Observations 4.2

Astronomy Cast

Episode 34 Discovering Another Earth
Astronomers have found three planets orbiting the red dwarf star Gliese 581. The smallest is roughly Earth size, with a radius of about 1.5 Earth radii, but it has more mass. Its gravitational acceleration is greater than Earth’s. It is a rocky planet, and it is the proper distance from Gliese for water to be liquid; it may actually be covered in oceans. It was detected by measuring changes in Gliese’s radial velocity caused by its satellites. The European Space Agency is currently planning to launch three 3m telescopes in a few years that would greatly help in terrestrial planet finding.

Episode 111 Nebulae
Giant molecular clouds are huge clouds of dust and gas that are cool and dark. They absorb light and block part of the sky from view. When light from another object passes through such a cloud, it scatters off particles and we see a Reflection Nebula. When there are bright objects inside the cloud, the gas may heat up and an Emission Nebula is seen. Our perspective determines whether we see absorption or emission lines from a star whose light passes through a cloud. Various causes can lead to the collapse of clouds; when they condense, stars are formed. Planetary nebula are created when a star dies and releases its material.

Episode 3 Hot Jupiters and Pulsar Planets
Our previous theoretical models of solar systems in general have proven inaccurate. Strange types of planets and systems have been discovered that we cannot explain. Astronomers have found large, gaseous planets like Jupiter, but very close to their parent stars, and orbiting incredibly quickly. It is strange that such planets can exist so close to stars, where the gas should evaporate, leaving rocky planets to be formed. Astronomers have also found at least two planets with the density of cork; in order to have such low densities, they are probably generating large amounts of heat, which is a process we can’t explain. It has been theorized that lone planets not orbiting a star were ejected from star systems, but a pair of apparently ejected planets have been found, barely bound together gravitationally. It is unlikely that they could have been ejected but still remain gravitationally bound, since the attraction is so small.

Episode 26 The Largest Structures in the Universe
Interactions between galaxies are common. The Magellanic Clouds may be being distorted by the Milky Way, or they could be being ripped apart by it. The impending collision with the Andromeda Galaxy is the next major interaction that the Milky Way will undergo; it will drastically alter both galaxies. Most stars won’t actually collide with each other, but their orbits and the structures of each galaxy will be transformed. New generations of stars will form, and the two supermassive black holes will eventually merge. The result will likely be an elliptical galaxy, which astronomers theorize is how elliptical galaxies usually form. Galaxies tend to be found in groups; galaxy clusters trace out the large-scale structure of the universe, which may be described as sponge-like.

Episode 76 Lagrange Points
Lagrange points are points between objects where the gravitational forces exactly balance. They are useful places for man-made satellites. Spacecraft at Lagrange points have their own engines making constant corrections in order to stay in place. There are five useful Lagrange points relating to the Sun and Earth: L1, L2, L3, L4, and L5. L1 is between them, but closer to Earth. Sun-observing objects are placed at L1; they have the same orbital period as Earth. L2 is beyond Earth, but objects there would still orbit the Sun. L3 is on the opposite side of the Sun as Earth; there are not any spacecraft there. L4 and L5 are in Earth’s orbit, but behind or ahead of Earth. They are the most stable points.

APOD 4.8

Rho Ophiuchi Wide Field
http://antwrp.gsfc.nasa.gov/apod/ap100524.html

Rho Ophiuchi is a binary star system in Ophiuchus, but it has a nearby cloud complex that is one of closest star-forming regions to us. Antares and the globular cluster M4 are visible in this picture, along with the notable red emission nebula and Blue Horsehead Nebula. To the top-left is Sharpless 1, yet another reflection nebula. Throughout the image are dark dust lanes.

APOD 4.7

Panorama of the Whale Galaxy
http://antwrp.gsfc.nasa.gov/apod/ap100517.html

NGC 4631, also known as the Whale Galaxy, is a large spiral galaxy that is seen edge-on from our perspective. This pictures shows the high diameter-to-height ratio characteristic of spiral galaxies. It is similar to the Milky Way in size. The Whale Galaxy is seen in the direction of Canes Venatici and is about 30 million light years away. The blue stars are evidence of star formation; also notable in this picture are the dark streaks of instellar dust clouds.

APOD 4.6

Iguaçu Starry Night
http://apod.nasa.gov/apod/ap100514.html

This is a picture of the night sky taken on May 4 near the Iguaçu Falls and National Park in Argentina. Many prominent objects are visible in this picture. The brightest star in the sky, Sirius, is to the right of the photo. It has an apparent magnitude of 1.46 and is 8.6 light years from Earth. Canopus, the second brightest star, is to the left of Sirius. Its apparent magnitude is -.72, and it is located about 310 light years away. The Large and Small Magellanic Clouds are to the left of Canopus. They are irregular dwarf galaxies that orbit the Milky Way. Alpha Centauri and Beta Centauri are above the Magellanic Clouds in the picture. Alpha Centauri is a binary star with a red dwarf companion, Proxima Centauri, which is the closest star to the Sun at 4.2 light years away.

APOD 4.5

Northern and Southern Owls
http://apod.nasa.gov/apod/ap100506.html

This is a comparison between two planetary nebulae, M97, called the Owl Nebula, and PLN283+25.1, also called the Southern Owl Nebula. M97 is in Ursa Major and PLN 283+25.1 is in Hydra. These nebulae are approximately the same size (two light-years in diameter), and have a similar round shape. The Owl Nebula was discovered in 1781 and received its name because it appears to have owl-like eyes that are visible when viewed through a telescope. Planetary nebulae form when a Sun-sized star exhausts its nuclear fuel, expands, and eventually releases gas and plasma in an expanding shell.

Interacting Galaxies

http://upload.wikimedia.org/wikipedia/commons/8/81/Whirlpool_%28M51%29.jpg
http://upload.wikimedia.org/wikipedia/commons/d/db/NGC4676.jpg
http://imgsrc.hubblesite.org/hu/db/images/hs-2008-37-a-large_web.jpg
http://maludan.3dtoast.com/outerspaced/NGC%201531,%201532%20Interacting%20Galaxies.jpg
http://www.cartachronicles.com/uploads/Interacting_Galaxies_Group_Arp_194_800__x_600.jpg
http://www.daviddarling.info/images/interacting_spiral_galaxies.jpg
http://www.sciencecodex.com/files/sciencecodex-ed6v2QEeT0lv1EqD.jpg
http://imgsrc.hubblesite.org/hu/db/images/hs-2010-08-a-web.jpg
http://www.astro.uni-bonn.de/~maltmann/stephan4.gif
http://geology.com/nasa/galaxy-collisions/galaxy-eso-593-8.jpg
http://geology.com/nasa/galaxy-collisions/galaxy-ngc-5754.jpg
http://images.astronet.ru/pubd/2004/03/25/0001197280/ngc1531_keel.gif
http://www.nasa.gov/images/content/166908main_galex-20070110-516.jpg
http://www.starteachastronomy.com/pictures/galaxies_collide.jpg
http://www.astr.ua.edu/gifimages/ngc6621hst.jpg

APOD 4.4

Virgo Cluster Galaxy NGC 4731
http://apod.nasa.gov/apod/ap100429.html

This is a picture of NGC 4731 in the constellation Virgo. It is a barred spiral galaxy in the Virgo cluster of galaxies and is about 65 million light-years away. The Virgo cluster contains around 1300 but possibly up to 2000 galaxies. This cluster is the center of the Virgo Supercluster, which contains the Local Group. The newly-formed blue stars are visible in the spiral arms. The galaxy's arms are affected by the gravity of the elliptical galaxy NGC 4697. NGC 4731A is an irregular galaxy and is also in this picture. Young blue stars are also evident in this galaxy.

Observations 4.1

4/15/10
Stargaze
8:00 PM - 9:00 PM
Conditions: cloudy
Moon: waxing crescent, very thin
Planets: Mercury and Venus were both visible near the Moon at sunset
Objects: M42, the Orion Nebula, M44, the star cluster in Cancer
Stars: the Alcor double and Mizar quadruple in Ursa Major

4/27/10
9:00 PM
Moon: waxing gibbous
Planets: Mars in Gemini, Saturn in Virgo
Constellations: Bootes, Cancer, Gemini, Leo, Ursa Major, Virgo
Stars: Arcturus, Castor, Denebola, Pollux, Regulus, Spica

4/29/10
10:00 PM
Star - Estimated Apparent Magnitude
eta Ursa Majorum - 2.2
beta Leonis - 2
gamma Leonis - 1.8
zeta Leonis - 3.5
epsilon Leonis - 3.2
lambda Leonis - 4
epsilon Virginis - 2.7
eta Virginis - 3.8
epsilon Corvi - 2.8
epsilon Bootis - 2.7
beta Bootis - 3.4

Astronomer Biography 4

GENE AND CAROLYN SHOEMAKER

Eugene Shoemaker was born in 1928 in Los Angeles. As a boy he became interested in collecting and observing minerals and gemstones. He attended high school classes in elementary school, graduated from high school in two years, and attended the California Institute of Technology at the age of 16. He earned a master’s degree in geology in three years. In 1950 he married Carolyn Spellman, who would later help him with his work.

In 1948, he started inspecting various sources of uranium, such as volcanic vents and various craters, for the United States Geological Survey. He learned how to distinguish between craters created by underground forces and craters created by aboveground forces. He acquired a Ph.D. from Princeton for proving that the Meteor Crater near Flagstaff, Arizona had been caused by a meteor rather than a volcano, as was previously believed. At the Meteor Crater, he helped identify a unique mineral that was formed by great heat and pressure, which was called coesite. In 1960, while inspecting the Ries basin in Germany with his wife, Shoemaker found coesite, thereby proving that the 17-mile depression was actually a massive impact crater. He also showed that the craters on the moon were caused by comets and asteroids and not volcanoes.

Shoemaker started the Palomar Planet-Crossing Asteroid Survey in 1973. He and his colleague, Eleanor Helin, identified 70 asteroids that cross Earth’s orbit and could potentially collide with the planet. Shoemaker believed there could be up to 2000 of these objects. He supported the theory that an asteroid or comet caused the extinction of the dinosaurs.

Shoemaker had long dreamed of going to the moon, but this possibility was ruined when he was diagnosed with Addison’s disease in 1962. He played an important role in the eventual successes of the Apollo missions. He investigated the structure of the moon and helped improve geologic mapping techniques. He suggested ideal landing sites for the Apollo missions.

Carolyn started working with her husband at Mount Palomar when Eleanor Helin left in 1982. She learned how to use the telescope and helped Shoemaker search for asteroids in pictures of the sky. Shoemaker began to use a stereomicroscope, which was a geological tool, to help locate these objects. Carolyn would look through the microscope at pictures taken at different times to try to identify moving objects. Eugene and Carolyn discovered 32 comets and more than 800 asteroids.

Eugene’s friend David Levy joined the husband-and-wife team in 1988. In 1993, they took a photograph of part of the sky that included Jupiter at the time. When Carolyn looked at the picture on March 25, 1993, she discovered a comet, which was soon named Comet Shoemaker-Levy 9. This comet became famous, especially when it was announced in May of that year that it was on a collision course with Jupiter. The comet was caught by Jupiter’s gravity and pulled apart into 21 pieces, which then made visible impacts on the planet.

Eugene Shoemaker was a proponent for more funding to search for objects that could possibly collide with Earth. He predicted that a potentially devastating asteroid should hit Earth on average once every 100,000 years. Although he may be best-known for Comet Shoemaker-Levy 9, he studied the other planets and their moons and is recognized as the founder of astrogeology. Shoemaker died in a car crash in 1997. Some of his ashes were carried to the moon on the Lunar Prospector in 1999.

Bibliography

"Gene Shoemaker." Encyclopedia of World Biography. 2nd ed. Vol. 20. Detroit: Gale, 2004. 335-338. Gale Virtual Reference Library. Web. 29 Apr. 2010.

Marsden, Brian. "Eugene Shoemaker (1928-1997)." Web. < http://www2.jpl.nasa.gov/sl9/news81.html >.

"Shoemaker, Carolyn (1929–)." Dictionary of Women Worldwide: 25,000 Women Through the Ages. Ed. Anne Commire and Deborah Klezmer. Vol. 2. Detroit: Yorkin Publications, 2007. 1719. Gale Virtual Reference Library. Web. 29 Apr. 2010.

"USGS Astrogeology: Eugene M. Shoemaker." USGS Astrogeology Science Center. Web. < http://astrogeology.usgs.gov/About/People/GeneShoemaker/ >.

APOD 4.3

Saturn's Moons Titan and Dione from Cassini
http://apod.nasa.gov/apod/ap100420.html

Saturn has 62 moons with confirmed orbits. This is a picture, taken by the Cassini spacecraft, of Titan and Dione. Titan is Saturn's largest moon; it is larger in volume than Mercury. It has an atmosphere and its surface is obscured by clouds. Both Titan and Dione are composed of water ice and rocky material. In the picture, both moon are in the gibbous phase because they are close to each other. The Cassini-Huygens spacecraft was launched in 1997 and entered into orbit around Saturn in 2004. The Huygens probe landed on Titan in 2005.

APOD 4.2

Bright Points on the Quiet Sun
http://apod.nasa.gov/apod/ap100416.html

This is a picture of granules on the Sun's solar surface. These granules are caused by convection currents of plasma from the convection zone of the Sun. The center of each granule is the top of the rising column of plasma; surrounding each granule is a darker area of less hot descending plasma. The light spots in these darker areas are caused by high-density magnetic fields that create holes into the deeper, hotter areas.

APOD 4.1

Millions of Stars in Omega Centauri
http://apod.nasa.gov/apod/ap100331.html

This is a picture of the globular cluster Omega Centauri, also known as NGC 5139. It was discovered by Edmund Halley in 1677, who did not at the time realize what it was. John William Herschel recognized it as a globular cluster in the 1830s. It contains around 10 million stars and is about 12 billion years old. It orbits the center of the Milky Way in the halo of the galaxy; it is the largest and brightest known globular cluster to do so. Because it is different from most other globular clusters, it is thought to have a different origin; it is speculated that it is the remnant of the core of a dwarf galaxy that was incorporated into the Milky Way.

Observations 3.2

3/3/10
9:15 PM
Planets: Mars, nearly overhead
Constellations: Auriga, Canis Major, Canis Minor, Cassiopeia, Gemini, Orion, Perseus, Taurus
Stars: Aldebaran, Betelgeuse, Orion's top shoulder on the left, Capella, Castor, Pollux, Procyon, Rigel, bottom right of Orion, and Sirius, which was bright blue and twinkling
Other: the kids in Auriga, the Pleiades (M45) in Taurus

3/6/10
Astronomy Night
7 PM - 9 PM
Planets: Mars, Saturn
With the telescope, I could see greenish color of Saturn and the rings on either side of the planet.
Constellations: Andromeda, Auriga, Canis Major, Canis Minor, Cassiopeia, Columba, Gemini, Leo, Lepus, Monoceros, Orion, Perseus, Ursa Major and the Big Dipper, Ursa Minor and the Little Dipper
Stars: Aldebaran, Betelgeuse, Capella, Castor, Mintaka, Polaris, Pollux, Procyon, Rigel, Sirius
Other: the Hyades, the kids, the Pleiades
Through binoculars, I saw the brighter stars of the Pleiades and many others in the cluster.
With a telescope, I saw the white dwarf companion stars of Sirius and Rigel. They were difficult to see, and looked like small white dots next to the brighter, larger companions.

3/8/10
9:00 PM
Planets: Mars
Constellations: Auriga, Canis Major, Canis Minor, Gemini, Lepus, Orion, Taurus
Stars: Aldebaran, Betelgeuse, Capella, Castor, Pollux, Procyon, Rigel, Sirius
Other: the Hyades, the kids, Orion's Belt, the Pleiades

3/21/10
9:30 PM
The Moon was a waxing crescent.
Planets: Mars overhead, Saturn about 30 degrees above the horizon to the east
Constellations: part of Andromeda, Auriga, Canis Major, Canis Minor, Gemini overhead, Leo and the sickle, high up when facing east, Orion to the southwest, Perseus, Ursa Major and the Big Dipper
Stars: Betelgeuse, Capella, Procyon, Regulus, Rigel, Sirius

3/22/10
10 PM
First quarter Moon
Planets: Mars, Saturn to the east
Constellations: Auriga, Canis Major, Canis Minor, Gemini, Leo and the sickle overhead towards the east, Ursa Major
Stars: Capella, Procyon, Regulus, Sirius

3/23/10
11 PM
First quarter Moon
Planets: Mars, faint because of the Moon, Saturn to the east
Constellations: Bootes, Canis Major, Canis Minor, Corvus, Gemini, faint because of the Moon, Leo, Orion was about 30 degrees above the horizon towards the west, Ursa Major, Virgo
Stars: Castor, Denebola, Pollux, Procyon, Regulus, Sirius

3/25/10
10 PM
The moon was at the waxing gibbous phase; it was too cloudy to see much.

APOD 3.8

Detailed View of a Solar Eclipse Corona
http://apod.nasa.gov/apod/ap100316.html

This is a picture of the Sun's corona during the 2008 total solar eclipse. The corona is normally not visible because of the brighter photosphere. Solar prominences and complex layers of gas in changing magnetic fields can be easily seen in this picture. The corona extends millions of kilometers into space. It is nearly 200 times hotter than the photosphere but is significantly less dense. It is not completely clear why the corona is so much hotter than the solar surface.

APOD 3.7

JWST: Mirrors and Masked Men
http://apod.nasa.gov/apod/ap100312.html

The James Webb Space Telescope is an international effort led by NASA. It was named after NASA's second administrator. It is an infrared space telescope and will replace some of Hubble's functions. It is intended to be able to see some of the most distant objects in the universe, and has four main goals: to find some of the original light created by the first galaxies and stars after the Big Bang, to study the formation of galaxies, to study the formation of stars, and to study planetary systems and the origins of life. The JWST is planned to be launched an an Ariane 5 rocket in 2014. It will orbit the Sun between the Sun and Earth, synchronized with Earth's orbit. The telescope has a 21.3-foot primary mirror with eighteen segments. The technicians in the picture are preparing some of the mirror segments.

APOD 3.6

Edge-On Spiral Galaxy NGC 891
http://apod.nasa.gov/apod/ap100225.html

This is an edge-on picture of the unbarred spiral galaxy NGC 891. An unbarred spiral galaxy is a spiral-shaped galaxy without a central bar formation. It is about 30 million light years away in the constellation Andromeda. NGC 891 was discovered in 1784 by William Herschel. It is similar to the Milky Way, with a disk shape and bulge in the center. Star formation or supernova explosions are likely causes for the streaks of dust that extend outward from the galaxy.

Astronomer Biography 3

PERCIVAL LOWELL

Percival Lowell was born on March 13, 1855, into a prominent Bostonian family. He developed interest in many fields during his early schooling, and graduated from Harvard University in 1876 with distinction in mathematics. He traveled around the Far East after graduating, and published several books, including The Sound of the Far East, about his experiences.

After reading La planète Mars by Camille Flammarion and hearing about the supposed Martian canals drawn by Giovanni Schiaparelli, Lowell resolved to devote himself to studying the planet full-time. He decided to build his own observatory using his wealth and resources. He wanted superior conditions so he could make superior observations, so he chose a mesa in Flagstaff, Arizona as the site for his new observatory because of its elevation, clear weather, and distance from lights. This was the first major observatory whose location was deliberately chosen because of optimal conditions for observation.

Lowell obtained some equipment and soon began his work. He published Mars in 1895, in which he supported the presence of canals on Mars and theorized that it was possible that intelligent life existed on the planet. He asserted that the general physical conditions on Mars could allow for life, that there appeared to be arid conditions on Mars so inhabitants would need irrigation systems, and that there were markings on the planet that appeared to be canals. He acknowledged that all this could mean nothing, but personally believed that there was life on Mars.

By 1896 Lowell was observing Mars at night and Mercury and Venus during the day. He took a break from his work when his health deteriorated, but observations at Flagstaff continued. He returned in 1901, and in 1905, he published Mars and its Canals, which was followed by Mars as the Abode of Life in 1908. Both books expanded on his earlier theories; he continued to argue that there was an extensive system of canals on Mars. However, many astronomers did not agree with him, and few believed that the supposed canals were as extensive and regular as Lowell stated. Lowell also supported the idea that the lighter areas on Mars were deserts, while the darker areas were vegetation.

In 1909, the sixty-inch Mount Wilson Observatory telescope revealed that the canals were likely irregular geological features, formed naturally by erosion or other means. The theory was definitively disproved by close-up images taken by Mariner 4 in 1965.

Lowell did not focus solely on Mars. He made maps of Venus and observed unusual features and a dark spot. However, it was later discovered that Venus’s atmosphere was opaque, so these observations were probably imagined; Lowell may have been seeing the blood vessels in his own eye. He confirmed Schiaparelli’s conclusion that Mercury’s rotational period is as long as its orbital period, although later studies revealed that it is actually only two-thirds as long. He helped find an accurate value for Uranus’s rotation and studied the clouds on Jupiter and the structure of Saturn’s rings.

Because of discrepancies in the expected orbits of Uranus and Neptune, Lowell hypothesized that there was an unknown mass near or beyond those planets that was perturbing their orbits. He began a search for this Planet X. This search was not completed during his lifetime, but it led to the discovery of Pluto in 1930. However, Pluto did not have sufficient mass to account for the unexpected orbits of Uranus and Neptune. This was later discovered to be caused by an inaccurate estimate of Neptune’s mass.

Although most of Lowell’s major work turned out to be invalid, he was a very influential astronomer. He started the practice of building observatories at locations with optimal conditions. He was responsible for significantly increasing the general public’s interest in astronomy and especially in Mars. However, his greatest contribution to astronomy was the result of his search for Planet X: the discovery of Pluto.


Works Cited

"Lowell, Percival." Complete Dictionary of Scientific Biography. Vol. 8. Detroit: Charles
Scribner's Sons, 2008. 520-523. Gale Virtual Reference Library. Web. 23

"Lowell, Percival (1855-1916)." The Worlds of David Darling. Web. < http://www.daviddarling.info/encyclopedia/L/LowellP.html >.

"Percival Lowell, Astronomer." The Hunterian Museum and Art Gallery - Scotland's oldest public museum. Web. < http://www.hunterian.gla.ac.uk/archive/mars/percivallowell.html >.

"Percival Lowell." Lowell Observatory. Web. < http://www.lowell.edu/Research/library/paper/lowell.html >.

"Percival Lowell." Universe Today. Web. < http://www.universetoday.com/guide-to-space/astronomy/percival-lowell/ >.

APOD 3.5

WISE Infrared Andromeda
http://apod.nasa.gov/apod/

This is a picture of the Andromeda galaxy, taken in infrared light and rendered as a false color image. It is a mosaic of pictures taken from the Wide-field Infrared Survey Explorer. The yellow and red portions of the picture consist of dust heated by the galaxy's younger stars, and the blue areas are created by its older stars. Andromeda, or M31, is 2,500,000 light years away and is the farthest object from the Milky Way that is visible with the naked eye. It has twice the diameter of the Milky Way, but may be less massive. 2006 observations by the Spitzer Space Telescope suggest that Andromeda has about one trillion stars, which is large compared to the estimated 200-400 billion stars of the Milky Way.

Observations 3.1

2/3/10
9:20 PM
Mars was about 45 degrees above the horizon to the east. It was about 10 degrees east of Pollux. Auriga and Capella were almost overhead, and Sirius was twinkling brightly as usual to the southeast. When facing south, Orion's Belt was about 55 degrees above the horizon.

2/4/10
8:15 PM
Trees and low clouds obscured most of the sky up to 30 degrees above the horizon. I could make out most of Lepus, which is 5 to 10 degrees south of Orion. Mars was about 35 degrees above the horizon to the east. I saw Perseus and the area where Aries is located.

2/11/10
8:30 PM
Mars was close to Cancer in the sky. I saw Orion, Taurus, Auriga, Perseus. I located Eridanus for the first time, but could barely make out most of its stars.

2/16/10
7:20 PM
Stargaze
The moon was in the waxing crescent phase to the west. Mars was to the east. With binoculars, I saw M31 to the northwest, west of Cassiopeia, and the Pleiades, which were overhead. Aries was to the west. I recognized Triangulum for the first time to the west, fairly high above the horizon. The cloud of the Milky Way was faintly visible. I saw the Double Cluster of Perseus southeast of Cassiopeia, Lepus and Columba south of Orion, and the kids in Auriga. I traced Eridanus southwest of Orion. I saw the area of the sky where Monoceros is located, in the middle of Canis Major, Canis Minor, and Orion. I looked at M42 in Orion through the telescope. Sirius appeared to be an even brighter blue through binoculars. With the telescope, I distinguished the double stars of Castor.

APOD 3.4

The Einstein Cross Gravitational Lens
http://apod.nasa.gov/apod/ap100207.html

This is a picture of the Einstein Cross, which is a case of gravitation lensing. The galaxy in the picture appears to have four nuclei rather than one. However, this is highly unlikely; a more probable explanation for what is seen is that the actual nucleus is not visible, and the light that appears to be coming from four sources is actually originating from a single quasar behind the galaxy. The galaxy's gravitational field breaks this light into the four images. Quasars likely form when matter in a large galaxy fall toward a central super-massive black hole. They are the brightest objects in the universe.

APOD 3.3

Stardust in Perseus
http://apod.nasa.gov/apod/ap070511.html

This picture shows a region of dust, gas, and stars in the direction of Perseus. Several reflection nebulae are visible in the picture. The largest blue shape is NGC 1333, which is a bright emission and reflection nebula. NGC 1333 is a star-forming region; it contains hundreds of young stars. The red area next to NGC 1333 is hydrogen released by forming stars. Dark dust nebulae are also visible in the picture; these nebulae obscure newly-formed stars and protostars.

APOD 3.2

Kemble's Cascade
http://apod.nasa.gov/apod/ap100128.html

Kemble's Cascade is an asterism, which is a pattern or shape in the stars that is not an actual constellation. This asterism includes around twenty stars that are nearly in a line. It is in the constellation Camelopardalis, and spans more than five full moon diameters. It was named recently; Lucian Kemble, an amateur astronomer, described it to Walter Scott Houston, who wrote about it in his magazine column in 1980, naming it "Kemble's Cascade." Also visible in this picture is NGC 1502, an open cluster of about 45 stars. Two Struve binary stars are present in NGC 1502.

APOD 3.1

Dust and the NGC 7771 Group
http://apod.nasa.gov/apod/ap100121.html

In this picture are several galaxies in the direction of Pegasus. The NGC 7771 Group and NGC 7769 are the most easily visible. The NGC 7771 Group includes several galaxies, one of which is the spiral galaxy in the center. NGC 7769 appears to be the largest galaxy in the picture and is also a spiral galaxy. The NGC 7771 galaxies may eventually merge because they are passing by each other at small distances. This is suggested by distortions and small streaks of stars in the galaxies. Large clouds of dust are also visible in the picture.

APOD 2.8

M94: A New Perspective
http://apod.nasa.gov/apod/ap100114.html

M94 is a spiral galaxy that is about 15 million light years away. It was discovered and catalogued in 1781. Its center is oval-shaped but bar-like. The center is an active star-forming region. This picture reveals the recently discovered spiral arms around the galaxy. More distant galaxies as well as stars from the Milky Way can also be seen in the picture.

APOD 2.7

The Tail of the Small Magellanic Cloud
http://apod.nasa.gov/apod/ap100107.html

This picture reveals the tail of the Small Magellanic Cloud. The Small Magellanic cloud is a satellite galaxy of the Milky Way and is a dwarf galaxy. It may have once been a spiral galaxy that was distorted by the Milky Way. It is 200,000 light years away and can been seen with the naked eye. This picture reveals the tail of the Small Magellanic Cloud. The tail is probably composed of dust, gas, and young stars, and may have been pulled out of the Cloud by gravitational tides. The picture was taken with infrared light.

Observations 2.2

11/30/09
8:11 PM
The Great Square of Pegasus was almost overhead but a little to the south and west. I saw most of Andromeda near Pegasus, and Perseus near Andromeda. I could see Deneb and Vega towards the west and northwest; Deneb was about 55 degrees above the horizon.

12/2/09
9:25 PM
Pegasus, Perseus, Andromeda, and Cassiopeia are easy to make out because they are almost overhead. I think I saw Taurus and Aldebaran about 40 to 45 degrees above the horizon to the east. I have had trouble finding Ursa Minor.

12/11/09
8:50 PM
Cassiopeia was about 80 degrees above the horizon towards the north. It is often the first constellation I recognize. Capella was about 50 degrees above the horizon to the northeast. As usual, I also easily spotted Perseus and Pegasus.

12/12/09
8:45 PM
I recognized Perseus, Pegasus, Andromeda, Cassopeia, Taurus, and Auriga. Because of lights, trees, and houses, I have had trouble locating some of the constellations closer to the horizon, like Ursa Minor, Gemini, and Orion. I can't see much below 25 degrees above the horizon.

12/16/09
9:00 PM
I saw Polaris about 40 degrees above the horizon to the north. I saw Capella and Aldebaran, which are about 25 degrees apart. With binoculars, I looked at the Circlet of Pisces, south of the Great Square.

12/17/09
8:10 PM
I looked at Pegasus, Perseus, Andromeda, Cassiopeia, Taurus, Auriga, Polaris, Hamal, and some other constellations and bright stars.

1/10/10
8:00 PM
Pegasus was to the west; the center of the square was about 45 degrees above the horizon. Orion and his belt were very easy to find. It was about 50 degrees above the horizon to the southeast. I saw Betelgeuse and Rigel, which is brighter. Cassiopeia was about 50 degrees above the horizon to the north. Auriga and Perseus were almost overhead. Sirius was to the southeast and was clearly twinkling. Taurus was almost overhead but slightly to the southeast. I could barely see the Pleiades.

1/11/10
9:15 PM
I couldn't see much below 20 degrees above the horizon. Sirius was very bright and about 30 degrees above the horizon to the southeast. Orion was about 45 degrees above the horizon to the southeast. Taurus was nearly overhead. I saw Auriga and Capella, and Mars to the east-northeast, about 30 degrees above the horizon. I spotted Castor and Pollux and recognized Gemini.

1/12/10
11 AM
I looked at sunspots, which were dark spots that clumped together rather than larger single spots.

10:05 PM
I noticed that the east is much brighter than the west. Sirius was about 55 degrees above the horizon to the southeast. Orion's belt was about 65 degrees above the horizon to the southeast. The Pleiades were almost overhead when facing west. Mars was about 45 degrees above the horizon to the east-northeast. 20 degrees up from Mars and a little to the north were Castor and Pollux of Gemini.

1/14/10
8:25 PM
Capella was about 75 degrees to the north-northeast. Perseua was almost overhead. Algol was about 20 degrees to the west of Capella. Procyon of Canis Minor was about 35-40 degrees above the horizon to the east and was twinkling like Sirius. Mars was about 25 degrees above the horizon to the east-northeast. I also saw Lepus, which is to the south of Orion.

Astronomer Biography 2

FRIEDRICH GEORG WILHELM VON STRUVE

Friedrich Georg Wilhelm Struve was born on April 15, 1793 and died in 1864. He was born in Altona, Denmark, and area that is now part of Germany. As a young man he moved to Russia to avoid military conscription in Germany during the Napoleonic wars. He conducted most of his work in Russia.

After graduating from the University of Dorpat in 1810, he turned his attention to astronomy, mathematics, and geodesy. He began to work in the university’s observatory and was eventually put in charge of it. He also taught mathematics and astronomy at Dorpat and became a popular lecturer. His first volume of observations was published in 1817, and seven other volumes followed.

Because of Struve’s improvements to equipment and methods at Dorpat, he was invited to the St. Petersburg Academy of Sciences to be the director of a new observatory. Struve helped with the design of the observatory and gathered state-of-the-art instruments, including a fifteen inch refracting telescope, which was the largest in the world at the time. The observatory was completed in 1839, and it soon became evident that it was one of the best in the world.

Some of Struve’s most influential work deals with double stars. He was the world’s foremost observer of double stars during his life. He studied William Herschel’s work on double stars when he was at Dorpat. By determining the revolutions of several binary stars, he finished some of what Herschel had started. Struve published a 795-item catalog of all known double stars in 1822. He continued on to observe more than 122,000 stars and discover 3,112 double stars. In 1837 he published Stellarum duplicium et multiplicium mensurae micrometricae, an important work that contained accurate measurements of most of these newly-discovered double stars. His identifying numbers are still used, and some of the stars have been renamed in his honor.

Although Struve was not the first to study stellar parallaxes, he was one of the first to do so accurately. He was, however, the first to measure the parallax of Vega. This work allowed him to better estimate the distances between some stars and Earth. He included some of his calculations in Stellarum duplicium et multiplicium mensurae micrometricae.

Struve also worked on various other projects. He attempted to determine whether there is a dependence between the brightness of stars and their distances. He supported the fact that the Sun is not the center of the Milky Way. His work supported the theory that the interstellar medium is not a complete vacuum. He concluded that there is sparse matter in space and that the intensity of light diminishes as it passes through it; his approximate calculation of this absorption is close to the currently accepted value. Struve also measured the aberration of light, which causes celestial objects to appear to move.

Struve produced 272 astronomical works and continued a family of astronomers; his son carried on his work, and his great-grandson was even more prolific and was one of the first astronomers to believe in extraterrestrial life. As a member of over forty scientific academies, Struve was famous during his lifetime and was one of the most prominent astronomers of the nineteenth century.


Works Cited

"Friedrich Georg Wilhelm Struve Biography." Biography.com. Web. < http://www.biography.com/articles/Friedrich-Georg-Wilhelm-Struve-9497860 >.

"Friedrich Georg Wilhelm Struve." NNDB. Web.< http://www.nndb.com/people/202/000097908/ >.

"Friedrich Georg Wilhelm von Struve." Encyclopedia.com. Web. < http://www.encyclopedia.com/doc/1G2-3404706203.html >.

"Struve, Friedrich Georg Wilhelm (or Vasily Yakovievich)." Complete Dictionary of Scientific Biography. Vol. 13. Detroit: Charles Scribner's Sons, 2008. 108-113. Gale Virtual Reference Library. Gale. Sarasota County High. 6 Jan. 2010 < http://go.galegroup.com/ps/start.do?p=GVRL&u=fl_sarhs >.

"Struve, Friedrich Georg Wilhelm von (1793-1864)." The Internet Encyclopedia of Science. Web. < http://www.daviddarling.info/encyclopedia/S/Struve_FGW.html >.