Xi Scorpii (ξSco）＋Struve 1999

Xi(ξ) Scorpii is located near the left scissor of Scorpion. It has a yellowish companion apart about 7.6 arcseconds. I looked into the telescope and found another double stars near Xi and I photographed them in one frame. I checked those pairs and found an interesting fact. That is; all of these stars are in one system. The two pairs are separated about 4.67arcminutes and yet they are moving with the influence of each other. As a beginner of astronomy fan, I was much surprised. They look isolated but not. I calculated how far they are apart and figured out 8000AU at least. It seems quite far but not so much, if you think the Oult Cloud is more than 30,000AU far from the sun.
Also Xi A has another companion that is separated only 0.4-0.8 arcseconds. So the system has two components of ABC and DE(+F?) at least.

ξ（xi）Scorpii ADS 9909, 9910 RA: 16h04m　Dec : -11.4° 　AB : mag4.8 - 5.1 　Distance : 0.4"arc　: 　AC : mag4.2 - 7.3　 Distance : 7.6"arc　: 　AD : mag4.8 - 7.4 　Distance : 4.67'arc Struve 1999 Scopii 　RA : 16h04m 　Dec : -11.5° 　 DE : mag7.4 - 8.1　Distance : 11.8" PA : 99° General Data: Observer: Keiko Chaki Location: Takatsuki Japan, 135deg37'E 　34deg50'N Date and time: 02:42 April 22, 2005 Classification: city Conditions: temp 17C Darkness: Limit mag 3.5 Transparency: 5/10 Seeing: 4/10 at best Telescope: Pentax 105 SDHF Eyepieces: TMB SM 8mm eyepiece View Magnification: app. 90x Camera: Nikon D70 Exposure: 1.3" Image process: trimmed

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