Resumen
We undertook two time-series photometric multisite campaigns for the rapidly oscillating Ap star HD 122970. The first one, conducted in 1998, resulted in 119 h of data and in the detection of three pulsation frequencies. The presence of possible further modes which held the promise of deriving a mode identification motivated a second worldwide campaign in the year 2001. This second campaign resulted in 203 h of measurement, but did not reveal further modes. Rather, one of the previously detected signals disappeared. The two modes common to both data sets have different spherical degree. They also showed slight frequency modulation, and one of them varied in amplitude as well. Possible causes of the latter behaviour include intrinsic instability of the pulsation spectrum or precession of the pulsational axis and orbital motion in a binary system. Frequency analysis of the Hipparcos observations of the star did not allow us to determine the stellar rotation period. The amplitude and phase behaviour of the two modes of HD 122970 in the Strömgren uvby bands is quite similar to that observed for other roAp stars.
| Idioma original | English |
|---|---|
| Páginas (desde-hasta) | 153-159 |
| Número de páginas | 7 |
| Publicación | Monthly Notices of the Royal Astronomical Society |
| Volumen | 330 |
| N.º | 1 |
| DOI | |
| Estado | Published - 11 feb 2002 |
Huella dactilar
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
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The pulsational behaviour of the rapidly oscillating Ap star HD 122970 during two photometric multisite campaigns. / Handler, G.; Weiss, W. W.; Paunzen, E.; Shobbrook, R. R.; Garrido, R.; Guzik, J. A.; Hempel, A.; Moalusi, M. B.; Beach, T. E.; Medupe, R.; Chagnon, F.; Matthews, J. M.; Reegen, P.; Granzer, T.
En: Monthly Notices of the Royal Astronomical Society, Vol. 330, N.º 1, 11.02.2002, p. 153-159.Resultado de la investigación: Article
TY - JOUR
T1 - The pulsational behaviour of the rapidly oscillating Ap star HD 122970 during two photometric multisite campaigns
AU - Handler, G.
AU - Weiss, W. W.
AU - Paunzen, E.
AU - Shobbrook, R. R.
AU - Garrido, R.
AU - Guzik, J. A.
AU - Hempel, A.
AU - Moalusi, M. B.
AU - Beach, T. E.
AU - Medupe, R.
AU - Chagnon, F.
AU - Matthews, J. M.
AU - Reegen, P.
AU - Granzer, T.
PY - 2002/2/11
Y1 - 2002/2/11
N2 - We undertook two time-series photometric multisite campaigns for the rapidly oscillating Ap star HD 122970. The first one, conducted in 1998, resulted in 119 h of data and in the detection of three pulsation frequencies. The presence of possible further modes which held the promise of deriving a mode identification motivated a second worldwide campaign in the year 2001. This second campaign resulted in 203 h of measurement, but did not reveal further modes. Rather, one of the previously detected signals disappeared. The two modes common to both data sets have different spherical degree. They also showed slight frequency modulation, and one of them varied in amplitude as well. Possible causes of the latter behaviour include intrinsic instability of the pulsation spectrum or precession of the pulsational axis and orbital motion in a binary system. Frequency analysis of the Hipparcos observations of the star did not allow us to determine the stellar rotation period. The amplitude and phase behaviour of the two modes of HD 122970 in the Strömgren uvby bands is quite similar to that observed for other roAp stars.
AB - We undertook two time-series photometric multisite campaigns for the rapidly oscillating Ap star HD 122970. The first one, conducted in 1998, resulted in 119 h of data and in the detection of three pulsation frequencies. The presence of possible further modes which held the promise of deriving a mode identification motivated a second worldwide campaign in the year 2001. This second campaign resulted in 203 h of measurement, but did not reveal further modes. Rather, one of the previously detected signals disappeared. The two modes common to both data sets have different spherical degree. They also showed slight frequency modulation, and one of them varied in amplitude as well. Possible causes of the latter behaviour include intrinsic instability of the pulsation spectrum or precession of the pulsational axis and orbital motion in a binary system. Frequency analysis of the Hipparcos observations of the star did not allow us to determine the stellar rotation period. The amplitude and phase behaviour of the two modes of HD 122970 in the Strömgren uvby bands is quite similar to that observed for other roAp stars.
KW - Stars: individual: HD 122970
KW - Stars: oscillations
KW - Stars: variables: other
KW - Techniques: photometric
UR - http://www.scopus.com/inward/record.url?scp=19044369808&partnerID=8YFLogxK
U2 - 10.1046/j.1365-8711.2002.05056.x
DO - 10.1046/j.1365-8711.2002.05056.x
M3 - Article
AN - SCOPUS:19044369808
VL - 330
SP - 153
EP - 159
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 1
ER -