Anyone see Stardate ?

On Thu, 10 Jun 2004 21:40:24 +0100, Martin Frey
wrote:

Problem 4: If I do what Pete says, my head explodes.

It was always the tried and trusted way of determining NSEW for the
image. A planetarium program or the www tells you where contact 1
will occur for your location so all you have to do is to determine at
worst the quadrant where the event is going to occur and at best the
~20 degree arc where things are going to kick off.

Now the pressure's off - try it. First find N and S by centering on
the Sun and moving the scope up and down (in dec) watching the
movement of the Sun through the scope. As you move N, the last limb
you see it the one with the highest declination. As you move south,
it's the southern most limb.

--
Pete Lawrence
http://www.pbl33.co.uk
Most recent images http://www.pbl33.fast24.co.uk/recent_images.html

Pete Lawrence wrote:

Now the pressure's off - try it. First find N and S by centering on
the Sun and moving the scope up and down (in dec) watching the
movement of the Sun through the scope. As you move N, the last limb
you see it the one with the highest declination. As you move south,
it's the southern most limb.

Pete, thanks. We got it right for all the scopes except the PST and
when I try to rinse away the smarty I will have a chance to see what's
its optical path actually is, but we sure guessed it wrong.

The extraordinary thing is the degree of concentration we bring to
these things. I don't know what the apparent field of view of the PST
is but magnification is not huge (about 35x on the day) and an image
of the whole Sun is sitting there on quite a small portion of your
retina.If you are concentrating on one edge of the disc, the Queen
could do Riverdance naked on the opposite edge without being noticed.

It's not a blind spot thing and I don't have tunnel vision: I suspect
we can narrow our area of concentration down on demand when we really
want to see a really subtle change.

But I will follow your scheme: next time it's sunny, take cover -
there may be an explosion.

--
Martin Frey
http://www.hadastro.org.uk
N 51 02 E 0 47

JRS: In article , seen in
news:uk.sci.astronomy, Martin Frey posted
at Thu, 10 Jun 2004 21:40:24 :
Dr John Stockton wrote:

But it usually has spots; the motion from day to day of a spot shows the
image orientation, and if compared with a known-orientation image so
usually does the spot pattern.

AIUI, anyone who can observe transits can observe spots.

Therefore, I suggest that during the month or so before the next event
diagrams of the Sun should be published, showing the current spots, the
direction of their motion, and the predicted path of the event. One
just observes the spots beforehand to determine how one's equipment
presents the solar image.

Probably, if one knew where to look, the current spots are already
published on the WWW, in a known orientation; all that need be added is
a diagram of the event in the same orientation, with enough publicity to
ensure that any blunders will be noticed.

Problem 1: there was only the faintest scattering of spots and they
were as near as dammit in the centre

AIUI, that's unusual; I wasn't suggesting that it could be done for the
previous transit. The orientation test for ToV 2012 can be done at any
time from now, provided that the observer can correct for moving the
equipment to somewhere that the phenomenon is not occulted by the Earth.
Of course, if the spots were in the centre on Tuesday, they'd have been
only half-way in on Friday evening.


Problem 2: they don't show up very well or unambiguously in an H-a
scope - there seems to be tons of activity on the surface but not
necessarily where the spots are.

If the activity is "fixed" to the "surface" and lasts for at least a
known minimum time, then the same can be done with an H-a picture in the
Web. In fact, a real-time display could be used, with a button for
unveiling an overlay of the future track.


Problem 3: The new PST looks like a scope with a built in star
diagonal - but the light path is clearly more complex than that as the
image is reversed top to bottom unlike a normal refractor+diag

Given an adequately unsymmetrical pattern, that too would be
demonstrated.


Problem 4: If I do what Pete says, my head explodes.

That's only significant if you can also show that if you do not do what
Pete says then your head does not explode. Showing that with an
already-exploded head is left as an exercise for the reader ...

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
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Dr John Stockton wrote:

That's only significant if you can also show that if you do not do what
Pete says then your head does not explode. Showing that with an
already-exploded head is left as an exercise for the reader ...

Ooh err

--
Martin Frey
http://www.hadastro.org.uk
N 51 02 E 0 47