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Saturday, January 19, 2008

ASTRONOMY NEWS AND EVENTS

Smith's Cloud is Coming

In 20 million to 40 million years, a colossal cloud of gas will collide with our galaxy. The impact could trigger an intense burst of star formation. The details were reported on January 11 at the American Astronomical Society meeting in Austin, Texas.

The large cloud is called Smith's Cloud, named after Gail Bieger (formerly Gail Smith), who discovered the cloud in 1963 while an astronomy student at Leiden University in the Netherlands. Some astronomers think Smith's Cloud is a remnant of the original formation of the Milky Way.

The cloud is currently 8,000 light-years from our galaxy's disk. It has enough hydrogen to make a million stars like the sun, it is 11,000 light-years long and 2,500 light-years wide. If you could look up from Earth and see the cloud, it would span 30 times the width of the moon, or 15 degrees, roughly an area the angular size of the constellation Orion.

For decades after its discovery, because the available images lacked any detail, scientists were puzzled as to whether the cloud was a part of the Milky Way or outside of it. The recent observations were made using the National Science Foundation's Robert C. Byrd Green Bank Telescope, the largest steerable radio telescope. Because the cloud is made of cold gas, it emits only in the radio wavelengths. The results showed Smith's Cloud is moving toward the Milky Way, not away, at more than 540,000 mph (869,000 kilometers per hour).

In the latest observations, the cloud is rubbing against the outer atmosphere of the Milky Way, and it is starting to push up gas in front of it. Also, it seems to be feeling a tidal force from the gravity of the Milky Way and the cloud may be in the process of being torn apart.

The cloud will likely strike a region somewhat farther from the galactic center than our solar system. The addition of new gas into our galaxy along with the shock of the collision may trigger a burst of rapid star formation. Many of the new stars are expected to be massive, with relatively short lives that end as exploding supernovae.

To learn more, visit these links:

The home page of the National Radio Astronomy Observatory:
http://www.nrao.edu/

The home page of the Robert C. Byrd Green Bank Telescope:
http://www.gb.nrao.edu/GBT/GBT.shtml


Even Thin Galaxies Have Supermassive Black Holes

A half-dozen supermassive black holes hide where they are least expected, in relatively skinny galaxies. The discovery implies galaxies don't need center bulges to harbor monstrous black holes.

Until now, astronomers thought central concentrations of stars called galactic bulges were required for black holes to grow. Like most spiral galaxies, our own Milky Way has such a bulge. In many large galaxies, the bulge feeds the black hole, creating high-speed consumption and a lot of radiation.

Up to now, it was thought that the small and thinner galaxies did not have supermassive black holes.
New observations from the Spitzer Space Telescope, however, show this is not the case.

The new information was presented the week of January 7 at the American Astronomical Society meeting in Austin, Texas. Now, astronomers think dark matter, an invisible substance thought to account for about 85 percent of all matter in the universe, might play a role in the early development of supermassive black holes.

The mostly dormant black hole at the center of our galaxy has several million times the mass of the sun. In more active galaxies, black holes can surpass a billion solar masses. (The record-setter, at 18 billion solar masses, was also announced during the annual meeting.)

A few recent studies have caused astronomers to question the conventional thinking. In 2003, scientists discovered a relatively "lightweight" supermassive black hole in a bulge-less galaxy. And even more recently, the reportingh team spotted another supermassive black hole lurking in a similar galaxy. In the new report, the team anounced the discovery of six more monstrous black holes in thin galaxies with minimal bulges.

The black holes were only recently detected because they have been shrouded by dust. Galaxies with minimal midsections tend to be extremely dusty. Infrared light can penetrate the dust, which means Spitzer could find the black holes with its infrared capabilities.

The team speculates that the missing piece of the black-hole puzzle may be dark matter. Early on in the galaxy's life, this invisible matter might somehow set the mass of the black hole. Other theorists have suggested in recent years that dark matter was integral to galaxy formation.

The study will be published in the April 10 issue of the Astrophysical Journal.

To learn more, visit the home page of the Spitzer Space Telescope:
http://www.spitzer.caltech.edu/


View of New Hydrogen Clouds In The M81 Group Of Galaxies

The M81 Group of galaxies, 11.8 million light-years from Earth, are interacting gravitationally with each other. The newly-discovered gas clouds, each containing from 14 to 57 million times the mass of our Sun, are similar to gas clouds also found near our own Milky Way Galaxy.

Astronomers analyzing these M81 Group clouds conclude that they are likely remnants of earlier interactions among the galaxies and that this suggests that the clouds observed near the Milky Way had a similar origin.

The astronomers presented their findings to the American Astronomical Society's meeting in Austin, Texas.

To learn more, visit these links:

The home page of the National Radio Astronomy Observatory:
http://www.nrao.edu/

The home page of the Robert C. Byrd Green Bank Telescope:
http://www.gb.nrao.edu/GBT/GBT.shtml


Distant Galaxy Contains Ingredients for Life

Astronomers from Arecibo Observatory radio telescope in Arecibo, Puerto Rico, have detected for the first time the molecules methanimine and hydrogen cyanide -- two ingredients that build life-forming amino acids -- in a galaxy some 250 million light years away.

When combined with water, the molecules form glycene, the simplest amino acid and a building block of life on Earth.

The Arecibo astronomers focused on the distant galaxy Arp 220, an ultra-luminous starburst galaxy, because it forms new stars at a very high rate. They used the 305-meter, or 1,000-foot diameter, Arecibo radio telescope, the world's largest and most sensitive, to observe the galaxy at different frequencies. The observations, made in April 2007, were the first use of the 800 megahertz wide-band mode of the telescope's main spectrometer.
The molecules were found by searching for radio emission at specific frequencies. Each chemical substance has its own unique radio frequency, much like people have unique fingerprints.

The astronomy team, led by Arecibo astronomer Christopher Salter, announced the discovery January 11 in a poster presented at the American Astronomical Society meeting in Austin, Texas.

To learn more, visit the home page of the Arecibo Observatory: http://www.naic.edu/


Ulysses Flying by of the Sun's North Pole

The timing could not be better. Just last week, solar physicists announced the beginning of a new solar cycle and on January 14th, the Ulysses spacecraft flew over a key region of solar activity--the sun's North Pole.

Launched in October of 1990 from the space shuttle Discovery, Ulysses is a joint mission of the European Space Agency and NASA. Unlike other spacecraft, Ulysses is able to fly over the sun's poles, looking down on regions that are difficult to see from Earth.

Ulysses has flown over the sun's poles three times before in 1994-95, 2000-01 and 2007. Each flyby discovered something interesting and mysterious, but this one may be most interesting of all.

Many researchers think the sun's poles are central to the ebb and flow of the solar cycle. Consider that when sunspots break up, their decaying magnetic fields are carried toward the poles by large currents of plasma, making the poles a kind of "sunspot graveyard." Old magnetic fields sink beneath the polar surface two hundred thousand kilometers, all the way to the sun's inner magnetic dynamo. There, dynamo action amplifies the fields for use in future solar cycles.

One big puzzle revealed by previous flybys is the temperature of the sun's poles. In the previous solar cycle, the magnetic north pole was about 80,000 degrees or 8% cooler than the south. And no one yet knows why there would be a difference.

The current flyby may help solve the puzzle because it comes less than a year after a similar South Pole flyby in February of 2007. Mission scientists will be able to compare temperature measurements of the north and south, with little time between them.

Ulysses also discovered the sun's high-speed polar wind. At the sun's poles, the magnetic field opens to allow the solar atmosphere to stream out at a speed of roughly a million miles per hour.

By flying around the sun, covering all latitudes, Ulysses has been able to monitor this polar wind throughout the solar cycle--and it is acting a bit odd.
Posner explains: Eleven years ago, during a similar change between solar cycles, the polar wind spilled down almost all the way to the sun's equator. But this time the polar wind is confined to latitudes above 45 degrees.

No one is certain whether this detail is important. That's why now is a good time to visit the sun's North Pole. Researchers will be monitoring the magnetic field above the north pole to see what it's like during the change of solar cycles.

To learn more about the latest solar observations, visit the Ulysses mission home page: http://ulysses.jpl.nasa.gov/


Flying Laboratory Meets the Public

On Monday, January 14, what NASA calls the "world's largest airborne observatory" was on display at Moffett Federal Airfield in California. Officials at NASA/Ames in Mountain View enthusiastically showed off the massive aircraft they hope will one day help them discover the origin of life.

Called the Stratospheric Observatory for Infrared Astronomy, or SOFIA, the former PanAm commercial airliner has been fully renovated, refurbished and rigged with a reflecting telescope similar to the Hubble Space Telescope.

Early next year, the modified Boeing 747SP is expected to take off from an airfield in Palmdale just northeast of Los Angeles and travel to an altitude of more than 45,000 feet - thousands of feet above the typical airliner - at speeds of over 600 mph, ushering in a new era of astronomy.

SOFIA is expected to do science that no other NASA observatory can do. According to some, it will be almost as good as going into space. SOFIA is maintained in Southern California, but its science and mission project office is based at NASA/Ames. NASA observers say the project that was nearly scuttled several years ago. As it is, SOFIA arrives several years behind schedule and hundreds of millions of dollars over budget.

That being said, SOFIA could help researchers learn about the birth and death of stars as well as the formation of new solar systems. Although unusual, it's not the first telescope in flight. From 1974 to 1995, NASA operated the Kuiper Airborne Observatory, which carried a 36-inch reflecting telescope in a converted C-141 military cargo plane.

SOFIA will be used to study planets, comets and asteroids in our solar system, and should help astronomers learn more about star formations and black holes at the center of galaxies.

There are a number of advantages to putting a 44,100-pound, 2.5-meter diameter telescope onboard an aircraft. First, SOFIA should be able to rise above most of the Earth's water vapor, enhancing its abilities to study the cosmos. Second, it can take advantage of infrared technology to study space, providing images that aren't possible from the ground.

SOFIA is meant to combine some of the best features from both mountain-top observatories and systems orbiting in space. Even with its initial $600 million price tag and $75 million annual operating budget, it is cheaper than space observatories and can be easily repaired or modified. The images scientists expect to capture should be relatively free of distortions and blocked views, unlike grounded observatories. Also, the pilots will be able to turn the plane and change the telescope's angle, allowing any point in space to be seen.

In its former life, the plane had been used by both PanAm and United Airlines before NASA bought it a decade ago and started modifications. The aircraft is still undergoing flight tests, and is scheduled for its first scientific mission in early 2009.

To learn more, visit the Web site of the Stratospheric Observatory for Infrared Astronomy (SOFIA): http://www.sofia.usra.edu/


Happy 25th, IRAS

January 25 marks the twenty-fifth anniversary of the launch of IRAS, the Infrared Astronomical Satellite. A joint project of the United States (NASA), the Netherlands (NIVR), and the United Kingdom (SERC), the Infrared Astronomical Satellite (IRAS) was the first space-based observatory to perform a survey of the entire sky at infrared wavelengths. It mapped 96% of the sky four times, at 12, 25, 60 and 100 micrometer wavelengths, with resolutions ranging from 30 arcseconds at wavelength 12 micrometers to 2 arcminutes at wavelength 100 micrometers. IRAS discovered about 350,000 sources, many of which have yet to be identified. About 75,000 of those are thought to be starburst galaxies, still in the stage of star-formation. Many other sources are normal stars surrounded by dusty disks, possibly in the early stage of planetary system formation. Discoveries included a dust disk around the star Vega and the first images of the Milky Way Galaxy's core.

Like most of the infrared satellites that followed, IRAS's life was limited by its cooling system: to effectively work in the infrared, a telescope must be cooled to extremely low temperatures. For IRAS, 475 liters of superfluid helium kept the telescope at a temperature of 2 kelvins (about -271 °C), keeping the satellite cool by evaporation. On November 22, 1983, 10 months after launch, the fluid helium depleted and the telescope temperature rose, preventing further observations.

IRAS was designed to catalog fixed sources, scanning the same region of sky several times. Jack Meadows led a team at Leicester University, including John Davies and Simon Green, which searched the rejected sources for moving objects. This led to the discovery of three asteroids, including 3200 Phaethon (an Apollo asteroid and the parent body of the Geminid meteor shower), six comets, and a huge dust trail associated with comet Tempel-2. The comets included the periodic comets 126P/IRAS and 161P/Hartley-IRAS and comet IRAS-Araki-Alcock (C/1983 H1), which made a close approach to the Earth in 1983.

To learn more, visit the IRAS page on the Caltech Web site:
http://irsa.ipac.caltech.edu/IRASdocs/iras.html


Happy 30th, IUE

January 26 marks the thirtieth anniversary of the launch of IUE, the International Ultraviolet Explorer. The IUE satellite was a collaborative project between the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), and the United Kingdom's Science and Engineering Research Council (SERC; now Particle Physics and Astronomy Research Council, or PPARC ). Launched January 26, The satellite carried a telescope and instruments for astronomical research. The instruments were used to obtain ultraviolet (UV) spectra of a wide variety of astronomical objects.

UV radiation is light created by processes more energetic than those that produce visible light. For example, the light one sees from the sun is produced at the solar surface, at a temperature of about 10,340 degrees Fahrenheit (6000 degrees Kelvin).The sun also produces ultraviolet light, from the much hotter gases above the surface, at temperatures of 17,540 to 179,540 degrees Fahrenheit (10,000 to 100,000 degrees Kelvin).

IUE had an expected lifetime of 3 years and a mission goal of 5 years, but greatly exceeded that time. When shut down on September 30, 1996, IUE had been in continuous operation for 18 years and 9 months.

IUE's geosynchronous orbit allowed for real-time operation, which made IUE very flexible. Astronomers came to the spacecraft command stations to direct their observations and inspect the data as they were collected, much as they do at ground-based observatories. Two on-board spectrographs covered ultraviolet wavelengths from 1200 to 3350 angstroms.

Observers around the world took advantage of the observatory, gathering data from a wide variety of astronomical sources. Objects observed by IUE include virtually every type of object in the universe, from planets and stars to galaxies. One of IUE's strengths was the ability to rapidly respond to targets of opportunity such as comets, novae, and supernovae. IUE obtained the only ultraviolet data of the outburst of Supernova 1987a in the Large Magellanic Cloud. By tracking on the nucleus of fast-moving Comet IRAS-Araki-Alcock, IUE was able to obtain the first detection of molecular sulfur in a comet. During July 1994, IUE, along with the rest of the world, observed Jupiter when Comet Shoemaker-Levy collided with the planet.

To learn more, visit the IUE archive section of the Space Telescope Science Institute:
http://archive.stsci.edu/iue/


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THE SKY THIS WEEK

Jan 19 - Moon at perigee
The point in the Moon's orbit when it is closest to Earth.

Jan 19 - Mars 1.1° south of Moon, occultation

Jan 22 - The planet Mercury is at its greatest eastern elongation (19 degrees)

Jan 22, 8:35 A.M. (13:35 UTC) - Full Moon

Jan 24 - The star Regulus is 0.7° north of the moon, occultation.

Jan 25 - The planet Saturn is 3° north of the moon

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THIS WEEK IN HISTORY

Jan 20, 1930 - Birthday of U.S. Astronaut Edwin "Buzz" Aldrin

Jan 20, 1986 - Discovery of Uranus moons Cordelia and Ophelia by Richard J. Terrile

Jan 22, 1968 - Launch of Apollo 5, 40th anniversary

Jan 23, 1906 - Discovery of Asteroid 582 Olympia by German astronomer, and discoverer of several comets and asteroids, August Kopff (1882 - 1960)

Jan 23, 1941 - Birthday of Glenn Research Center

Jan 23, 1986 - Discovery of Uranus moon Bianca by Bradford A. Smith

Jan 24, 1882 - Birthday of Harold Babcock

Jan 24, 1986 - Voyager 2 spacecraft flyby of the planet Uranus

Jan 24, 1990 - Launch of Hiten (Japan Moon Orbiter)

Jan 24, 2000 - Discovery of Dhofar 019 Meteorite (Mars Meteorite)

Jan 25, 1736 - Birthday of Italian / French mathematician and astronomer Joseph Louis Lagrange (1736 – 1831).

Jan 25, 1983 - Launch of the Infrared Astronomical Satellite (IRAS), 25th anniversary.

Jan 25, 1994 - Launch of Clementine spacecraft (U.S. Moon Orbiter)

Jan 25, 2004 - Successful Mars landing of Mars Exploration Rover B, named "Opportunity," which is still going strong long after its 90 sol (90 Martian days) primary mission.

Jan 26, 1905 - Discovery of Asteroid 557 Violetta by German astronomer and astrophotography pioneer Max Wolf (1863 - 1932).

Jan 26, 1962 - Launch of Ranger 3 (U.S. Lunar impact)

Jan 26, 1978 - Launch of the International Ultraviolet Explorer (IUE), 30th anniversary

Jan 26, 1980 - Discovery of Saturn moon Epimetheus by Voyager 1 spacecraft


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MUSICAL DIVERSION

Born in South Carolina, Benjamin Franklin White (1800-1879) began his musical career at an early age, playing a fife during the War of 1812. He later collaborated with his brother-in-law, William Walker, in collecting folk tunes and camp meeting melodies. In 1835 Walker published "The Southern Harmony and Musical Companion," which used the shaped not music notation system. Unfortunately, Walker gave no credit to White for his contributions to the work. This created a lifelong rift between the two men. In 1844, White published his own collection, entitled "The Sacred Harp," which also used the shaped note music notation system.

In his collection, White included a hymn set to a folk tune from the Appalachians. The roots of the melody probably go back to the folk music of the English, Irish or Scotts. White named the tune after the Beech Springs Baptist Church, which is still in existence near Pine Mountain, Georgia. Founded in 1832, the church was originally located near two beech trees at a spring, hence the name. However, White misspelled the name as "Beach Spring" and it stuck. The tune was paired with a hymn text that had been written in 1759 by Joseph Hart (1712 - 1768).


Beach Spring

Come, ye sinners, poor and needy,
Weak and wounded, sick and sore,
Jesus ready stands to save you,
Full of pity, love and pow’r.
He is able,
He is willing, doubt no more.

Let not conscience make you linger,
Nor of fitness fondly dream,
All the fitness He requireth
Is to feel your need of Him.
This He gives you,
’Tis the Spirit’s rising beam.

Agonizing in the garden,
Lo! your Master prostrate lies;
On the bloody tree behold Him,
Hear Him cry before He dies;
“It is finished!”
Sinners will this not suffice?

Lo! th’incarnate God ascended,
Pleads the merit of His blood;
Venture to Him, venture wholly,
Let no other trust intrude.
None but Jesus,
Can do helpless sinners good.

-----

In 1962, a teacher from Missouri named Eva Brown Lloyd (1912 - 2006) wrote a hymn text. She submitted it in 1966 submitted it to a hymn writing contest sponsored by the Church Music Department of the Southern Baptist Convention. She won the competition and later that year her hymn was published in a pamphlet along with seven other new hymns.

Lloyd intended her text to be sung to the tune of "Beecher," the tune composed for and most familiar as the setting for "Love Devine, All Loves Excelling." However, when the text was published, it was set to the tune "Beach Spring."


Come, All Christians, Be Committed

Come, all Christians, be committed
To the service of the lord;
Make your lives for him more fitted,
Tune your hearts with one accord.
Come into His courts with gladness,
Each his sacred vows renew,
Turn away from sin and sadness,
Be transformed with life anew.

Of your time and talents give ye,
They are gifts from God above;
To be used by Christians freely
To proclaim His wondrous love.
Come again to serve the Savior,
Tithes and off'rings with you bring.
In your work, with Him find favor,
And with joy His praises sing.

God's command to love each other
Is required of every one;
Showing mercy to one another
Mirrors His redemptive plan.
In compassion He has given
Of His love that is divine;
On the cross sins were forgiven;
Joy and peace are fully thine.

Come in praise and adoration,
All who in Christ's name believe;
Worship Him with consecration,
Grace and love you will receive.
For His grace give Him the glory,
For the Spirit and the Word,
And repeat the gospel story
Till mankind His name has heard.

-----

81t Beach Spring
Indexes for The Sacred Harp, 1991 Edition
Sacred Harp Singing
Copyright © 2007 Sacred Harp Musical Heritage Association
Retrieved January 14, 2008
http://fasola.org/indexes/1991/?p=81t

Benjamin Franklin White. The Cyber Hymnal.
Last updated December 23, 2007.
Retrieved January 14, 2008.
http://www.cyberhymnal.org/bio/w/h/white_bf.htm


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