Shedding Light on Mysterious Stars

Astronomers Launch New Survey of Nearby "Tint Galaxies"

by Annie Shao, age 17

Although star formations have been in existence much longer than human beings, little is understood about them. Astronomer Deidre Hunter has been studying small galaxies known as dwarf irregular galaxies for the past 17 years. She and her team at Lowell Observatory hope to shed some light on these mysterious stars.

According to Hunter, “Star formation in dwarfs [irregular galaxies] today is similar to star formation right after the Big Bang.”    

Scientists know that stars are formed from gas clouds called nebulae. What they do not know is what types of molecules make up these clouds, or exactly how the stars are formed. In order to investigate star formation, the National Science Foundation funded Hunter’s project Local Irregulars That Trace Luminosity Extremes and The HI Nearby Galaxy Survey (LITTLE THINGS).   

The LITTLE THINGS team is focusing on 41 dwarf irregulars and tracking the gases in them. So far, they know that stars form in nebulae in a manner that compares to the way precipitation forms in moisture clouds on Earth. As the dust and gas particles in a nebula move around, the particles begin to bond together due to their gravitational pull. Because the particles group together, the center becomes extremely hot. This is called a protostar, which has the potential to become a star.   

Scientists speculate that there are many processes that occur within a nebula, and these are what the LITTLE THINGS team of scientists hopes to learn more about.   

The LITTLE THINGS team uses many methods to research dwarf irregulars. One example is pre-doctoral student Megan Jackson. She is currently studying the velocities and rotations of stars. Another pre-doctoral student, Hongxin Zhang, is studying the existing data sets of these galaxies to learn their histories in star formation.    

Because current data sets are limited, Zhang is also launching an observation program in order to collect new data. He will be using an infrared instrument called Mimir, which is attached to a 1.8 meter telescope. With all this data, LITTLE THINGS has much to sort and analyze. Post-doctoral fellow Kim Herrmann is responsible for organizing the data.   

The data Hunter and her team are collecting will change how astronomers view star formation. This is primarily because what is known about typical galaxies does not always apply to dwarf irregulars. The LITTLE THINGS project will provide scientists with valuable information about the billions of stars in space.

[Sources: National Science Foundation; The Wall Street Journal]