The Pure Dipole Pulsation Mode of the Rapidly Oscillating Ap-Star Alpha-Circini - Determination of the Rotation Period and Evidence for Frequency Variability

Details The Pure Dipole Pulsation Mode of the Rapidly Oscillating Ap-Star Alpha-Circini - Determination of the Rotation Period and Evidence for Frequency Variability The Pure Dipole Pulsation Mode of the Rapidly Oscillating Ap-Star Alpha-Circini - Determination of the Rotation Period and Evidence for Frequency Variability

Oct 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994mnras.270..674k&link_type=abstract

Monthly Notices of the Royal Astronomical Society, Vol. 270, NO. 3/OCT1, P. 674, 1994

Mathematics

Logic

38

Scientific paper

New, multisite observations of the rapidly oscillating Ap star a Cir (HR 5463, HD 128898) show that its principal pulsation mode is a pure oblique dipole mode with a frequency of 2442 Hz. A rotationally split triplet shows the rotation period to beProt = 4.463 * 0.010 d. Reanalysis of Johnson B data spanning the years 1981 to 1993 refines the rotation period to rot = 4.4790 t 0.0001 d. Four low-amplitude secondary frequencies are present, with separations that are multiples of 25 Hz. From this we suggest that Av0 =50 Hz. The asteroseismological luminosity inferred from this agrees with the luminosity determined independently from the parallax. The principal frequency in a Cir is variable. The available data suggest that this variability is cyclic on a time-scale of hundreds of days. Cyclic frequency variability appears to be the norm in rapidly oscillating Ap stars; since binary motion can be ruled out in some cases, and shown to be extremely unlikely in other cases, this frequency variability is intrinsic to these stars. Key words: stars: activity - stars: chemically peculiar - stars: individual: a Cir - stars: oscillations - stars: rotation - stars: variables: other.

Affiliated with

Also associated with

No associations

Rating

The Pure Dipole Pulsation Mode of the Rapidly Oscillating Ap-Star Alpha-Circini - Determination of the Rotation Period and Evidence for Frequency Variability 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 Pure Dipole Pulsation Mode of the Rapidly Oscillating Ap-Star Alpha-Circini - Determination of the Rotation Period and Evidence for Frequency Variability, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Pure Dipole Pulsation Mode of the Rapidly Oscillating Ap-Star Alpha-Circini - Determination of the Rotation Period and Evidence for Frequency Variability will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1072150