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Liu Zong-Li, Jiang Shi-Yang, Zhou Ai-Ying, Liu Yan-Ying, Li Zhi-Ping
The photoelectric observations of HR 5437 were carried out between 1986 and
1988 at the Piszkéstetö Station of Konkoly Observatory of Hungary and
the Xinglong Station of Beijing Observatory of China.
Using the data obtained at the Xinglong Station in 1988
Jiang and Li (1988) discovered HR 5437 to be a
Scuti variable star.
They did not derive frequencies. From the 1988 data set
obtained at the Piszkésteto Station and the Xinglong Station, Paparó
et al. (1990) determined two frequencies. The first frequency is 8.437
cd-1, the second is 12.362 cd-1. Joining the 1988 data
set and the data obtained at the Piszkéstetö Station in 1986-1987,
Paparó et al. (1990) gave two other frequencies. The first is 8.5367
cd-1, the second is 11.3759 cd-1. Paparó et al. pointed out that
due to the poor quality of the data distribution and the complex structure of
the spectral window the precise values of frequencies were not found.
Li and Jiang (1992) obtained only one frequency of 11.38993 cd-1 from
their data obtained in 1989. However, comparing with the results given by
Paparó et al. (1990), Li and Jiang (1992) thought that the frequency
of 8.5367 cd-1 given by Paparó et al. (1990) was the
fundamental frequency, the frequency of 11.38993 cd-1 was the first
overtone frequency. The situation is quite confused.
Beijing Astronomical Observatory, Chinese Academy of Sciences, 100012 Beijing,
The light curves of HR 5437 obtained during
The ordinate is the v magnitude difference (HR 5437 - SAO 16408) normalized
to zero. The abscissa is the time (+HJD 2450000). The fit of the
two-frequency solution given in Table 12 is shown as a solid curve.
In order to obtain the correct pulsation frequencies of HR 5437 and study its character we observed this star
from 8 to 17 April 1997, and from 6 to
8 March 1998 using the 85 cm telescope at the Xinglong Station of Beijing
Astronomical Observatory. The 4-channel photometer (Michel and Chevreton 1991) with
Strömgren v filter was used.
The star SAO 16408 was used as comparison, and SAO 16394 was used as check
star. The three stars and sky background were observed simultaneously. The
integration time was one minute. No evidence for any variability of SAO 16408
Seven tracks of data were obtained for HR 5437 from 1997 to 1998 covering a
period of 334 days. The light curves are shown in Fig. 13, where the
ordinate is the v magnitude difference normalized to zero. The abscissa is
the time (+HJD 2450000).
Period analysis were made using the Hao's program (1991), the program PERIOD
(Breger 1990), and PERIOD96 (Sperl 1996).
After careful calculation of power spectra we obtained two frequencies.
The computed two-frequency solution of the data is given in Table 12.
Power spectra of the 1997-1998 data of HR 5437.
The ordinate is the Power (mag2). The abscissa is frequency (cd-1).
The pulsation frequency solution of HR 5437.
||Standard error of fit
The power spectra of the data are shown in Fig. 14 together with the spectral
window. The frequency with strongest power in the second panel is the
frequency of 11.3545 cd-1. The frequency with strongest power in
the third panel is the frequency of 5.9966 cd-1. Due to the high signal
to noise ratio of the power spectra the 11.3545 cd-1 has the far highest peak .
The two frequencies can fit the variable light curves very well. The fit of
the two-frequency solution derived is shown as a solid curve (see Fig. 13).
This work was supported by a research grant from National Natural Science
Fund of China (NSFC). The authors would like to express their thanks.
Breger M., 1990, Comm. Asteroseismology 20, Austrian Acad. Sciences, Vienna
Hao Jin-Xin, 1991, Pub. of the Beijing Astron. Observatory 18, 35
Jiang Shi-Yang, Li Zhi-Ping, 1998, Astronomical Circular, 22
Li Zhi-Ping, Jiang Shi-Yang, 1992, A&AS, 93, 87
Michel E., Chevreton M., 1991, ASPCS, 11, 332
Paparó M., Jiang Shi-Yang, Li Zhi-Ping, Kollath Z., 1990, IBVS, No. 3451
Sperl M., 1996, Delta Scuti Star Newsletter, 10, 5
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