WR 104

WR 104 is a Wolf-Rayet star that is part of a double or triple star that includes a B-type close companion which is near a more distant A-type star that is also possibly a companion. WR 104 is of interest as an example of a pin-wheel nebula, a cloud that twirls around the star in sync with the orbit of its close companion. Characteristics of the system:

• Sagittarius - constellation.
• 18h02m04.07s - right ascension.
• -23deg37m41.2s - declination.
• +13.28 - apparent magnitude.
• 2580 pc - distance.
• 120,000 - luminosity(solar).

WR 104 specific characteristics:

• WC9d - spectral type.
• ~10 - mass(solar).
• ~3.3 - radius(solar).
• 40,000 - luminosity(solar).

The close companion has spectral type B0.5V.

The star made some news when analysis suggested it could supernova such as to send a dangerous gamma-ray burst (GRB) toward Earth.