| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Leo (constellation) |
| Right ascension | 09h 47m 57.406s[1] |
| Declination | +13° 16′ 43.56″[1] |
| Characteristics | |
| Spectral type | C |
| Apparent magnitude (R) | 10.96[1] |
| Apparent magnitude (J) | 7.34[1] |
| Apparent magnitude (H) | 4.04[1] |
| Apparent magnitude (K) | 1.19[1] |
| Astrometry | |
| Distance | 390–490[2] ly (120–150 pc) |
| Details | |
| Mass | 1.5-4 M☉ |
| Radius | 250 R☉ |
| Luminosity | 20,000 L☉ |
| Temperature | 2,300 K |
| Age | 10,000 - 30,000 years |
| Other designations | |
IRC +10216 or CW Leonis is a well-studied carbon star that is embedded in a thick dust envelope. It was first discovered in 1969 by a group of astronomers led by Eric Becklin, based upon infrared observations made with the 62 inches (1.6 m) Caltech Infrared Telescope at Mount Wilson Observatory. Its energy is emitted mostly at infrared wavelengths. At a wavelength of 5 μm, it was found to have the highest flux of any object outside the Solar System.[4]
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. Based upon isotope ratios of magnesium, the initial mass of this star has been constrained to lie between 3–5 solar masses. The mass of the star's core, and the final mass of the star once it becomes a white dwarf, is about 0.7–0.9 solar masses.[5]
The gaseous envelope surrounding this star is at least 69,000 years old and is losing about 2 × 10−5 solar masses per year. The envelope contains at least 1.4 solar masses.[2] 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. Various chemical elements and molecules have been detected in the outflows from CW Leonis, among others nitrogen, oxygen and water, silicon and iron.
If the distance to this star is assumed to be at the lower end of the estimate range, 120 pc, then the astrosphere surrounding the star spans a radius of about 84,000 AU. The star and its surrounding envelope are advancing at a velocity of more than 91 km/s through the surrounding interstellar medium.[2] It is moving with a space velocity of [U, V, W] = [21.6 ± 3.9, 12.6 ± 3.5, 1.8 ± 3.3] km s−1.[5]
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