Sökning: "substellar"

Hittade 3 avhandlingar innehållade ordet substellar.

1. 1. Characterising Emblematic Binaries at the Lowest Stellar and Substellar Masses

   Författare :Per Calissendorff; Markus Janson; Koraljka Mužić; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; astrometry; binaries; brown dwarfs; low-mass stars; multiplicity; substellar; Astronomy; astronomi;

   Sammanfattning : Stars are involved in most research fields of astronomy, ranging from studies of faraway galaxies, exploding supernovae, to more nearby exoplanets and even our own Sun. As such, it is paramount that our physical interpretation of stars is accurate. LÄS MER

3. 2. High-contrast imaging of faint substellar companions and debris disks

   Författare :Rubén Asensio Torres; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; astronomi;

   Sammanfattning : Star formation results in the accumulation of circumstellar material orbiting around their host stars, such as debris disks and planetary-mass objects. A relatively modern technique that has shown to be very valu- able for studying these faint companions is high-contrast imaging, which allows to distinguish the light emitted or scattered off these objects, otherwise hidden behind the brighter stellar halo. LÄS MER

4. 3. The faintest stars : A study of white, red and brown dwarfs

   Författare :Leif Festin; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; brown dwarfs; white dwarfs; M dwarf; low luminosity; luminosity function; mass function; Pleiades; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; astronomi; Astronomy;

   Sammanfattning : The local space density of the faintest stars, including M dwarfs, white dwarfs and brown dwarfs has been studied by two different methods.By using dark nebulae as opaque outer screens, the luminosity functions of M dwarfs and white dwarfs were studied as volume-limited and dynamically unbiassed foreground samples. LÄS MER