UBVRIJH photometry of two new luminous δ Scuti stars and the discovery of δ Scuti pulsation in the most evolved Ap star known

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

9

Techniques: Photometric, Stars: Individual: Hd 199434, Stars: Individual: Hd 21190, Stars: Oscillations, Delta Scuti

Scientific paper

Time-series photometry of the Hipparcos variable stars HD 199434 and 21190 is reported. Both stars are pulsators of the δ Scuti type. Reclassifications of the MK types of the stars, based on new spectrograms, are given. HD 21190 is found to be F2III SrEuSi:, making it the most evolved Ap star known. Its Strömgren photometric indices support the peculiar spectral type. It is also one of the most evolved δ Scuti stars known. Its combined Ap-δ Scuti nature makes it an important test of models of pulsation in peculiar stars recently developed by Turcotte et al., although it is more extreme than any model they examined. Physical parameters of both stars are estimated from Strömgren and Hβ photometry, and Hipparcos absolute magnitudes. We attempt mode identifications based on amplitude ratios and phase differences from our photometry. The dominant pulsation of HD 21190 may be an overtone radial mode. The model fits for HD 199434 are even less satisfactory, but favour an l=2 mode. Given the good quality and wavelength coverage of our data, the poor results from the application of the photometric theory of mode identification may call into question the use of that technique.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

UBVRIJH photometry of two new luminous δ Scuti stars and the discovery of δ Scuti pulsation in the most evolved Ap star known does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with UBVRIJH photometry of two new luminous δ Scuti stars and the discovery of δ Scuti pulsation in the most evolved Ap star known, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and UBVRIJH photometry of two new luminous δ Scuti stars and the discovery of δ Scuti pulsation in the most evolved Ap star known will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1155159

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.