WR 46
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Crux |
| Right ascension | 12h 05m 18.72s |
| Declination | −62° 03′ 10.1″ |
| Apparent magnitude (V) | 10.8 |
| Characteristics | |
| Spectral type | WN3pe |
| U−B color index | -0.83[1] |
| B−V color index | -0.02[1] |
| Astrometry | |
| Proper motion (μ) | RA: -5.44[1] mas/yr Dec.: 1.84[1] mas/yr |
| Parallax (π) | 2.45[1] mas |
| Distance | 13000 ly (4000 pc) |
| Absolute magnitude (MV) | -4.05 |
| Details | |
| Mass | 18 M☉ |
| Radius | 2.9 R☉ |
| Luminosity | 500000 L☉ |
| Temperature | 90210 K |
| Other designations | |
WR 46 (DI Crucis) is a star in the constellation of the Southern Cross of apparent magnitude +10.8. It is located at 55 arcmin north of Theta2 Crucis . The star is a member of the distant stellar Association OB4 Cru, and is a distant 4000 parsecs or 13,000 light years from the Solar System.
Features
WR 46 is a Wolf-Rayet star of spectral type WN3pe. Its spectrum is characterized by the presence of strong lines of NV and HeII and the absence of hydrogen. Although in the past was considered a bit of low-mass X-ray or a star V Sagittae, today Wolf-Rayet stars' nature is unquestionable.
The physical parameters of WR 46 are all estimates. Has an effective temperature of 90,210 K and a luminosity greater than 500,000 times the solar luminosity. With a mass 18 times that of the Sun, has a radius of 2.9 times the solar radius . The terminal velocity of the stellar wind reaches 2450 km / s, losing mass at a rate 4 × 10 -6 times the solar mass per year.
WR 46 is a known source of X-rays , an aspect that was discovered by the Einstein Observatory . Its X-ray luminosity between 0.2 and 10.0 keV , is 7.7 × October 32 erg / s. Its X-ray spectrum is dominated by a soft component but there was also a hard component above 3 keV, similar to other stars WN.
Binary star
WR 46 is thought to be a binary system , in which an OB type star accompanies the Wolf-Rayet star. Comparing helium lines of WR 46 spectrum with those of WR 152 WN-lone-star has been speculated that the spectral type of the companion is B7V. The orbital period of the system would be 0.3113 days.
Variability
WR 46 exhibits complex variability on relatively short time scales of a few hours. In the past there have been regular but intermittent changes in the radial velocity , multiple periods and photometric . It has been proposed that this short-term behavior is due to pulsations radial not to fast rotational modulation, or is motivated by the presence of a low-mass companion. Also, the study of DI Crucis in the ultraviolet far has revealed significant variations on time scales of about eight hours, it which is also manifested in ultraviolet and X-ray region
References
External links
This article is based on the Spanish version es.wikipedia.org/wiki/DI Crucis
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