Analyzing “Double Star” SAO146716(XZ31598)

Oct.26.2007 Kazuhisa Miyashita

Masayuki Ishida (Moriyama city, Shiga pref., Japan) had sent a .CSV data analyzing SAO146716. The star is known double consists of two components which has 9.9 magnitude. The position angle is 84 degree and the separation is 0.2 arcsecond. It is mentioned in the WDS catalog as RST4724. Discoverer of this double is Rossiter, R.A.

Figure 1 shows the light curve of SAO146716 observed by Ishida. It seems light dropped slowly at the disappearance event. However the spectrum type of star is G0 and the proper motion is not large value (RA:0.0047sec, Dec:0.0087arcsec). If it is due to the angular size of star then the star's angular is 0.13 arcsec! (The relative velocity is 0.430arcsec/sec. The brightness dropped during 9 frames. Therefore the angular velocity is 0.430*9/29.97=0.13 ) . I can not accept the value because it is larger than largest star antares(0.08 arcsec). Even if it is assumed to be a double star, the intensity change is too slow.

Figure 1. Raw data (frame measure)

Figure 2. Raw data (field measure)

Figure Moving average (5 frame)

Figure Low pass firtre (under 17.4Hz)