Jan H. Oork Biography

Born in 1900, Jan H. Oort was one of the greatest astronomers of the twentieth-century. Oort, who lived to be ninety-two, made a number of very important discoveries regarding astronomy, especially regarding galactic motion. Born in Franeker, Friesland, Oort later moved to the United States to study at Yale University. Oort moved back to the Netherlands after graduating from Yale, and that was where he spent the rest of his career.

Oort began his career in astronomy as a text book writer. He eventually became the director of the Leiden Observatory and worked as secretary and president of the International Astronomical Union. Working with both theoretical and observed date, Oort made many important contributions to astronomy, beginning with one he made while still in his early twenties.

Oort first impressed the astronomy world when he proved that the Milky Way is rotating, using Kapteyn’s two streams of stars as evidence. He also used the motion of the stars surrounding the Sun to show that the Sun is not located in the center of the galaxy, but in fact, it is found more than half way into the disk from the nucleus. He also discovered that the center of the galaxy is located in the constellation Sagittarius. In addition, Oort was the first to discover dark matter, which is matter that does not emit enough radiation to be detected. It is now believed that over 90% of the galaxy is made up of the substance.

Another contribution made by Oort was his foresight in the area of radio astronomy. He was one of the first scientists to believe that radio waves could be used to map out the galaxy. Prior to the use of radio astronomy, Oort hypothesized that the galaxy’s spiral arms, were rich in hydrogen and were areas of star formation. As a result or World War II, radio technology was improved and eventually used to prove Oort’s hypothesis to be correct.

Oort’s most famous contribution was probably the theoretical discovery of the Oort Could. Named for the astronomer, the cloud has never been observed, but it is commonly accepted amongst astronomers that the cloud exists. The Oort Cloud lies far beyond Pluto encircling the outer edge of the galaxy. After studying long-period comets, Oort found that most seemed to come from the area that he designated as the Oort Cloud, and he proposed that this cloud is the home to 100,000s of comets.

One interesting anecdote about Oort’s life is that he was one of the few people able to see the Halley’s Comet twice. He saw it for the first time when he was ten years old, and again when he was eighty-six.

Oort made major contributions to the field of astronomy. He was honored with many prestigious awards including the Bruce Medal and the Vetliesen Prize, and is remembered as one of the greatest astronomers in modern history.

Works Cited

"Comet Pioneer: Jan Hendrik Oort." Space Science. 27 Feb. 2004. European Space Agency. 19 May 2008 .

"Jan Hendrick Oort." The Bruce Medalists. 19 May 2008 .

Wilford, John N. "Jan H. Oort, Dutch Astronomer in Forefront of Field, Dies At 92." 12 Nov. 1992. New York Times. 19 May 2008 fullpage.html?res=9E0CE6DF1531F931A25752C1A964958260&sec=&spon=&pagewanted=1>.

4.7 APOD

This is a photo taken from on board the International Space Station. The picture shows a spacecraft, called Soyuz TMA-12, bringing new supplies and members to the ISS. Three new astronauts were delivered on this mission. In the shot, you can see the docking system used to connect the spacecraft to the ISS. The supplies brought by the Soyuz TMA-12 will help astronauts make repairs to the ship, and do research regarding the effects of radiation on vitamin molecules and better ways to live in space. The ISS is currently orbiting about 350 km from Earth's surface and it can be seen by observors with the naked eye. The ISS is run in cooperation between several differnt countries including the United States, Russia, Canada, and Japan, among others.

4.6 APOD

The giant black nebula rests on top of a thick star field. The dark black nebula, made up of dust and gas, is likely a star forming region. Located in the constellation Scorpio, the nebula spans up to 40 light-years across. The dark black cloud, a cometary globule, is shaped by the ultrviolet radiation that is emitted by the bright stars that surround it. The red color comes from hydrogen gas. The small blue reflection nebulae around the dark cloud are hot young stars embedded in cosmic dust. Some say that the dark cloud looks ominous against the bright background. The name dark tower is an allusion to Shakespeare's play "King Lear," in which Gloucester's son Edgar acts as though he is a crazy begger, named Tom. Tom says, "Child Rowland to the dark tower came, His word was still 'Fie, foh, and fum, I smell the blood of a British man'." This was also referenced in a poem by Robert Browning.

4.5 APOD

This is a really cool picture of NGC 6188. This emission nebula is located about 4000 light-years away in the constellation Ara. The glow comes from the intense ultraviolet radiation and stron winds emitted by the young stars in this cluster which is only a few million years old. The area of young stars likely developed as a result of strong winds and supernova explosions that may have compressed molecular gas. Spanning about 300 light-years across, the false color photograph was taken by the Hubble. The colors come from the ionization of hydrogen, sulfer, and oxygen, which create red, green and blue shades in this picture. This nebula can be seen in the Southern Hemisphere, although it requires a very strong telescope to see the large cloud in any detail.

4.4 APOD

This nebula was created by the interaction between dust and gas with the light and wind from hot young stars. Known as the Fox Fur Nebula, it is located in the constellation of Monoceros. The Fox Fur Nebula is just a small section of a larger area known as The Christmas Tree Cluster. The red color in the photograph comes from ionized hydrogen gas. The blue comes from dust clouds that are reflecting light. This is located just north of the Cone Head Nebula, a mysterious star nursery. The Fox Fur Nebula is located about 2500 light-years away from earth.

4.3 APOD

This is a really pretty picture of the night sky taken over Sweden. What makes this picture really cool are the amount of amazing things that can be seen in it. Not only are the snow-capped mountains and the trees very picturesque, but there are quite a few astronomical beauties captured in the photo as well. Red and green auroras can be seen in the distant sky. The red comes from a number of different emission nebulas including the Heart and Soul Nebula which is located in the constellation Cassiopeia, about 6,000 light-years away from Earth. Also in the picture, the Andromeda galaxy and the central plane of the Milky Way are visible. In addition to the Heart and Soul Nebula, the red gas comes from IC1396 and the North America Nebula. It is very rare to see all of these celestial bodies in one night, let alone to capture them in one photograph.

4.2 APOD

This is a really cool picture of a Large Magellanic Cloud, the largest satellite galaxy of our own galaxy, the Milky Way. The cloud, which lies about 180,000 light-years away from Earth, spans about 15 light-years across. In long exposure photographs like this one, LMC's resemble spiral galaxies. This specific cloud was home to the largest supernova in modern history. It got it's name because it is visible to the naked eye in the Southern Hemisphere and the explorer, Magellan, used the cloud to help him navigate. The Small Magellanic Cloud is located next to the Large Magellanic Cloud. The SMC is home to hundreds of millions of stars.

4.1 apod

On the left is a galaxy called M81. It is surrounded by blue spiral arms as it rests across from the red gas and dust clouds of M82. The galaxies are in a gravitational combat, and they have been for billions of years. In the next few billion years, only one of the two galaxies will have survived. Scientists suspect that the gravity waves sent off by M82 caused the richness of the blue spiral arms on M81. Both galaxies are huge. M81 is located in Ursa Major, and is one of the brightest galaxies as seen from Earth. M82 is an irregular galaxy, sometimes known as the cigar galaxy.

Planetary Nebulae

Website with pictures and explananations of planetary nebulae

This is another interesting website

Observation 3.2

Date: March 8, 2008
Time: 9:30-10:15
Place: Bee Ridge Road (East of the Interstate)
Sky conditions: Pretty clear, there were a few clouds

Bright Stars: Betelgeuse, Rigel, Orion's Belt, Sirius, Castor, Pollux, Capella

Constellations: Orion, Ursa Major, Gemini, Auriga

Other: The moon was too new to be seen; the Big Dipper was visible in Ursa Major (it was standing on its handle)

3.8 APOD

In this shot we see the International Space Station. Last month, the the space shuttle Atlantis added another piece to the ISS, the Columbus Science Library. This picture was taken by the crew of Atlantis as it returned to Earth. The ISS, which began contruction in 1998, has grown a lot in recent years. The ISS now has a supply ship, a robotic arm, and solar panels, all recent additions. According to the ISS, it is "the largest and most complex international scientific project in history." The orbit of the ISS is at a perfect angle to allow ships from the member countries to reach it with new technology, supplies, and crew members. It's angle also allows it to make good observations of Earth. Over 85% of the planet, housing over 95% of the world's population, can be observed from the ISS.

Asaph Hall Biography

Asaph Hall was born in Connecticut in 1829. He originally planned to work as a carpenter, but later decided to enroll in classes at Central College in New York. In 1856, Hall began a career at Harvard where it was discovered that he had a special talent for calculating the orbits of celestial objects.

After working at Harvard for six years, Hall took a job at the US Naval Observatory. Here, he quickly gained responsibility, and in 1875, he was made in charge of the largest refractor telescope in the world, USNO 66 cm/ 26in. In 1896, Hall returned to Harvard where he became a professor of astronomy, but not before making several important discoveries.

While working in Washington DC, Hall discovered a spot on the surface of Saturn that helped him determine the orbital speed of the planet. He later calculated the orbital patterns of Saturn’s moons. Hall’s most famous accomplishment was his discovery of the two moons of Mars, Phobos and Deimos. Hall named the two moons after the sons of Ares, the God of War. The names mean fear and panic.

Hall published a number of works including Determination of Aberration Constant, which he wrote while working as the Director of the Detroit Observatory at the University of Michigan. In this work, he discussed the parallax. Hall used parallax on his measurements for the size and distance of the Pleiades.

In 1879, Hall received the Gold Medal of the Royal Astronomical Society, the award’s highest honor. There are also craters on the Moon and Phobos named after Hall. Hall, who died at age 78, also did work in the area of mathematics. He inspired Captain O.C. Fox’s experiments involving random sampling. Hall’s contributions to astronomy have had an undeniable impact on the science.

3.7 APOD

I chose this picture because we talked about the Eagle Nebula in class and it is a really great photograph. In the dark off-shoots we see the formation of bright blue stars occuring. The colors in the photo of M16 come from hydrogen, sulfur, and oxygen. Stars have been forming in this area for about 5 million years. The light we see from M16 was actually emitted 7,000 years ago and is just now reaching Earth. Clearly M16 is very far away from Earth, but its large size (it spans about 20 lightyears) allows us to see it with only binoculars when looking toward Serpens.

Biographer Sources

"Asaph Hall." 28 Feb. 2008 .

Hall, Asaph. "A Suggestion in the Theory of Mercury." 2 June 1894. American Astronomical Society. 28 Feb. 2008 .

Sheehan, William. "The Planet Mars: a History of Observation and Discovery." University of Arizona. 28 Feb. 2008 .

Star Formation

The blue regions in this false color image are star forming regions.

Here is another nice picture of star formation from space.com


Info on star formation
A site on the very first star

This site has pictures and videos of N11B, a star forming region

Here is a cool simulation of a large star collapsing into smaller starts

Observation 3.1

Date: February 25, 2008
Time: 8:30-9 pm
Place: Bee Ridge Road (East of the Interstate)
Sky conditions: Some clouds

Bright Stars: Sirius, Orion's Belt, Betelgeuse (looks orange), Aldebaren, Procyon

Constellations: Orion, Taurus, Canis Major, Canis Minor; Of all the constellations visible, Orion was the most recognizable because of Betelgeuse, it was almost directly overhead

Other: The moon was not really visible with the clouds; the most unobstructed view was looking straight up while it was cloudy around the horizon

3.6 APOD

In the center of this picture is the elliptical galaxy, NGC 1132. This galaxy, which is located near to the constellation Eridanus, has contains an enormous amount of dark matter and hot gas. This is a composite false-color photograph of the galaxy which is home to over 1 trillion stars. Some scientists believe that NGC 1132 may be the product of a merging of several galaxies. NGC 1132 is located over 300 million light-years away from Earth. This means that the light we currently see coming from the galaxy was actually produced before the human race even existed. The other bright spots in the photo are background galaxies.

3.5 APOD

In January 2002, V838 Mon became the brightest star in the galaxy after it's surface suddenly expanded for an unknown reason. The star shrunk just as quickly, confusing scientists as to why the outburst occured. In this photo, the Hubble Space Telescope captured a light echo associated with the flash. In a light echo, interstellar dust reflects light. V838 Mon's transformations amazed scientists who saw the star change from a small under-luminous star that was hotter than the Sun, to a cool supergiant. The star is about 20,000 light-years away from Earth in the Monoceros Constellation. It's light echos extend about 6 light-years, and it is expected that the light echos will continue to occur until 2010.

3.4 APOD

I chose this painting because Art History is one of my favorite classes I'm taking this year. Historians think this could be the first accurate depiction of a solar eclipse in history. It was done by the German artist, Cosmas Damian Asam, who completed the work in 1735. Asam, born in Germany, was one of the famous artists from the late Baroque period. Not only does the paintng portray a total solar eclipse, but it also shows the solar Corona. Asam may have seen a total solar eclpise himself as they occured in 1706, 1724, and 1733. In the painting, St. Benedict is looking up at the solar phenomenon. It looks as though he's having some sort of religious experience, especially with the inclusion of the cherubs and the billowing movements of his cloak and beard in the wind.

3.3 APOD

This is such a beautiful picture that it doesn't even look like it could be real. The building in the photo is the Pic du Midi Observatory in the French Pyranees. Also in the photo are the white ski slopes of La Mongie Ski Resort and the distant lights of Southern France and Spain. In the night sky, observers can see Mars in the top left corner. The Orion and Gemeni constellations are also visible. Pic du Midi is really cool. It is accessible to tourists who can reach the observatory by riding a cable car. The largest telescope they have there is the CLIMSO which primarily studies solar activity.

3.2 APOD

This nebula, NGC 2359, is more commonly known as Thor's Helmet. Thor is the Norse god of thunder. His helmet spans over 30 light-years. The star in the center of the cloud is supposed to be a very hot giant in the pre-supernova stage of evolution. The star is classified as a Wolf-Rayet Star which means that it has an atmosphere that compares to the thickness of the star itself. Most stars, however, have much thinner atmosphere. WR Stars also lose mass through wind at an extremely fast rate as it compares to the rate at which stars like our Sun lose mass. The emerald color in Thor's Helmet is is due to the immission of oxygen. The nebula is located about 15,000 light-years away from the Canis Major constellation.

3.1

This emission nebula, IC 1396, is made up of dark dust clouds and cosmic dust. The nebula is located about 3,000 light-years from Earth, and it stretches across several hundred light-years in size. This nebula is home to a star-forming region, called the Elephant Trunk Nebula, or IC 1396A. It is home to several stars that are less than 100,000 years old. It is a well-known nebula because it emits ligth in a visible wavelength. It alone is nearly 20 light-years long. The nebula, which is located in the constellation Cepheus, gets it's color from the hydrogen gas it emits.

Johann Madler

Johann Madler was born in Berlin in 1794. Madler’s interest in astronomy was sparked when he saw a comet as a child. Orphaned at a young age, Madler was responsible for raising his younger sisters. Madler studied astronomy and mathematics at the University of Berlin. During his time there he studied under both Encke and Ohm. To take care of his family and help pay for his education, Madler worked as a private tutor.

While working as a tutor, Madler meant a wealthy banker and amateur astronomer named Wilhelm Beer. Beer realized Madler’s abilities and offered him a position at the observatory that Beer was building. Madler, with Beer’s help, made a number of important contributions to astronomy.

Madler, while working at Beer’s observatory, made the most comprehensive map of the moon to date. He was the first to divide the moon into four separate quadrants. His maps of the moon were considered its most accurate documentation for the three decades after they were created.

Madler also made observations of Mars. He and Beer were the first astronomers to map the planet. Using Hershel’s calculations, they attempted to determine Mars’ rotational period, eventually coming within 1.1 seconds of finding the exact period. Though Madler was most famous for his observations of Mars and the moon, he made observations of Jupiter early in his career. His first contribution to astronomy was his discovery of two dark spots on Jupiter’s rings.

He also developed the Central Sun Hypothesis which said that the center of the universe, or more accurately the center of the universe’s gravity, is located in the star cluster known as the Pleiades. To find this, Madler observed the motions of over 3,000 stars. Though this hypothesis was eventually proven false, his observations were used by later astronomers.

After working with Beer, Madler accepted a position as director of the Dorpat Observatory in Estonia. Here he continued his observations of the moon and Mars. He also continued the research of the observatory’s former director, Friedrich Struve, who studied binary stars.

Madler also made important meteorological observations. He made the most accurate calculations of Earth’s tropical year.

Madler published his complete works, History of Descriptive Astronomy, in 1873. This was after he retired from his position in Estonia as a result of eye problems that prohibited him from doing observations. He retired to Germany, where he died in 1874.

Works Cited

Hockey, Thomas A. Galileo's Planet. CRC P, 1999. 8 Jan. 2008 .

"Monthly Notices of the Royal Astronomical Society." NASA Astrophysics Data System. Harvard University. 8 Jan. 2008 .

"Science Center AHHAA." Teaduskeskus. Dorpat Observatory. 8 Jan. 2008 .

Observation 2.2

Date: January 2, 2008
Time: 11:00-1:00
Place: Fruitville Road (East of the Interstate)
Sky conditions: Somewhat cloudy

Planets: Mars (orange in color and bright)

Bright Stars: Sirius, Orion's Belt, Beetlejuice (Beetlejuice looks like Mars, except it is not as bright and it twinkles)

Constellations: Gemini, Lepus, Orion

Other: The Quadrantids meteor shower was going on; most of the meteors we saw were small and vanished quickly; there was one meteor with a huge tail, it varied in brightness and the tail stretched about 100 degrees in the sky, it was bright white