Siena Galaxy Atlas (SGA)

About Siena Galaxy Atlas

• It is a digital atlas that was created to get to know our universe better through several of the known galaxies.
• It was created using data from three astronomical surveys collected between 2014 and 2017 at Cerro Tololo Inter-American Observatory (CTIO) and Kitt Peak National Observatory (KPNO). Together these surveys are known as the DESI Legacy Surveys.
• How is it different from other atlases?
  • It is dependent on state-of-the-art digital images captured by advanced technology, unlike previous atlases which relied on antiquated equipment and photographic plates. 
  • As it is built on the images captured with highly sensitive instruments, it boasts of having the most accurate data.
  • It is also the first cosmic atlas to feature the light profiles of galaxies - a curve that describes how the brightness of the galaxy changes from its brightest point to its dimmest. 
• Significance
  • Cosmic atlases help astronomers spot patterns that help categorise new discoveries, such as stars that suddenly flare and then disappear (thus called ‘transients’).
  • These atlases also allow astronomers to identify which objects are contenders for detailed follow-up studies. 
  • It helps in investigate everything from the births and evolutions of galaxies to the distribution of dark matter and propagation of gravitational waves through space. 

Q1) What is the Milky Way?

The Milky Way is the galaxy in which our solar system is located. It is a barred spiral galaxy, which means it has a central bar-shaped region made up of stars, surrounded by spiral arms that contain stars, gas, dust, and other celestial objects.

Source: See 400,000 galaxies near Milky Way in this amazing ‘galactic atlas’