IRC +10216

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**CW Leonis**
Observation data Epoch J2000
Constellation (pronunciation)	Leo
Right ascension	09h 47m 57.38s
Declination	+13° 16' 43.6"'
Apparent magnitude (V)	11.0
Characteristics
Spectral type	C
U-B color index	?
B-V color index	?
Variable type	None
Astrometry
Absolute magnitude (M_V)	?
Distance	650 Ly
Details
Mass	1.5-4 M_☉
Radius	250 R_☉
Luminosity	20.000 L_☉
Temperature	2.300 K
Metallicity	?
Rotation	?
Age	10.000 - 30.000 years
Other designations
CGCS 2619, NAME PEANUT NEBULA, V* CW Leo,PK 221+45 1, Zel 0945+135, RAFGL 1381, 2MASS J09475740+1316435, SCM 50.

IRC +10216 or CW Leonis is the brightest and best studied carbon star, but also a very peculiar one with the central star being embedded in a thick dust envelope. Therefore, its energy is emitted mostly at infrared wavelengths: in fact, IRC +10216 is the brightest object in the sky at a wavelength of 10 μm. Recent speckle observations (Weigelt et al. 1998 A&A,333,51, Haniff and Buscher 1998 A&A,334,5) are beginning to show the complex structure of the dust envelope.

CW Leonis is believed to be in a late stage of its life, blowing off its own sooty atmosphere to form a white dwarf in a distant future. Various chemical elements and molecules have been detected in the outflows from CW Leonis, among others nitrogen, oxygen and water, silicon and iron.