Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.apo.nmsu.edu/35m_operations/35m_manual/General_Information/Standards/Echelle/Standard_Stars_For_ARCES.html
Дата изменения: Wed Apr 30 00:26:18 2008
Дата индексирования: Sun Apr 10 10:15:24 2016
Кодировка:
Standard Stars For ARCES

Spectrophotometric Standard Stars For Use With The ARC Echelle Spectrograph (ARCES)

Last updated 5 November 2003 by JMD

Last link checked 9 October 2003 by JCB


Data from 191 observations of stars with the ARCES were analyzed to calculate exposure times to reach particular signal-to-noise values for bright standard stars. The S/N ratio was normalized in each case by the exposure time, and plotted against the V magnitude of the stars observed; data are shown below:

An exponential fit to the data shows pretty good agreement and allows for forecasting to fainter stars beyond the limit of the data set (V ~ 12). The fit was used to calculate the exposure times in the table below:

All times are given in seconds.


Questions? Comments? Complaints? Email John Barentine at jcb/apo.nmsu.edu