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Posts Made By: Stanley Yen

October 12, 2002 12:21 PM Forum: Equipment Talk

wideband nebular filters

Posted By Stanley Yen

In moderate to severe light pollution conditions,
would a wide-band light pollution filter
significantly improve the view of non-nebular
objects like open clusters, globulars and galaxies?
I've heard that narrowband filters dim these
types of objects too much, and are useful only
on nebulae, is this correct?

October 18, 2002 10:44 AM Forum: Deep Sky Observing

Re: Rukl on-line

Posted By Stanley Yen

Maybe this is the one you are looking for:

http://www.astro.hr/library/atlas_mjeseca/

November 1, 2002 08:00 PM Forum: Deep Sky Observing

breath fogging optics

Posted By Stanley Yen

Now that the cold weather has returned,
every time I breathe, my breath fogs up
the eyepiece. Anyone have a solution
for this?

July 2, 2006 08:24 PM Forum: Celestron

NexStar 8

Posted By Stanley Yen

I've used hand-pushed GEM's all my life, and I'm wondering if a computerized
GO-TO alt-az mounting like the NexStar 8 would be suitable for my needs.
Here are my questions:

What is the difference between the NexStar 8 SE and NexStar 8i (XLT) ?

With both these scopes, one has to do a 3-star alignment first for
automatic tracking to work, correct? Now, suppose I see the crescent moon
in the western sky at dusk, and I want to observe it and track it.
But there are no other objects visible in the sky because it's still
too light, so I can't do a 3-object alignment. I can't track it then?
Are there at least manual alt/az slow motions
that I can use to follow the object?

Is there any option that would allow the telescope to remember the previous
alignment? If I do the alignment in my back yard one night, then I transport
the scope to a remote location the following night, and set it up in the same
orientation (with a magnetic compass attached to the tripod, say), would the
alignment be close enough that I could track an object like the Moon
that I first center manually in the scope? I'm not anticipating that the magnetic
compass could be accurate enough to allow me to FIND a object at my remote
location, but is it accurate enough to allow me to TRACK an object once I find it?

Does the hand control allow me to slew the telescope in RA and DEC, or only in altitude
and azimuth? Or neither?

October 4, 2006 06:34 PM Forum: Mounts

What drive for Skyview Deluxe

Posted By Stanley Yen

What kind of single axis drive do I need for
an Orion Skyview Deluxe equatorial mount?
Is it EQ-2, EQ-3, ... ? What is the Synta
equivalent of this mount, if any?

December 23, 2007 05:55 PM Forum: Solar System Observing

Mars this apparition?

Posted By Stanley Yen

There aren't many sketches of Mars for the 2007 apparition being posted. Why's that?

October 1, 2009 05:18 PM Forum: Equipment Talk

dielectric diagonals

Posted By Stanley Yen

I see that William Optics has a "Durabright" dielectric diagonal
with a 15mm thick mirror, instead of the 10mm thick mirror of
their standard dielectric diagonal. Is the thicker mirror
supposed to prevent warping of the surface due to the many layers
of dielectric? Is warping a known problem, and if so, how bad is it?
Anyone here have any personal experience with this, or can anyone
point to any studies or anecdotes?

August 7, 2002 03:09 AM Forum: Deep Sky Observing

O the pains of being young

Posted By Stanley Yen

Nothing compared to the pains of being OLD !

September 24, 2002 05:26 PM Forum: Equipment Talk

Too Many Telescopes

Posted By Stanley Yen

Tom, do you ever *observe* with any of these
scopes? Maybe if you spend some time and energy
*using* these scopes, you'll get to know what
kind of astronomical observing you like
(planets? double stars? astro-photography?
comet-hunting?), and you'll know which scopes to
keep and which ones to sell.

October 3, 2002 04:23 PM Forum: Deep Sky Observing

The sun to exlpode within 6 years?

Posted By Stanley Yen

Definitely not! The core temperature of the Sun has
not increased by nearly a factor of 2 in recent years
as the article claims. The nuclear fusion reactions
that occur in the sun are extremely sensitive to
temperature, and a factor of 2 increase in core temperature
would tremendously increase the flux of Boron-8 neutrinos that we observe in neutrino detectors on Earth, by
much, much more than a factor of 2. No such increase
has been observed.