Click here to see page 8 of Visual Observations Click here to see page 10 of Visual Observations
One of the advantages of long winter nights is that astronomical twilight starts late in the afternoon and continues into the next morning. Depending upon where you live this can mean twelve hours of darkness or more in which to observe. Also you don't always need a telescope to enjoy the view.
Another advantage for lunar observers is that the Moon passes higher overhead than it does during the summer months so it is up longer.
So when we had some clear weather recently I had the opportunity to observe the Moon and planets. For exmaple with the Moon heading towards last quarter phase I watched it rise later and later each night in the east-northeastern sky, and then watch it set in the west-northwestern sky the following morning. On some nights I would wake up after midnight and watch it as rose behind the trees.
On another evening I observed Jupiter in the eastern sky and Venus in the western sky. On the following morning I woke up early and saw crescent Moon near Mercury in the southeastern sky, so I stepped outside for a better view. The sky was clear and the transparency was very good. The crescent Moon was in the constellations of Scorpius while Mercury was near by Ophiuchus. At magnitude -0.3 Mercury seemed quite bright.
Higher up the sky Saturn was in Virgo and at magnitude of 0.7 did not appear as bright as Mercury. Mars was nearby in Leo with a magnitude of 0.4.
In the western sky the winter constellations of Orion and Gemini were setting, while in the eastern sky spring and summer constellations of Cygnus, Lyra, and Hercules were rising.
It was a pleasant observing session, and fun to observe the Moon, Jupiter, Venus, Mercury, Mars and Saturn in a single night.
Recently while heading off to work I noticed a pretty scene. The Moon, one day past full, was low in the northwestern sky and over a large open field with farmhouses. The farmhouses were old enough that it wasn't clear when they were built, perhaps in the 20th century, or perhaps earlier such as the 19th or 18th century.
The scene had a timeless quality to it. It was as if I was no longer in the present but rather sometime in the past when the Moon set over these farmhouses and field decades or even centuries ago.
How many times I wondered had the Moon set over this open field before we humans walked this Earth and first saw it? It was a timeless and soulful moment. It is something I have always appreciated about astronomy, its ability to provide us with a different perspective on our daily lives.
The weather and seeing looked promising for observing so I set up the TMB 130mm (5.1") f/9.25 on its alt-az mount and let it cool down. After the Sun had set and twilight set in I began observing Venus. I inserted the Baader binocular viewer with a 1.7x corrector. Also I used the Baader Moon & Skyglow filter while I observed Venus, Jupiter, and Mars.
Through the telescope Venus was impressive and bright at magnitude -4.2 and a diameter of 17.05". It showed a gibbous phase and near the terminator dusky markings were visible. The seeing was variable so magnification varied from 170x to 292x.
Next was Jupiter, and the seeing was generally good to excellent so I used a magnification of 292x to 341x. The amount of detail visible was the best I have seen in months. The combination of the binocular viewer, steady seeing, magnification, and optics produced one of the most memorable views of Jupiter I have ever had. For lack of a better word, the view seemed very "real" or "natural" to me.
Jupiter was dimmer than Venus with a magnitude of -2.2 and with a phase of 0.992 showed pronounced limb darkening on the following edge. Jupiter's equatorial diameter was 37.28"and its polar diameter was 34.87". I made a rough sketch and noted the following features.
The North Polar Region (NPR) appeared gray on color. The North Temperate Zone (NTZ) was white in color, and the North Temperate Belt (NTB) had darker portions to it. The North Tropical Zone (NTrZ) was white in color, and the North Equatorial Belt (NEB) had an irregular outline. Red barges were noted along the NEB north (NEBn).
The Equatorial Zone (EZ) was white in color. The Great Red Spot (GRS) was visible in the South Equatorial Belt (SEB) and appeared pink in color. Following the GRS there was a light colored disturbance in the SEB that extended to the following limb.
The South Temperate Zone (STZ) appeared white in color, and the South Polar Region (SPR) appeared brown in color. There appeared to be a dark barge or oval near the SPR. Here is a link to my Jupiter Nomenclature page that shows that shows the Jovian features.
The moons were resolved as disks and I was able to determine which moon was which based on the size and color.
By the time Mars got higher in the sky the seeing was not as good as it had been for Jupiter and high clouds were moving in, so this reduced the amount of fine detail visible.
With a magnitude of -1.0, a diameter of 13.41", and phase of 0.991 it appeared smaller and dimmer than Venus and Jupiter. When the seeing settled down I was able to see North Polar Cap, Mare Acidalium, and Mare Erythraeum. Still it was the best view I have had of Mars so far this season. Here is a link to my Mars Nomenclature page that shows that shows the Martian features.
Venus would be skimming through the Pleiades star cluster this evening and I had originally hoped to set up a telescope to observe it and make a sketch.
However while the sky was clear it was also very windy so I knew it would be almost impossible to observe and get a steady view with the telescope being buffeted by the wind gusts. So I took out my pair of Oberwerk 11x70mm binoculars and braced them against the house. Through the binoculars it was a pretty view with the Pleiades just above Venus.
The view provided a perspective on the scale of the universe. Before the scale of the universe was understood ancient observers would look at Venus and the Pleiades near each other in the sky and assume that they were near each other in space as well. Today we know that while Venus is around 4 light minutes away the Pleiades are around 440 light-years away.
I set up the TMB 130mm (5.1") f/9.25 on its alt-az mount to observe Venus and Mars. The seeing was mostly fair for both Venus and Mars so I used magnifications of 170x - 255x with the Baader binocular viewer and 1.7x corrector.
I tried a green filter this time for Venus and it did help to bring out some of the dusky appearance that I noted that last time I observed it. A red filter helped to bring out the cusp extensions.
For Mars I used an orange filter to enhance the surface features, and a blue filter to bring out atmospheric features. The surface features visible included a gibbous phase of Mars, Syrtis Major, Utopia, and the North Polar Cap with melt band, sometimes referred to as "Lowell's Melt Band", named after Percival Lowell. Atmospheric features included limb clouds.
After I finished observing Mars I noted that the Moon was rising behind some pine trees, so I swung the telescope over to observe the Moon. As I focused the telescope through the pine trees I found that I went from observing craters on the Moon to pine needles on the trees. It provided sense of connection between the Moon and life on the Earth.
I set up the TMB 175mm f/8 apo refractor on it's homemade Dobsonian-style mount to observe Venus, Mars, and Saturn. The seeing was mostly fair so I used magnifications of 265x - 298x with the Baader binocular viewer and 1.7x corrector.
I used a Baader deep blue (W38A) and yellow (W25) filter for Venus, which seemed to help enhance the dusky appearance in clouds. It was similar to the last time I observed it but there were darker areas within the shading (like mottling) as well as lighter areas. These were not easy to represent in the sketch. The next morning I got up early and observed the last quarter Moon with the unaided eye. It reminded me of the view of Venus I had through the telescope the night before in terms of its phase as well as the dark lunar mare similar to shading in the atmosphere of Venus.
Mars, well past opposition, is getting pretty small. An orange filter helped to bring out the gibbous phase of Mars, as well as some surface features including the North Polar Cap, Lowell's Melt Band, Utopia, Mare Boreum, and Syrtis Major.
By the time I finished observing Mars high clouds began to drift across the sky and the seeing started to deteriorate so this made it harder to see the finer detail on Saturn. Still I was able to see the Equatorial Zone which had a light yellow color to it, the North Equatorial Belt that had a light brown color to it, and the North Polar Region that had a green color to it. The visibility of the Cassini Division came and went with the clouds and seeing.
At this point I got up from my observing chair to stretch and walk around. Looking up I noticed that Venus was quite bright and still high in the northwest sky, while Orion was in the southwestern sky. Normally when Orion is up it stands out as if to demand our attention. However this year Venus seems to be competing with Orion for our attention.
Annular Solar Eclipse on May 10, 1994. Taken using a large format camera on a single sheet of 4"x5" color film.
The weather prospects looked good for the eclipse. I wanted to both observe it and photograph it, so I brought along a 90mm refractor that I would observe with, a 35mm camera with 400mm lens, and a large format camera. I had made solar filters for all of them as well as for my sunglasses so I could observe it with the unaided eye.
After arriving at my observing site I set up my telescope and camera gear. With the 35mm camera I planned to take close up photographs of the Moon and Sun as the eclipse progressed. The large format camera took a single piece of 4"x5" color negative film in a film holder. With this camera I planned to record the entire eclipse by taking a picture every fifteen minutes or so.
A little before 12:00 PM I noted first contact where the disk of the Moon was visible on the limb of the Sun. At this point the Moon and the Sun were around 63 degrees in elevation. During the next few hours I would observe, take photographs, and show visitors the eclipse through the 90mm refractor.
The maximum annularity occurred around 1:42 PM, when the Sun was around 89% obscured. It lasted around eight minutes. The eclipse ended around 3:23 PM. It was neat to watch and quite different than the Total Solar Eclipse I observed on March 7th, 1970.
After I got home and had the photographs developed and printed I realized that there had been some light leakage in the film holder of the large format camera on one side. This occurred when I removed the dark slide from the film holder each time to take a pictures of the Sun. Still, I liked the way it turned out as it showed the entire eclipse as it progressed.
I woke up before sunrise recently and looking out of the back window noted that Jupiter and Venus were visible in the eastern sky above the trees. So I decided to go out back and observe with the unaided eye.
Both planets were in the sky in the constellation of Taurus, and at magnitude 4.5 Venus was noticeably brighter than Jupiter at magnitude 2.0. It was a pretty sight.
Jupiter is currently undergoing major outbreaks on the North Equatorial Belt and the North Temperate Belt so observers with telescopes should try and observe Jupiter when they can. Here is a link to the British Astronomical Association that shows how these outbreaks appear.
Jupiter is currently low in the sky, but will be getting higher in the sky each day. It will be at opposition on December 4th, 2012.
I got up early recently to observe the Moon, Venus and Jupiter in the early morning sky with the TMB 105mm (4.1") f/6.2 on its alt-az mount. I used the Baader binocular viewer with the 1.7x corrector, Baader Planetarium Moon & Skyglow filter, and TMB Monocentric eyepieces.
Initially the sky was partly cloudy when I was setting up. But it quickly became mostly cloudy where the Moon, Venus, and Jupiter were located in the sky so I needed to wait for the clouds to move out. However for the rest of the observing session high clouds occasionally obscured the view. Despite this, the seeing was often quite good so I could use 50x per inch of aperture.
The Moon was one day before last quarter and the view through the telescope was striking. It reminded me of a view I had some years ago through a larger telescope.
Venus looked bright with a magnitude -4.5. It had a gibbous phase of 0.251 and a diameter of 38.44".
Jupiter was at magnitude -2.1 with a phase of 0.995. Its equatorial diameter was 34.43" and its polar diameter was 32.20".
I had last observed Jupiter on March 19th, and at the time there were predictions of a North Equatorial Belt (NEB) revival, like the South Equatorial Belt (SEB) revival but not as pronounced. However on that night I did not note anything unusual.
So when I began observing Jupiter this morning it took me a while to figure out what I was seeing. At low power the South Polar Region appeared light brown in color, while the South Tropical Zone was white in color. The SEB had a darker red color than the NEB. The Equatorial Zone was off white in color. The NEB was red brown in color, and appeared to be bisected by a rift. The North Tropical Zone was white in color. The North Temperate Belt was not visible. The North Polar Region was light gray in color.
However as I increased magnification I realized that the rift in the NEB was larger than I have ever seen before in either the NEB or SEB since I began observing Jupiter with a telescope in the early 1970's. At higher magnification it appeared that the NEB was being torn apart. I studied geology in school and it reminded me of a rift zone here on Earth where continents are being torn apart. The view was one of the most profound and impressive I have ever had. I understand that what we are seeing on Jupiter is an atmospheric feature, and continental drift here on Earth is due to plate tectonics, but the resemblance was striking.
According to John H. Rogers, Ph.D. Jupiter Section Director of the British Astronomical Association, we may be witnessing a fully-fledged NEB Revival such as used to happen a century ago.
I got up early recently before astronomical twilight set in to observe the Jupiter in the early morning sky with the TMB 105mm (4.1") f/6.2 on its alt-az mount. Jupiter was still low in the sky and behind the trees so I decided to observe some deep-sky objects first. It was a clear morning but there were some high clouds that moved through from time to time.
There were a number of fall constellations up and it was nice to see them again, like greeting some old friends. This included Andromeda, Pegasus, Perseus, and the Pleiades star cluster.
I decided to observe the Andromeda Galaxy, M31 first so inserted the TMB 40mm Paragon into the star diagonal. All three galaxies, including M31, M32, and M110 were relatively bright and showed some detail. For example the Andromeda Galaxy appeared large and elongated that extended over a couple of degrees with a bright central region to it. There appeared to be hints of one or two dust lanes. M 32 was somewhat oval in shape and showed a fainter outer region, while M 110 appeared elongated and longer than M 32. I inserted the 17mm Ethos and it helped to bring out some additional detail.
Next I swung the telescope over to observe the Pleiades star cluster, M45. They were just above the trees and through the 17mm Ethos I was able to fit both the cluster and the trees in the same field of view. It was an interesting sight.
The Double Cluster in Perseus was beautiful as always including the red stars mixed in.
By this time Jupiter had risen above the trees, but unfortunately the seeing was not very good. So I was not able to see much detail of the North Equatorial Belt (NEB) revival. However the NEB appeared more brown in color than the last time that I observed it.
At my observing site I have often seen and heard wild animals such as owls, hawks, bats, turtles, frogs, turkeys, geese, deer, mice, fox, coyotes, and even a bear. Usually they are off in the distance, but sometimes closer. On this particular night I heard a pack of coyotes starting howling off in the distance to the east. I have learned that when a pack starts to howl it means that a parent has brought food back for the cubs to eat.
A little while later I heard another pack start to howl, this time to the west but much closer in a nearby open field. It is a reminder that as successful we humans are as a species on the Earth there are other animals out at night that can see, hear, and smell better then we can.
I woke up early again before astronomical twilight set in and decided to do some observing with just the unaided eye. The clear sky with just a few clouds. As it was well before rush hour there was no traffic. So it was very peaceful and serene just sitting on the back porch under the starry sky and looking up.
What caught my attention when I first stepped outside was the constellation of Orion, which was rising in the east - southeastern sky. I was reminded of the poem by Robert Frost The Star-Splitter, where Frost wrote:
'You know Orion always comes up sideways.
Throwing a leg up over our fence of mountains,
And rising on his hands, he looks in on me'
For me seeing Orion brings back memories of observing the constellation when it is high in the sky on cold winter nights when there is nary a sound, except for the crunch of snow under my boots. This is in contrast to this morning where the air temperature was mild and I listened to the crickets as they chirped.
In the eastern sky the crescent Moon, Venus, and Jupiter showed the path of the ecliptic. Also, Jupiter is located in Taurus, so the Bull now looked as if it had a new white eye.
Overhead I saw two meteors, with one of them being a Perseid meteor based on its path.
As astronomical twilight set in and the sky grew brighter I looked once more over to Orion and wondered how many times I have watched it rise over the decades, and how many more times I will watch it in the future. I was reminded again of Frost's poem where he wrote:
'We've looked and looked, but after all where are we?
Do we know any better where we are,
And how it stands between the night tonight
And a man with a smoky lantern chimney?
How different from the way it ever stood?'
I set the TMB 105mm (4.1") f/6.2 on its alt-az mount to observe Jupiter. I used the Baader binocular viewer with a 1.7x corrector with magnifications of between 79x - 185x. It was mostly clear night with a limiting magnitude of around 4.0. The seeing was often steady.
The South Polar Region appeared gray in color, while the South Temperate Zone appeared white in color. The South Equatorial Belt (SEB) was red in color. The Equatorial Zone appeared dusky or veiled.
The North Equatorial Belt (NEB) was red in color, but it appeared to have a more irregular outline to it than the SEB. There appeared to be rifts in the NEB. Also a light blue festoon was visible along the southern edge of the NEB.
The North Tropical Zone appeared white in color, while the North Temperate Belt was red in color. The North Temperate Zone appeared white in color, and the North Polar Region appeared gray in color.
Here is a link to my Jupiter Nomenclature page that shows that shows some of the Jovian features I observed.
On Christmas night a conjunction occurred with Jupiter and the Moon that were within a degree or two of each other with the orange colored star Aldebaran in the constellation Taurus visible nearby. I observed them with the Oberwerk 22x100mm binoculars.
The Moon showed a lot of fine detail in the craters and the mare. The stars of the Hyades star cluster were visible in the background.
When observing Jupiter there were times that the South Equatorial Belt (SEB), North Equatorial Belt (NEB), and Equatorial Zone (EZ) were visible, as well as the polar regions. Also three of the Galilean satellites were visible.
On January 8th, 2013 I set the TMB 130mm (5.1") f/9.25 refractor on an alt-mount to observe and make a sketch Jupiter. I used the Baader binocular viewer with a 1.7x corrector with magnifications of between 255x - 292x. Filters used: none, Baader Moon & Skyglow filter.
It was a partly cloudy night with a limiting magnitude of around 2.0. The seeing was variable, mostly fair but sometimes settling down to good. This made it difficult to make a completed sketch so I ended up making a rough one.
Central meridian longitudes: System I: 139.5°, System II: 191.0°.
The South Polar Region appeared gray in color, while the South Temperate Zone appeared white in color. The South Temperate Belt had a darker and wider section to it above the Great Red Spot (GRS).
The South Equatorial Belt (SEB) was red in color preceding the GRS, which was orange in color. A very large rift followed the GRS and curved up.
The Equatorial Zone appeared dusky or veiled.
The North Equatorial Belt (NEB) was red in color, but it appeared to have a more irregular outline to it than the SEB. There appeared to be rifts in the NEB. Also light blue festoons were visible along the southern edge of the NEB.
The North Tropical Zone appeared white in color, while the North Temperate Belt (NTB) was red in color. The NTB had an irregular outline.
The North Temperate Zone appeared white in color, and the North Polar Region appeared gray in color.
Callisto, Io, and Europa formed an arc along the preceding side while Ganymede was visible on the following side.
Here is a link to my Jupiter Nomenclature page that shows that shows some of the Jovian features I observed.
As I finished observing and stood up from my observing chair to stretch it dawned on me that it has been almost forty years since I made my first telescopic observation of Jupiter. My first was on August 13, 1973. At the time I was using a 60mm achromatic refractor on an alt-az mount, and tonight I was using a 130mm apo refractor on an alt-az mount. While I have owned larger aperture telescopes (20" reflector) and used them at star parties (32" reflector) I find it is easier to take notes and make sketches if I am seated at the eyepiece.
One of the biggest problems I had when I bought the 60mm achromatic refractor was lack of information. For example the local library only had a few books on astronomy, and they were for young children. They did not contain information on the constellations, deep-sky objects or how to identify the planets. So during the winter when I saw three bright stars in a row in the sky I did not know they were part of the constellation of Orion.
Also I did not know of anyone else who had an interest in astronomy, or if there was an astronomy club in area. Even if there was a club in the area there was no way for me to learn about them or get in touch with them. This is in stark contrast to today where the internet makes it much easier to learn and get in touch with others interested in hobbies such as astronomy.
So after observing the Moon and stars through the telescope I wasn't sure what to do next. Then just by chance I was flipping through a local newspaper one day and came across an almanac. It gave the times of Sunrise, Sunset, Moonrise and Moonset. Also it mentioned that the bright "star" in the eastern sky following the Moon after sunset wasn't a star but rather the planet Jupiter. Also it mentioned how Jupiter had 12 moons (today it has at least 67 moons).
As it got dark I saw the bright star like object in the eastern sky following the Moon, opened the window and pointed my telescope out it to observe it. Back then I did not know that pointing a telescope out a window was not a good idea because it degrades seeing.
Still as I increased the magnification I could resolve Jupiter as a disk with three bands on it, and see the four moons nearby. The fact I could see this on a planet that was over 480 million miles away really was amazing to me.
I wanted to make a permanent record of what I saw so I picked up a piece of paper, drew a circle on it and recorded the detail. Without realizing it I had started to train my eye to see more detail. This was because each time I observed Jupiter again I made a sketch and could see more detail, even though it was the same telescope and same magnification.
I have sometimes wondered if my interest in astronomy would be as strong as it has been over the years if I had not read the almanac and was able to find Jupiter in the night sky. This is because not only did the almanac help me to find Jupiter it also started my interest in sketching at the eyepiece. This has helped me to see more detail over the years, and provided me with an artistic outlet. I still have that almanac as I pasted it into my first astronomy logbook.
Here is a link to some of the Jupiter observations and sketches I have made over the past forty years. Note it does not include numerous observing reports and sketches that I have made since 1973.
Also in 1978 I purchased a C-90, and in addition to using it for observing I started to do astrophotography. This continued when I bought a C8 in 1980, and from the early to mid-1980's I did a lot of deep-sky astrophotography.html. So from 1978 to 1985 I still observed but did not make sketches during this time.
Also being outside with a telescope under a starry sky often provides a sense of connection with nature and the cosmos. It can be a very spiritual experience.
So in a number of ways reading that almanac changed my life in a very positive manner ;-).
I went out to observe Jupiter tonight using the AP 4" f/6 on an alt-az mount. The seeing was good so I used magnifications up to 154x.
I was surprised by the amount of detail visible. This included a number of belts and zones in the northern hemisphere of the planet including the North Tropical Zone, the North Temperate Belt, and the North Temperate Zone. In the North Polar Region there was also the North North North Temperate Belt and the North North North Temperate Zone.
Also there was a large festoon visible along the North Equatorial Belt.
In the Southern portion of the globe the South Polar Region was visible as was the South Temperate Zone, the South Temperate Belt, the South Tropical Zone and the the South Equatorial Belt.
I went out to observe this evening after sunset and viewed Mercury, Jupiter, Mars, the Pleiades Star Cluster, and M65, M66 using the AP 4" f/10 on an alt-az mount. Mercury was fairly low in the western sky but was surprisingly bright. However the seeing was poor so I had trouble resolving it as a disk. The Pleiades were just above Mercury.
Jupiter, located to the up left of the Pleiades and to the upper right of Aldebaran, also did not show a lot of detail through the telescope. I was only able to see the North and South Equatorial Belts and two of the Galilean moons.
Mars appeared as a small reddish globe with a gibbous phase. It was hard to believe it had been so much larger last summer and fall.
M65 and M66 in Leo appeared as faintly glowing objects in the 56mm Meade eyepiece.
I set up the AP 7" f/9 up tonight to observe Jupiter. It was a clear night and the seeing was generally good so I used magnifications between 259x and 323x. The South Equatorial Belt (SEB) has faded considerably lately, even though I could resolve several faint belts in the area where the SEB faded. The Great Red Spot, although faded, was also visible. It appeared also that the North Equatorial Belt (NEB) has shrunk in size as well. The planet looks odd with just the NEB visible.
Also I noted that a satellite (Io) was transiting across the front of Jupiter, which at first was only visible as a crisp, dark shadow. Shortly there after it reached the limb of the planet and it became visible as it moved away from Jupiter, with the shadow was still visible on Jupiter.
Then near the other limb of the planet I noted what appeared to be another faint moon. As I watched I realized it was Europa, which was just emerging from eclipse. This was the first time I ever saw anything like this, so it was neat to observe.
I got up early around 8:30 UT to observe the occultation of Jupiter by the Moon using the AP 7" f/9. The weather was warm and humid, and I noted that mosquitoes do in fact swam at dawn (and dusk as I have found out before during other observing sessions). However long pants, a long sleeve shirt and light jacket, and plenty of Cutters bug spray helps cut down on he number of mosquito bites.
This is probably the "oldest Moon" I have ever observed, and it showed a lot of interesting detail.
I began observing Jupiter and noted that the South Equatorial Belt (SEB) was still faded, but the Great Red Spot was visible in its usual location. It looked odd as I was used to seeing it along the SEB, but now it appeared to be sitting by itself. The North and South Polar regions were visible, as were the North and South Temperate zones and belts.
As the sky grew lighter I noted that the indeed the colors of the belts do tend to change a bit. For example When I first set up the NEB appeared medium to dark brown, but as the sky grew lighter the color changed to more of a natural color, sort of a creamy light brown or light-brownish pink, reminding me somewhat of the Voyager photographs.
As the sky continued to get brighter I could no longer see Io, Europa, Ganymede, or Callisto, and the Jupiter appeared smaller than I recall seeing it before. I realized later that Jupiter was just past conjunction, and so was on the other side of the Sun from Earth. Usually I observe it when it is near opposition.
By 9:50 UT it was no longer possible to see the Moon as the sky grew brighter and the haze reduced transparency, so I would not be able to watch the Occultation of Jupiter.
I got a call from an observing buddy of mine this evening who mentioned that Callisto would be transiting across the North Polar Region of Jupiter. It is one of the darker moons of Jupiter so can be seen when transiting.
So I set up AP 6" f/9 apo on it's homemade Dobsonian-style mount to observe the transit.
The seeing was mostly fair at best so I could only use magnifications between 86x - 137x. It was a partly cloudy night with a limiting magnitude of around 2.0.
The South Polar Region appeared gray in color, while the South Temperate Zone appeared white in color. The South Equatorial Belt was brown in color. The Equatorial Zone appeared white in color.
The North Equatorial Belt (NEB) was brown in color. Also a light blue festoon was visible along the southern edge of the NEB.
The North Tropical Zone appeared white in color, while the North Temperate Belt was brown in color. The North Temperate Zone appeared white in color, and the North Polar Region appeared blue in color.
It was interesting to watch the transit even though the seeing was mostly fair at best.
I was watching a TV program recently about Jupiter and it mentioned that Jupiter's Great Red Spot (GRS) is shrinking in length. I had heard this before but it got me wondering if I had seen and recorded this phenomena during my telescopic observations of the planet since 1973.
First, here is a sketch of Jupiter and the GRS made by Étienne Léopold Trouvelot of Jupiter on November 1, 1880 using the U.S. Naval Observatory 26" refractor. Note that even accounting the larger aperture he was using compared to mine the length GRS back then was significantly longer than what I recorded.
In looking back at one of my earliest observations and sketches of Jupiter in 1973 with a 60mm refractor the GRS looked elongated to me:
The same held true with Jupiter in 1974 when I was using a 4.25" reflector:
The GRS had faded to a dim gray color in 1976 but the Red Spot Hollow was noticeably elongated when I observed it with a 6" reflector in early 1977:
During my observations of Jupiter with a 6" refractor in the 1980's the GRS had a more oval shape to it:
My more recent sketches of Jupiter using a 5.1" refractor shows the same thing:
So it seems likely I was recording the decreasing length of the GRS from 1973 until today. This is because leaving aside differences in the telescopes and magnifications employed over the years they all show the same trend in the data.
To verify this I went I went to the Sky and Telescope website and came across a couple of articles that discussed how the GRS has been shrinking in length since the late 1800's. In the late 1800's it was almost 35 degrees wide. However by the time Voyager 1 and 2 visited Jupiter in 1979 it had shrank to 21 degrees. The height of the GRS has remained approximately the same.
It confirmed also that between 1975 and 2010 the GRS has been shrinking in length from around 24 degrees to around 15 degrees. So my observations were accurate. It was a good thing I made sketches over the years as without them I may not have realized how much the GRS has changed over time if I had just taken notes.
On Tuesday evening, March 26th, 2013, in the Eastern portion on North America, only one Galilean moon will be visible staring at 8:41 PM.
Here are the approximate times of the satellite events. Note they were generated for the Northeastern portion on North America so the time maybe be different for you depending upon your observing location.
7:47 Ganymede (III) Occultation disappearance
8:20 Europa (II) Transit start
8:41 Io (I) Occultation disappearance
10:12 Ganymede (III) Occultation reappearance
10:43 Europa (II) Shadow transit start
10:48 Europa (II) Transit end
00:04 Io (I) Eclipse reappearance
I observed this event once before in August of 1976, although in that case I did not have an advanced warning. I had set up my Criterion RV-6 reflector to observe Jupiter and was surprised to see that only one moon was visible. I have often wondered since then if I would get the chance to observe this event again.
Note that Jupiter with only one Galilean moon visible will occur again on April 3rd, 2013 at 12:03 AM for all of North America except the East.
I set up the TMB 105mm (4.1") f/6.2 on its alt-az mount to observe Jupiter with only one Galilean moon visible.
Unfortunately while the sky was clear the seeing was mostly fair at best, and a westerly breeze picked up from time to time that also degraded the seeing.
So this made it difficult to observe Ganymede as it disappeared into occultation, and I was only able to catch a quick look at Io before it disappeared. The same held true for start of the Europa shadow transit. By the time they were to reappear Jupiter had slid behind the trees from my observing location.
Still it was nice to observe Jupiter with only one Galilean moon visible (Callisto) again since the last time I observed it back in 1976.