Salutations, celestial sightseers, I'm David Fuller. Welcome to Eyes on the Sky -
what's up this week? Well we have a full Moon coming up at the middle part of
next week on the 22nd 23rd so we're gonna have a lot of - I don't want to call
it light pollution because the moon is not really light pollution - but it's an
artificial light that's gonna wash out some of the things that we would
normally be able to see that are fainter like star clusters or galaxies or
whatever else. So instead we're going to focus on some double stars which will
sort of punch through that light. And I will start over in the northern part of
the sky because you can see the moon is gonna be way over here... here's where our
center of our galaxy is, starting to fade off below the horizon... at least here in
the northern hemisphere at 40 degrees north latitude where I'm located. But if
we look towards the north - turn on our constellation markers and lines - over in
Cassiopeia, here's the North Star. We can find that actually by going from the Big
Dipper across Cassiopeia sort of this M or W shape. If we zoom in on that some
we've got a lots of stuff that's happening for deep sky objects, but we're
gonna take those off, and not show those because we want to focus on some double
stars. Here's our brighter stars within Cassiopeia. Beta is a 2.25, Alpha is a 2.2
Ggamma is a 2.2. We got a little bit dimmer over here with 2.65
and that 3.35. So our brighter side of that we're gonna focus
on the middle star and then go towards Alpha. And see this star right in the middle?
That's Eta Cassiopeiae. Don't get confused
by these two double stars. We're gonna focus on this one you won't be able to
see that as a double in a finderscope or in binoculars. You really will need to
use some telescopic magnification on this. So if we center that and zoom in
what we find is is that.... Ah! We can't really see a lot. So what do we have to
do with Stellarium? Well click over on the Sky Viewing Options" window and what
you want to do is go to the "Sky" tab. And see the absolute scale and relative
scale? Bring those down some at least the relative scale. Then all of a sudden
"Oh hey look!" There's our double star now. These are pretty cool because they're
close they're only about 19 light-years away. There is a little bit of a
difference in terms of the type and temperature of these stars. So our main
one is an F class star. It is therefore somewhat brighter. But our dimmer one. the
Eta Cassiopeiae B is - I don't actually see it on there, but I believe it's a K-class
star. So therefore it's quite a bit dimmer. But when you look at these
through a telescope you'll see a color difference. The question is: What color
difference do you see? Because this star is quite a bit dimmer than A. See, A is 3.5
and this we're looking at 7.4. So due to that difference in
magnitude you may see some interesting color changes. So post that for me
whether you found me on Twitter or Facebook or follow on YouTube, post what
colors you see when you look at those two stars. I know what I see but tell me
what you see through your telescope when you view that. So that's a really easy
one to find because the distance between these two stars not that far. You can
find that right into any finder scope. You're looking at just four and a half
degrees or so and Eta is not quite halfway in between there, so pretty
simple to find. The harder one to find is on the other part of the sky towards the
south and that one you may want to wait for the moon to kind of get out of the
way a little bit. So we're gonna head over towards where the Summer Triangle is.
I'm actually bring some of our relative scale back up
so we can see some of this a little bit more easily. And we'll bump that out of
the way. So here's where the Great Square Pegasus is and then the flying horse's
nose. So if we go that direction and kind of shoot off that way towards the Summer
Triangle, there's this little teeny tiny constellation over here called Delphinus
which is supposed to be a dolphin. So it's made up of pretty dim stars.
It's like mostly fourth magnitude stars! As you can see these are not bright
stars at all. So if you cannot find this because of light pollution or the moon,
I understand. But, you're gonna look about 15 degrees away from Enif which is a
2nd magnitude star. And some people may even be able to see this star right
here, Gamma Sagittae.
So look kind of halfway in
between those - that's a 3.5 magnitude star - so you might be able to
find that. Or even just look for Altair and then just kind of go above there
with a finderscope. And then these stars will kind of pop out fairly easily.
The distance across these little ones right here - only three degrees. Even the entire
thing it's only about five and a half six degrees across. So not very big
as far as constellations. But what you want to aim for is that one. The one on
the nose of the dolphin itself. I don't think it looks like a dolphin but that's
where you want to focus. So centering that bringing our relative scale back down,
And then zooming in, we can split these. Boom! And there they go.
So there's two stars. Now these ones are closer in magnitude to each other because we've
got 4.3 and 5.1, so a little more balanced, And they're
further away, these are about a hundred light years away. But that's still kind
of in our relative neighborhood I guess you could say? But just interesting the
the difference and what you see in terms of brightness for something that's you
know only 20 light years away versus hundred light years away and really
comparable in kind of what you're seeing there. But tell me what you see with
those two. And tell me if you can split those. Now what I did was I just had a 70mm
refractor aimed at both of these.I was able to split both with just
50 times the magnification. I did bump it up to about 90 later on just to kind of
get a little bit more separation and see a little bit more color. So take a look
at both of these stars with a small telescope and tell me what colors that
you see in these when you observe them. That's all for this week! Keep your eyes
on the sky, and your outdoor lights aimed down, so we can all see what's up! I'm
David Fuller wishing you clear, and dark skies!
you