Sökning: "cepheid"

Visar resultat 6 - 7 av 7 uppsatser innehållade ordet cepheid.

1. 6. A kinematic check of the distance scale of Galactic Cepheids

   Kandidat-uppsats, Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation; Lunds universitet/Astronomi - Genomgår omorganisation

   Författare :Brian Thorsbro; [2014]
   Nyckelord :cepheid; period-luminosity relation; distance scale; kinematics; Physics and Astronomy;

   Sammanfattning : A selection of well known period luminosity relations for cepheid variables are studied under the assumption that cepheid variables have a mean vertical velocity of zero in the galactic plane. Proper motion data from Hipparcos and Thyco-2 catalogues are coupled with the distances obtained from applying the period luminosity relations on a database of known classical cepheids to calculate the velocities of the cepheids. LÄS MER

3. 7. Astrophysical validation of Gaia parallaxes

   Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

   Författare :Fredrik Windmark; [2010]
   Nyckelord :Physics and Astronomy;

   Sammanfattning : The Gaia satellite, to be launched in August 2012, will measure highly accurate absolute parallaxes of hundreds of millions of stars. This is done by comparing parallactic displacement of stars in different parts of the sky. LÄS MER