CP Puppis (or Nova Puppis 1942) was a bright nova occurring in the constellation Puppis in 1942. The nova was discovered on 9 November 1942 by Bernhard Dawson at La Plata, Argentina, when it had an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...

of about 2. It was independently discovered at 18:00 10 November 1942 (UT) by a 19-year-old Japanese schoolgirl, Kuniko Sofue, who looked at the sky after patching her socks and noticed the nova. For this discovery, asteroid 7189 Kuniko was named in her honor. From a 17th magnitude star, it reached an apparent visual magnitude of –0.2 then began a rapid decline. It had dropped by three magnitudes in an interval of 6.5 days, one of the sharpest declines ever noted for a nova. About 14 years later, the shell ejected by the nova event was detected, which allowed the distance to be computed. In 2000, this distance was revised to after correcting for probable errors. The

Gaia spacecraft ''Gaia'' is a space observatory of the European Space Agency (ESA), launched in 2013 and expected to operate until 2025. The spacecraft is designed for astrometry: measuring the positions, distances and motions of stars with unprecedented preci ...

later measured the parallax of the star leading to an accurate distance of parsecs. The nova outburst can be explained by a

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes ...

that is accreting matter from a companion; most likely a low-mass main sequence star. This close binary system has an orbital period of 1.47 hours, which is one of the shortest periods of the known classical nova. Unusually, the white dwarf may have a magnetic field. Other properties of the system remain uncertain, although observations of X-ray emission from the system suggest that the white dwarf has a mass of more than 1.1 times the mass of the Sun.

References

External links

S.Balman,M.Orio,H.Ögelman - copyright the American Astronomical Society
retrieved 21/09/2011
B.Warner,Department of Astronomy,University of Cape Town
retrieved 21/09/2011 * https://web.archive.org/web/20051026122516/http://www.otticademaria.it/astro/Costellazioni/st_pup.html {{DEFAULTSORT:CP Puppis Novae Puppis 1942 in science Puppis, CP