Friday, January 28, 2011

APOD 3.2

NGC 660 is near the center of this photo which is in the boundaries of the constellation Pisces.  It is over 20 million light-years away and it has a peculiar appearance because it is a polar ring galaxy.  These galaxies are rare and have substantial populations of stars, gas, and dust orbiting in rings nearly perpendicular to the plane of the galactic disk.  It is postulated that the configuration could have been caused by the chance capture of material from a passing galaxy by the disk galaxy, with the captured debris strung out in a rotating ring.  The polar ring component can be used to explore the shape of the galaxy's otherwise unseen dark matter halo by calculating the dark matter's gravitational influence on the rotation of the ring and disk.  NGC 660's ring spans about 40,000 light-years.

Friday, January 21, 2011

APOD 3.1

This is a photo of globular star cluster 47 Tucanae, also known as NGC 104.  It roams the halo of our Milky Way Galaxy and so does some 200 other globular star clusters.  This is the second brightest globular star cluster (Omega Centauri being the brightest) as seen from Earth, and it is about 13,000 light-years away.  It can be spotted by the naked-eye near the Small Magellanic Cloud in the constellation of the Toucan.  This dense cluster is made up of several million stars in a volume of only 120 light-years across.  The red giant stars on the outer regions of the cluster are easy to see as yellowish stars in this photo.  Globular cluster 47 Tucanae also has x-ray binary star systems.

Wednesday, January 19, 2011

Lunar Eclipse Observation

I came to Pin View on December 20th, 2010 to view the lunar eclipse.  I got there around 1 A.M. so I guess it was technically the 21st.  I stayed and watched the whole thing.  It was amazing to be able to see an entire cycle of the moon , which usually takes a moth, all in just a few hours.

Friday, January 14, 2011

APOD 2.8

This is a photo of the spiral galazy NGC 3521 and it is 35 million light-years distant.  It is toward the constellation Leo.  It spans about 50,000 light-years, and its central region is shwon in this image.  This photo was constructed from data from the Hubble Legacy Archive.  The galaxy has multiple patychy, irregular spiral arms laced with dust and clusters of young, blue stars.  Many other spirals have large, sweeping arms.  NGC 3521 is a bright galaxy in Earth's sky and is easily visible in small telescopes.

Monday, January 10, 2011

Quarter 2 Astronomer Biography

Dictionary of Scientific Biography.  C. Gillispie, editor.  Charles Scribner's Son, publisher. 1981



Quarter Two Astronomer Biography
            Pierre Simon Laplace was born in Beumont-en-Auge, Normandy, France on March 23rd, 1749.  His father, Pierre Laplace, was involved in the cider trade and did well for himself and his mother, Marie-Anne Sochon came from a farming family in Tourgeville.  Pierre Simon Laplace attended a Benedictine priory school in his home town of Beaumont-en-Auge between the ages of 7 and 16.  His father sent him to this school because he expected him to pursue a career in the Church.  When he was 16, Laplace enrolled in Caen University to study theology because he was still planning on a career in the Church.  But during his two years at the University of Caen, Laplace realized that he was gifted in the area of mathematics and how much he loved the subject.  This realization is accredited largely to two mathematics teachers at Caen: C Gadbled and P Le Canu.
            Laplace chose to leave Caen without his degree and went to Paris.  He was given an introduction letter to d’Alembert from Le Canu, his teacher.  Laplace was only 19 years old when he got to Paris but d’Alembert was very impressed by him and he began to direct his mathematical studies and found him a position as professor of mathematics at the Ecole Militaire.  Laplace began to produce many groundbreaking mathematical papers and the first was presented in the Academie des Sciences in Paris on March 28th, 1770.  Laplace’s first paper to be published was one on the integral calculus which he translated into Latin and published at Leipzig in the Nova acta eruditorum in 1771.  On March 31st, 1773, Laplace was elected an adjoint in the Academie des Sciences.  By the time he was elected, he had already read thirteen papers to the Academie in less than three years.  In 1780, Laplace and the chemist Lavoisier applied quantitative methods to a comparison of living and nonliving systems, with the aid of an ice calorimeter that they had invented, showed respiration to be a form of combustion.  In 1784, Laplace was appointed as the examiner at the Royal Artillery Corps.  Laplace was promoted to a senior position in the Academie des Sciences in 1785.  Laplace marries Marie-Charlotte de Courty de Romanges on May 15th, 1788.  They had two children and their son, Charles-Emile, who was born in 1789, went on to a career in the military.  Before the 1793 Reign of Terror, Laplace and his wife and two children left Paris and lived 50 km southeast of Paris. He did not return to Paris until after July 1794. 
            Laplace presented his famous nebular hypothesis in 1796 in Exposition du systeme du monde, which looked upon the solar system as originating from the contracting and cooling of a large, flattened, and slowly rotating cloud of incandescent gas.  Exposition du systeme du monde was written as a non-mathematical introduction to Laplace's most important work Traité de Mécanique Céleste whose first volume appeared three years later.  Laplace had discovered the invariability of planetary mean motions.  In 1786 he had proved that the eccentricities and inclinations of planetary orbits to each other always remain small, constant, and self-correcting.  These and many other of his earlier results formed the basis for his second work.  Laplace became Count of the Empire in 1806 and he was named a marquis in 1817 after the restoration of the Bourbons.  Laplace continued to apply his ideas of physics to other problems such as capillary action (1806-07), double refraction (1809), the velocity of sound (1816), the theory of heat, in particular the shape and rotation of the cooling Earth (1817-1820), and elastic fluids (1821).  Laplace died on the morning of March 5th, 1827. 

Friday, January 7, 2011

APOD 2.7

This is a photo of the Winter Hexagon.  They say if you can find Orion in the sky, you will probably be able to locate the Winter Hexagon.  The Winter Hexagon is composed of some of the brightest stars that are visible.  They combine to form a large and easily spotted "pattern" in the winter sky located in Earth's northern hemisphere.  These stars can usually be seen even in the inconducive to star watching bright night skies of a big city.  This photo was taken in Stagecoach, Colorado.  There are six stars in the Winter Hexagon: Aldebaran, Capella, Castor (and Pollux), Procyon, Rigel, and Sirius.  In this photo, the band of the Milky Way Galaxy runs through the center of the Winter Hexagon, and the Pleiades open star cluster can be seen just above.  The Winter Hexagon "asterism" takes over many constellations including Orion. 

Thursday, January 6, 2011

Quarter 2 Astronomer Biography Sources

Ball, Rouse. "Pierre Simon Laplace (1749 - 1827)." TCD School of Mathematics. Web. 04 Jan. 2011.    <http://www.maths.tcd.ie/pub/HistMath/People/Laplace/RouseBall/RB_Laplace.html.>
  
Robertson, E.F. "Laplace Biography." MacTutor History of Mathematics. School of Mathematics and Statistics. Web. 06 Jan. 2011. <http://www-history.mcs.st-and.ac.uk/Biographies/Laplace.html>.
 
"Pierre-Simon Laplace." NNDB: Tracking the Entire World. Soylent Communications. Web. 04 Jan. 2011. <http://www.nndb.com/people/871/000031778/>.