Newsletter of the Pomona Valley Amateur Astronomers
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nightwatch Newsletter of the Pomona Valley Amateur Astronomers |
In this issue:
Alex McConahay to Speak
October General Meeting Icy Oddball Moons
Holiday Dinner Sirius and
Canopus Joint Star Party
December Star Party
Space Science Night
Comet Observing Double Cluster
November 2005
Next month on December 9th PVAA will hold its annual Holiday Dinner. As for the last several years, it will be held at Jounni’s in Upland. There will be a drawing for prizes. Also you will have the opportunity to see and converse with friends in a different setting (in a warm, lighted room where you can see them). The Holiday Dinner is great fun! I hope many of you will be able to attend.
Our next star party is at Mesquite Spring (near Scotty’s Castle) at the north end of Death Valley. It is a long drive, but it is one of my two favorite observing sites. Mesquite Spring is a very dark site and there is a lot to see and do there during the day too.
I have been in communication with Marie Massey, the Outreach Coordinator at the Goldstone facility of the Deep Space Network. They will not schedule a tour for a weekend. Our choices are Tuesday through Friday 9:00 AM or 1:00 PM. If you still want me to arrange something I will. Let me know your ideas on this at the November general meeting or by e-mail:
astro.ron@juno.com.Our joint RAS / PVAA star party at RAS’s Landers site was both fun and educational. They have great observing site and have made many improvements since last time we were there. A few of us caught David Levy’s (of Comet Shoemaker/Levy 9 fame) presentation in Yucca Valley before the observing session. After his talk there was a book signing.
I hope to see you at our next meeting.
Ron Hoekwater
PVAA member, Alex McConahay will be speaking at our November Meeting. In addition to being a member a PVAA, Alex is Vice President and Newsletter editor of the Riverside Astronomical Society. He is a retired educator and school administrator and an avid amateur astronomer. He has built two telescopes, one of which earned a Merit Award at the Riverside Telescope Makers Conference. In 2004, Alex traveled to Greece to observe the transit of Venus. His presentation is called "Eclipse Hibrido de Panama." It is about the solar eclipse that he observed from Panama, earlier this year.
Ron Hoekwater
Announcements
We passed out information sheets for the upcoming Club trip to Mount Wilson on November 11th. By the time you read this the trip will have already happened so here’s hoping there were clear skies – both on Mars and on the Earth. As the Martian summer occurs during this close approach to our planet, there is an increased risk of the temperature differentials of the season causing dust storms which can cover the planet and obscure surface details. I think those of us who read news reports this year of the hurricanes during Earth’s summer are aware of the powerful effects that warmer temperatures can have on planetary storms.
Dave Gardner of Lockheed gave us a space news report. The next Space Shuttle launch is tentatively scheduled for May of 2006 with 18 flights by 2010. If this goal is met, these trips should complete construction of the International Space Station. Due to the delays as foam application methods are being refined, the retirement date of the Shuttle fleet has been relaxed until the replacement CEV (Crew Exploration Vehicle) has been developed. The foam problems during the last mission are currently thought to have been the result of damage to the foam as it was accidentally crushed as while work was done on nearly areas of the ship.
Lee’s What’s Up covered the sky around the Great Square of Pegasus – which contains the Andromeda and Pinwheel galaxies as well as the variable stars Mira and Algol - a good area for spending some time with your telescope.
Featured Speaker
We were lucky to have Joanne Eisberg speak to us again on the life of Astronomer and Cosmologist Beatrice Tinsley (1941 – 1981). Born in England and educated through her Masters degree in physics in New Zealand, Beatrice moved to Austin, Texas where she completed her PhD in 1966. Her dissertation is titled Evolution of Galaxies and its Significance for Cosmology. She worked at both the University of Texas in Austin then at Yale University, which happens to be Joanne’s alma mater as well.
Tinsley’s studies were among the first to look at the details of the components of galaxies and to analyze how the stars within them evolved over time and how that affected what we observe in these distant objects. Prior to her research, galaxies were considered a sort of standard candle to help measure the size and age of the universe. The three different galaxy types – spiral, elliptical, and lenticular – were thought to have each have a standard size, shape, and luminosity. Comparing these observed qualities would then give you an accurate distance to the galaxy as it was felt these other characteristics were constant. Tinsley’s studies showed this was not the case; that both the stellar and non-stellar matter which make up a galaxy evolves differently over time based on the size of the galaxy, it’s chemical composition, and it’s rate of star formation. Only when these different factors are taken into consideration can an accurate picture of the galaxy be determined. This revelation affected studies into determinations of the size and age of our universe. Thank you, Joanne for your fascinating story of the interesting and challenging life and career of this pioneer of Astronomy in the 20th Century.
Thank You
I have a special Thank You to Ray Magdziarz for his many years of service to PVAA - begging for articles up to and past the deadlines each month then assembling, printing and mailing out the Club’s Nightwatch. I suspect thanks are also in order to his wife, Irene, as I’m sure she provided crucial support services on many occasions to make sure the news got out to all of us. Ray has a long history of service to the amateur astronomical community and in addition to his many years with our club, he served as the President of the Chicago Astronomical Society for 1-2 years in the 1970s. He continues to fill a vital role not only attending and providing input at our Club Board and General Meetings and at Club star parties but he and Irene are the providers of the coffee and cookies we enjoy at our monthly meetings. Thank you, Ray and Irene, for all those Nightwatch issues and your continuing service to the Club.
Claire Stover
As the Cassini-Huygens mission continues its voyage of exploration we can see how unique are Saturn's icy oddball moons. Newly discovered tiny moons race around interacting with the famous rings in unforeseen ways. Some called ring shepherding moons orbit within the ring gaps clearing and rippling them like cosmic motorboats. Two little moons switch position at one orbital point like dancers in a ballet. Icy material passes subtly from moons to rings and back again. Gravitational forces from the larger outer moons also influence the rings in mysterious ways. An understanding of the complex physics of Saturn's rings could take ages.
Most unique among Saturn's larger moons is huge Titan, the solar system's only moon with a soupy atmosphere. How did it get it and how does it maintain it? Is this atmosphere rebuilt from within this Mercury sized moon? It's believed that its nitrogen was formed by an action of the Sun's ultraviolet photons on Titan's ammonia. Further study of observations collected by the miraculously successful Huygens probe will tell us more about this little world hidden in global haze.
As for the Huygens probe, never has a man made object landed so far from home. As it drifted down, it photographed Titan's unique "streams" which flow down into marshy "lakes." One "lake" may be as large as Lake Ontario. It all results from a frigid hydrocarbon "rain." Liquids which would be instantly unstable on our hot Earth. Although only Earth has a similar weather cycle. Water, or course, lies rock hard on the sub-zero surface. Stream worn ice rocks were photographed by the Huygens lander as they lay about in the spooky orange light of this smoggy lost world.
Other oddball moons include little 397 mile wide Minas with its heavily cratered surface. It has its unique crater (Herschel) which is the largest in relation to its object's area in the solar system. This gives it a nickname resemblance to the Star Wars' "Death Star." Almost the same size, but totally different, is Enceladus. Whereas Mimas looks like it has been used for eon's of target practice, Enceladus is as smooth and white as a marble ball. It's the most reflective body in the solar system. Saturn's other moons look battered and dirty by comparison. The Cassini spacecraft has found Enceladus not only to have an extremely thin atmosphere, but "warmer sub-zero spots" near its sinuous tiger striped cracks. Here is where its "air" is thickest. It seems to be recycling its white as driven snow surface by venting water, possibly from a subsurface ocean. Also, Cassini Cosmic Dust Analyzer (what a cool name) has matched Enceladus' vented particles with Saturn's water ice rich E ring. This demonstrates an ongoing dynamic interrelationship between the moons and the rings.
Interaction with a ring system may have colored the most outlandish of Saturn's moons, Iapetus. Long known to have one side as white as ice and the other as black as asphalt, Iapetus is really an oddball. Iapetus was originally written up as the alien gateway in Arthur C. Clarke's 2001, A SPACE ODYSSEY. But it had to be replaced in the movie by the Jupiter system when special effects folks found they couldn't do Saturn's rings convincingly. But now Iapetus is back to reveal weird aspects never seen before. Recent Cassini photos reveal it has a raised ridge only on its black side that coincides almost exactly with its equator. Pictures of this belt like ridge running halfway around it make Iapetus look like a giant seamed walnut waiting to be opened. Disturbingly, the ridge is quite straight as if built by intelligent forces, invoking memories of Clarke's alien gateway. It's twelve miles wide and eight miles high. Is it a great alien Wall of China? Adding to the mystery are recent photos of the larger moon Tethys' surface showing that it bears a much fainter dark band around part of its equator. One theory of equatorial belts on a moon's leading side suggests that they once plowed into dark rings that splattered across their forward surfaces like bugs on a car's windshield. But such dark rings no longer exist nearby. But then with Saturn's oddball moons, an event could have taken place millions of years ago but still remain frozen on the sub-zero surface as if it happened only yesterday.
In time, Saturn's other deep frozen moons will also reveal unexpectedly oddball features. There will always be amazing surprises on unknown worlds.
Lee Collins
I know it is only October but you can tell from the chill in the air at night that fall is upon us and winter is coming soon. Your Astronomy Club would like to invite one and all to our annual Holiday Dinner at 7:00 p.m. on Friday, December 9th at Jouni’s Cafe on Central Ave. in Upland, near Foothill Blvd. Please feel free to bring along a guest. There will be a raffle again this year and everyone will win a prize. We plan a pleasant evening of getting to know one another and sharing some holiday cheer. The menu choices and prices will be in the next newsletter but I wanted you to have the date now for your calendars. I hope to see many of you there.
Claire Stover
Of all the stars in the night sky, which ones stand out to your eye? How about Antares, the red star that represents the “heart of the Scorpion?” Maybe Sirius the Dog Star? This brilliant blue-white star certainly stood out to the Greeks since the name comes from the Greek work for “scorching.” Other candidates could be Betelgeuse, the red giant star representing Orion’s shoulder, or Vega, the brightest star of the Summer Triangle. Two stars really stand out because of their exceptional brilliance although most of us are only familiar with one of them. Sirius and Canopus are the two stars of exceptional brilliance.
While Sirius is well up in the sky for those of us willing to brave the chilly winter evenings, Canopus is so far south that it cannot be seen from the northern United States. Fortunately, it can be seen from our vantage point in southern California. During the fall months one has to stay up way past their normal bedtime to see Canopus when it culminates and just peeks over the southern horizon. Its brilliance will surprise you and it may twinkle in various colors since it is so close to the horizon.
Although Sirius and Canopus appear to be of similar magnitude and color to our eves, the two are as unlike as they could possibly be. Sirius happens to be one of our closest stellar neighbors, only 8.6 light years distant and shines about 26 times as bright as our Sun. Canopus, on the other hand, is a real stellar powerhouse. Canopus is much farther away at about 1700 light years from us. For Canopus to appear about as bright as Sirius, it must be very luminous. If the distance measurement is correct, Canopus must be around 200,000 times as powerful as our Sun. Imagine 200,000 Suns put together. It’s really hard to comprehend that amount of energy since we really don’t have any life experience to put that kind of power within any frame of reference. Canopus is not even the most luminous star in its constellation. Eta Carina is more luminous that Canopus but it is so remote that in cannot be seen at all with the unaided sys. If Canopus is so luminous, then it must be “burning” its fuel at a furious rate. A mild star such as our Sun will shine steadily for many millions of years to come. Canopus will not least nearly as long. It is a cosmic flash in the pan. It will rapidly use up its fuel and will change drastically. Canopus is to massive that it will undergo a violent outburst called a supernova, blowing much of its material away into space and leaving remnants such as the Veil Nebula, which we all enjoy observing during the warn summer nights. It may even collapse into a black hole. It will probably take over a million years for this to occur, a very short time in the cosmic time scale. If we could travel in time and look millions of years into the future, our Sun would appear much the same as it does today, while Canopus would not.
Allen Whang
This past Saturday, Oct. 29 turned out to be another mini vacation for me. I joined PVAA and the Riverside Astronomical Society for a joint star party at the RAS’s own viewing site in Landers. On the way to Landers I was delighted to find time to stop in Yucca Valley where David Levy was speaking at another astronomical event. Armed with a signed copy of one of David Levy’s books, I was excited to enjoy a night of stargazing. I was not disappointed.
The Landers site is well situated and has many amenities that many star party sites don’t have. RAS purchased the site a few years ago and the amenities include a house with a nice bathroom(!) and a kitchen where we can warm up over hot drinks. There are several concrete pads and three small observatories built for RAS members who pay a yearly fee for their use.
Besides myself, there were three other PVAA members attending, some unaffiliated observers, and a host of RAS members. Besides the viewing, the nicest part of the trip was the welcoming reception we received by the RAS members This was the first star party I have attended where people really milled around a lot. There were many different kinds of equipment being used. It was very interesting to see what other observers were doing and how they did it. I am just learning to use an SLR 35mm film camera on my small Meade telescope and I have been curious to see how CCD imaging works. Well, there were plenty of opportunities to observe others using CCDs. While some observers were very experienced astronomical photographers and captured some phenomenal images, others were learning how to use their equipment. People were enjoying sharing knowledge and information.
I enjoyed using my little telescope to hunt out nebulae and star clusters. Mars seemed to be experiencing atmospheric turbulence and observers were comparing notes on Mars’s appearance. It was fun to get to see Venus, Mars, and Saturn all in one night and through different scopes. Meteors were out in force and they frequently made me think about my new book and the accomplishments of David H. Levy.
My one regret is the lack of the female gender being represented among us stargazers. Just as most of us Earthling amateur astronomers believe that we are not alone in this universe, so I know I am not the lone female observer in these clubs. I encourage women, men, and children alike to partake in our star parties. When I got back to work the next Monday, I felt like I had been gone on a long restful vacation and was ready to face my day to day activities until the next star party-vacation, only a month away!
Laura Jaoui
The December star party will be held on Saturday, the 3rd at Mesquite Spring, Death Valley. Mesquite Springs is at the north end of Death Valley about five miles from Scotty’s Castle. Although it is a bit of a drive to get there, Mesquite Springs is one of the two darkest “dark sky sites” that PVAA visits. During the day there are the natural and historic sights of Death Valley. Joe Hillberg always makes a run through Titus Canyon. It is about a two hour drive on a one way dirt road with many interesting sights to see (animal, vegetable, mineral, and of human origin) along the way. Ubehebe volcanic crater is also nearby.
Sycamore Elementary in Upland has once again requested PVAA to participate in their annual fifth grade Space Science Night scheduled for Friday, February 3rd, 2006. We had a great night last year, starting with a hamburger/hotdog dinner grilled on site (that was free to participating PVAA members) followed by a short presentation. After the presentation, the students separated into groups and rotated through about 5 different learning stations, including: asteroid drop, build a rocket, identify the constellations, and of course, the telescopes. We look forward to an equally fun night this year. There will be a number of good objects up that night, including the 1st quarter moon, Mars, Saturn, and Orion, so it would be nice to have at least 4 or 5 scopes. If you have questions or would like to volunteer, contact Craig Matthews at (909) 981-3131 or sycamorepta@hotmail.com.
Before the October 29th star party with RAS, Laura Jaoui and I went to hear David Levy speak at the Starry Nights Festival in Yucca Valley. During much of his presentation he spoke of the discovery by Clyde Tombaugh of a Dwarf Nova and of his (Levy’s) contribution to the confirmation of that discovery. It was a fascinating talk on a subject about which I previously knew nothing. For more on this topic see:
http://www.aavso.org/publications/ejaavso/v28n1/38.pdf
http://www.aavso.org/publications/newsletter/number26/spooky.shtml.
But David Levy is probably best known for the co-discovery (with the Shoemakers) of Comet Shoemaker-Levy 9.
The 1990s were a decade of once-in-a-lifetime comets. With its 60-degree ion tail, there was the bright, 0 magnitude Comet Hyakutaki in March of 1996. Then in 1997 there was the even brighter Comet Hale-Bopp with its 15-degree tail. But in July of 1994 the first of the three great comets of that decade was (in my opinion) also the most spectacular, Comet Shoemaker-Levy 9.
My fascination with the night sky began in childhood back in rural Michigan during the early 1960s. In 1993-94 I had just started to rekindle that interest in astronomy which had lain dormant for more than a decade. I purchased a pair of 80mm Meade binoculars and 13-inch Coulter Odyssey Dobsonian telescope. As it turned out, I couldn’t have chosen a better time to start observing again. About this same time, using the 0.4-meter Schmidt telescope on Palomar Mountain, Eugene and Carolyn Shoemaker and David Levy took the photograph upon which Comet Shoemaker-Levy 9 was found during the night of March 24, 1993. With more observations from the University of Hawaii, Kitt Peak, and McDonald Observatory soon it was determined that the comet had been gravitationally captured by Jupiter. The gravity of the massive planet had broken the comet up into more than twenty smaller objects, which were now on course for an eventual collision with Jupiter.
In mid July, during the period of the first impacts with Jupiter, Mount Wilson Observatory held an observing session for the public. Hundreds of amateur astronomers, including a group from PVAA were there. I was fortunate enough to be among them. The comet fragments actually impacted on the far side of the planet. The impact sites then rotated around into view.
That first night I didn’t see much. I was hoping, but I didn’t really expect to see much. Then a couple of days later I was observing Jupiter from my back yard with the 13-inch Odyssey Telescope. I was stunned by what I saw. Huge dark splotches were scattered across the planet. The comet impact sites were the most prominent features of the planet.
As the weeks passed the dark ovals on Jupiter smeared out and elongated. The impact sites remained visible in a telescope until late October when Jupiter passed behind the Sun, making observation impossible. When it reemerged in December the impact sites had merged into a faint cloud belt.
Getting to hear David Levy speak brought back memories of Comet Shoemaker-Levy 9 and that exciting time in 1994. As far as anyone knows, that was the first time humans have observed a comet impacting a planet. It was a sight that remains vivid in my memory to this day. I will never forget it.
Ron Hoekwater
Located at the southern end of Perseus, neat the border with Cassiopeia, the Double Cluster is a prominent haze, about a degree long and elongated E-W, visible to the naked eye. Surprisingly, although he included objects whose stellar composition is obvious – like the Pleiades – Messier did not list the Double Cluster in his catalog. Hipparchus did mention it as one of a number of "clouds" in this second century BC star catalog. The two components of this fine object have separate entries in the NGC, and the Double Cluster is also known as the Sword Handle, and has the alternative designation of h and x Per (NGC 869 is h, NGC 884 is x).
While not resolved by the naked eye, the Double Cluster is seen as a pair of overlapping circular masses of faint stars, well contained in the field, in 10 x 50 binoculars. The stars range in brightness from 7th magnitude down to the detection limit of around mag. +10.
A small telescope will reveal many more faint stars within each component of the Double Cluster. A low magnification is preferable each of these clusters has an apparent diameter of nearly 30’, and a X40 the two will fit into the 1.3 degree field. Higher powers will emphasize the colors of the several prominent red giant stars there, indicators of the clusters’ ages. NGC 869 is 5.6 million years in age while NGC 884 is 3.2 million years. They are young, but old enough for some of their most massive stars to have evolved into red giants. The Double Cluster is an excellent object for observers during the fall and winter months. The Double Cluster passes over head in late evening hours during December, and, viewed with binoculars from a lounger, are a spectacular sight.
From Deep Sky Observer’s Guide
"Equipped with his five senses, man explores the universe around him and calls the adventure Science".
Edwin Hubble