4 research outputs found
A Search for Doradus-Type Variable Stars in the Hyades
Doradus stars are photometrically variable early F-type stars on or
just above the main sequence in the Hertzsprung-Russell Diagram. They vary by
as much as 0.1 mag on time scales an order of magnitude slower than the
fundamental radial pulsation period. These brightness variations are presumably
due to non-radial gravity-mode pulsations. We obtained high precision -band
photometry of 8 F0 to F5 stars in the Hyades (BS 1319, BS 1354, BS 1385, BS
1408, BS 1430, BS 1432, BS 1459, and BS 1472) and found that none of them
showed strong evidence of Dor-type variability. Since
Dor-type candidates are found in the Pleiades and in NGC 2516 (having ages of
78 and 137 Myr, repectively) but apparently not in the Hyades (age 600
Myr), we hypothesize that the Dor phenomenon is a characteristic of
relatively young F stars.
Two of the stars investigated showed marginal evidence of low-amplitude
variability. The 3 mmag variability of the F5 star BS 1319 is most likely
due to rotational modulation of star spots, though it is not impossible that it
is a Dor star. Another F5 star BS 1459 ( mmag) has a
possible period similar to Scuti stars, but no firm conclusions should
be made concerning its behavior unless and until its variability is confirmed.Comment: 8 pages, Latex, uses MN.STY, 6 figures, available via Fax or regular
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