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7/12/2009

Jupiter Losing its Galliean Moons; Jupiter and Neptuen 2nd Conjunction Monday July 13th and Jupiter and Uranus Triple Conjunction 2010

I did not mention on my observation on the 9th and 10th of July I finished my night watching Io come out from behind of Jupiter on the side. Wonderful watching this though I wish the transparency had been better.

This made me do some research on Jupiter. On the night of September 2nd and 3rd, of this year the Galilean moons will not be visible for around 2 hours. This last occurred on May 21st,
2008. According to this article from MSNBC:

In case your wondering, Kelly Beaty in Sky and Telescope discussed the same event that happen in 2008 for Europe, Africa and very briefly for the eastern coast of North America. As Jean Meeus points out this event occurs about 25 or so times a century but the key is how many times it happens where we live so we can see it. I figure I have this event in September and then maybe one or two more times in my life for t his to be seen where I live. Here's some further info:

According to Jean Meeus
Centry occurances
1600-1699 39
1700-1799 25
1800-1899 19
1900-1999 19
2000-2099 25
2100-2199 21
2200-2299 30

Kelly Beaty's article from last year:

Sky&Telescope has a nice Jupiter Almanac as a PDF called Phenomena of Jupiter’s Moons that shows the event in their September 2009. Add six hours to the times listed as they are
universal times. That link is found here:

Another site I found interesting is this one at mjpowell astro site.
It has some interesting information regarding Jupiter and objects to view with it.

One is the position of Neptune with Jupiter this year located here

I'm sure most of you know that Jupiter and Neptune are undergoing a triple
conjunction this year, first time since 1971.

"The first of the 2009 conjunctions took place on May 25th 2009, when
Jupiter (at magnitude -2.4) was moving direct (or prograde, i.e. West
to East) against the star background and Neptune (at magnitude +7.9)
was approaching its Eastern stationary point. The two planets were
separated vertically by 25' (25 arcminutes, or just under half a
degree) at this point, and were visible in the morning sky before
sunrise. The second conjunction takes place on July 13th 2009, when
both Jupiter (mag. -2.7) and Neptune (mag. +7.8) are retrograding
(moving East to West) against the star background; the planets are
separated by 36' (0°.6) at this point, and are visible from the late
evening onwards. Jupiter then reaches opposition to the Sun on August
14th (having brightened to mag. -2.8), followed only three days later
by Neptune (at mag. +7.8). Finally, the planets are again in
conjunction on December 20th 2009, when both Jupiter (-2.2) and
Neptune (+7.9) have resumed direct motion, the pair then being
separated by 33' (0°.55); this conjunction is visible in the evening
sky, shortly after sunset."

So Monday is a time when you may want to take a look at Jupiter and
Neptune with the second of three conjunctions and then again on
December 20th, 2009 per the site.

If you follow this link from the same site from the same website you can learn that from 2010 to 2011 Jupiter and Uranus will have a triple conjunction and this will not happen again until 2037 to 2038 (I'll be in my early 70's if I live that long I hope) and this hasn't happen since 1983. So for me I am putting this down in my calendar since I don't want to miss them. If you don't want to go and scroll halfway down to see the info I'll quote part of it here:


"The first of the 2010-11 conjunctions takes place on June 6th, 2010, when both Jupiter (at magnitude -2.3) and Uranus (at magnitude +5.9) are moving direct (or prograde, i.e. West to East) against the star background. The two planets are separated vertically by 29' (29 arcminutes, or just under half a degree) at this point, and are visible in the early morning sky. The second conjunction takes place on September 22nd, 2010, when both Jupiter (mag. -2.9) and Uranus (mag. -+5.7) are retrograding (moving East to West) against the star background; the planets are separated by 53' (0.88 degrees) at this point, and are visible throughout the night. This is also the day on which both planets reach opposition to the Sun, there being just 5 hours separating the two planet's opposition times (this is known as paired opposition). Finally, the planets are again in conjunction on January 2nd, 2011, when both Jupiter (-2.3) and Uranus (+5.9) have resumed direct motion, the pair then being separated by 34" (0.56 degree); this conjunction is visible in the evening sky shortly after sunset."

So remember to go out on Monday the 13th of July (tomorrow) and see the 2nd conjunction of Neptune and Jupiter for this year. Also, the links above on Jupiter and Neptune have a finder chart for finding Neptune from Jupiter from now until December so if you haven't seen Neptune, now is a good time to do so. Finally, I hope you look forward to viewing the four Galilean moons disappear from around Jupiter. Clear skies to each of you.

July 9th &10th Observations; Light Shields and Carbon Stars

Well the last month or so has been very interesting. I have only had a couple of nights of observing as the weather in Utah this year is not what it usually is. Winter is by far my favorite season for observing as when there isn't a storm the quality of the air is such that I think I get my best observing in. However, with summer I usually count on getting at least one session a week in but not this year.

I do have an observation from June 27th and June 28th to post but that information in on my MacBook Pro that had its display replaced under warranty. I'll get that information and my sketches and post that up tomorrow when I get the laptop back.

I did get an observation in on July9th and July 10th. The moon was in the first day of its waning gibbous stage so any major plan to see deep sky objects was not feasible. I got out and using the XT10 tonight ( just so everyone knows, I use either an XT8, XT10 or a 15 inch Obsession once I get the final parts in that it needs; I bought it used and got a good deal but part of that is I needed to order a few replacement parts. The price I paid with the replacement parts is still far less than a new one and the mirror itself is in excellent condition). I will state which scope I used for each session from now on. Also right now I use either the Orion Stratus EP's or the B. Hyperion's in my observations though I also own other eyepieces that I won't mention for now.

I set up tonight using all 8 light shields in place and later after the moon had come up, I wondered why I had done that? In June around 2:30a.m. to 3:30a.m. using the shields to keep my dark adaptation I could discern the Milky Way along with hints of dark details from my backyard. Nothing like from what I've seen from a dark site, and very milky and faint, but I have been able to discern it as a fellow observer has verified as well.. So having a pair of light shields helps in terms of keeping one's eyes dark adapted allowing one to see more of what is in the skies around you. This is a link where you can go to and see the instructions for what I used to design my light shields. They are basically the same in construction. Here are some images of mine:

Light Shield Frames






























Light Shield Completed with 14 Mil Plastic Attached



























Now back to the observation for this night. While setting up I saw Vega glowing in brightness as the twilight deepened. Before the moon came up I decided to quickly take a look at M57 which I did. I found it quickly in Lyra and noticed that at 92x the ring shape was evident as was the milky interior of the ring. I noticed at 200x with the 5mm hyperion that the transparency was going to be not so good this night as the image came and went in terms of the details I could discern.

After M57 I prepared to do my double star observing for this night which is the type of observing that I really like doing around a full moon. One thing also that I am going to add is to begin looking at Carbon Stars also. These are stars that are either late red giant stars or sometimes a red dwarf who atmosphere's contain more carbon than oxygen. These two elements combine in the upper atmosphere of the star to make carbon monoxide allowing the remaining carbon atoms to form other carbon compounds and giving the star a really "red" look if you catch it at the right time. A local member of our astronomy board gave me a list that I'll share if you contact me and want to take a look at a few. Or you can go to this link which is from the North Kansas Astronomical Society. T Lyra is the one I'm going after this week. Nice red contrast I've been told. In the S&T Sky Pocket Atlas you can identify a carbon star by the a (c) next to an open ring for the star location.

I haven't scanned my actual sketches from my double stars so I used them to create a digital sketch in GIMP. I'll post them as an edit tomorrow or Tuesday. So my first double that night, July 9, 2009 at 10:59p.m. was Graffius or Beta Scorpii, or also known as Acrab, Akrab or Elacrab. The primary is a large white star in the 5mm Hyperion I used that night on all of the doubles. The secondary was smaller and a very faint blue in color. The separation is 14 arc seconds. I split this double easily at 57x, 92x and 200x.
Here is the sketch:





















My next observation was of Al Niyat Sigma. I used the XT10 with the 5mm Hyperion at 200x to make this observation. The primary is a very bright, to the point where if one is rushing they could fail to observe the companion which is west-southwest of the primary. The primary in the EP was white while the companion was a faint white with a bluish tint. You can find details about this star at this link by Jim Kaler at Stars. Here is the sketch.



















My next double/multiple star system that I observed was Delta Serpentis or Qin/Chin by its other two names. There are four stars, or two binaries in this system that are roughly 210 light years (ly) from Earth, while the pair of binaries are 66 arc seconds apart.

The two visible that I drew are F stars that are yellow white subgiants, but I saw them as white for the primary and white with a bluish hue on the companion. They are 4 arc seconds apart and orbit each other every 3200 years. My observing notes state that these are a very, very close double that I barely split at 200x, and had to bring out my 2x barlow to get a better view of the split at 400x. Transparency though didn't allow for a lot of clears views of this double at 400x.






















My next observation was of Delta Herculis or Sarin, located just south of the keystone of Hercules. This multiple star system/"double" was the most interesting to me because of what it is. The primary here seems to be a large white class A (A3) star but it isn't. It is actually made of two vibrant, fairly youthful, hydrogen-fusing dwarf stars. The two are called Delta Her Aa and Ab are not visible in amateur scopes since you need a "sophisticated interferometer to split them."
From this site we learn the following:

"Delta Her Aa, the brighter, at near-fourth magnitude (3.49), radiates the light of 18.5 Suns from its 8500 Kelvin surface, which gives a radius of 2.0 times that of the Sun. With a projected equatorial rotation velocity of 270 kilometers per second, the star really whizzes around, its rotation period under nine hours. Luminosity and temperature -- plus theory -- give a mass of 2.0 Suns and an age of 370 million years, only about a third of its hydrogen-fusing lifetime. We have to do some guessing about the companion, Delta Her Ab. From its absolute visual brightness, it is probably a class F (F0) dwarf with a temperature of 7500 Kelvin, a luminosity of 6.8 Suns, a radius of 1.5 solar, and a lower mass of 1.6 solar. A physical separation between Aa and Ab of at least 1.45 Astronomical Units, together with the sum of masses, yields a period of at least 335 days."

Here is my sketch. Interesting looking at it and thinking what the large white primary really represents. Please go to the link for information on the other 3 stars in this system.




















Well, my next one will be Xi Scorpii and few more doubles/multiples and then returned to DSO's. I will post my June 28th observations tomorrow.