Question about viewing Uranus in the southwest sky

Hi:

I am a relative novice, and I have a Meade ETX 90 PE. Last night, after
nights of fog (in the SF Bay Area), I was finally able to track down
what I am fairly sure was Uranus. However, what I found was
suspiciously small - not more than a greenish star, but certainly
brighter than its nearest point of light which according my charts
would have been magnitude 8.97. Even when using a 12.4 lens, Uranus was
nothing more than a dot - I could not even call it a blob. Am I on the
correct object? And, should I really not be able to see more than a dot
of light with my telescope?

If this is the best it gets, is there any reason to try to track down
Neptune with a magnitude at about 8 with my setup?

Thanks for your interest and replies.

-Dave

Dave wrote:
I am a relative novice, and I have a Meade ETX 90 PE. Last night, after
nights of fog (in the SF Bay Area), I was finally able to track down
what I am fairly sure was Uranus. However, what I found was
suspiciously small - not more than a greenish star, but certainly
brighter than its nearest point of light which according my charts
would have been magnitude 8.97. Even when using a 12.4 lens, Uranus was
nothing more than a dot - I could not even call it a blob. Am I on the
correct object? And, should I really not be able to see more than a dot
of light with my telescope?

Uranus is pretty small. If what you saw was green, that's a pretty dead
giveaway. To the eye, no star looks green. Uranus does, though--or
blue, depending on your eyes, but green makes sense, too.

At 100x, Uranus is still pretty small. Magnified that much, it's really
more than 1/5 the width of the Moon as seen by the unaided eye, but I
agree that subjectively, it doesn't look nearly that big. I had much
the same impression that you did. Of course, the Moon offers up a lot
more detail than Uranus does.

If this is the best it gets, is there any reason to try to track down
Neptune with a magnitude at about 8 with my setup?

Neither of these planets will reveal a lot of detail visually without a
lot of aperture, patience, and atmospheric cooperation. Neptune likely
won't do it even with those. So if you're looking for a spectacle, the
outer planets probably aren't your cuppa. The allure of these planets
is mostly in the hunt. (Their color is something neat to behold, in my
opinion, but lots of folks disagree.)

--
Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.html

Hi Dave -

Sounds like you got it alright.

"Worth" is relative, especially in the context of finding objects in
the sky. If you go and look, you'll find out what the scope and you
can do, you might notice color, passage by (or occultation of) a star,
and it gets you some fresh air.

I'd think it's worth looking for Neptune.

"Quixotic1" wrote:
I am a relative novice, and I have a Meade ETX 90 PE. Last night, after
nights of fog (in the SF Bay Area), I was finally able to track down
what I am fairly sure was Uranus. However, what I found was
suspiciously small - not more than a greenish star, but certainly
brighter than its nearest point of light which according my charts
would have been magnitude 8.97. Even when using a 12.4 lens, Uranus was
nothing more than a dot - I could not even call it a blob. Am I on the
correct object? And, should I really not be able to see more than a dot
of light with my telescope?

If this is the best it gets, is there any reason to try to track down
Neptune with a magnitude at about 8 with my setup?

Thanks for your interest and replies.

-Dave


=============
- Dale Gombert (SkySea at aol.com)
122.38W, 47.58N, W. Seattle, WA
http://flavorj.com/~skysea

In sci.astro.amateur, Quixotic1 wrote:
: I am a relative novice, and I have a Meade ETX 90 PE. Last night, after
: nights of fog (in the SF Bay Area), I was finally able to track down
: what I am fairly sure was Uranus.

Dang. I'm up in Sonoma, and have been waiting for the same skies so I can
find the same thing. :-( Where are you located?

Scoop wrote:
In sci.astro.amateur, Quixotic1 wrote:
: I am a relative novice, and I have a Meade ETX 90 PE. Last night, after
: nights of fog (in the SF Bay Area), I was finally able to track down
: what I am fairly sure was Uranus.

Dang. I'm up in Sonoma, and have been waiting for the same skies so I can
find the same thing. :-( Where are you located?

Thanks to everyone for the replies! I appreciate it. I will shoot for
Neptune on the next available night, then.

I am located in Fremont, smack dab in the center of the city - and
frankly being able to see anything is a real treat with all the
lighting we have around here. I'm moderately disabled, so it isn't easy
for me to go out somewhere. The best I can do is move my telescope to
the backyard, and look out at the only chunk of sky I get - Southwest.
Last night was the first night in over a week that I had clear skys,
and by the time I came inside, about 4:15AM, I was starting to get
streaming fog. If you are a novice like me, I found that using
binoculars to track down the correct area, and the surrounding stars to
be very, very helpful in finding it. I also have Planetarium on my
Palm, and that helps significantly, too!

Thanks again, to all,

-Dave

"Quixotic1" wrote in message
ups.com...

Hi:

I am a relative novice, and I have a Meade ETX 90 PE. Last night, after
nights of fog (in the SF Bay Area), I was finally able to track down
what I am fairly sure was Uranus. However, what I found was
suspiciously small - not more than a greenish star, but certainly
brighter than its nearest point of light which according my charts
would have been magnitude 8.97. Even when using a 12.4 lens, Uranus was
nothing more than a dot - I could not even call it a blob. Am I on the
correct object? And, should I really not be able to see more than a dot
of light with my telescope?

Probably. I caught a glimpse of it 2 years ago with my 60mm scope and it did
look distinctly green, but it was below my scope's ability to resolve to a
disk (CartesDuCiel reports a disk 3.6" wide, although I am not sure how
correct this is). Although I upped the magnification to 180x, it did no good,
as I began to lose light so it started becoming a peripheral vision object.

The difference between 60mm and 90mm is not very big, so I'd expect the image
to be similar, although I suspect you may be able to resolve the disk if the
sky allows you to use magnifications in excess of 100x.

Based on some earlier discussions we had on this forum, assuming a disk of
3.6" and your scope, you should be able to see the disk at a magnification of
200"/3.6" = ~ 55x, although I am not sure if the same considerations apply for
resolving planetary disks as they do for star binaries. I suspect you may need
more magnification :-(

If this is the best it gets, is there any reason to try to track down
Neptune with a magnitude at about 8 with my setup?

Neptune will be even fainter and smaller, but it is definitely worth a try,
just so you can brag that you "bagged" the object. :-)

I was very happy that I was even able to locate Uranus with my 60mm scope.

Thanks for your interest and replies.

-Dave
--
Ioannis

I am a relative novice, and I have a Meade ETX 90 PE. Last night, after
nights of fog (in the SF Bay Area), I was finally able to track down
what I am fairly sure was Uranus. However, what I found was
suspiciously small - not more than a greenish star, but certainly
brighter than its nearest point of light which according my charts
would have been magnitude 8.97. Even when using a 12.4 lens, Uranus was
nothing more than a dot - I could not even call it a blob. Am I on the
correct object? And, should I really not be able to see more than a dot
of light with my telescope?

Our club's website has an article on observing Uranus:
http://www.vtastro.org/articles/uranus2006.html

Dennis

"Quixotic1" wrote in
ups.com:

Hi:

I am a relative novice, and I have a Meade ETX 90 PE. Last night, after
nights of fog (in the SF Bay Area), I was finally able to track down
what I am fairly sure was Uranus. However, what I found was
suspiciously small - not more than a greenish star, but certainly
brighter than its nearest point of light which according my charts
would have been magnitude 8.97. Even when using a 12.4 lens, Uranus was
nothing more than a dot - I could not even call it a blob. Am I on the
correct object? And, should I really not be able to see more than a dot
of light with my telescope?

Your observation is exactly what would be expected. The hint of colour is the
giveaway and you can definitely tell that it is not a star once you get over
100X. You should be also able to see it using binoculars quite easily. It
should even be possible to see it without any optical aid at all at mag 5.7
if the skies are dark enough and your eyes are well adapted. Unfortunately my
own eyesight isn't good enough.


If this is the best it gets, is there any reason to try to track down
Neptune with a magnitude at about 8 with my setup?

Sure, even if just to test your star hopping skills.

Klazmon.


Thanks for your interest and replies.

-Dave

Ioannis wrote:

I caught a glimpse of [Uranus] 2 years ago with my 60mm scope
and it did look distinctly green, but it was below my scope's ability
to resolve to a disk

I'm very surprised by that statement. In my 70mm refractor at 120X,
Uranus is an absolutely unmistakeable extended circular disk.
Neptune is subtle, but Uranus isn't subtle at all.

That's not surprising, since at 120X, Uranus's apparent size is 7',
about the size of Mare Imbrium to the naked eye. Few people find
Mare Imbrium hard to distinguish, yet it's a dark feature, and dark
features are harder to resolve than bright ones like Uranus.

- Tony Flanders

Quixotic1 wrote:

Even when using a 12.4 eyepiece, Uranus was
nothing more than a dot - I could not even call it a blob.

That sounds right. A dot like the period at the end of a sentence,
right? As opposed to a point, like a star. The difference should
be apparent if you compare it to a star of similar brightness.

- Tony Flanders