In 1997 February, the second Space Shuttle servicing mission to the Hubble Observatory installed the Space Telescope Imaging Spectrograph (STIS). This new instrument greatly enhances the spectroscopic capabilities of the Hubble Space Telescope by providing a long-slit format and CCD detector technology. STIS can also be used as an imager, providing an alternative to the Wide Field Planetary Camera 2. The optical filter set of STIS is limited and does not contain standard bandpasses, but we show here that this does not preclude useful two-color broadband photometry. Because the STIS bandpasses reach ∼ 1.5 mag deeper than WFPC2, the STIS photometric system may be preferable for many applications where a faint limiting magnitude and fine spatial resolution are overriding considerations. The two optical wideband choices on STIS are a clear aperture and a longpass (λ. > 5500 Å) filter. We define an effective shortpass filter from the difference of these, making two-color photometry possible with STIS. We present preliminary transformations between the STIS system and Kron-Cousins BVRI bandpasses, showing that these transformations are very well behaved over almost all temperatures, luminosities, and abundances for normal stars. In an 8-orbit cycle, STIS will be able to reach signal-to-noise of ∼ 5-10 at V = 30.0 in its clear and longpass imaging modes, a significant increase in the power of HST to address a number of fundamental issues out of reach of current instrumentation capabilities on the ground or in space.
|Número de páginas||6|
|Publicación||Publications of the Astronomical Society of the Pacific|
|Estado||Publicada - sep 1997|
Áreas temáticas de ASJC Scopus
- Ciencias planetarias y espacial
- Astronomía y astrofísica