A professor at The University of Toledo is examining a new space object that is half planet, half star, and has a name similar to a phone number.Dr. Mike Cushing, director of Ritter Planetarium and associate professor of astronomy, is observing a newly discovered brown dwarf, named WISE 1405+5534. He is utilizing both the Spitzer Space Telescope, named for Toledo native Lyman Spitzer, and the Hubble Space Telescope simultaneously.
“Hubble looks at UV, visible and infrared light. Spitzer looks at infrared light with wavelengths longer than Hubble can see,” Cushing said. “Since they look at different wavelengths, they are good for examining different things.”
He is able to access the data from each telescope, stored as images, and download what he needs to his computer.
Cushing’s team is using Hubble to look deeper into the atmosphere and Spitzer to look higher into the atmosphere. Their observations, which can take months to review, will help astronomers not only better understand brown dwarfs, but also advance knowledge about the atmospheres of gas giant planets located outside of our solar system.
“What we want to do is look at multiple levels of the atmosphere at the same time,” Cushing said. “Then we can try to connect what’s going on in an atmosphere at different levels.”
Brown dwarfs, sometimes referred to as “failed stars,” share characteristics with both low-mass stars and gas giant planets. Many theories suggest that brown dwarfs originate from clouds of gas and dust that gravitationally collapse to form a dense core, similar to the formation of stars.
“The idea we want to try to understand is the three-dimensional structure of the atmosphere by looking at different wavelengths,” Cushing said. “We think brown dwarfs, cold ones especially, are very similar to the planet Jupiter.”
However, brown dwarfs form without the ability to sustain nuclear fusion, which is the process that allows stars like our sun to shine and emit light. Without a lasting internal energy source, brown dwarfs cool as they age and become fainter, which makes them difficult for astronomers to detect.
“Brown dwarfs are so cold and low-mass that instead of generating their own heat and light, they are similar to embers plucked from a fire — warm at first, but slowly cooling off with nothing to keep them hot,” Cushing explained.
Cushing and his team will study how the brightness of the brown dwarf changes as it spins on its axis, which will help astronomers learn how clouds are distributed in the atmospheres of brown dwarfs.
“We know these objects have clouds of potassium chloride and sodium sulfide, and that they are probably patchy like we see on Jupiter,” Cushing said.
More than 1,000 have been spotted since the first brown dwarfs were confirmed in 1995. Brown dwarfs come in various sizes and temperatures, but Cushing and his group are focusing on the colder brown dwarfs, measuring less than 500 Kelvin, which is equal to 440 degrees Fahrenheit. The coldest brown dwarfs on record have reached temperatures as low as 300 Kelvin or 80 degrees Fahrenheit.
Prior to joining UT in 2011, Cushing completed postdoctoral fellowships with NASA, the University of Hawaii and the University of Arizona.