WISE 1541−2250

WISE 1541−2250 (full name WISEPA J154151.66−225025.2) is a brown dwarf of spectral class Y0.5. It is found in the constellation Libra and is about 18.6 light-years from Earth.

A brown dwarf looks like a star but is not big enough to burn energy like our Sun. Instead, it shines because of heat left over from when it formed.

This object got a lot of attention when it was found in 2011. At first, people thought it was only about 9 light-years away, which would have made it the closest brown dwarf known. Later, they found it was a bit farther, but it is still very close to us in space.

Brown dwarfs like WISE 1541−2250 are interesting because they are different from stars and planets. They help scientists learn more about how stars form and what happens when objects are not big enough to become true stars. Other close brown dwarfs include Luhman 16, WISE 1506+7027, Epsilon Indi Ba, Bb, and UGPS 0722-05.

History of observations

WISE 1541−2250 was found in 2011 using data from the Wide-field Infrared Survey Explorer (WISE). WISE took infrared pictures from December 2009 to February 2011. Two teams of scientists wrote about this discovery almost at the same time.

One team, led by Kirkpatrick, said they found 98 brown dwarf systems, including WISE 1541−2250. Another team, led by Cushing, said they found seven brown dwarfs. This included WISE 1541−2250 and the first very cool and faint stars of the Y-type spectral class.

Distance

WISE 1541−2250 is a brown dwarf star about 18.6 light-years from Earth. Scientists found its distance using a method called trigonometric parallax.

When they first found WISE 1541−2250 in 2011, they thought it might be closer — about 9 light-years away. This would have made it the nearest known brown dwarf. But better measurements later showed it is farther away.

Space motion

WISE 1541−2250 moves across the sky quickly. It moves about 899 milliarcseconds each year. This movement is called proper motion. It helps astronomers learn how objects in space move compared to Earth.

Physical properties

WISE 1541−2250 is one of the coldest known brown dwarfs. It is a Y-class object, which are the coolest types of stars. This brown dwarf has a temperature of about 381 K, which is roughly 108 °C or 226 °F.

Scientists think there may be water clouds in its atmosphere, but they are still learning more about what it is made of. Studies using the JWST have found more carbon monoxide and carbon dioxide than expected. The atmosphere seems to have thick clouds, possibly made of different chemicals, but how these clouds form is still a mystery.