[vsnet-campaign-deltavel 16] Other possibilities for delta Velorum

[Sebasti若n Otero <varsao@fullzero.com.ar>]

Dear friends:

Thanks Lew for your suggestion. The JD of Albert's photograph was right. I
think we need more observations.
There are 420 observations but some were made under bad conditions.
In order to check all the possibilities, I was trying periods shorter than
45 days. Chris Loyd was worried about it and maybe he was right: a 27.1 day
period seems interesting.
We would have a secondary eclipse again but at phase 0.41 (11 days after
primary).
That would mean that the probable eclipse of JD 2451147.7 would be out of
phase. But it was just 0.1 mag. deep and now that we are knowing of some
observations that seem to show delta Vel a little fainter (including Brian
Fraser's photometry at 1.99V), maybe the same small fading happened by that
time and wasn't an eclipse.

However, one very important thing makes me believe we are okay with the 45
day period:
The Hipparcos satellite measured the star in one of the predicted times of
minima, near JD 2448717.7 and everything was normal at 1.94.

Of course, it doesn't mean another weird thing has occured so it would be
worth taking a look, just in case, the night of November 12/13. You never
know.....


Best wishes,
Sebastian.

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