Observations of the exciting stars of NGC 2023 and M 43 - Interstellar extinction.
Abstract
Both low and high resolution International Ultraviolet Explorer (IUE) observations of the exciting stars of two nebulosities in Orion, NGC 2023 (HD 37903) and M43 (HD 37061) are discussed. Comparison with Astronomical Netherlands Satellite (ANS) observations shows that, in the 2.5 min X 2.5 min ANS field of view, a substantial nebular contribution is included. The extinction curve for HD 37903 is smilar to that of the inner region of the rho Oph cloud whereas for HD 37061 it is even lower throughout UV with the normalized extinction at 2200 being only 3.8. It appears that the ratio of small aperture to large aperture data is not wavelength independent in the long wavelength range. From the high resolution observations it seems that carbon may be less and oxygen may be more under/abundant in these directions.
- Publication:
-
Ultraviolet observations of Quasars
- Pub Date:
- April 1980
- Bibcode:
- 1980ESASP.157...19G
- Keywords:
-
- Astronomy;
- Interstellar Extinction;
- Iue;
- Nebulae;
- Orion Constellation;
- Ultraviolet Astronomy;
- Abundance;
- Astronomical Netherlands Satellite;
- Carbon;
- Oxygen;
- Silicon