More star crib proposals

["Bradley E. SCHAEFER" <schaefer@xxxxxxxxxxxxxxxxxxx>]

Hi;
	Below is another attempt to name the stars that appear in the
'Pleiades' diagram.  It sounds reasonalbe...
Cheers,
Brad


---------- Forwarded message ----------
Date: Thu, 12 Oct 2000 10:32:10 -0400
From: George Gilbart-Smith <georgegs@xxxxxxxxx>
To: schaefer@xxxxxxxxxxxxxxxxxxxxx
Subject: November Issue p40

Dear Dr Schaefer
I read your article in the November Sky and Telescope with interest. The
only light I can shed on any of it concerns the segmented diagram at the
bottom of page 42. I'm sure this has already been pointed out, but the four
octants containing labelled stars would seem to be seasonal asterisms:
Aldebaran and the Pleiades (Winter), Arcturus and Mufrid (Spring), with
Mufrid being the star in the diagram nearer the Sun, Vega with epsilon and
zeta Lyrae (Summer), with Vega nearest the Sun and the Aquarius water jar
(Autumn), with Sadalachbia nearest the Sun. All the stars in these
asterisms are plotted with too much accuracy to be coincidental, e.g. the
"summer triangle" is not quite equilateral, and the autumn asterism is
remarkably accurate. There are 61 stars and asterisms in the figure
altogether, so the unnamed stars might be six-day markers between the
asterisms. Or the unnamed stars might just be bright stars which culminate
between the asterisms (I would not speculate which stars).
Using Guide 7 software, set to precession for 1200, I tried to see on what
days of the year the asterisms pointed towards the Sun, and things went a
bit haywire! The spring asterism could mark where summer turns to autumn
(about 10h RA) and the autumn asterism where winter turns to spring (about
21h RA). But the summer asterism is only properly orientated at the
autumnal equinox (and is in any case miles from the ecliptic) and the
ecliptic passes right between Aldebaran and the Pleiades (admittedly just
as spring turns to summer)!
So I'm not sure if I've been any help at all, but I've had fun (and found
yet another application for the invaluable Guide software).

Yours sincerely,
George Gilbart-Smith
georgegs@xxxxxxxxx
70 Allington Drive
Tonbridge
Kent TN10 4HH
UK