... Stellar Evolution is driven entirely by the never ending battle between Pressure and Gravity . As imbalances are reached, the star is driven to find a new Energy source. ... Pressure and gravitational forces are equal, the star is stable and its core is sufficiently hot to fuse Hydrogen into Helium More about main sequence stars . ... The luminosity generated by the core fusion of Helium into Carbon is far greater than the shell luminosity associated with the fusion of Hydrogen into Helium. ...

The pipeline calibrated data are not flux calibrated and the data are in units of Data Numbers (DN). However, a flux calibration is supplied in the header keywords. ... where m is in the STMAG system which is based on a spectrum with constant flux per unit wavelength set to roughly match the Johnson system at V. The more conventional systems are based on Vega's spectrum. Table 8.1 was generated using SYNPHOT to provide rough conversions from STMAG to the Johnson UBVRI and Cousins RI systems. ...

... The first step to improve the FORS calibration is therefore to obtain data to allow a computation of the illumination correction across the field. ... Another limitation on the calibration accuracy has been the brightness of the Landolt standards which have forced the use of extremely short exposures introducing small but non-negligible shutter-time errors and also resulting in a very small number of useful standards per frame. ...

Next: GRISMCAL Up: COLORTRANS Previous: Generation from Ground Calibration Contents . The transformations from the OM instrumental system to the standard Johnson's system were established based on in-flight observations. ... We have derived the flux conversion factors from OM observations of seven spectrophotometric standard stars (white dwarfs: Hz4, GD50, GD153, LBB227, BPM16274, Hz2 and G93-48). ...

... The New 1997 IEEE Standards Products Catalog features the complete listing of standards publica-tions and services IEEE Standards offers, along with the information you need to place your order. ... Books and Other Products on Standards - contains a detailed listing of informative print and electronic publications relevant to standards and their implementation in areas of electrical engineering, electronics and computer technology. ... IEEE Standards Products Listing 22 . ... Power Electronics 41 . ...