They have observed that while the magnitude of the primary minimum stays roughly the same, the magnitude of the secondary minimum varies from year to year, which is believed to be caused by starspot
The lightcurve simulation led to two interesting features being identified; a hotspot and two starspots
Chromospherically active stars with starspots
appear to vary as they rotate;
Steven Vogt, Don Penrod and Artie Hatzes of the University of California at Santa Cruz have developed a method for finding starspots
, cool spots on a star's surface that are similar to sunspots (SN: 7/17/82, p.
The stars seem to become dimmer when their starspots
are on their visible sides.
By comparing these observations, the astronomers figured out that the starspots
were too hot to have any steam.
To measure a star's spin, astronomers look for changes in its brightness caused by dark spots, known as starspots
, crossing the star's surface.
These stars have large starspots
, which are much larger than those of our sun," says astronomer and study coauthor Hiroyuki Maehara.
A sampling of topics: the microstructure of a sunspot penumbra, penumbral moving magnetic features, SOLIS-VSM solar vector magnetograms, multigrid methods for polarized radiative transfer, tunable narrow-band filter for imaging polarimetry, the diffraction limited spectro-polarimeter, a brief overview of the Second Solar Spectrum, polarizability factors for molecular bands, spectro-polarimetry of cool stars, molecular diagnostics of the internal structure of starspots
and sunspots, and the effect of turbulent electric fields on the scattering polarization of hydrogen lines.
To measure a star's spin, astronomers look for changes in its brightness caused by dark spots known as starspots
crossing the star's surface.
Observing as many stars as they can, and continuing to do so, they started to see rotation periods from the periodic brightening and dimming of the stars, as starspots
come in and go out of view.
Some show starspots
, which are similar to sunspots, and a few produce flares that would sterilize their nearest planets.
On this star, a patchy distribution of elements on the surface is apparent, and starspots
can be mapped.
If you have any starspots
or celeb gossip, e-mail angeleyes@ncjmedia.
With a resolving power in the microarcsecond range, it should be able to see stars as disks -- not as shimmering points of light -- and to resolve features such as starspots
on their surfaces.