Stellar makeup impacts planet habitability

September 6, 2012

A star’s internal chemistry can doom a planet’s life long before the star itself dies

The search for potentially habitable planets involves discussion of what is sometimes referred to as the Goldilocks Zone – the relatively thin band in a solar system in which conditions on a planet can support life. Goldilock's zone Download Full Image

Astrobiologists and planetary scientists agree that a planet’s distance from its parent star is of paramount importance for creating those optimum conditions – like Goldilocks’ porridge, it has to be just right.

A new study by Arizona State University researchers suggests that the host star’s chemical makeup also can impact conditions of habitability of planets that orbit them. The team’s paper, published in the August issue of The Astrophysical Journal Letters, demonstrates that subtle differences in a star’s internal chemistry can have huge effects on a planet’s chances of long-term habitability.

“We have identified changes in the ratios of different elements as particularly important for a given solar system’s habitability,” says Patrick Young, an assistant professor in ASU’s School of Earth and Space Exploration and lead author on the paper. “The more abundant elements carbon, oxygen, silicon, magnesium and sodium are particularly important. The greater the abundances of these four elements in a star, the slower it, and the location of its Goldilocks Zone, will evolve.”

As a star evolves, it becomes brighter, causing the habitable zone to move outwards through its solar system. The team’s study indicates that a greater abundance of oxygen, carbon, sodium, magnesium and silicon should be a plus for an inner solar system’s long-term habitability because the abundance of these elements make the star cooler and cause it to evolve more slowly, thereby giving planets in its habitable zone more time to develop life as we know it.

To explore whether stellar internal chemistry causes significant changes in the evolution of stars and therefore their habitable zones, Young and his colleagues, graduate students Mike Pagano and Kelley Liebst, did simulations of stars that are like our sun.

“We used spectra from 145 broadly sun-like stars targeted by planet to estimate the amount of variation in the abundance ratios of elements," explains Pagano, who is a graduate student in the School of Earth and Space Exploration astrophysics program. "For each model, we varied the amount of one element to the extremes of variation we estimated from our analysis of the observations.”

The largest changes, unsurprisingly, arise from variation in oxygen.

“Oxygen is the most abundant element in the universe besides hydrogen and helium, so a change in the oxygen abundance results in a significant change in the total amount of heavy elements in the star," Pagano said. "Oxygen turns out to be highly variable in abundance. The effect of increased heavy element abundance on a star is to make it harder for the energy produced by nuclear fusion to escape the star. This means less energy needs to be produced to support the star, and it can live longer.”

The stellar abundance of oxygen seems crucial in determining how long planets stay in the habitable zone around their host star. If there had been less oxygen in the Sun’s chemical makeup, for example, Earth likely would have been pushed out of the Sun’s habitable zone about a billion years ago, well before complex organisms evolved. Considering the first complex multicellular organisms only arose about 650 million years ago, such a move would have likely destroyed any chance of complex life taking hold on Earth.

Planets being searched for signs of life may be about to leave their habitable zones or only have just entered them.

“Habitability is very difficult to quantify because it depends on a huge number of variables, some of which we have yet to identify,” says Young. “It also depends on the definition of habitable that we choose to use. We chose to use a relatively simple model that predicts whether a planet can sustain liquid water on its surface with reasonable assumptions about planetary atmospheres.”

Nikki Cassis

marketing and communications director, School of Earth and Space Exploration

Young alum seeks to inspire others with success story

September 6, 2012

As a former student at Arizona State University, Jeff Kunowski knows how it feels to be a young entrepreneur looking to desperately get your first big break.

It is these fond memories that have led him on a mission to share the tips for success he used to create Ilumin8 Outdoor Media, one of the most endorsed signage platforms. Jeff Kunowski Download Full Image

So how did he do it?

While a student at ASU’s West campus, Kunowski majored in integrative studies, a hybrid degree that allows students to design a curriculum based on a selected concentration that is unique to their career aspirations. Kunowski chose to purse a concentration in business, while simultaneously obtaining an international business certificate.

To further gain the business sense he needed to succeed, Kunowski simply began cold-calling local companies and asking if they had internships available. Taking the skills that he learned from one company and putting them to use in another, he was quickly making connections and gaining hands-on experience.

He went on to complete 12 internships, including those with Omni Real Estate Solutions, Clear Channel Communications, the U.S. Attorney’s Office in Phoenix, and the Phoenix Suns.

“You can learn a lot in the classroom about the foundations of business, but in order to know how it works you have to be placed in that situation. If you see internships as a learning experience they can open your eyes as to how things really work within a company,” he said.

By having the broad spectrum of internships that he did, Kunowski says it also helped him identify his business strengths and what he was passionate about.

“They showed me what I enjoyed doing and I was able to hone in on what I wanted to do with my career,” he said.

Driving home from work one night in 2010, Kunowski unexpectedly found the inspiration he needed to create his very own business.

To advertise, companies will often hire individuals to hold up signs on streets corners to draw in customers. As the sun starts to go down, it becomes harder to make out what exactly these signs are advertising though. While sitting in commuter traffic, Kunowski realized that illuminating these signs would be the best way to extend the promotional hours and attract key audiences.

After countless hours of research and trying out different light sources, Illumin8 Outdoor Media was born.

“I also came up with a lazy-susan type device using a ball bearing with a handle mounted to the sign that would allow a regular store employee to spin the sign easily instead of paying an outside contractor who can do special tricks with it,” he said.


Jeff’s tips for success:

1. Write short autobiographies to help map out your goals and the steps you need to take to achieve them.

2. Get to know your professors. Even upon graduating, they can still give you advice and even help you network professionally.

3. You can never have too many internships. Internships mean experience and it’s even better if they are willing to pay you.

4. Network! It is all about who you know and being a student should be used to your advantage.

5. Don’t be afraid to give your business venture a try. Find what you’re passionate about and get investors excited in it.


Armed with a prototype, Kunowski turned to the ASU Edson Student Entrepreneurship Initiative for help with funding. He put together a business plan, renderings, market research and gave a compelling presentation to the judges about why his business would succeed in today’s market. Illumin8 was selected for a $10,000 grant, plus office space at ASU SkySong and access to university mentors.

“I really took advantage of the resources available at SkySong, specifically the venture capitalists who helped look into my markets and see where it might fit, where it won’t, the numbers, etc. I was also able to use the Sandra Day O’Connor ad clinic and had graduate students working on my patents to cut back on costs.”

After graduating from ASU in 2011, Kunowski went on to showcase his product at the International Sign Expo in Las Vegas. He also contacted his former internship bosses at the Phoenix Suns who were eager to jump on board and order his product. Kunowski is currently working with the Arizona Diamondbacks, Coamerica Theater, the Phoenix Coyotes and Panasonic as well.

“Illumin8 is now in a partnership with Panasonic, which is one of the biggest technology companies there is. It is really cool to be able to learn from them and share my product. This is what you dream about when you start a business,” Kunowski said.

The long hours and hectic schedule that come hand-in-hand with a successful business are just proof that the former Sun Devil is accomplishing his dreams. 

“It’s a lot of time management but this is what I live for. I enjoy growing the business and creating something from nothing. Being so young has allowed be to enjoy the success while it’s happening,” he said.

For more information on Illumin8 Outdoor Media or to learn about applying for an internship, please email