Kevin Luhman is a professor of astronomy and astrophysics from

Pennsylvania State University The Pennsylvania State University (Penn State or PSU) is a Public university, public Commonwealth System of Higher Education, state-related Land-grant university, land-grant research university with campuses and facilities throughout Pennsyl ...

who discovered both the third-closest stellar system,

Luhman 16 Luhman 16 (also designated WISE 1049−5319 or WISE J104915.57−531906.1) is a Binary system, binary brown dwarf, brown-dwarf system in the southern constellation Vela (constellation), Vela at a distance of from the Sun. These are th ...

, and the fourth-closest stellar system,

WISE 0855−0714 WISE 0855−0714 (full designation WISE J085510.83−071442.5, or W0855 for short) is a sub-brown dwarf of Y dwarf, spectral class Y4, located from the Sun in the constellation Hydra (constellation), Hydra. It is the fourth-List of ne ...

,Credit: weareCentralPA.com, to the Sun. Both systems are composed of substellar objects (objects less massive than stars), falling into the category of

brown dwarf Brown dwarfs are substellar objects that have more mass than the biggest gas giant planets, but less than the least massive main sequence, main-sequence stars. Their mass is approximately 13 to 80 Jupiter mass, times that of Jupiter ()not big en ...

s (Luhman 16) or even less massive objects (WISE 0855−0714) which are categorized as

sub-brown dwarf A sub-brown dwarf or planetary-mass brown dwarf is an astronomical object that formed in the same manner as stars and brown dwarfs (i.e. through the collapse of a gas cloud) but that has a planetary mass, therefore by definition below the limi ...

s but also referred to as "free floating planets" or "planetary mass objects". WISE 0855−0714 (discovery published 2014) is the coldest massive object outside the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Sola ...

that has been directly imaged. Luhman 16 was named for its discoverer, following common practice for very nearby stars discovered in modern times. These discoveries were made through analysis of mid-infrared data from the WISE satellite, a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

mission that mapped the entire sky and detected several hundred million stars. The satellite mapped the entire sky twice between January 2010 and January 2011, thereby providing two sets of images and coordinates for every star. The motions of the nearest stars over the six-month interval between the two sets of observations were measurable, enabling the discovery of these new objects. Luhman graduated from the University of Texas with a B.A. in astronomy and a B.S. in physics in 1993.Eberly College of Science, Department of Astronomy & Astrophysics, Penn State University, http://www.astro.psu.edu/people/kll207 He earned his Ph.D. in astronomy from the University of Arizona in 1998.

References

21st-century American astronomers Pennsylvania State University faculty Living people Year of birth missing (living people) Place of birth missing (living people) {{US-astronomer-stub