periastron


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Related to periastron: periapsis, Pericenter

per·i·as·tron

 (pĕr′ē-ăs′trən, -trŏn)
n. pl. per·i·as·tra (-trə)
The point at which an object is closest to the center of mass of the star it is orbiting.

[peri- + Greek astron, star (probably on the model of perihelion); see ster- in Indo-European roots.]

periastron

(ˌpɛrɪˈæstrɒn)
n
(Astronomy) astronomy the point in the orbit of a body around a star when it is nearest to the star, esp applied to double-star systems

periastron

The point in the orbit of an object around a star at which the object is at its closest to the star.
Translations
Periastron
périastre
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References in periodicals archive ?
Astronomers observe dramatic changes in the system during the months before and after periastron.
In 2009 they motivated amateurs to visit Tenerife to observe the periastron of the ultra-hot binary WR 140, the best-studied member of a class of objects called colliding-wind binaries (S&T: April 2011, page 28).
General relativity predicts that, like the precession of the perihelion of Mercury, the periastron of the pulsar (the point of its closest approach to the black hole) will precess in the plane of its orbit, at rates that are highly sensitive to the orbital parameters, from more than 4 degrees per year for an eccentricity of 0.
The original idea was for a small workshop for researchers involved in the observations for the 2011 delta Sco periastron campaign, but it grew into a conference that drew scientists from around the world and generated 56 papers for the proceedings.
In July of 2011, the highly-eccentric Be star system Delta Scorpius was predicted to have an interaction between its companion star and its circumstellar disk during its periastron passage which takes place every eleven years.
The paper includes four other bright southern systems including Beta Phoenicis which has now apparently passed unobserved through periastron.
In planets the latter motion is called precession of perihelion; in stars it is either precession of periastron or precession of apsides.
The orbit of 70 Ophiuchi continued to confound observers until remarkably recently; even the 1984 periastron (when the two stars passed closest to each other in space) occurred much later than expected.