[vsnet-chat 3712] Re: re vsnet-alert 5312 (delta Vel)

[crawl@zoom.co.uk]

Taichi Kato wrote [re AZh, 72, 400 (1995)] :

>   According to the full version of the paper (translated article), this
>paper discusses the possibility of detecting such planets, and apparently
>no discussion about individual objects.  As far as I surveyed, the name
>delta Vel only appears in the figure, which was apparently selected to
>show the location on the diagram (mass of the primary versus semimajor axis
>of potential planets) of a relatively massive "Vega-type" star.

Thanks very much indeed for that.

To the best of my knowledge "AZh" is one of the major Russian Astronomic
periodicals... ...and I must admit I did find it a bit strange for a new
variable to be noted in a Russian journal in 1995 and yet fail to appear in
either the recent NSV supplement or either of Namelists 72, 73 or 75 ;^)


[re the Aa pair... ...a little rough adding up [and don't quote me] gives
the following : projected separation (1979) in AU = 0.6/0.04 = 15 [where
0.04 = parallax], and for the special case of a face on orbit that was
circular [which is unlikely to be the real case, but it gives us something
to work with] we could say that this was equivalent to the sem-major axis,
so the period would be 15^(3/2), or 58 years, which tallies with the "few
decades" estimated by the discoverers of this pairing, and is not
appropriate in the context of the current eclipses.  I'm quite willing to
accept I've made an arithmetic error here though, cos I couldn't find the
sums in the books, and have had to use my beleaguered memory]

Note to eclipsing binary people : IF it turns out to be star A that is
eclipsing, and given that star a orbits A in say 40 to 70 years, what are
the chances, and more importantly timescale, of the "third body" affect via
apsidal motion causing star A's orientation to go in and out of suitability
for eclipses to occur?  In other words, if this star has not been detected
as an eclipser in the past, is it at all possible that is is simply because
it has only started being so over the past few years, after a long period
of not doing so, due to apsidal motion... ...if you follow?!?!

Cheers

John

John Greaves
UK

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