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From: Lynn.ES@XEROX.COM
Newsgroups: net.space
Subject: Re: Red Sirius?
Message-ID: <860312-112018-1772@Xerox>
Date: Wed, 12-Mar-86 14:19:54 EST
Article-I.D.: Xerox.860312-112018-1772
Posted: Wed Mar 12 14:19:54 1986
Date-Received: Fri, 14-Mar-86 05:39:01 EST
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Organization: The ARPA Internet
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Why don't people go out and look at Sirius instead of arguing in a
vacuum?  It turns out I often do (I mean look; the fact that I often
argue is not the point :-), not to prove the "Red Sirius" theory, but
because I like the stars.  Sirius almost always looks blue-white to me,
but it has on occasion looked as red as a stop light.  It has also
looked quite green, in fact within minutes of looking red.  These funny
colors occurred when Sirius was low in the sky and the air was fairly
turbulent.

While I must commend Firth for looking rather than blindly arguing, his
observation of Venus instead of Sirius is probably irrelevant, because
the finite size of planets (roughly a minute of arc for Venus) makes
them behave differently than stars with regard to atmospheric effects;
for example, planets twinkle decidedly less than stars.

After seeing Sirius quite red from atmospheric effects, I have to
believe it simply got into the literature as red from such a viewing,
and has been perpetuated in print.

/Don Lynn