Little Bits of History

A Star (Searcher) is Born

Posted in History by patriciahysell on June 26, 2015
Charles Messier

Charles Messier

June 26, 1730: Charles Messier is born. The French astronomer was born in Badonviller and is most noted for publishing an astronomical catalogue filled with what is today called the 110 Messier objects. He was a comet hunter and he wished to help others distinguish between permanent and transient objects found in the sky. He began compiling this list in 1771 along with his assistant, Pierre Mechain. The hope was to avoid wasting time on these permanent features in the sky and make comet discovery more efficient. Giovanni Hodierna had published a similar list in 1654 but it had no impact on astronomy and Messier probably did not know about it.

The first edition of the catalog contained 45 objects which Messier numbered M1 to M45. The total list, as published by Messier, contained 103 objects but other astronomers have added some items since Messier’s death in 1817. After finding some notes of Messier’s M104 was added in 1921. Kenneth Glyn Jones added the last item, M110, in 1967. The Frenchman’s final catalog was published in 1781 even though it was called Connaissance des Temps for 1784, and the objects listed are still known by the Messier number.

Messier lived and worked at the Hotel de Cluny (today the Musee national du Moyen Age) in Paris. The objects found in the listing are only found in the night sky which he could observe. These items reside in the band of sky from the north celestial pole to latitudes of about -35.7⁰. Southern hemisphere items are not listed by Messier. What he was finding were nebulae and star clusters. He found something interesting on October 13, 1773 and it was later named the Whirlpool Galaxy. The object is located with the constellation Canes Venatici and has recently been calculated to be 23 ± 4 million light years from the Milky Way. Different methods of measurement give the distance between 15 and 35 million light years.

Close to the Whirlpool Galaxy is NGC 5195, also sometimes called Messier 51b. These two galaxies are one of the most famous pair of interacting galaxies in the sky. Many amateur astronomers can easily find the pair and they can even be seen with a good pair of binoculars. Professional astronomers study the Whirlpool galaxy in order to better understand galaxy structure, especially spiral arm galaxies. The galaxy is thought to be made of 160 billion solar masses with a black hole in the center, surrounded by a ring of dust. The distinctive spiral arm structure is thought to be the result of the interaction with the companion galaxy, NGC 5195.

What caused me to undertake the catalog was the nebula I discovered above the southern horn of Taurus on September 12, 1758, while observing the comet of that year.

This nebula had such a resemblance to a comet in its form and brightness that I endeavored to find others, so that astronomers would not confuse these same nebulae with comets just beginning to shine.

I observed further with suitable refractors for the discovery of comets, and this is the purpose I had in mind in compiling the catalog.

After me, the celebrated Herschel published a catalog of 2000 which he has observed. This unveiling the sky, made with instruments of great aperture, does not help in the perusal of the sky for faint comets. Thus my object is different from his, and I need only nebulae visible in a telescope of two feet [focal length]. – all from Charles Messier

Also on this day: Helicopters – In 1934, the FW-61 helicopter was flown for the first time.
Cyclone – In 1927, Coney Island opened a new ride.
Pied Piper – In 1284, a piper led 130 children out of Hamelin.
CN Tower – In 1976, the Ontario tower opened to the public.
Fast France – In 1906, the first Grand Prix race was held.

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Whirlpool

Posted in History by patriciahysell on October 13, 2012

Charles Messier

October 13, 1773: Charles Messier looks into the night sky. The French astronomer was born in 1730, the tenth of twelve children. Six of the children died while young and when Charles was 11, his father died. The child’s interest in astronomy was piqued by a great six-tailed comet (C/1743 X1, Comet de Chéseaus, or the Great Comet of 1744) and a solar eclipse as seen from his hometown on July 25, 1748. In 1751 he was employed by Joseph Nicolas Delistle, an astronomer with the French Navy. It was there he learned to make careful observations and keep detailed records. Charles’s first documented observation was the transit of Mercury on May 6, 1753.

Messier was made a fellow of the Royal Society in 1764 and five years later was elected a foreign member of the Royal Swedish Academy of Sciences. In 1779 he was elected to the French Academy of Sciences. He discovered 13 comets between the years 1760 and 1785. His first catalog, published in 1774 contained 45 objects but since then the list of discoveries has grown to 103. However, at least 20 of the objects listed were, in fact, discovered by his assistant, Pierre Méchain. There is a crater on the moon called Messier and an asteroid called 7359 Messier – both named in his honor.

On this day, while looking at the night sky, Messier found something a bit larger than a comet. Designated as M51, the object is what is today sometimes called the Whirlpool galaxy. In 1781, Méchain discovered its companion galaxy NGC5195. Although the mass was seen in the sky, it wasn’t until 1845 that it was discovered the galaxy was spiral in nature. It took Lord Rosse using a 72-inch telescope to discover the shape. In 2005, a supernova was observed in the Whirlpool Galaxy which had an apparent magnitude of 14. And in 2011 a type II supernova with a magnitude of 13.5 was seen there.

The galaxy is located in the constellation Canes Venatici and is found following the easternmost star of the Big Dipper. The galaxy is visible with binoculars under dark sky conditions and can, obviously, be seen with amateur telescopes. However, it takes a larger telescope to be able to see the spiral arms. Stars are usually formed in the center of a galaxy and M51 seems to be undergoing a period of star formation, but this is a relatively short lived period and shouldn’t last more and another 100 million years. This could be the reason for the spiral shape of the galaxy, but not the only one. There is also hydrogen compression in other areas leading to starbirth regions and these show up as bright blue dots in the spiral arms.

Is it not careless to become too local when there are four hundred billion stars in our galaxy alone. – A. R. Ammons

Keep up the good work, if only for a while, if only for the twinkling of a tiny galaxy. – Wislawa Szymborska

When you look at the stars and the galaxy, you feel that you are not just from any particular piece of land, but from the solar system. – Kalpana Chawla

Astronomy compels the soul to look upwards and leads us from this world to another. – Plato

Also on this day:

Service – In 1843, B’nai B’rith was founded.
Miracle of the Sun – In 1917, Our Lady of Fatima appeared to thousands.
Yellow Jackets – In 1885, Georgia Tech was founded.

Close Call

Posted in History by patriciahysell on July 1, 2012

Charles Messier

July 1, 1770: Lexell’s Comet misses Earth. The comet was discovered by French astronomer Charles Messier in June 1770. It was named for Anders Johan Lexell, a Swedish-born Russian who computed the course of the heavenly body. It is noted for being the comet to pass closest to Earth in all of recorded history. The comet passed by at a distance of 0.0146 astronomical units (au) or 1,360,000 miles. The moon is 238,857 miles from our planet. Because distances are so great in space, the au was developed and is defined at the mean distance between the Earth and Sun or 92,960,000 miles.

Scientists of the time recorded sightings and listed the comet as having a nucleus as large as Jupiter and “surrounded with a coma of silver light, the brightest part of which was as large as the moon’s orb.” Messier not only was the first to find the comet in the constellation Sagittarius, but also the last to see the space traveler as it passed from view on October 3. The comet has not been seen since and is considered to be a lost comet. It may have been so affected by the gravitational forces of Jupiter as to have its course completely altered.

Comets are small solar system bodies bigger than meteoroids. As they near the sun, they exhibit a visible coma and sometimes a tail. Both become visible due to solar radiation affecting the comet’s nucleus. Most are made of ice, dust, and small rocky particles and can be a few hundred yards to miles across. Comets have a variety of orbital periods, some arriving every few years and some with orbits so erratic they only come near after thousands of years. Comets are different from asteroids because comets have a coma and tail. When they lose their volatile substances, they are more like asteroids and become known as extinct comets.

Comets can be ejected from the solar system usually by interacting with the gas giant planets with high gravity wells. They may become extinct after repeatedly approaching the sun and having their volatiles burned away. They may break apart or disintegrate if hit by enough conflicting gravitational forces. They may also collide with other objects, some fall into the Sun and some strike planets or moons. Four billion years ago, when the Earth was young, it is thought many comets collided with the planet and may have been responsible for bringing along water and the precursors of life, if not life itself to Spaceship Earth.

The cosmos is all that is or ever was or ever will be. Our feeblest contemplations of the Cosmos stir us—there is a tingling in the spine, a catch in the voice, a faint sensation, as if a distant memory, or falling from a height. We know we are approaching the greatest of mysteries. – Carl Sagan

I have loved the stars too fondly to be fearful of the night. – Sarah Williams

The moon and the stars no longer come to the farm. The farmer has exchanged his birthright in them for the wattage of his all-night sun. His children will never know the blessed dark of night. – Leslie Peltier

Those who study the stars have God for a teacher. – Tycho Brahe

Also on this day:

Four Score and Seven Years Ago – In 1861, the Battle of Gettysburg begins.
Can I Get a Witness? – In 1879, The Watchtower was first published.
Russians Reading – In 1862, the Russian State Library is founded.