Andromeda Galaxy
The Finding and Research
In 964 CE, Persian astronomer Abd al-Rahman al-Sufi took the first written note of the "small cloud." Then, in 1764 Charles Messier named it M31 (Messier Object 31), but he also gave false credit to the German astronomer Simon Marius. Marius recorded the first image with a telescope, but inaccurately called it a nebula. Until 1920, people believed that M31 was only a nebula, but, 2 astronomers began debating over it. Harlow Shapely, who had already predetermined that the Milky Way was 100,00 light years wide, believed in the science of the time, which said that the Milky Way was the only galaxy, and the patches like M31 were "nebulae." Curtis Heber saw a nova inside Andromeda and argued that it was another galaxy.
The argument ended in 1925 when Edwin Hubble found a Cepheid Variable Star; a star that's brightness changes. The star was used to measure the precise distance, data showed that the “fuzzy patch” was too far away. Then used Doppler shifts to find that the universe was expanding and rotating in a "bumpy" way due to the arms on the spiral.
The argument ended in 1925 when Edwin Hubble found a Cepheid Variable Star; a star that's brightness changes. The star was used to measure the precise distance, data showed that the “fuzzy patch” was too far away. Then used Doppler shifts to find that the universe was expanding and rotating in a "bumpy" way due to the arms on the spiral.
Appearance, Comparison to Milky Way, and Other Facts
The Andromeda Galaxy is a spiral, like our own Milky Way. Most of the matter is located in the middle, with a sun in the direct center and lots of stars and dust surrounding. M31 has more stars than the Milky Way, but the Milky Way is more massive due to all of the dark matter. Two of the most noticeable things about M31 are the dust ring in the center - which scientists believe is from the galaxy swallowing other galaxies as it passed by them - and the massive hydrogen cloud that surrounds it. M31 is 260,000 million light years long. There are many minor galaxies located near the Milky Way, but M31 is by far the closest to us, 2.5 million light years away. In fact, Andromeda is heading towards us, at about 70 miles per second. Scientists believed that in 5 billion years, Andromeda will have swallowed our own.
How to Find The Andromeda Galaxy
The Andromeda is only visible as a small blur in the sky, which is only the inside bulge. If we could see the whole galaxy, it would be six times as large as our moon. Below is a link with instructions on how to find it.
How to Find the Andromeda Galaxy
How to Find the Andromeda Galaxy
Citations
Thilker, David A et al. "On the continuing formation of the Andromeda galaxy: detection of HI clouds in the M31 halo." The Astrophysical Journal Letters 601.1 (2008): L39.
"Andromeda Galaxy (M31): Location, Characteristics & Images ..." 2012. 29 Jan. 2013 <http://www.space.com/15590-andromeda-galaxy-m31.html>
"eSky: Andromeda Galaxy." 29 Jan. 2013 <http://www.glyphweb.com/esky/galaxies/andromeda.html>
"The Andromeda Galaxy - National Optical Astronomy Observatory." 29 Jan. 2013 <http://www.noao.edu/image_gallery/html/im0424.html>
http://www.solstation.com/x-objects/and2gal.jpg
http://files.myopera.com/FranklinBR/albums/12602222/Andromeda%20Galaxy.jpg>
"Andromeda Galaxy (M31): Location, Characteristics & Images ..." 2012. 29 Jan. 2013 <http://www.space.com/15590-andromeda-galaxy-m31.html>
"eSky: Andromeda Galaxy." 29 Jan. 2013 <http://www.glyphweb.com/esky/galaxies/andromeda.html>
"The Andromeda Galaxy - National Optical Astronomy Observatory." 29 Jan. 2013 <http://www.noao.edu/image_gallery/html/im0424.html>
http://www.solstation.com/x-objects/and2gal.jpg
http://files.myopera.com/FranklinBR/albums/12602222/Andromeda%20Galaxy.jpg>