... 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 absolute flux calibration of NICMOS will be calculated from observations of standard stars with known flux distributions F( ). ... In order to expand the set of IR standard stars in the appropriate flux range for NICMOS, M. Rieke, R. Thompson, and collaborators at the University of Arizona are making photometric observations of solar-analog stars, which will be used to normalize the solar spectrum to the observed IR magnitudes. ... Relative flux references accurate to 1.5% for standard...

Next: Examples of Setup Files Up: Setup Files Previous: Setup Files Contents . Over 200 standard setup files have been created, covering many of the normal modes of observing. ... These especially include precisely defined, and somewhat complex cases like the Mark III standard modes (although MarkIII went the way of the dinosaur long ago. ... v '' files: . These are setup files for VLBI observations using VLBA recording formats. ... These are setup files for Mark III observations. ...

Next: Reduction procedure Up: Extinction and transformation Previous: Strategy . Standard stars can be included in the extinction solution, if one is careful. The problem is that there are usually appreciable ``conformity errors'' due to mismatch between the instrumental and the standard passbands [ 16 ]. ... Thus, it is wrong to assume that the transformation between the instrumental system and the standard system is exact, even if there were no measurement error in either system [ 1 ]. ...

... Science Users Information > Data Handling and Products > Data Reduction FAQ > Why are my spectra not flux calibrated, even though there are standard star observations in the data set? ... Observing with ESO Telescopes . ... ESO-MIDAS . ... Data Handling and Products . ... Data Pipelines and Calibrations . ... ESO Data . ... ESO Data Access Policy . ... If there is no reference table for the flux standard star no response curve is created and therefore the science data are not flux-calibrated. ...

Optical and UV Spectrophotometric Standard Stars . ... Two papers detail the observations: the first is devoted to wavelengths from 3300 to 7550A (Hamuy et al., ... -------------------------------------------------------- 718 Xi2 Cet B9 III -O.107 -0.056 4.279 -0.023 -0.063 1544 Pi2 Ori Al V 0.01 4.355 0.014 0.039 3454 Eta Hya B3 V -0.743 -0.200 4.295 -0.083 -0.200 4468 Theta Crt B9.5 V -0.18 -0.07 4.700 -O.023 -0.063 4963 ...

... This routine is designed to read in the current correlator set-up, go to the chosen source, and then take data pointing directly at the specified source. This routine will automatically wait until you are on source before beginning to take data. ... Additionally, this routine allows you to take an ON/OFF calibration pair (one 10s scan with the noise diode on, followed by a 10s scan with the diode off), using the chosen noise diode configuration (see Section 1.6 . ...