The Faintest Stars: From Schmidt Plates to Luminosity Functions
Abstract
We describe the construction of a photometric catalog from scans of IIIaF and IVN plate material in 11 fields of the UKSRC and POSSII surveys. The procedures used and quality checks applied are described in detail, and should be considered as illustrative for those planning scientific programs with the forthcoming scans of these surveys. We find our plate material is complete to I of about 18 and R of about 20.5 with photometric uncertainties of +/- 0.20 and +/- 0.25 magnitudes (respectively) at those limits. These data are used to construct luminosity functions for stars within 150 pc of the sun in four distinct directions. We find no significant evidence for variations in the form of the luminosity function in different locations within the Galactic disk. Approximately 10-20 percent variations are seen in the normalization of the luminosity function.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1993
- DOI:
- 10.1086/173074
- Bibcode:
- 1993ApJ...414..254T
- Keywords:
-
- Astronomical Photometry;
- Brown Dwarf Stars;
- Photographic Plates;
- Stellar Luminosity;
- Stellar Mass;
- Astronomical Catalogs;
- Milky Way Galaxy;
- Sky Surveys (Astronomy);
- Stellar Magnitude;
- Astronomy;
- STARS: LOW-MASS;
- BROWN DWARFS;
- STARS: LUMINOSITY FUNCTION;
- MASS FUNCTION;
- SURVEYS