'Y Dwarf Chillin' in Space

Wise_wise2011-ydwarf-a_500

WISE_WISE2011-ydwarf-a August 23rd, 2011

Credit: NASA/JPL-Caltech/R. Hurt (SSC)

This artist's conception illustrates what a "Y dwarf" might look like. Y dwarfs are the coldest star-like bodies known, with temperatures that can be even cooler than the human body. NASA's Wide-field Infrared Survey Explorer uncovered these elusive objects for the first time, using its heat-sensing, infrared vision. The telescope found six Y dwarfs, ranging in atmospheric temperatures from 350 degrees Fahrenheit (175 degrees Celsius) to less than about 80 degrees Fahrenheit (25 degrees Celsius).

Y dwarfs belong to a larger family of objects called brown dwarfs. Brown dwarfs begin their lives like stars but they never accumulate enough mass to fuse atoms steadily at their cores and shine with starlight -- as our sun does so well. Instead, they fade and cool with time, giving off most of their light in infrared wavelengths.

WISE was able to pick up this faint glow for six Y dwarfs, which are the coldest class of brown dwarfs and the latest letter in the stellar classification scheme. This scheme describes stars of all temperatures, beginning with the hottest "O" stars and now ending with the coldest Y dwarfs. The entire scheme includes the classes: O, B, A, F, G, K, M, L, T, Y. Our yellow sun belongs to the G class of stars. M stars are colder than our sun, and reddish in color.

While the O through K classes are all considered stars, M and L objects are a mixture of stars and brown dwarfs, and T and Y objects are all brown dwarfs. The term "brown dwarfs" was chosen because at that time, astronomers didnt know what colors these objects would actually have at the visible wavelengths our eyes see, and brown is not a true color of light (there are no "brown photons"). Astronomers now know that T dwarfs would appear reddish, or magenta, to the eye. But they are not certain what color Y dwarfs are, since these objects have not been detected at visible wavelengths. The purple color shown here was chosen mainly for artistic reasons. In addition, the Y dwarf is illustrated as reflecting a faint amount of visible starlight from interstellar space.

Image Credit: NASA/JPL-Caltech/UCLA/WISE Team

Image Source: /image/WISE/WISE2011-ydwarf-a

Curator: Wide-field Infrared Survey Explorer, Berkeley, CA, USA

Image Use Policy: Pulic Domain

Image Details

Image Type
Artwork
Object Name
Y dwarf
Subject - Milky Way
Star » Type » Brown Dwarf
Wise_wise2011-ydwarf-a_1280
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ID
WISE2011-ydwarf-a
Subject Category
B.3.2.3  
Subject Name
Y dwarf
Credits
NASA/JPL-Caltech/R. Hurt (SSC)
Lightyears
Redshift
Reference Url
/image/WISE/WISE2011-ydwarf-a
Type
Artwork
Image Quality
Good
Distance Notes
Facility
Instrument
Color Assignment
Band
Bandpass
Central Wavelength
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
Equinox
Reference Value
Reference Dimension
Reference Pixel
Scale
Rotation
Coordinate System Projection:
Quality
FITS Header
Notes
Creator (Curator)
Wide-field Infrared Survey Explorer
URL
http://wise.astro.ucla.edu
Name
Email
outreach@ssl.berkeley.edu
Telephone
Address
7 Gauss Way
City
Berkeley
State/Province
CA
Postal Code
94720
Country
USA
Rights
Pulic Domain
Publisher
Publisher ID
WISE
Resource ID
Resource URL
/image/WISE/WISE2011-ydwarf-a
Related Resources
Metadata Date
2012-10-10 18:55:02 -0700
Metadata Version
1.2
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Detailed color mapping information coming soon...

 

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There is no distance meta data in this image.