Star Is Discovered To Be a Close Neighbor of the Sun and the Coldest of Its Kind


April 25, 2014
Space

A “brown dwarf” star that appears to be the coldest of its kind — as frosty as Earth’s North Pole — has been discovered by a Penn State University astronomer using NASA’s Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescopes. Images from the space telescopes also pinpointed the object’s distance at 7.2 light-years away, making it the fourth closest system to our Sun.

“It is very exciting to discover a new neighbor of our solar system that is so close,” said Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State and a researcher in the Penn State Center for Exoplanets and Habitable Worlds. “In addition, its extreme temperature should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures.”

Brown dwarfs start their lives like stars, as collapsing balls of gas, but they lack the mass to burn nuclear fuel and radiate starlight. The newfound coldest brown dwarf, named WISE J085510.83-071442.5, has a chilly temperature between minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius). Previous record holders for coldest brown dwarfs, also found by WISE and Spitzer, were about room temperature.

Although it is very close to our solar system, WISE J085510.83-071442.5 is not an appealing destination for human space travel in the distant future. “Any planets that might orbit it would be much too cold to support life as we know it” Luhman said.

“This object appeared to move really fast in the WISE data,” said Luhman. “That told us it was something special.” The closer a body, the more it appears to move in images taken months apart. Airplanes are a good example of this effect: a closer, low-flying plane will appear to fly overhead more rapidly than a high-flying one.

WISE was able to spot the rare object because it surveyed the entire sky twice in infrared light, observing some areas up to three times. Cool objects like brown dwarfs can be invisible when viewed by visible-light telescopes, but their thermal glow — even if feeble — stands out in infrared light.

After noticing the fast motion of WISE J085510.83-071442.5 in March, 2013, Luhman spent time analyzing additional images taken with Spitzer and the Gemini South telescope on Cerro Pachon in Chile. Spitzer’s infrared observations helped to determine the frosty temperature of the brown dwarf.

WISE J085510.83-071442.5 is estimated to be 3 to 10 times the mass of Jupiter. With such a low mass, it could be a gas giant similar to Jupiter that was ejected from its star system. But scientists estimate it is probably a brown dwarf rather than a planet since brown dwarfs are known to be fairly common. If so, it is one of the least massive brown dwarfs known.

Combined detections from WISE and Spitzer, taken from different positions around the Sun, enabled the measurement of its distance through the parallax effect. This is the same principle that explains why your finger, when held out right in front of you, appears to jump from side to side when you alternate left-eye and right-eye views.

In March of 2013, Luhman’s analysis of the images from WISE uncovered a pair of much warmer brown dwarfs at a distance of 6.5 light years, making that system the third closest to the Sun. His search for rapidly moving bodies also demonstrated that the outer solar system probably does not contain a large, undiscovered planet, which has been referred to as “Planet X” or “Nemesis.”

“It is remarkable that even after many decades of studying the sky, we still do not have a complete inventory of the Sun’s nearest neighbors,” said Michael Werner, the project scientist for Spitzer at NASA’s Jet Propulsion Laboratory (JPL), which manages and operates Spitzer. “This exciting new result demonstrates the power of exploring the universe using new tools, such as the infrared eyes of WISE and Spitzer.”




 Star Is Discovered To Be a Close Neighbor of the Sun and the Coldest of Its Kind

5 Responses to Star Is Discovered To Be a Close Neighbor of the Sun and the Coldest of Its Kind

  1. u14182182 May 3, 2014 at 1:01 pm #

    it very fascinating that we human being we know what is happening around the solar system. Because this information we have really make a clear picture and understanding of the universe. Research states that older brown dwarfs are sometimes cool enough that, over very long period of time, their atmospheres can gather observable quantities of methane. Dwarfs confirmed in this fashion include Gliese 229B. Main-sequence stars cool, but eventually a minimum bolometric luminosity that they can sustain through steady fusion. This varies from star to star.

    another interesting information is that many brown dwarfs undergo no fusion; those at the low end of the mass range 13 Jupiter masses are never hot enough to fuse even deuterium, and even those at the high end of the mass range ( over 60 Jupiter masses) cool quickly enough that they nolonger undergo fusion after a period of time on the order of 10 million years.

  2. u14182182 May 3, 2014 at 11:42 am #

    it very fascinating that we human being we know what is happening around the solar system. Because this information we have really make a clear picture and understanding of the universe especially the use of

  3. L Vorster (12089304) May 2, 2014 at 3:47 am #

    Even though it is always exciting to hear and read about new findings in outer space, I have to agree with Favian about the uneasiness felt about this new discovery. Apart from the information given I did a little research myself and found several articles about Nemesis or the ‘Death Star’, believed to be either a red dwarf or brown dwarf in the Oort Cloud causing a number of comits visiting our solar system with impact events on earth.
    The outer layer of the Oort is loosely bound to the solar system and thus easily affected by gravitational pull by ofpassing stars and of the Milky Way as well. With the newest technology and the use of WISE, astrobiologists can identify if there is a brown dwarf lurking there somewhere, however, I believe that their research is far from over and although they find it exciting I find it somewhat unsettling that there were many brown dwarfs discoverec over the years that’s farther away from our solar system.

    My question is this, how sure are they that these stars are going to stay so far away from us? What will stop them from entering our solar system and creating mass extinction once more on earth?

  4. M Henri Day April 27, 2014 at 12:55 am #

    The fact that «since brown dwarfs are known to be fairly common» hardly suffices to characterise a celestial body with a mass «estimated to be 3 to 10 times the mass of Jupiter» as a brown dwarf. From what I have been led to understand, the lowest limit for brown dwarfs according to the IAU classification is some 13 Jupiter masses, i e, well above the estimated mass of this object. Is there something about, e g, the spectral classification of WISE J085510.83-071442.5 which makes it more reasonable to classify it as a brown dwarf than a so-called «planetary mass object» (other, of course, than the fact that it doesn’t seem to be in orbit around a star or a stellar remnant) ?…

    Henri

  5. Favian(u14016053) April 26, 2014 at 6:14 am #

    It is quite interesting to hear the other day that we as humans know more about the universe than we know about the ocean that surrounds our continents everyday. Why is it though, why have we spent more time learning about what is out beyond us than rather getting to know what is nearest to us?

    A question that has been asked is if brown dwarfs experienced fusion in their life span as a star, due to the fact that in their cores burning nuclear fusion maintains hydrogen on their surface. If the disintegration of stars or rather the imploding of stars often cause black wholes is it “comforting” to know that we have a star as a neighbour.

    Dwarf stars fall with in a range that is placed between the heaviest gas giants (planets not made entirely out of rock but also made out of gas) and the lightest stars due to them not being able to have sustainable hydrogen reactions thanks to these reactions, their original name was called black stars because they were shown as black spots on infrared scanners.

    A very good article though, being able to get information, that for someone like me is quite complicated, out in such a simple and well presented manner.

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