'Pole Stars' on the Moon?

OK, I thought I was Internet-literate and could google with the best of 'em,
but after half an hour of dead-endism, I've given up. Please help!

For an article i'm writing, I need the RA/Dec of the Moon's axis
of rotation, so I can check out whether there are any 'pole stars' of note.

The axis is within about a degree of perpendicular to the ecliptic, if that
helps.

Jim O

www.jamesoberg.com

"JimO" wrote in message
.. .

OK, I thought I was Internet-literate and could google with the best of
'em,
but after half an hour of dead-endism, I've given up. Please help!

For an article i'm writing, I need the RA/Dec of the Moon's axis
of rotation, so I can check out whether there are any 'pole stars' of
note.

The axis is within about a degree of perpendicular to the ecliptic, if
that
helps.

Jim O

www.jamesoberg.com

If you happen to have "Starry Night Pro" here is what you can do.

Set your location as 90 deg N Lat on the Moon and then move to view Zenith.

The North Pole is vary close to the North Ecliptic Pole (as you state
above).

The closest stars are "Omega Daconis" and "27 Draconis" both about a degree
away.

The pole is roughly between the North Ecliptic Pole and these two stars.

Great. And could you tell me the south polar region in the sky?

"John Zinni" wrote in message
.. .
"JimO" wrote in message
.. .

OK, I thought I was Internet-literate and could google with the best of
'em,
but after half an hour of dead-endism, I've given up. Please help!

For an article i'm writing, I need the RA/Dec of the Moon's axis
of rotation, so I can check out whether there are any 'pole stars' of
note.

The axis is within about a degree of perpendicular to the ecliptic, if
that
helps.

Jim O

www.jamesoberg.com

If you happen to have "Starry Night Pro" here is what you can do.

Set your location as 90 deg N Lat on the Moon and then move to view
Zenith.

The North Pole is vary close to the North Ecliptic Pole (as you state
above).

The closest stars are "Omega Daconis" and "27 Draconis" both about a
degree
away.

The pole is roughly between the North Ecliptic Pole and these two stars.

"JimO" wrote in message
.. .
Great. And could you tell me the south polar region in the sky?

Hey Jim

South Pole is about 2 deg away from Delta Doradus, 1 deg away from Epsilon
Doradus.

Epsilon Doradus is roughly between South Pole and South Ecliptic Pole.

Hi Jim,
The axis is within about a degree of perpendicular to the ecliptic,
if that helps.

Doesn't the moon's libration affect it ?
jc



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.551 / Virus Database: 343 - Release Date: 11/12/2003

"John Carruthers" wrote in message
...
Hi Jim,
The axis is within about a degree of perpendicular to the ecliptic,
if that helps.

Doesn't the moon's libration affect it ?
jc

Hey John

Nope, the Moon does not actually wobble due to libration, it only appears to
wobble from the perspective of the Earth.

Doesn't the moon's libration affect it ?
jc

Hey John

Nope, the Moon does not actually wobble due to libration, it only
appears to
wobble from the perspective of the Earth.

Well you learn something every day; (if you're lucky)
jc :-)





---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.551 / Virus Database: 343 - Release Date: 11/12/2003

"John Carruthers" wrote:

Doesn't the moon's libration affect it ?
jc

Hey John

Nope, the Moon does not actually wobble due to libration, it only
appears to
wobble from the perspective of the Earth.

Well you learn something every day; (if you're lucky)
jc :-)

The apparent wobble comes from the Moon rotating at a pretty rock
steady rate but orbiting at different speeds dependent on distance
from earth.

Near perigee, when it's going faster, its constant spin rate per unit
time isn't quite enough to keep the exact same face pointing towards
us and we see a bit further round the trailing edge.

At apogee the spin rate per unit time is a bit too much and we see a
bit further round the leading edge.

And, as Pete Lawrence's Parallax demo shows, it depends where you are
on the Earth how far round any edge you can see. It's only when you
stand on the North Pole that you can see they don't bother to dust the
top of the Moon, the slatterns.

http://www.pbl33.co.uk

There - you've learned something, John. Still feeling lucky? Hmm...

-----------------------------
Martin Frey
http://www.hadastro.org.uk
N 51 01 52.2 E 0 47 21.1
-----------------------------

John Zinni wrote:

Nope, the Moon does not actually wobble due to libration, it only appears to
wobble from the perspective of the Earth.

Another way to put it is to say that the "wobble" is not in the
Moon's rotation about its axis, but in its orbit around the earth: it
moves faster near perigee and slower near apogee, while its rate of
rotation remains fairly constant. So although the two motions are
synchronized over a whole monthly cycle and on average, at any given
point in time they may show a slight leading or lagging effect. A
similar phenomenon concerning the Earth's orbit around the Sun
produces one component of the "equation of time" that relates solar
time to clock time (the other component coming from the obliquity of
the ecliptic).

--
Odysseus

John Zinni wrote:

"JimO" wrote in message
.. .
Great. And could you tell me the south polar region in the sky?

Hey Jim

South Pole is about 2 deg away from Delta Doradus, 1 deg away from Epsilon
Doradus.

Epsilon Doradus is roughly between South Pole and South Ecliptic Pole.

The Earth's Pole Star changes over 25,000 years,
Polaris - Vega - [somewhere else I can't remember].

Does this happen with the moon, "in sympathy" as it were?

Peter