emamajek on 01-Sep-2017 02:08:09 GMT about * 70 Oph A
70 Oph A & B comprise a well-known resolved physical binary system, which was resolved by Hipparcos (ESA 1997; CCDM J18055+0230; sep=1.592"). See detailed discussion on system and illustration of orbit at:
http://stars.astro.illinois.edu/sow/70oph.html
The earliest Washington Double Star catalog observation included in orbit determination is from the year 1777 (by Herschel), and multiple orbits (P ~ 88 years) have been observed. The system is so well-studied that the agreement between the observed trig parallax and calculated dynamical parallax was demonstrable nearly a century ago: http://adsabs.harvard.edu/full/1925Obs....48..112D, http://adsabs.harvard.edu/full/1928AJ.....38...89R. So the physicality of the pair is beyond dispute - 70 Oph A & B share the same parallax and that should probably be reflected in their default SIMBAD parallax values.
original Hipparcos parallax:
196.62+-1.38 mas
revised Hipparcos parallax:
196.72+-0.83 mas
[check: dynamical parallax:
201+-3 mas!
1988JRASC..82..140H
]
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