... 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. ...

... Data Handling and Products > Data Reduction FAQ > The spectrum of my MOS flux standard star is shifted in wavelength by several pixels. Why is that and how can I correct for it? ... Observing with ESO Telescopes . ... The shift of the flux standard spectrum is caused by a combination of bad centering within the slit and possible wavelength calibration issues. To align the spectrum to the tabulated flux, use the parameter --resp_shift in vmmosscience when determining the response curve. ...

... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Parkes radio telescope . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... We discuss variations of the atmospheric extinction coefficients and transformation equations to the standard UBVRI system based on observations of standard stars during 1996-1997 at Siding Spring Observatory using a thinned SITe CCD and coloured glass filters. ... Standard System Transformations . ...

... Current APO Weather . ... Search Site . ... Information for New Users . ... Technical Staff pages . Night Logs and Mailing Lists (maintained by APO) . ... Technical Documents and Database Search . ... Observer's Documentation and Procedures . ... Problem Reporting and APO Technical Documents Database Search . ... APO Drawing/Document Management Procedures . ... APO Technical Documents Database Search . Home Astrophysical Research Consortium . ... Mail Lists (maintained by APO) . ...

... We present easy-to-use web applications and XML Web Services to search, plot and manage spectral energy distributions and filter profiles. We provide keyword search, advanced query forms and SQL interfaces to select spectra and band passes that may be retrieved in a variety of formats including XML, VOTable and ASCII. ... We built a relational database of SEDs and implemented effective search algorithms as well as common spectrum and bandpass manipulation functions in the form of XML Web Services. ...