Nonstationarity of the α CYG atmosphere: IV. Some peculiarities of time variation in line profiles

Details Nonstationarity of the α CYG atmosphere: IV. Some peculiarities of time variation in line profiles Nonstationarity of the α CYG atmosphere: IV. Some peculiarities of time variation in line profiles

Jan 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010astbu..65...26r&link_type=abstract

Astrophysical Bulletin, Volume 65, Issue 1, pp.26-33

Astronomy and Astrophysics

Astrophysics

1

Scientific paper

We use 240 CCD spectra taken in 1998-2000 with the coude echelle spectrograph of the 2-m telescope of the National Academy of Sciences of Azerbaijan to study temporal radial velocity and line profile variations of the ion, HeI, and H β lines in the spectrumof the α Cyg supergiant. We demonstrate that these variations are caused by pulsation-type motions in the star’s atmosphere. Ion and HeI lines oscillate in the main fundamental mode with a period of about 12.0 ± 0.5 d and an amplitude of 5.0 ± 0.5 km/s. These ion-line oscillations continue for about 35 days. Then the difference between the radial velocities of strong and weak ion lines results in a gradual decay of oscillations over a time interval of about 5.0 ± 1.0 d . Thereafter the process repeats itself. For the H β line we found two significant periods, two amplitudes, and three characteristic radial velocity variability behaviors for the blue and red halves of the absorption profile: with equal variability parameters (period P and amplitude A); with equal P and A, but with a phase shift between the radial velocity variations of the blue and red halves of the absorption profile; with different P and A for the two halves of the absorption profile. The star’s center of mass radial velocity as inferred from the γ-velocity is -4.5 ± 0.5 km/s. The average expansion velocity of the atmospheric layers, where the H β line forms, amounts to about -16.5 ± 0.5 km/s and varies temporally with an amplitude of about 3.0 km/s.

Affiliated with

Also associated with

No associations

Rating

Nonstationarity of the α CYG atmosphere: IV. Some peculiarities of time variation in line profiles 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 Nonstationarity of the α CYG atmosphere: IV. Some peculiarities of time variation in line profiles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonstationarity of the α CYG atmosphere: IV. Some peculiarities of time variation in line profiles will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1439977