[Originally published here at OnwardState.com on November 19, 2014]
We all know that Penn State professors are experts in their fields — after all, we’re one of the top 30 universities in the country for a reason. But the professors in a certain department take “expert” to the next level.
In fact, many of the professors in Penn State’s astronomy department have discovered amazing and awe-inspiring things thousands of miles into space.
Since I couldn’t take it upon myself to pick which Penn State astronomers were most important or impressive, see the timeline below to learn about the five of the most recent discoveries of planets and other objects of the like made by Penn State astronomy professors.
Coldest Brown Dwarf, April 25, 2014 – Kevin Luhman, Astronomy 001 professor, discovered a “brown dwarf” star that appears to be the coldest of its kind (as frosty as the Earth’s North Pole, according to the press release). Luhman was able to detect the brown dwarf using NASA’s Wide-Field Infrared Survey Explorer, aka WISE, and Spitzer Space Telescopes. Brown dwarfs are, by NASA’s definition, objects that are a size between that of a giant planet like Jupiter and that of a small star.
The press release states that brown dwarfs start their lives like stars, as collapsing balls of gas, but they lack the mass to burn nuclear fuel and radiate starlight. Though their importance is not as obvious to those of us who aren’t astronomically inclined, NASA’s website explains that brown dwarfs are noteworthy because a large chunk of the universe may be in brown dwarf form, and since these bodies do not give off a significant amount of light, their existence could contribute in part to the “missing mass” problem faced by cosmology.
First Earth-Sized Planet in Habitable Zone, April 17, 2014 – Eric Ford, Penn State’s Ph.D. Dissertation in Science full-time mentor, is one of a team of astronomers (including other Penn State scientists) that discovered the first Earth-sized planet in another star’s “habitable zone,” the distance from a star where liquid water might pool on the surface of an orbiting planet.
The planet, named Kepler-186f after NASA’s Kepler Space Telescope by which it was discovered, is described as what “may be the most similar planet to the Earth yet discovered” by Ford in the press release. Regardless, even though Kepler-186f is likely to have a mass similar to Earth’s, Ford explains that many of its other elements could differ from those of Earth, including its atmosphere, surface terrain, and how heat and light coming from the sun it’s orbiting (about half the size of our sun) affect it.
Third-Closest Star System to the Sun, March 11, 2013 – Luhman strikes again with the discovery of a pair of stars making up the third-closest star system to the Sun and the closest star system discovered since 1916, according to the press release. The star system, called WISE J104915.57-531906 because it was discovered via NASA’s WISE satellite, is made up of two brown dwarfs (We just learned about these, remember?), and it is located marginally farther away than the second closest star to our Sun, Barnard’s star, which falls just over six light years away.
The closest star system consists of Alpha Centauri, found to be a neighbor of the Sun in 1830 at 4.4 lightyears, and the fainter Proxima Centauri, discovered to be a neighbor in 1917 at 4.2 lightyears away. Along with discovering WISE J104915.57-531906 (the easy part – duh), Luhman was also able to measure its distance to our sun via parallax (the apparent shift of a star in the sky due to the Earth’s orbit around the Sun).
Three New Planets & Mystery Object, October 26, 2011 – Alex Wolszczan, Astronomy 140 (Life in the Universe) professor, led an international research team to the discovery of three new planets and a mystery object outside of our solar system. As a side note, this isn’t his first rodeo – back in 1992, Wolszczan became the first astronomer ever to discover planets outside of our solar system. The team used the Hobby-Eberly Telescope to discover the three planets, all orbiting their own giant, dying star.
On top of discovering three planets, the team led by Wolszczan stumbled across something a bit more intriguing: a bonus mystery object orbiting one of the stars alongside one of the newly discovered planets. Let’s tally that up and simplify it, shall we? Wolszczan and team discovered not one, not two, but three new planetary systems that are more involved than our own solar system, on top of encountering an object that they aren’t even sure what to make of. That being said, the team speculates that the “object could be another planet, a low-mass star, or – most interestingly – a brown dwarf,” according to the press release.
Planet-like Object With Earth Temperature, October 19, 2011 – Kevin Luhman once more discovered a planet-sized object as cool as Earth. The object was discovered via photograph taken by NASA’s Spitzer Space Telescope. Luhman explains in the press release that they chose to use the Spitzer because “it is the most sensitive infrared telescope available.”
This ability was crucial to their discovery because objects with cool temperatures like the Earth are brightest at infrared wavelengths, Luhman explains. Luhman and his colleagues compared infrared images taken years apart of more than 600 stars near our solar system in order to spot any faint points of light that showed the same motion across the sky as the targeted star. Any faint lights with the same motion indicated the object was orbiting a star.
A more complete and detailed timeline on more cool stuff that Penn State astronomers and scientists have discovered can be found at the News and Events for Eberly College of Science webpage.