The iron, carbon and nitrogen abundances of the subdwarf Groombridge 1830.

An effective temperature of 5000 K has been determined for the subdwarf Gmb 1830 using spectral scan data. The iron abundance is found to be about 20 X less than that of the Sun, this being a revision of an earlier result (Tomkin). The carbon abundance is about 25>( less than the solar value. The weak features of the violet (o, o) band of CN have been used to estimate the nitrogen abundance. This has been done by comparing the actual spectrum with synthetic spectra that have been computed for various nitrogen abundances. The comparison shows that nitrogen is about 5 x more deficient than iron.