HD 163151 is discovered to be a new variable as a part of a W UMa system. In this paper we presen... more HD 163151 is discovered to be a new variable as a part of a W UMa system. In this paper we present complete uvby light curves. Additional Crawford H_beta and Johnson BV data are also obtained. A detailed photometric analysis based on these observations is presented using the WD code. Several tests have been carried out concerning mass ratio and
We used a 50 cm telescope plus a Princeton Instrument Vers Array 512B CCD atXinglong station of t... more We used a 50 cm telescope plus a Princeton Instrument Vers Array 512B CCD atXinglong station of the National Astronomical Observatory of China to observe UY Cam inFebruary 2008 and totally 7 times of maximum light were obtained. We used omc01.exesoftware for (O-C) analysis and found that its pulsation period is steadily increasing with arate of about 4.8 × 10-9 per year. This is reasonable from the stellar evolution theory point ofview. We conclude that it has an unseen companion with an orbital period of about 49.5years. Due to few observations of this variable star, we call for more people to observe andcollect more data on this star. Keywords: variable stars, Delta Scuti, HADS, period changes, light time effect. Stellarevolution
Sugar-conjugated pH sensors discriminate stressed lysosomes in different cell starvation conditio... more Sugar-conjugated pH sensors discriminate stressed lysosomes in different cell starvation conditionsviared-to-green fluorescence switch.
In this study 180 δ Scuti type variables with v sin i values are listed out from different source... more In this study 180 δ Scuti type variables with v sin i values are listed out from different sources. It is found that even for low amplitude non-pulsating δ Scuti type variables, the average v sin i of different groups of variable with different amplitude continuously declines with the amplitude increasing.
On November 13, 1989, the largest telescope of China and the Far East-the 2.16 metre telescope-wa... more On November 13, 1989, the largest telescope of China and the Far East-the 2.16 metre telescope-was formally opened to the public at Xinglong Station of Beijing Astronomical Observatory. The scheme was proposed in early 1958, and began to carry out in 1974. The key component, a 3-ton concave hyperboloidal main mirror, is made of V02 type cervit with its diameter of 2.2 m, clear aperture of 2,16 m and its focal length of 6.48 m.
Multisite photoelectric B and V photometry of the delta Scuti star 63 Her was obtained on three c... more Multisite photoelectric B and V photometry of the delta Scuti star 63 Her was obtained on three continents. Three frequencies of pulsation (f1 = 11.32, f2 = 20.07 and f3 = 7.72 c/d) were detected with a signal/noise amplitude ratio greater than or = 4.0. The three frequencies fit all the available data ranging back to 1968. Reports in the
Table 2 contains 408 simultaneous measurements collected in each of the four uvby colours of the ... more Table 2 contains 408 simultaneous measurements collected in each of the four uvby colours of the Stromgren photometric system for the W UMa system HD 163151. The data are magnitude differences (Du, Dv, Db, Dy, D(b-y), Dm1, Dc1) of the variable star minus comparison star in the standard system versus Heliocentric Julian Day. Tables 3, 4 and 5 are the
The concept of a gradient index liquid mercury (GRINL-Hg) Schmidt corrector is presented, which g... more The concept of a gradient index liquid mercury (GRINL-Hg) Schmidt corrector is presented, which gives a possibility to break over the diameter limit of Schmidt telescopes.
Abstract On the basis of a re-examination of hitherto published photoelectric maximum times plus ... more Abstract On the basis of a re-examination of hitherto published photoelectric maximum times plus some of our photoelectric observations we found that the period of YZ Boo is increasing at 0.026 ± 0.0004 seconds per century, or (8.3 ± 1.1) × 10 −12 d d .
The differential photoelectric measurements of HR 5437, HD 127759, HD 127411, and HD 127822 which... more The differential photoelectric measurements of HR 5437, HD 127759, HD 127411, and HD 127822 which are all located on the instability strip, were obtained during 1991 March 22 to April 5. Based on these measurements, the authors suggest that HD 127759 is a short period variable whose period and amplitude are about 1h6 and 0m06 respectively with a visual magnitude of 8m41.
Extensive differential time-series CCD photometry has been carried out between 2003 and 2009 for ... more Extensive differential time-series CCD photometry has been carried out between 2003 and 2009 for the high-amplitude δ Scuti (HADS) star GP And. We acquired 12,583 new measurements consisting of 41 nights (153.3 hr) spanning over 2221 days. This is the largest time-series data set to date for the star. Based upon these data and others available in the literature, a comprehensive analysis has been conducted to investigate the pulsational properties of the star. Except for the known fundamental period and its harmonics we failed to detect any additional pulsation periods either radial or nonradial. We show clear amplitude variability, but we failed to verify the previously claimed periodic amplitude modulation. Classic O−C analysis indicates that the fundamental pulsation period of GP And is slowly increasing at a rate ofṖ /P = (5.49 ± 0.1) × 10 −8 yr −1 in accordance with the predictions of stellar evolutionary models. Findings of nonradial oscillations in previously known radial high-amplitude pulsators are being increasingly reported. We have briefly reviewed the current status of multiperiodicity and nonradial pulsation features among the high-amplitude pulsators in the classic instability strip.
A multi-period analysis has been conducted on the data set of BDS 1269 A made up of the observati... more A multi-period analysis has been conducted on the data set of BDS 1269 A made up of the observations obtained by Percy and Rucihski during October 9 to November 6, 1976. In our period analysis, many possible frequencies, which include all frequencies suspected, are selected to constitute the initial frequency estimates. By fitting various combinations of the initial frequencies to the data set, the best one can be determined, which has a minimum number of different frequencies with the lowest residuals. The best fitting frequency solution includes f1=6.22999 cycle d-t, f2 = 6.50840 cycle d-1, f3 = 11.77324 cycle d-1, f4= 9.71369 cycle d-1 and f3= 11.33694 cycled-1. The numeric experiment justifies this five-frequency solution. Based on this solution, a reasonable non-radial rotational splitting pulsation mode is identified, and a rotational velocity v3 = 30 km s-1 is predicted, which tends to agree with the fact that BDS 1269 A is a slowly rotational star.A total of 459 new measurements of four nights during 1987 October 16 to 24 were taken by authors with a Johnson V filter. The fitting with the five-frequency solution to the new data is very good with a residual which is near the uncertainty of the observation.
ABSTRACT It is shown that the set of equations of stellar structure within certain parameter rang... more ABSTRACT It is shown that the set of equations of stellar structure within certain parameter ranges, is capable of producing intermittent chaos. This is in qualitative agreement with the irregular light variations observed in some pulsating variable stars.
I have carried out a large amount of photoelectric observation in the V-band on AD CMi. Small var... more I have carried out a large amount of photoelectric observation in the V-band on AD CMi. Small variations in maximum and minimum lights are found. A combined analysis of the 12 maximum times I determined and those by previous workers shows that the pulsation period of this star is continually increasing at a rate equal to (1.89 +/- 0.09) × 10-8 d/yr. From its position in the ``amplitude-period'' diagram, it is inferred that this star has been pulsating for at least 8.6 million years.
HD 163151 is discovered to be a new variable as a part of a W UMa system. In this paper we presen... more HD 163151 is discovered to be a new variable as a part of a W UMa system. In this paper we present complete uvby light curves. Additional Crawford H_beta and Johnson BV data are also obtained. A detailed photometric analysis based on these observations is presented using the WD code. Several tests have been carried out concerning mass ratio and
We used a 50 cm telescope plus a Princeton Instrument Vers Array 512B CCD atXinglong station of t... more We used a 50 cm telescope plus a Princeton Instrument Vers Array 512B CCD atXinglong station of the National Astronomical Observatory of China to observe UY Cam inFebruary 2008 and totally 7 times of maximum light were obtained. We used omc01.exesoftware for (O-C) analysis and found that its pulsation period is steadily increasing with arate of about 4.8 × 10-9 per year. This is reasonable from the stellar evolution theory point ofview. We conclude that it has an unseen companion with an orbital period of about 49.5years. Due to few observations of this variable star, we call for more people to observe andcollect more data on this star. Keywords: variable stars, Delta Scuti, HADS, period changes, light time effect. Stellarevolution
Sugar-conjugated pH sensors discriminate stressed lysosomes in different cell starvation conditio... more Sugar-conjugated pH sensors discriminate stressed lysosomes in different cell starvation conditionsviared-to-green fluorescence switch.
In this study 180 δ Scuti type variables with v sin i values are listed out from different source... more In this study 180 δ Scuti type variables with v sin i values are listed out from different sources. It is found that even for low amplitude non-pulsating δ Scuti type variables, the average v sin i of different groups of variable with different amplitude continuously declines with the amplitude increasing.
On November 13, 1989, the largest telescope of China and the Far East-the 2.16 metre telescope-wa... more On November 13, 1989, the largest telescope of China and the Far East-the 2.16 metre telescope-was formally opened to the public at Xinglong Station of Beijing Astronomical Observatory. The scheme was proposed in early 1958, and began to carry out in 1974. The key component, a 3-ton concave hyperboloidal main mirror, is made of V02 type cervit with its diameter of 2.2 m, clear aperture of 2,16 m and its focal length of 6.48 m.
Multisite photoelectric B and V photometry of the delta Scuti star 63 Her was obtained on three c... more Multisite photoelectric B and V photometry of the delta Scuti star 63 Her was obtained on three continents. Three frequencies of pulsation (f1 = 11.32, f2 = 20.07 and f3 = 7.72 c/d) were detected with a signal/noise amplitude ratio greater than or = 4.0. The three frequencies fit all the available data ranging back to 1968. Reports in the
Table 2 contains 408 simultaneous measurements collected in each of the four uvby colours of the ... more Table 2 contains 408 simultaneous measurements collected in each of the four uvby colours of the Stromgren photometric system for the W UMa system HD 163151. The data are magnitude differences (Du, Dv, Db, Dy, D(b-y), Dm1, Dc1) of the variable star minus comparison star in the standard system versus Heliocentric Julian Day. Tables 3, 4 and 5 are the
The concept of a gradient index liquid mercury (GRINL-Hg) Schmidt corrector is presented, which g... more The concept of a gradient index liquid mercury (GRINL-Hg) Schmidt corrector is presented, which gives a possibility to break over the diameter limit of Schmidt telescopes.
Abstract On the basis of a re-examination of hitherto published photoelectric maximum times plus ... more Abstract On the basis of a re-examination of hitherto published photoelectric maximum times plus some of our photoelectric observations we found that the period of YZ Boo is increasing at 0.026 ± 0.0004 seconds per century, or (8.3 ± 1.1) × 10 −12 d d .
The differential photoelectric measurements of HR 5437, HD 127759, HD 127411, and HD 127822 which... more The differential photoelectric measurements of HR 5437, HD 127759, HD 127411, and HD 127822 which are all located on the instability strip, were obtained during 1991 March 22 to April 5. Based on these measurements, the authors suggest that HD 127759 is a short period variable whose period and amplitude are about 1h6 and 0m06 respectively with a visual magnitude of 8m41.
Extensive differential time-series CCD photometry has been carried out between 2003 and 2009 for ... more Extensive differential time-series CCD photometry has been carried out between 2003 and 2009 for the high-amplitude δ Scuti (HADS) star GP And. We acquired 12,583 new measurements consisting of 41 nights (153.3 hr) spanning over 2221 days. This is the largest time-series data set to date for the star. Based upon these data and others available in the literature, a comprehensive analysis has been conducted to investigate the pulsational properties of the star. Except for the known fundamental period and its harmonics we failed to detect any additional pulsation periods either radial or nonradial. We show clear amplitude variability, but we failed to verify the previously claimed periodic amplitude modulation. Classic O−C analysis indicates that the fundamental pulsation period of GP And is slowly increasing at a rate ofṖ /P = (5.49 ± 0.1) × 10 −8 yr −1 in accordance with the predictions of stellar evolutionary models. Findings of nonradial oscillations in previously known radial high-amplitude pulsators are being increasingly reported. We have briefly reviewed the current status of multiperiodicity and nonradial pulsation features among the high-amplitude pulsators in the classic instability strip.
A multi-period analysis has been conducted on the data set of BDS 1269 A made up of the observati... more A multi-period analysis has been conducted on the data set of BDS 1269 A made up of the observations obtained by Percy and Rucihski during October 9 to November 6, 1976. In our period analysis, many possible frequencies, which include all frequencies suspected, are selected to constitute the initial frequency estimates. By fitting various combinations of the initial frequencies to the data set, the best one can be determined, which has a minimum number of different frequencies with the lowest residuals. The best fitting frequency solution includes f1=6.22999 cycle d-t, f2 = 6.50840 cycle d-1, f3 = 11.77324 cycle d-1, f4= 9.71369 cycle d-1 and f3= 11.33694 cycled-1. The numeric experiment justifies this five-frequency solution. Based on this solution, a reasonable non-radial rotational splitting pulsation mode is identified, and a rotational velocity v3 = 30 km s-1 is predicted, which tends to agree with the fact that BDS 1269 A is a slowly rotational star.A total of 459 new measurements of four nights during 1987 October 16 to 24 were taken by authors with a Johnson V filter. The fitting with the five-frequency solution to the new data is very good with a residual which is near the uncertainty of the observation.
ABSTRACT It is shown that the set of equations of stellar structure within certain parameter rang... more ABSTRACT It is shown that the set of equations of stellar structure within certain parameter ranges, is capable of producing intermittent chaos. This is in qualitative agreement with the irregular light variations observed in some pulsating variable stars.
I have carried out a large amount of photoelectric observation in the V-band on AD CMi. Small var... more I have carried out a large amount of photoelectric observation in the V-band on AD CMi. Small variations in maximum and minimum lights are found. A combined analysis of the 12 maximum times I determined and those by previous workers shows that the pulsation period of this star is continually increasing at a rate equal to (1.89 +/- 0.09) × 10-8 d/yr. From its position in the ``amplitude-period'' diagram, it is inferred that this star has been pulsating for at least 8.6 million years.
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Papers by Shi-Yang Jiang