in the bottom white zone.
In another 10 minutes, at 10:41pm EDT, Ganymede's shadow had fully entered the Jovian disc. An observer sitting within one of these shadows on Jupiter would see the Sun eclipsed by a Jovian moon!
In the next image, taken 30 minutes later at 11:11pm EDT, you can finally see the tiny white disc of Io about to exit the dark belt on Jupiter's right edge.
At 11:21pm EDT, Io had completely exited the Jovian disc and was now clearly visible on the right against a black sky. Jupiter's great Red Spot was also rotating into view on the lower left edge.
My hopes of following shadows entirely across the disc were dashed by increasing haziness over the whole sky. Jupiter was also getting closer to the horizon. Soon, a bright 22-degree circle formed around the nearby Moon. I had to increase my exposure times as Jupiter began to fade behind the thickening haze. My last image, at 12:01am EDT, June 4th, shows the Red Spot, two shadows, and three moons! Wow!
I made a time lapse animated GIF using 14 images recorded between 9:41pm EDT and midnight. This little video compresses 2 hours and 20 minutes of Jovian motion into about 2 seconds. Jupiter rotates, moons orbit, and shadows transit the disc!
By the time I got to bed after 1:00am, I was exhausted. My 52-mile bike ride the next morning completely wiped me out. But it was worth the effort to record this beautiful celestial event! 

Friday, May 19, 2017

Jupiter

Red Spot!

More than a year has gone by since my last attempt to image Jupiter. It was time to try again in nearly perfect conditions on the evening of May 15th. The sky was completely clear with very little wind and low humidity as the temperature dropped from pleasant middle 60's to slightly chilly low 50's during my time outside.

I lost some telescope operating efficiency while my Stellarvue 130mm refractor sat idle for so many months. Consequently, I made several blunders during set up. The most serious mistake was forgetting to sufficiently tighten screws holding the telescope in the mount. When the mount performed its initial homing slew the telescope began sliding down out of the mount and was well on its way to crashing into the concrete observing pad below. Fortunately, I happened to be standing next to the mount and desperately caught the sliding telescope in my arms at the last minute before any damage was done. Yikes! How could I be so dumb?

I also used a new laptop for this imaging session, so there were several delays getting software to communicate with the mount and the camera. Finally, since I stupidly forgot to line up the finder scope with the main telescope, it took way too long to get Jupiter centered in the eyepiece after the mount initially failed to place Jupiter in the field of view. In spite of these problems Jupiter eventually appeared on my laptop screen and I began recording images. The initial view looked like the first image below, recorded at 10:23 pm EDT with a 3X Barlow lens.
Three Galilean moons are visible to the right of Jupiter. They are, from left to right, Io, Europa, and Ganymede. The fourth moon, Callisto, was out of the field of view far off to the right. At first I didn't realize that Jupiter's Red Spot was located on the lower left edge of Jupiter, ready to rotate into view over the next hour. Can you see the hint of the Red Spot on the left edge of the lowest white band?

Just 29 minutes later, at 10:52 pm EDT, the Red Spot had become more visible as you can see in the next image.
The moons hardly changed position during the 29 minutes between the first two images. The Red Spot, however, was coming into better view. The next image was captured at 11:18 pm EDT, 26 minutes after the previous image.
I switched to a 5X Barlow for the next image, captured 17 minutes after the previous image at 11:35 pm EDT. The 5X Barlow gives too much magnification for my telescope/camera combination, so I have to reduce the image size by half to display a pleasing amount of detail.
Finally, I switched to a 2X Barlow lens and took this last image after midnight at 12:08 am EDT on May 16th. Another 33 minutes had passed since the previous image.
While I captured the images above over a span of one hour and 45 minutes the Red Spot rotated from the edge of Jupiter around to nearly the central meridian. From the image sequence you can see it would take more than two hours for the Red Spot to rotate halfway across the face of Jupiter. The exact time is 2 hours and 29 minutes, making the Red Spot's transit time across Jupiter's face 4 hours and 58 minutes. (The sidereal rotation period of Jupiter is about 9 hours 55 minutes. Half this period is 4 hours 58 minutes.) 

Because the Red Spot isn't obviously visible near the very edges of Jupiter, visual observers have less than four hours to see it cross the Earth-facing disc of Jupiter. During these four hours good observing conditions are required. Jupiter needs to be above the horizon on a clear night. No wonder I've rarely seen the Red Spot.

Wednesday, April 12, 2017

Rock Show

Minerals, Meteorites, Fossils, Gems!

I recently visited the NY/NJ Mineral and Gem Exposition in Edison, NJ. The long, unpleasant drive from Virginia on Interstate 95 wasn't much fun, but when I first entered the vast exposition hall, I immediately knew my journey was worthwhile! Spread before me was the equivalent of hundreds of rock shops all in one place. It took more than one day to see all the displays and shop for additions to my modest collection of curiosities.

Many display cases were simply beautiful. For example, look at this orderly array of colorful crystals.
Some dealers had elaborate glass display cases.
I wanted to purchase one of the beautiful blue specimens of benitoite, pictured below, but they were incredibly expensive. The benitoite specimen in the upper left of the next image was priced at about $7,000!
Next to the benitoite was a meter-high array of blue fluorite crystals.
High intensity lights, strategically placed, increased the attractiveness of many displays like this next one.
During a visit to Denver years ago I saw red rhodochrosite crystals and thought they would be a great addition to my collection. I hoped to buy a rhodochrosite specimen, but, as you can see below, they were surprisingly expensive, even for a small specimen. I really liked the large $775 specimen with the colorful pyrite foreground.
A few vendors were selling meteorites like the ones in this display case.
I'm particularly fond of pallasite meteorites whose cross-sectional slices look like stained glass windows. Several expensive slices were displayed in the case shown in the next image. Meteorites are usually sold by weight. The pallasite slices were going for something like $20/gram! Since the slices are mostly heavy nickel and iron, there are quite a few grams involved! The slice in the upper left was about $2,600! (Unfortunately, there was no way to get a picture without white reflections from overhead lights.)
Many exquisite fossils were also on sale.
Not sure where I would display this enormous 30,000 year-old cave bear fossil even if I could afford its $29,500 price!
By the end of my second day at the expo I was completely exhausted from walking around peering at specimens. As I was about to leave I saw a sign for an ultraviolet light display, so I took one final detour from the main floor to look at displays of fluorescent minerals under ultraviolet light. I'm glad I made the effort because the exhibit was amazing and beautiful as you can see in the next two images.
I ended up buying an ultraviolet flashlight and a couple of phosphorescent minerals to show my granddaughter. I left the expo very satisfied with the whole experience.

At this point it was way past lunch time, and I was starving in addition to being exhausted. I decided to eat at nearby Harold's New York Deli, an over-the-top authentic Jewish deli, where truly ENORMOUS portions are served. For example, the sandwiches are about a foot high, packed with so much meat it's nearly impossible for one person to eat an entire sandwich at one sitting. (The patrons deconstruct towering sandwiches into manageable sizes and, either share the smaller sandwiches with companions, or take the remains home to eat for a week.) The smallest menu item I could find was the thick, foot-long hot dog with sauerkraut seen below. I was able to finish it, but it was quite a salty overload to my system. It cured my hot dog craving for the foreseeable future. I enjoyed the NJ atmosphere of the place with NJ/NY accents all around.
Below are pictures of some of the minerals I bought. First is brilliant green dioptase from Kazakhstan. This specimen was surprisingly beautiful under short wave ultraviolet light. The white matrix fluoresced bright red!
Next is lazurite and pyrite from Afghanistan. The blue and gold colors are dazzling under bright light.
This strange round ball is prehnite sitting on epidote from Mali.
Multiple cubic pyrite crystals are always interesting. These are from Spain.
Finally, below are three images of my favorite purchase, a polished slice of the Seymchan pallasite meteorite discovered in 1967 in Magadan, Russia. This bit of extraterrestrial material was once located near a boundary between the core and mantle of a differentiated asteroid. It contains silvery crystallized iron and nickel, characteristic of the core, and pieces of the silicate olivine, characteristic of the mantle. Some unknown ancient catastrophe blasted the asteroid to bits. One of these bits ended up in Russia! Now it sits in my living room. The first image, made with a flash, shows fascinating structure resembling a stained glass window.
The next image, made without flash, emphasizes light passing through the partially transparent olivine.
This last image best shows the unique silvery iron/nickel crystallization structure known as the Widmanstatten pattern.
I'm so glad I made the effort to attend this expo. 

 

Thursday, April 6, 2017

Sun Wakes Up

Two Significant Sunspots

Recent months of sunspot drought temporarily ended on April 2nd when two good-sized sunspots were visible on a cool, cloudless day. A northerly breeze accompanied 51-degree temperature as I set up my solar telescope to begin observing before noon. Seeing was not particularly good, but blue skies and sunshine were very welcome.

My attempt to construct a whole disc mosaic failed because I was careless when capturing constituent panels. But the smaller successful 9-panel mosaic below shows almost all major solar features present. Complex sunspot group 2645 is on the lower left. Sunspot group 2644 is near the right limb. A few prominences sit on the western limb.
Seeing conditions improved for a while as morning hours passed. The next image is a close view of sunspot group 2645 made by stacking the best 100 frames from a 3,000-frame video. Notice the fine detail present in the dark sunspot umbras. This sunspot group deformed surrounding spicules making a pattern similar to iron filings sprinkled near a bar magnet. White energetic eruptions sit between outlying umbras. (Click on the images for a larger view.)
Sunspot group 2644 was churning with activity near the western limb. I recorded 21 minutes of the action by capturing one 500-frame video clip every 60 seconds. Each video clip yields a still image which becomes one movie frame. The repeating movie below runs at 10 frames per second, so it compresses 21 minutes of solar action into about 2 seconds. Movies like this always make me wish I had recorded longer. Unfortunately, I had to stop too soon.
The Sun may soon go back to sleep, so I'm glad I was able to observe this temporary burst of activity. 

Wednesday, February 22, 2017

Modest Sunspot

Erupting Prominence

I recently enjoyed my first solar imaging session since July, 2016. Hardly any major sunspots or filaments had appeared for 7 months. When a modest sunspot group rotated into view near the eastern limb on February 20th, it was time to return to the activity I love. Conditions were comfortable with nearly cloudless skies, temperature in the low 60's, and a slight breeze. I worried about forgetting steps in the imaging routine, but, even after 7 months away, I had no trouble setting up equipment and capturing video clips.

The first image below is a 3-panel mosaic showing modest sunspot group 2638 left of center and a large prominence which happened to be in the midst of a dramatic eruption. Not long after this image was made the prominence had lifted off into space leaving no trace behind.
Seeing was not particularly good this day. Aside from the one modest sunspot, there were hardly any remarkable features present on the solar disc. One active area, 2636, near disc center looked like this.
I captured 21 video clips from locations around the solar rim. Below is an imperfect 21-panel mosaic showing a number of prominences scattered around the limb. (Click on the images for larger views.)
It was good to use the solar telescope again after so many idle months. 

Sunday, January 15, 2017

Grandfather's Joy

Grandkids Frolic

How could I be a grumpy old man when I have grandkids like these?
Little Annabelle has made great progress lately exploring the world with increasing mobility.
Annabelle was so happy to crawl on her own through snow after a recent storm.
Big sister Sophie enjoys building elaborate marble runs with three sets of Hape Quadrilla Marble Runs I have given her over the years. A few days ago Sophie and her Dad constructed some magnificent cascades.
Marbles descend on straight or curved tracks, spiral on circular tracks, take alternate paths at random, and even strike musical chimes as they steadily travel downhill. These monumental marble runs were exactly what I had in mind when I pictured Sophie and her Dad working together to build them.
Looks like fun, doesn't it?

People say I'm crazy doing what I'm doing
Well they give me all kinds of warnings to save me from ruin
When I say that I'm o.k. well they look at me kind of strange
Surely you're not happy now you no longer play the game

People say I'm lazy dreaming my life away
Well they give me all kinds of advice designed to enlighten me
When I tell them that I'm doing fine watching shadows on the wall
Don't you miss the big time boy you're no longer on the ball

I'm just sitting here watching the wheels go round and round
I really love to watch them roll
No longer riding on the merry-go-round
I just had to let it go

John Lennon