Community Comments
As editors we occasionally receive comments from our readership that we
feel would be worthwhile sharing with the active B star community. We
have thus decided to launch a new section in the Be Star Newsletter
entitled Community Comments. It is our intention to publish these e-mails
with only minimal editing in order to preserve the original flavor of the
communication. Our first item comes from Petr Harmanec.
Gerrie Peters
From: Petr Harmanec
Date: Mon, 21 Nov 2005 13:46:33 +0100 (CET)
To: Dr. Geraldine J. Peters,
Dr. David McDavid
Subject: Re: Be Star News Update (fwd)
Dear Gerrie and David,
I am pleased in the continuing interest in Bpe stars but I
would like to remind the community that it was found quite some
time ago (Hunger et al. 1989 A&A 224, 57) that V1030 Ori = HD 37479
is a field star, not a true member of the sigma Ori cluster. It would
be wise to stop using the name sigma Ori E for this star, I believe.
My very best wishes to both of you
Petr
Please send Community Comments to
benews@mucen.usc.edu with a copy to
dam3ma@virginia.edu.
Thanks, Eds.
From: Nolan Walborn
Date: Wed, 21 Dec 2005 21:44:55 -0500 (EST)
To: Dr. Geraldine J. Peters,
Dr. David McDavid
Subject: Re: Be Star News Update
Hi. I have a Community Counter Comment to that of Petr Harmanec
regarding the location of Sigma Ori E. As acknowledged by Hunger et
al. (A&A 224, 57, 1989), the magnitudes and colors of components D and
E are very similar, and both share very similar radial velocities and
extinctions with AB. On the other hand, they fail to mention that E
and AB also share a common proper motion (according to the notes in
the Third Edition of the Bright Star Catalogue). Moreover, the Orion
Association is at an extreme of the Gould Belt, far out of the
Galactic Plane, so any distant background B star would have to be a
runaway, for which there is no evidence in this case.
As also acknowledged by Hunger et al., Sigma Ori E has a very peculiar
and variable spectrum, for which they try their best to compensate in
their careful analysis, but the very sensitive gravity determination,
on which their distance is based, is quite uncertain. I recommend
that any reader seriously interested in this problem read their paper
in detail. Moreover, the atmospheric structure and extent of this
peculiar object may well be different from those of the normal
comparison stars, which would produce systematic effects not accounted
for in their analysis. It is quite difficult to derive accurate
spectroscopic masses for even normal OB stars, and the results are
frequently discrepant with those from other methods.
In conclusion, we may hope that Gaia and/or SIM will eventually tell
us where the OB stars really are! In the meantime, it is highly
premature to banish Sigma Ori E from the multiple system. Saludos!
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