APOD 3.3

Located in the constellation Andromeda, m31 is the most distant object visible to the unaided eye. The Andromeda Galaxy is some two and a half million light-years away, which is outside the reaches of our own Milky Way Galaxy. Spanning over 200,000 light-years, this huge spiral galaxy is seen as a faint, nebulous cloud, even without the use of a telescope. This telescopic digital mosaic shows the bright yellow center, dark dust, long blue spiral arms, and star clusters can all be seen. In another image of m31, the moon and m31 are compared in angular size, and m31 is clearly much larger. The moon covers about 1/2 degree of the sky, which is no comparison to the amount m31 spans. This is a pretty incredible picture. It is truly amazing how large this galaxy is, and the fact that you can see an object outside our own galaxy is unbelievable.

APOD 3.2

This cosmic cloud, shaped like a helmet with wing-like appendages, is commonly referred to as Thor's Helmet. It seems, though, that Thor's Helmet is actually like an interstellar bubble, blown as a wind from the bright, massive star near the bubble's center passes through a molecular cloud. Thor's Helmet, or interstellar gas bubble, is almost 30 light-years across. The central star appears to be a Wolf-Rayet star, meaning it is an extremely hot giant, which is thought to be in a short pre-supernova stage of evolution. Located in the constellation Canis Major, Thor's Helmet, NGC 2359, is almost 15,000 light-years away. This image shows an emerald color, from a strong emission due to oxygen atoms in the glowing gas. It's truly amazing how you can see the shape of helmet, and evem the outline of what could be considered the wings on the helmet. The colors are so vibrant and amazing to see, and it is incredible how this "Helmet" or "interstellar bubble" spans over 30 light-years across.

Astronomer Biography

Danielle McCoy

Mr. Percival

Astronomy Honors

9 Jan. 2008

Nathaniel Bowditch

An American astronomer and mathematician, Nathaniel Bowditch was a great influence and made a huge impact on the world in his time. Rewriting John Hamilton Moore’s Practical Navigator and correcting errors in many other works, going to sea and becoming a master were just some of his many accomplishments.

Nathaniel Bowditch was born on March 26, 1773 in Salem, Massachusetts to mother Mary Ingersoll and father Habakkuk Bowditch. While Nathaniel was still a baby, his family moved to Danvers, Massachusetts, but returned to Salem by the time Nathaniel was seven. Due to strained family finances, Nathaniel was forced to quit school at the age of 10, and help his father in his father’s cooperage shop. After two years of helping his father, Nathaniel was able to become an apprentice clerk in the ship chandler’s shop Hodges and Ropes in Salem. By the age of 17, Nathaniel began working in the shop of Samuel C. Ward. Throughout this whole time, Nathaniel was continually educating himself. In March 1798, he married Elizabeth Boardman, but she died later the same year. In October of 1800, he married his cousin Mary Ingersoll, and they later had six sons and two daughters.

In 1795, Nathaniel went to sea making four voyages by 1799. On his fifth voyage, in 1802, Nathaniel was in command of the merchant chip and also was joint owner. Four of the voyages were to the East Indies, while one was to Europe. During this time when Nathaniel was constantly on the seas, he never once put his studies to the side.

In 1799, with the collaboration of his brother, the first American edition of Moore’s Practical Navigator was published with many corrections to Moore’s work. Nathaniel greatly enjoyed computing complex mathematical computations, checking, and correcting Moore’s work. He later published a second edition, but when it was time to publish the third, the name had to be changed. Nathaniel had made so many changes and so greatly changed Moore’s work that it only made sense to change the name and the author. In 1802, Nathaniel published the New American Practical Navigator with his name as the author. Soon, Nathaniel published an article of observations of the moon, and in 1806, he published naval charts of the harbor at Salem and many others. He had a scientific publication on a meteor explosion in 1807 and three papers on the orbits of comets (1815, 1818, 1820). Nathaniel translated the first four volumes of Laplace’s Traite de Mecanique Celeste by 1818, but did not publish them for many more years because he was enhancing and improving it over the years. Nathaniel’s main purpose for translating the text was not merely to have a translation, but to add many missing elements, including adding credits omitted by Laplace. He edited and translated this book in such a way that even the ordinary seaman could use and understand it, and it became known as the seaman’s bible.

In 1799, Nathaniel was elected to the American Academy of Arts and Sciences. Harvard offered Nathaniel the chair of mathematics and physics, but he decidedly turned it down. He was also admitted to the American Philosophical Society in 1809, both the Royal Societies of Edinburgh and London in 1818, and the Royal Irish Academy in 1819. In 1818, West Point offered him a chair, and also the University of Virginia offered him a chair. He was offered $2000 from Virginia, but that was about 50% less than his salary from the Essex Fire and Marine Insurance Company. He never accepted any of the mathematics chairs he was offered. He later left the Essex Fire and Marine Insurance Company and became an actuary in the Massachusetts Hospital Life Insurance Company. He later died on March 16, 1838 in Boston, Massachusetts.

Due to all the additions and contributions Nathaniel Bowditch made, he acquired much international fame, especially by many European scientists. Nathaniel Bowditch was a self-taught man with exceptional mathematical abilities. He was an original and forward thinker, and without his works, who knows where we would be today.

Works Cited

"Nathaniel Bowditch." The History of Mathematics Archive. Aug. 2005. University of St. Andrews. 6 Jan. 2008 .

Nugent, Jim. "Nathaniel Bowditch." Dictionary of Unitarian and Universalist Biography. 6 Jan. 2008 .

APOD 3.1

Created by high-speed winds of gas and dust coming from an aging central star at over 600,000 km per hour, the Boomerang Nebulais a symmetric cloud. The "rapid expansion" has cooled molecules within the nebular gas to one degree above absolute zero, which makes it the coldest known region in the Universe. It is believed that the Boomerang Nebula is a star or stellar system developing into a planetary nebula. Shining with light from the central star reflected by dust, the Boomerang Nebula spans around 1 light-year and lies 5,000 light-years away near the constellation Centaurus. This Hubble Image is pretty amazing, especially how it shows the array of colors.