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The Stars

The Atacama Large Millimeter/submillimeter Array (ALMA) will allow scientists to determine the radius and the rotation of stars and identify the chemical composition of dust being emitted from red supergiant stars (a star which is 10 to 1,000 times the diameter of our Sun, such as Betelgeuse).

One way in which a star is classified is by color (or spectra). Stars were first categorized in the 1890s by Annie Cannon. She used letters to classify the different spectra of light stars emitted. Originally the letters used were A through Q, since then, astronomers have narrowed and rearranged the classification index to the letters O, B, A F, G, K, M. O representing the hottest stars and M the coolest.

Below is a list of common stars and their attributes, the graph above represents how quickly the Atacama Large Millimeter Array will be able to detect these different stars.

Constellation
Star
Example
Aproximated
Temperature
Color
Emitted
Spectral
Class
Orion
Alnitak
40.000 K
bluest
O
Orion
Mintaka
Virgo
Spica
18.000 K
bluish
B
Orion
Rigel
Orion
Bellatrix
Leo
Regulus
Ursa Major
Mimosa
Canis Major
Sirius
10.000 K
bluish-white
A
Gemini
Castor
Lyra
Vega
Cygnus
Deneb
Ursa Minor
Polaris
7.000 K
white
F
Carina
Canopus
Canis Minor
Procyon
Capricorn
Dabih
Cygnus
Sadr
The Sun
5.500 K
yellowish-white
G
Auriga
Capella
Bootes
Muphrid
Bootes
Nekkar
Pegasus
Matar
Draco
Edasich
4.000 K
orangish
K
Ursa Minor
Kochab
Bootes
Izar
Ursa Major
Dubhe
Gemini
Pollux
Taurus
Aldebaran
Orion
Betelgeuse
3.000 K
reddish
M
Andromeda
Mirach
Centaurus
Menkar
Scorpio
Antares
Pegasus
Scheat