The Delta Scuti star 38 Eri from the ground and from space
Por:
Paparo, M., Kollath, Z., Shobbrook, R. R., Matthews, J. M., Antoci, V., Benko, J. M., Park, N. -K., Mirtorabi, M. T., Luedeke, K., Kusakin, A., Bognar, Zs., Sodor, A., Garcia-Hernandez, A., Pena, J. H., Kuschnig, R., Moffat, A. F. J., Rowe, J., Rucinski, S. M., Sasselov, D., Weiss, W. W.
Publicada:
1 jul 2018
Resumen:
We present and discuss the pulsational characteristics of the Delta
Scuti star 38 Eri from photometric data obtained at two widely spaced
epochs, partly from the ground (1998) and partly from space (MOST,
2011). We found 18 frequencies resolving the discrepancy among the
previously published frequencies. Some of the frequencies appeared with
different relative amplitudes at two epochs, however, we carried out
investigation for amplitude variability for only the MOST
(Microvariability and Oscillation of STars) data. Amplitude variability
was found for one of the three frequencies that satisfy the necessary
frequency criteria for linear-combination or resonant-mode coupling.
Checking the criteria of beating and resonant-mode coupling we excluded
them as possible reason for amplitude variability. The two recently
developed methods of rotational splitting and sequence search were
applied to find regular spacings based only on frequencies. Doublets or
incomplete multiplets with l = 1, 2, and 3 were found in the rotational
splitting search. In the sequence search method we identified four
sequences. The averaged spacing, probably a combination of the large
separation and the rotational frequency, is 1.724 +/- 0.092 d(-1). Using
the spacing and the scaling relation (rho) over bar = [ 0.0394,
0.0554] g cm(-3) was derived. The shift of the sequences proved to be
the integer multiple of the rotational splitting spacing. Using the
precise MOST frequencies and multicolour photometry in a hybrid way, we
identified four modes with l = 1, two modes with l = 2, two modes with l
= 3, and two modes as l = 0 radial modes.
Filiaciones:
Paparo, M.:
Konkoly Observ Budapest, MTA CSFK, Konkoly Thege MU 15-17, H-1121 Budapest, Hungary
Kollath, Z.:
Eotvos Lorand Univ, Savaria Dept Phys, Karolyi G Ter 4, H-9700 Szombathely, Hungary
Shobbrook, R. R.:
Australian Natl Univ, Siding Spring Observ, Coonabarabran, NSW 2137, Australia
Matthews, J. M.:
Univ British Columbia, Dept Phys & Astron, 6224 Agr Rd, Vancouver, BC V6T 1Z1, Canada
Antoci, V.:
Aarhus Univ, Stellar Astrophys Ctr, Dept Phys & Astron, 120 Ny Munkegade, DK-8000 Aarhus, Denmark
Benko, J. M.:
Konkoly Observ Budapest, MTA CSFK, Konkoly Thege MU 15-17, H-1121 Budapest, Hungary
Park, N. -K.:
Korea Astron & Space Sci Inst, 39-18 Hwaam Dong, Daejeon 34055, South Korea
Avcorp Ind Inc, 10025 River Way, Delta, BC V4G 1M7, Canada
Mirtorabi, M. T.:
Alzahra Univ, Dept Phys, POB 1993893973, Tehran, Iran
Luedeke, K.:
98100 Barstow St NE,Apt 6104, Albuquerque, NM 87122 USA
Kusakin, A.:
Fesenkov Astrophys Inst, Observ 23, Alma Ata 050020, Kazakhstan
Bognar, Zs.:
Konkoly Observ Budapest, MTA CSFK, Konkoly Thege MU 15-17, H-1121 Budapest, Hungary
Sodor, A.:
Konkoly Observ Budapest, MTA CSFK, Konkoly Thege MU 15-17, H-1121 Budapest, Hungary
Garcia-Hernandez, A.:
Univ Granada UGR, Dept Theoret Phys & Cosmol, E-18071 Granada, Spain
Pena, J. H.:
Univ Nacl Autonoma Mexico, Inst Astron, Apartado Postal 70-264, Mexico City 04510, DF, Mexico
Kuschnig, R.:
Univ Wien, Inst Astron, Turkenschans Str 17, A-1180 Vienna, Austria
Graz Univ Technol, Inst Kommunikationsnetze & Satellitenkommun, Infeldgasse 12, A-8010 Graz, Austria
Moffat, A. F. J.:
Univ Montreal, Dept Phys, 15, CP
Univ Montreal, CRAQ, 15, CP
Rowe, J.:
Canadian Coast Guard Coll, Dept Arts Sci & Languages, Sydney, NSW B1R 2J6, Australia
Rucinski, S. M.:
Univ Toronto, Dept Astron & Astrophys, Toronto, ON M5S 3H4, Canada
Sasselov, D.:
Univ Western Australia, Int Ctr Radio Astron Res, Australia 35 Stirling Hwy, Crawley, WA 6009, Australia
Weiss, W. W.:
Univ Wien, Inst Astron, Turkenschans Str 17, A-1180 Vienna, Austria
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