Login
New User

Welcome to AOAS.ORG
Wednesday, April 16 2014 @ 08:52 AM CDT

Email Article To a Friend View Printable Version

Start an Astronomical League observing program tonight!

Backyard AstronomySent by - John Jardine Goss

Secretary, Astronomical League

After finally finding some time under the stars, have you ever thought, "What should I observe? There's so much up there!"



The Astronomical League offers nearly 30 observing programs to help in just that situation. Some are designed for the novice such as Constellation Hunters, Universe Sampler, and Lunar Clubs. Other programs, including the Messier, Urban, and Planetary Observer Clubs, are better suited for intermediate observers. More experience deep sky hunters can hone their skills with the tougher selections of the Herschel, Arp Peculiar Galaxies, and Galaxy Groups and Clusters Clubs. Truly, there is a program for everyone!

Upon completion of each club, the observer is presented a certificate suitable for framing and a nifty lapel pin. These lists are a low stress way to enjoy the many wonders of the night sky.

Check out which program is right for you! Visit the League Observing pages here
Email Article To a Friend View Printable Version

NASA's Spitzer Space Telescope

Deep SkyI was just looking at a great pictorial article (8pp), Night Vision - NASA's Spitzer Space Telescope Lights Up The Heart of a Dark Universe, in the Dec. 2005 issue of National Geographic magazine. Launched in August 2003, this car-size telescope is 26 million miles from Earth. Spitzer utilizes 3 different instruments to capture and analyze different infrared frequencies. The telescope's infrared vision is the sharpest ever, using a mirror nearly 3 feet across, sensitive detectors cooled almost to absolute zero, along with an orbit far from the distracting heat of our planet, Earth. Spitzer is expected to run out of the liquid helium that helps cool it, in about 2008.

The color pictures in the article, compiled from Spitzer, are well worth the time to look at and to read this brief article.
Chuck Larson

Email Article To a Friend View Printable Version

New Solar System found

General News

I was watching the ABC national news early this morning. They ran a crawler across the bottom of the screen announcing that a new solar system had been discovered 500 light years away.

I did not hear anything about this, nor see any other information on this since I had to leave early this morning to do a presentation on campus at UAFS.

Has anyone seen or heard about this???

Chuck Larson
Email Article To a Friend View Printable Version

KIDS! - Play "Black Hole Rescue!"

NASA Space PlaceNearby matter is not the only thing attracted by a black hole. These mysterious objects also attract a great deal of curiosity from kids here on Earth. Taking advantage of this interest, NASA’s Web site for kids, The Space Place, has just added a new game called “Black Hole Rescue!” After (or before) reading a short, illustrated article introducing black hole concepts, game players “rescue” the vocabulary words, one letter at a time, before they get sucked into the black hole. After playing this mesmerizing game for a while, kids of all ages will not soon forget what black holes are all about.

http://spaceplace.nasa.gov/en/kids/blackhole/
Email Article To a Friend View Printable Version

Voices from the Cacophony

NASA Space PlaceBy Trudy E. Bell and Dr. Tony Phillips

Around 2015, NASA and the European Space Agency plan to launch one of the biggest and most exacting space experiments ever flown: LISA, the Laser Interferometer Space Antenna.

LISA will be able to detect gravitational waves from as far back as 10-36 second after the Big Bang, far earlier than any telescope can detect. (Click image for larger view.)
LISA will consist of three spacecraft flying in a triangular formation behind Earth. Each spacecraft will beam a laser at the other two, continuously measuring their mutual separation. The spacecraft will be a mind-boggling 5 million kilometers apart (12 times the Earth-Moon distance) yet they will monitor their mutual separation to one billionth of a centimeter, smaller than an atom's diameter.

LISA's mission is to detect gravitational waves—ripples in space-time caused by the Universe's most violent events: galaxies colliding with other galaxies, supermassive black holes gobbling each other, and even echoes still ricocheting from the Big Bang that created the Universe. By studying the shape, frequency, and timing of gravitational waves, astronomers believe they can learn what's happening deep inside these acts of celestial violence.

The problem is, no one has ever directly detected gravitational waves: they're still a theoretical prediction. So no one truly knows what they "sound" like.

Furthermore, theorists expect the Universe to be booming with thousands of sources of gravitational waves. Unlike a regular telescope that can point to one part of the sky at a time, LISA receives gravitational waves from many directions at once. It's a cacophony. Astronomers must figure how to distinguish one signal from another. An outburst is detected! Was it caused by two neutron stars colliding over here or a pair of supermassive black holes tearing each other apart in colliding galaxies over there?
Email Article To a Friend View Printable Version

A Wrinkle in Space-Time

NASA Space PlaceBy Trudy E. Bell

LISA's three spacecraft will be positioned at the corners of a triangle 5 million kilometers on a side and will be able to detect gravitational wave induced changes in their separation distance of as little as one billionth of a centimeter.
When a massive star reaches the end of its life, it can explode into a supernova rivaling the brilliance of an entire galaxy. What's left of the star fades in weeks, but its outer layers expand through space as a turbulent cloud of gases. Astronomers see beautiful remnants from past supernovas all around the sky, one of the most famous being the Crab Nebula in Taurus.

When a star throws off nine-tenths of its mass in a supernova, however, it also throws off nine-tenths of its gravitational field.

Astronomers see the light from supernovas. Can they also somehow sense the sudden and dramatic change in the exploding star's gravitational field?

Yes, they believe they can. According to Einstein's general theory of relativity, changes in the star's gravitational field should propagate outward, just like light -- indeed, at the speed of light.

Those propagating changes would be a gravitational wave.

Einstein said what we feel as a gravitational field arises from the fact that huge masses curve space and time. The more massive an object, the more it bends the three dimensions of space and the fourth dimension of time. And if a massive object's gravitational field changes suddenly -- say, when a star explodes -- it should kink or wrinkle the very geometry of space-time. Moreover, that wrinkle should propagate outward like ripples radiating outward in a pond from a thrown stone.

The frequency and timing of gravitational waves should reveal what's happening deep inside a supernova, in contrast to light, which is radiated from the surface. Thus, gravitational waves allow astronomers to peer inside the universe's most violent events -- like doctors peer at patients' internal organs using CAT scans. The technique is not limited to supernovas: colliding neutron stars, black holes and other exotic objects may be revealed, too.

NASA and the European Space Agency are now building prototype equipment for the first space experiment to measure gravitational waves: the Laser Interferometer Space Antenna, or LISA.

LISA will look for patterns of compression and stretching in space-time that signal the passage of a gravitational wave. Three small spacecraft will fly in a triangular formation behind the Earth, each beaming a laser at the other two, continuously measuring their mutual separation. Although the three 'craft will be 5 million kilometers apart, they will monitor their separation to one billionth of a centimeter, smaller than an atom's diameter, which is the kind of precision needed to sense these elusive waves.

LISA is slated for launch around 2015.

To learn more about LISA, go to http://lisa.jpl.nasa.gov. Kids can learn about LISA and do a gravitational wave interactive crossword at http://spaceplace.nasa.gov/en/kids/lisaxword/lisaxword.shtml.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
Email Article To a Friend View Printable Version

U. of A. Support of Nasa Hera Project

General NewsLocal journalists report that Derek Sears and his team at the University of Arkansas are among the leading contenders for the $450-mm NASA Hera project. This is a proposed mission to retrieve actual samples of an asteroid and return to Earth. I will contact Sears and find out if there is news that can be shared with the AOAS membership about this exciting mission. If they prevail in their bid, it appears that Fayetteville would become the brain-center for this major NASA project.
Email Article To a Friend View Printable Version

AOAS to Seek Funding for Bifilar Micrometer

Chart RoomColeman Observatory would be a great place to begin a program dedicated to the study of binary stars, more popularly referred as "double stars". In order to perform proper measurements of binary star systems, a professional-quality bifilar micrometer would be required, just exactly the kind that is manufactured by Van Slyke Engineering (VSE). The cost will be between $2000 and $2500 for the micrometer we'd like to have, and I believe this should be our newest project to raise the funds needed for our own bifilar micrometer during 2006.

The VSE "NeedleEye" digital bifilar micrometer. Paul Van Slyke Engineering produces a limited number of high-quality, precision bifilar micrometers for sale to amateur astronomers and private observatories. The digital model shown here retails for $2450, but during the current sale, the price has been reduced to $1950. AOAS hopes to raise the funds needed to buy one of these professional-level instruments in 2006, to begin our own binary star program.
Binary, or double stars, are two or more stars which appear close to one another in our telescopes. Double stars can simply be two stars aligned such that they only "appear" to be a true pair, but in reality the two stars may be quite far apart with one star being much closer to us than the other. Such chance line-of-sight alignments of stars is not what a program of binary star study is about.

True binary stars are pairs of stars that share a common center of gravity, and are bound together by gravity throughout time, forever locked in a spiral dance whereby they actually orbit each other. The only accurate way to measure the masses of stars is by carefully measuring the changing positions of the two stars over long periods of time. Binary systems may complete each orbit in as few as 5 to 10 years, or they may take as long as 20 to 50 years to do so. Such measurements are made by using an instrument known as a bifilar micrometer.

A bifilar micrometer is an instrument which has an illuminated reticle etched into a glass as a "crosshair", with a second single-line reticle that can be moved, with exquisite precision, and be placed over the secondary star of a pair allowing for their separation to be recorded with extreme accuracy. The crosshair reticle can be rotated so that one of the illuminated lines might be oriented to celestial north. This thereby allows the angle of a binary pair to be determined as measured in a clockwise direction away from 0 degrees, which begins at true north. Such instruments are not a common item for sale to amateur astronomers, and those with the quality of workmanship desireable for high-quality measurements are not cheap. A very limited number of companies offer such instruments, and among the best in the world today, are those available from Van Slyke Engineering.

Click on "read more" for the rest of this story.
Email Article To a Friend View Printable Version

Mars Night at Coleman Observatory Oct 29th

Coleman ObservatoryUPDATE: October 29th saw upwards of 85 visitors at Coleman Observatory to enjoy views of Mars. Telescopes of every type and from 5" diameter up to the 14" aperture of our primary instrument were used, and will again be in use for the next Mars Star Party on November 5th! Come to Coleman Observatory and join us before Mars begins to rapidly shrink in size after mid-November.

Mars marks its closest point to Earth since 2003 on Saturday, October 29th, at a distance of "merely" 43,000,000 miles away. Join members of AOAS at our Coleman Observatory located 8 mi. NW of Van Buren for the best views of the mythological Roman "God of War" until 2018!

AOAS member Jeff Treshnell captured this image of Mars through his telescope in 2003. This is very similar to what the view of Mars will look like through the telescopes at Coleman Observatory on the weekends of October 29th and November 5th. The public is invited to both events, and as always there are NO FEES to share the views of our universe with us. UPDATE: Visitors to Coleman Observatory on Oct 29th saw virtually the exact same view of Mars as is depicted here. If you missed it last Saturday, join us again THIS Saturday, Nov 5th.
It's a fact, Mars is as close to Earth as it'll be for the next 13 years on the 29th of October and the public is invited to come out and see it with us through our telescopes. The viewing begins at sunset that evening with brilliant Venus in the SW skies. Then we'll watch as Mars slowly creeps above the eastern horizon shortly after sunset. By 7:45, Mars will be high enough to view through most of the telescopes we have on site, but as the evening progresses and Mars continues rising, the views will just get better and better.

The reason for this is simple. Low on the horizon, we view objects through the thickest part of Earth's atmosphere. You are literally seeing every object near the horizon through a couple hundred miles of haze, water vapor, pollution, etc. The best views of a planet like Mars comes after it has risen at least 30 degrees or more above the horizon where the atmosphere is less than 40 miles thick.

Between there and the time when it reaches a point overhead known as the zenith, you'll see the most detail available through whatever size and type of telescope you're viewing with. The best views of Mars will be between around 9:00 p.m. and midnight. For any night owl visitors who stay even later, those great views will continue until as late as 3:00 a.m. when Mars once again begins to sink into the thicker parts of our atmosphere in the western sky.

Mars will be well placed for viewing from mid-October through late November. For this reason, AOAS and Coleman Observatory will host a second public night on November 5th, the Saturday after the 29th. This will give everyone ample opportunities to come and view Mars at its best during this apparition.

Click "read more" for the rest of this story.

Email Article To a Friend View Printable Version

Where No Spacecraft Has Gone Before

NASA Space Placeby Dr. Tony Phillips

Voyager 1, after 28 years of travel, has reached the heliosheath of our solar system. (Click image for larger view.)
In 1977, Voyager 1 left our planet. Its mission: to visit Jupiter and Saturn and to study their moons. The flybys were an enormous success. Voyager 1 discovered active volcanoes on Io, found evidence for submerged oceans on Europa, and photographed dark rings around Jupiter itself. Later, the spacecraft buzzed Saturn’s moon Titan—alerting astronomers that it was a very strange place indeed! —and flew behind Saturn’s rings, seeing what was hidden from Earth.

Beyond Saturn, Neptune and Uranus beckoned, but Voyager 1’s planet-tour ended there. Saturn’s gravity seized Voyager 1 and slingshot it into deep space. Voyager 1 was heading for the stars—just as NASA had planned.

Now, in 2005, the spacecraft is nine billion miles (96 astronomical units) from the Sun, and it has entered a strange region of space no ship has ever visited before.

"We call this region ‘the heliosheath.’ It’s where the solar wind piles up against the interstellar medium at the outer edge of our solar system," says Ed Stone, project scientist for the Voyager mission at the Jet Propulsion Laboratory.

Out in the Milky Way, where Voyager 1 is trying to go, the "empty space" between stars is not really empty. It’s filled with clouds of gas and dust. The wind from the Sun blows a gigantic bubble in this cloudy "interstellar medium." All nine planets from Mercury to Pluto fit comfortably inside. The heliosheath is, essentially, the bubble’s skin.

"The heliosheath is different from any other place we’ve been," says Stone. Near the Sun, the solar wind moves at a million miles per hour. At the heliosheath, the solar wind slows eventually to a dead stop. The slowing wind becomes denser, more turbulent, and its magnetic field—a remnant of the sun’s own magnetism—grows stronger.

So far from Earth, this turbulent magnetic gas is curiously important to human life. "The heliosheath is a shield against galactic cosmic rays," explains Stone. Subatomic particles blasted in our direction by distant supernovas and black holes are deflected by the heliosheath, protecting the inner solar system from much deadly radiation.

Voyager 1 is exploring this shield for the first time. "We’ll remain inside the heliosheath for 8 to 10 years," predicts Stone, "then we’ll break through, finally reaching interstellar space."

What’s out there? Stay tuned…

For more about the twin Voyager spacecraft, visit voyager.jpl.nasa.gov. Kids can learn about Voyager 1 and 2 and their grand tour of the outer planets at spaceplace.nasa.gov/en/kids/vgr_fact3.shtml.

What's New

STORIES

No new stories

COMMENTS last 2 days

No new comments

LINKS last 2 weeks

No recent new links

Who's Online

Guest Users: 4

User Functions






Lost your password?

Want It ALL?

Become a card-carrying member of AOAS. Paying dues gives you several advantages over other registered users, including a subscription to the club newsletter, an AOAS.ORG e-mail address, use of club materials, including books and telescopes, and access to the Coleman Observatory facilities. On top of all that, you also qualify for a 20% discount on all books at any Books-A-Million location.

To get your membership application, click here.