June 2002 Newsletter

Stockton Astronomical Society

Valley Skies

Valley Skies - June 2002 Issue

Editor's Corner...

The Stockton Astronomical Society has enjoyed a symbiotic relationship with the Clever Planetarium at Delta College since its construction in 1973. The club has had the ongoing use of the facility for meetings and workshops. It is a wonderful asset which has added immeasurably to the appeal of the club, and has enabled us to offer programs such as the Summer Skies Workshop planned for our June 13 meeting.

The planetarium is a valuable academic resource as a classroom for astronomy lab classes. It is also an invaluable community resource. In addition to the public programs offered on weekends, the planetarium hosts field trips for elementary school classes, currently on Tuesdays and Thursdays every week during the school year. Typically 8,000-10,000 youngsters are introduced to the night sky in the Clever Planetarium each year. Who knows how many of those kids will develop a growing interest in astronomy, or science in general, as a result of that initial exposure to the planetarium sky.

Not all education comes from the regular classroom. Intellectual growth takes place wherever the imagination is sparked or challenged. I know that my interest in science was greatly stimulated by regular visits to the Griffith Planetarium in Los Angeles in the 1950's. The Clever Planetarium at Delta College has the potential to continue to provide such stimulus to young minds throughout this community.

However, that potential is in danger of dying from benign neglect. Broken seat mechanisms are only the most obvious evidence of the lack of maintenance. At the heart of the planetarium is the Spitz projector, which has not been serviced since 1998. The planetarium has apparently been low on the college's budget priority list and funds for regular service have not been made available. Astronomy lab capabilities are impaired and it has become an ever-growing challenge to provide a quality show experience for those attending public shows or school field trips.

At our Executive Committee meeting on May 23rd, the committee decided, subject to membership approval, to offer to contribute $1000 toward essential maintenance of the Spitz system, in the hope of spurring a financial commitment from the College. We feel it would be money well spent, since we have a vested interest in keeping the facility operating at an effective level. In addition to monetary support, we will offer to contribute any available expertise and time that we can muster to help maintain the audio-visual and control systems that enhance the show experience.

At the June 13 general meeting, we will ask the membership present for approval of the proposed $1000 offer to the college.

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A Challenge to serious observers...
Tim Castellano's talk at our April 11 meeting was about how amateurs can follow up candidate stars identified by planet searches, and possibly join the ranks of planet discoverers, if relative photometry with better than 1% precision can be achieved.

Starting on page 4 is the second half of the text of Tim's presentation, an invitation to amateur astronomers to join him in this quest for discovery.

...Trevor Atkinson

SAS Observing Program

The focus this month will be on southern skies and a few objects overhead.

Between the spout of the Sagittarius teapot and the stinger on the tail of Scorpius, look for beautiful open clusters M6 and M7. M7 especially is dazzling and is a naked eye cluster. The two constellations are also rich in globular clusters. M4 is next to Antares and is a very loose globular cluster. M107, M9, M80, M19 and M62 are smaller and denser. None of these hold a candle to M22, upper left from the lid of the teapot. About 10,000 light-years distant, it is a rich, dense globular of perhaps 70,000 stars, every bit as impressive as M31 in Hercules.

Overhead in Hercules, look next to M13 for NGC 6207, a fine spiral galaxy with a stellar nucleus. NGC 6802 is the Peanut Cluster, located at the end of the Coathanger, an asterism in Vulpecula. While in that area, drop in on the Dumbbell Nebula, M27, located about 5° east from the Coathanger.

Comet Ikeya-Zhang

Rosemary and I were at Lake Tahoe the night of May 4. With binoculars we spotted the comet in the head of Draco. Not a spectacular observation...little more than a faint smudge in my 8x56 binocs. Still, it was the first comet we've seen for a while.

According to the chart on page 97 of the June issue of Sky & Telescope, the comet will have passed through Hercules and Corona Borealis in late May, and will spend all of June working its way slowly through Serpens Caput. It will pass very close to the globular cluster M5 between June 26 and July 1.

...Trevor Atkinson

Solar Eclipse June 10

If you happen to be within a very narrow E-to-W strip of the Pacific Ocean on June 10, you may see an annular eclipse of the Sun. It won't be a total eclipse because the Moon's angular size won't be quite big enough to cover the Sun.

Here in N. California, the Moon will cover about 72% of the Sun's diameter, about 65% of its area. In Stockton, first contact will be about 5:05 pm, maximum eclipse about 6:15 pm and last contact about 7:18 pm.

With 35% of the Sun's disk area still uncovered at max. eclipse, it will be just as dangerous to observe directly as at any other time. Direct observation should only be attempted if you have a safe solar filter mounted to block light from entering the telescope. Do not attempt it with an eyepiece filter, which can crack or melt, exposing you to instant eye damage. Don't take chances.

Observing Through 60 Inches
by Jane Houston Jones

Nothing prepares you properly for your first look at or through a big telescope. We drove to Pasadena and up into the San Gabriel mountains during the January 2002 new moon weekend. Our destination was the historic 60-inch telescope at Mount Wilson. Our hosts for the weekend were the Los Angeles Sidewalk Astronomers, who usually set up their homemade reflectors outside the dome for public star parties.

This weekend they arrived without telescopes, and spent Friday and Saturday night peering through the eyepiece of the 60-inch telescope instead. I could write an entire article about the the history of Mount Wilson, the mirrors and telescopes, the current research using adaptive optics with the 100-inch Hooker telescope, but you can read that yourselves if you are interested. Here is the website for Mt. Wilson Observatory and the Mount Wilson Observatory Association http://www.mtwilson.edu/General/ for your telescope and history fix.

The author peers through the Telrad mounted near the cassegrain focus of the 60-inch telescope on Mt. Wilson.

Before dark, I made sure to walk by the famous storage lockers. One square foot in size each, a wall of three rows of four lockers bore the names of some of the famous Mount Wilson astronomers: Minkowski, Zwicky and Hubble, to name but a few. An old phone list on the bulletin board lists Halton "Chip" Arp, next to one of the many black rotary telephones.

The telescope operator and Mount Wilson Observatory Association docents have a list of target objects that show well in the 60-inch f/16 telescope. And in-between objects they tell tales, give telescope and observatory history, and answer any questions you may have. The upper cage had been removed and the telescope was in its cassegrain configuration for the star party.

With a group of 25 people, it takes about an hour for everyone to view one object. As with most group star parties, many of the participants seemed to poop out by midnight or so, which meant they had only looked at about 5 objects. After midnight, with a smaller crowd, we were able to move through objects more quickly, and for those of us who stayed until 5:00 a.m. that meant we got plenty of observing time. The conditions on the two nights at latitude 118 degrees 3.6 minutes west, longitude 34 degrees 13.0 minutes north were not too bad. The sky brightness at Mount Wilson from Los Angeles is approximately equal to the sky brightness from the full moon, and the seeing ranged from good to poor. Even so, we had some spectacular views of some amazing objects.

Jupiter through the 60-inch. Europa and its shadow were transiting the disk very near the Great Red Spot.

Our first observation on the first night was the blue and yellow double star, iota Triangulum. Next was Saturn, with six moons (even Mimas) visible and a large brown oval storm on the north equatorial band. The storm was as big or bigger than the red spot of Jupiter. And speaking of that other big planet, Jupiter's red spot was near the central meridian too early for observing on the first night, but we went back to it the second night at about 1:00 a.m. and got a real treat! The red spot hollow sported a black dot of moon shadow near where a tear duct would appear on a drawing of an eye. Right next to the shadow of the moon, I saw the round beige disk of Europa. The red spot itself was nearly invisible, a washed out faint pink oval. All belts and zones, including the faint equatorial band were visible. The four of us who were sketching were busy getting looks at the planets, and then comparing drawings.

Other highlights (for me, at least) were IC418 in Lepus (the red planetary), Eskimo NGC2392 in Gemini, and Ghost of Jupiter NGC3242 in Hydra at about 800 power. It looked like a Hubble Photo!

NGC2392 "The Eskimo" or "Clown Face" planetary nebula.

NGC3242 "The Ghost of Jupiter" planetary nebula.

The trapezium and surrounding nebula in M42 was spectacular. I was able to see the G star inside the trapezium, and the telescope operator told me it is not unusual on a sub arc-second night to see a dozen stars inside the trapezium through this telescope! He also told me that spring and summer are the best observing months, with steady air, and that January is pretty dismal. NGC3115 needle galaxy in Sextans was one of the few high-surface brightness galaxies we attempted to view, the other being the Sombrero Galaxy, M104, in Corvus.

M87 the giant elliptical galaxy in Virgo. In the 60-inch visually, the famous jet could be seen as a bright streak radiating from near the center of the galaxy.

But the absolute highlight for me was to clearly see the jet in M-87. It looked like blobs of material, a string of clumpy clusters, forming a pipe of hydrogen blowing off the elliptical galaxy and pointing at 9:30 in our eyepiece view at 220 and 440 power. The x-ray images we see of this object do not do justice to the visual observations. All pictures I have ever seen of the jet show the galaxy overexposed as a bright oval with no detail and the jet appears outside the oval, almost like a nearby companion cluster or small galaxy. The 60 inches of light gathering power, and the 50 mm eyepiece view for 440 power, showed the jet forming within the galaxy itself. It was worth the trip to the southland just to see this object with my own eyes!

Speaking of quasars, we also observed magnitude 17 Q957 +561 A and B, the variable double quasar in Ursa Major. This "double" quasar is the first example found that demonstrates Einstein's prediction of gravitational lensing. This is a single quasar that has two nearly identical images caused by the gravitational effect of an (unseen) intervening galaxy. Here's a picture of the quasar and the galaxy, compliments of the Hubble Space Telescope. http://www.astr.ua.edu/keel/agn/q0957.html

We also observed our nearest quasar, only 2 billion light-years away, magnitude 12.8 3C273 in Virgo. The strange name "3C273" comes from a radio survey that detected many strong radio sources in the sky such as this quasar. Not only do these objects emit prodigious amounts of energy (more than 100 times an ordinary galaxy), they also change in brightness on very small timescales.

At midnight on our first night, we walked over to the 100-inch Hooker telescope, and got to stand outside on the catwalk as the dome rotated. We got a cook's tour (thanks to a friend who is the telescope operator on the 100-inch adaptive optics system), and then went into the control room, the shop, saw where the 100-inch gets bathed and realuminized, and then, back to the 9-inch thick, 1900-pound 60-inch mirror, for more peeks into the past.

A night on Mount Wilson isn't your typical star party, and although a deep sky observer may get antsy waiting for a telescope operator to cycle through the crowd to the next object, it was a deeply satisfying New Moon observing weekend. I wonder what Mr. Hubble stored in his locker on those observing nights long ago?

Jane Houston Jones is a member of San Francisco Amateur Astronomers, San Francisco Sidewalk Astronomers and Sonoma County Astronomical Society. She is also the current president of the AANC and a director of Astronomical Society of the Pacific.

All sketches by the author.