Discovery of magnetic field variations with the 12.1-minute pulsation period of the roAp star gamma Equulei

Details Discovery of magnetic field variations with the 12.1-minute pulsation period of the roAp star gamma Equulei Discovery of magnetic field variations with the 12.1-minute pulsation period of the roAp star gamma Equulei

Aug 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003a%26a...407l..67l&link_type=abstract

Astronomy and Astrophysics, v.407, p.L67-L71 (2003)

Astronomy and Astrophysics

Astrophysics

22

Stars: Magnetic Fields, Stars: Chemically Peculiar, Stars: Oscillations, Stars: Individual: Hd 201601

Scientific paper

We have discovered the first magnetic field variations over the pulsation period in an roAp star. The amplitude of the magnetic variability we have found is significant at the 4.1- to 6.6 sigma level measured for four strong lines of NdIII for gamma Equ with the highest amplitude found being 240 +/- 37 G for the lambda 5845.07 Å line, with a period of 12.1 min. This magnetic field variation is in good agreement with theoretical expectations, and the period agrees well with the known photometric periods. We have also found that the time of most negative effective magnetic field occurs 0.15 +/- 0.05 cycles prior to maximum pulsation velocity of recession. There is a small but significant variation in the equivalent width of two of the NdIII lines, but no equivalent width variation is detectable for the other two lines. Measurements of four lines of CaI show no variations at all in equivalent width, radial velocity or effective magnetic field strength. We find a difference in the mean effective magnetic field strength of four NdIII lines and four CaI lines and speculate that this could be a real effect caused by the surface concentration of NdIII towards the magnetic pole. If true, this provides a new way to map the horizontal abundance distribution of elements in slowly rotating Ap stars for which Doppler imaging is not possible.

Affiliated with

Also associated with

No associations

Rating

Discovery of magnetic field variations with the 12.1-minute pulsation period of the roAp star gamma Equulei 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 Discovery of magnetic field variations with the 12.1-minute pulsation period of the roAp star gamma Equulei, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Discovery of magnetic field variations with the 12.1-minute pulsation period of the roAp star gamma Equulei will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1662947