Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-03-21
Astronomy and Astrophysics
Astrophysics
16 pages, 4 figures, accepted by ApJ
Scientific paper
10.1086/588550
The discovery that Vega is a rapidly rotating pole-on star has raised a number of questions about this fundamental standard, including such issues as its composition, and in turn its mass and age. We report here a reanalysis of Vega's composition. A full spectral synthesis based on the Roche model derived earlier from NPOI interferometry is used. We find the line shapes in Vega's spectrum to be more complex than just flat-bottomed, which have been previously reported; profiles range from slightly self-reversed to simple ``V'' shapes. A high SNR spectrum, obtained by stacking spectra from the ELODIE archive, shows excellent agreement with the calculations, provided we add about 10 km/s of macroturbulence to the predicted spectra. From the abundance analysis, we find that Vega shows the peculiar abundance pattern of a \W Bootis star as previously suggested. We investigate the effects of rotation on the deduced abundances and show that the dominant ionization states are only slightly affected compared to analyses using non-rotating models. We argue that the rapid rotation requires the star be fully mixed. The composition leads to masses and particularly ages that are quite different compared to what are usually assumed.
Armstrong Thomas J.
Pauls Thomas
Peterson Deane M.
Yoon Jinmi
Zagarello Robert J.
No associations
LandOfFree
The effect of rotation on the spectrum of Vega 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 The effect of rotation on the spectrum of Vega, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The effect of rotation on the spectrum of Vega will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-587203