During the past 11 years, spanning three periastron
passages, the Goddard group has developed a model based on routine observations of the stars using ground-based telescopes and multiple NASA satellites.
2011) or the analysis of the periastron
precession of the orbits (Lucchesi & Peron 2010) have been experimental verified.
This effect is even more sensitive to the orbital parameters than the periastron
Their orbit is highly elliptical; at the far end of the ellipse the two stars are 30 astronomical units apart, but around periastron
they rapidly dip to within about 2 a.
This prediction comes from "definitive" new orbital elements for the binary published in 2007, based partly on speckle-interferometry measurements made during the critical time around the 2005 periastron
and closest separation (0.
To compute a really accurate orbit, you need to observe the stars near periastron
, when they're closest, and most strongly affected by each other's gravity.
In 2035 the stars will be at periastron
, closest together in space.
At the time of periastron
(closest orbital approach) in May 2005 they were just 0.
(when the two stars of a binary are closest together in space) probably came in April 2005 with the stars just 0.
88[degrees]-per-year advance--the largest ever observed--is 140,000 times greater than the relativistic precession of Mercury's perihelion and four times larger than the periastron
advance of the Taylor-Hulse binary pulsar.
6-inch Dorpat refractor in Russia (see page 70 of the May/June 2005 Night Sky), managed to measure the pair near the time of periastron