HD 148937

Based on parallax measurements, it is located at a distance of approximately 3,900 light years from Sun,[1] but is drifting closer with a radial velocity of about −54 km/s.

[12] However, the apparent brightness of HD 148937 is brighter than any other nucleus for a nebula of this class, and the spectra of the star raised questions about their evolutionary status.

[12] A very luminous absolute visual magnitude of −6 was confirmed for the central star in 1972, which demonstrated that the surroundings are not a planetary nebula.

Radial velocity measurements made during this period suggest that this is a double-lined spectroscopic binary system of high mass stars.

This younger star may have been formed by a merger with a third member of the system, an event that can explain both the magnetic field and the surrounding nebula.