salutations celestial sight seers I'm David fuller welcome to eyes on the sky
what's up this week the currently farthest planet in the solar system
sorry Pluto! I still think you're a planet but the IAU says no - neptune is
visible in our evening sky it reached opposition on September 10th so we're a
couple weeks past that but at that time it was really close to a fourth
magnitude star so close it was actually a little difficult to separate because
Neptune is only about magnitude oh seven point eight so where can we find the
eighth planet out there well along the ecliptic to start so when we look at
where the ecliptic goes pull up our markings and we could do the ecliptic of
date we can see how Jupiter is over in the southwest
Saturn is over there by Sagittarius also in the southwest and then we move over
to the south east then Neptune is right there near that ecliptic line but
finding it is not necessarily all that easy because it's in the constellation
of Aquarius - Aquarius is not a bright constellation there are some brighter
stars in Aquarius but if you look at how the constellation goes yeah these are
the two bright stars in it and the ones over here not so much even the stars
over here in one of the fish heads of Pisces not terribly bright but we have
some stars that are bright enough to help get you in that neighborhood of
where you want to be able to look if you can't see the fourth magnitude star that
Neptune is near which a lot of us can't because of light pollution so if you
look at these stars of Pegasus these are all about 13 to 15 degrees apart in the
great square of Pegasus so that's fairly simple to find we can look into find the
Horsehead over here and aquarius is below kind of where the head goes upside
down across the sky so if you take this star which is right there at the neck
Pegasus and then this one by the foot so not where Andromeda goes out this way
but these two stars like this and then you just keep that line going you're
gonna go past this western fish head of Pisces and if you use binoculars you
might even see this star as you kind of pass by there and you're gonna go about
not quite double that length so these stars if you measure them very carefully
they're just about 13 degrees so if we go another 13 degrees
yeah we're not quite there and then you'd have to go basically another seven
or eight to get to where Neptune is so one-and-a-half times that distance of
those stars in that great square Pegasus now that's a long way to go because most
binoculars are only gonna get you about five to seven degrees so we kind of have
to just trust that we're going there but I want to show you what stars are gonna
be visible that will make it easy to know that you're in the right spot so
I'm gonna take off our measuring tool here and zoom in on this area and look
at these stars right here there's that three stars really close together and
then this other star right there and then that one so if we actually take
away those stars the lines from Aquarius you can see how this is gonna look in
the sky so these three little stars are gonna be very obvious let's Center on
this one for the moment and then pull up some binoculars and we'll see what we're
looking at so here's a binoculars view which is gonna be similar to what many
finder scopes will also show you as well and as you can see there's those three
stars one two three they're all really close to each other pretty simple to
find this one and then there's the this is the star that we really want to be
looking at Phi Aquarii because Neptune is not even a degree away from
there so almost any wide field telescopic view it's gonna show you that
so just barely past there you can see how those three
stars are but we want to know how we get there from Pegasus so here's what we can
do so here's our star from Pegasus that we're gonna start from we bring up the
binoculars which direction are we going we're going this way
right so we're gonna follow these we're gonna see these stars so there's like I
don't know if that's a parallelogram really or what but that's sort of a
rhombus shape maybe we keep going there are some Pisces stars actually pull over
just a little bit we these are kind of like that's that fish head area I think
of Pisces go this direction and keep going and again it's just sort of
trusting that were there oh there it is and there's Phi Aquarii so I'm gonna do
that again but I'll do it so I kind of go about a seven degrees distance each
time so here's this again we're gonna pull right in there so we go all the way
over so Markab is all the way on the opposite side now we're gonna take this
star and keep that going all the way over so we're not there yet but there's
that fish head and now we keep going with that push those stars all the way
out of the field of view and then just a little farther and there is Phi Aquarii
so if you keep going and find Phi Aquarii there's those three stars right
here that you're gonna find so once you've gone past Phi Aquarii I to find
those now you know exactly where you're at so these stars are I mean these are
also fourth magnitude stars so for point four or four point two four point nine
five that's actually a fifth magnitude star and there's a fifth thing to start
but these are comparable in brightness so you'll know you're in that right spot
and then go over to Phi Aquarii I move just a little bit over boom there's the
planet now how do you observe Neptune well in binoculars or a finderscope this
might be difficult unless you're into really pretty dark skies and have a very
steady view because 8th magnitude that's not easy to see you can see it
but seeing it for sure and identifying it yeah I could see it averted vision
from my front yard I'm like excuse me a 70 millimeter telescope that was
actually a little more difficult than I expected it to be I have seen it in
binoculars but I think I had a really super transparent night that made that
simpler to do so it's possible but let's go ahead and try to use the telescope
because the more magnification you can put on it the more opportunity you're
gonna have to be able to see any kind of disk because it's not big 2.36
arc seconds across that's not a lot that's very small so let's bump up the
magnification and we're gonna get a little bit more than what we need to see
or would be able to see probably using Stellarium
but it'll help so we can get some idea so I've really pushed this up so this is
about 280 times magnification I can get that fairly easily in about a
6 inch telescope that I have and you would be able to do the same if you've
got the right lenses to be able to achieve that kind of magnification you
can see how the disc is not very disc like it's just a little bit larger but
the thing about Neptune is is that it doesn't look like a star its point
almost point-like but it doesn't twinkle and so therefore and the blue doesn't
look like typical blue-white stars when you look at an O-class star you can kind
of see it's like a whitish blueish this is really more of a deeper blue so it
really does kind of stand out and I would definitely encourage you to try
and take a look at our farthest planet in our solar system now by the way this
is not gonna move all that much over the next several months so check this out
I'm just gonna keep moving out and you can see how Neptune right about the
middle or so of November it sort of stops over by this star but it's still
not that far away from Phi Aquarii and then it starts to zoom back in now
it is gonna drop in the sky so by the time we get out to around early February
or so it's going to be pretty low and makes it difficult to see you can
see how we start to get pretty low but Venus drops by, and will probably wash
it completely out by late January or so once we get past there you can see how
low it is there's the horizon but we could back up a little bit in time get a
little bit higher in the sky and then it gets back in the same range where it's
difficult to see right near Phi Aquarii but it is possible to see eight
magnitude we can see that in almost any telescope seeing it well is gonna
require more aperture more magnification 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