Hey Facebook, we're live from Goddard Space Flight Center.
I'm Erin Kisliuk with the Hubble Space Telescope.
Did you know that this weekend is the peak of the
Orionid meteor shower? So if you go out and look up and happen
to see a few shooting stars, which you're actually seeing is
debris from Halley's Comet.
In the mid 1700's there was an astronomer named Charles Messier
and he studied comets, but sometimes when he'd go out and look
up, he'd catch these fuzzy images
so he decided to categorize them
and make a list so he would never be
distracted by them ever again. Thus began
the Messier Catalog. Hubble just today released it's own
album full of Messier objects
taken by the space telescope and
we're going to talk about them here today with you.
Make sure to send in questions
and we'll answer them at the end of the show.
I'm going to introduce you to some very special guests.
So today we're joined by Michelle Thaller
and Kevin Hartnett and thank you both for being here today.
Hey, it's great to be here.
All right were are going to jump right on into it.
Who is Charles Messier and why is catalog so cool?
Well Erin you just said, Charles Messier was an astronomer who was active
in the late 1700's and he was really interested in finding
comets, he actually found many of them over
the course of his career, but there was some fuzzy
little blobs in the sky that looked like comets
but he could tell that they weren't comets
because the didn't move with respect to the stars.
Comets appear and disappear
and they actually move with respect to the background stars
but these little fuzzy blobs stayed right
where they were. So he made a catalog
of basically things to avoid
that weren't comets and the thing that is a
wonderful irony is what he actually had
discovered were some of the dramatic and beautiful
objects in the entire universe.
He discovered things like dead
stars or stars being born
or what we know now are very distant galaxies.
So in fact Messier found
some of the most fascinating things in the sky.
Yep, what's very
interesting is the first object
that we'll talk about, the Crab Nebula.
He was looking actually for the
return of Halley's Comet himself
which was predicted to show up in the
constellation of Taurus in that period
and so he was scanning to find
Halley's Comet and came across this object
that we're going to talk about.
So the catalog is
numbered basically in the order that Messier
discovered these things. So we are going to
start with M1 and just like Kevin
said, M1 is called the Crab Nebula.
So we actually have a depiction here
of where the Crab Nebula is in the sky
and a little bit of what it looks like.
See it's actually in the constellation
Taurus, it's going to be honing in on that
and as this begins to pan in
look there's a fuzzy little thing there
and that is what he saw and that
what he thought might me a comet.
But as we pan into even more
you see that there is wonderful dramatic
structure and what this turns out to be
is an exploded star.
It's what we call a supernova remnant.
So there was a star long ago
that exploded and actually spread its
material over hundreds and hundreds of light years
and in the middle there is the dead
core of a star call a neutron star.
Neutron stars are amazing
they have the density of Mt. Everest
pushed into every teaspoon full of
material and they rotate hundreds
of times a second and I remember
you knew what year this star exploded.
Yes. So historians
have figured out that this
is associated with
the Chinese sighting
of a guest star. they called it
that was visible, so bright
it could be seen during the day time and
that was 1054 A.D.
So we are very sure when this star actually exploded.
Now Kevin is an amazing
amateur astronomer, he actually takes pictures
of these objects with his own telescope
so should we go to some of the images that you
taken yourself?
Sure why not. In this case
I don't have one of M1
we'll see others but I wanted to show you
both this chart and where M1
can be found. Do you see
the constellation of
Taurus here?
This little cluster of stars
called the Hyades is V shaped
and it marks the horns
of the bull of Taurus.
He's up and to the right of Orion.
Very easily spotted in the winter sky
and you take the
lower horn and look at it
with a telescope and your
sure to find M1
if you sweep around the field
of view with that
star in it because it's very close
to that star named
Zata Tauri.
I want you to
know that in the Hubble catalog
that's been released
we have a star chart like this
for every Messier that's in the catalog.
Even if you don't know
anything about the Messier objects
you'll know basically where to find them in the sky.
What season to look for them in
what constellation they're in and
we also tell you in the album what
telescope is a good one to look for this
object and what time of the month
or what month of the year you should be looking for it.
So keeping with the theme of
dead stars there's another one of my
Messier objects, it's one of my favorites
it's called the Ring Nebula. So we talked about M1
being the first one, this is all the way M57
Now the Ring Nebula is in the
constellation Lyra and this is
actually different, sort of dead star.
The first on exploded violently
in a super nova, this star is
basically, generally unraveling itself
into space. It was a star that was
more about the mass the of sun
it's dying and losing shells of gas
around it. In the middle there's the
remnant of this tiny little star,
which is cooling off and basically dying.
The Ring Nebula is a beautiful object
and you can see some of the complexity
that the Hubble Space Telescope discovered
when it took many different visuals of
this Ring Nebula.
The thing that I really love about the Ring Nebula
is it's not very easy to see
in a telescope, you have to use a special technique
to see it, so tell us a bit about your
observation and how you see an object
like this.
Ok, sure be happy to.
It's one of my favorites, it's a great
summer favorite for amateur astronomer
it's high in the sky and it's
fairly easy to locate
in the constellation of Lyra
but as Michelle said
it's small and a little bit hard to find
and when you a
put in an eye piece that has more
magnification it dims
It gets a little
tricky to see especially the hole that's in
the center.
What you have to do and this a trick
that we amateurs use
is look to the side of the object
because the edge of your eye
is more sensitive to light then
the center is, oddly enough.
You have rods and cones in your eye
and the rods are along
the edge so at night
your peripheral
vision is better then your
center vision and you can see things
that move, so as a trick
we get the object
in the telescope and then
look to the side of the object
and wiggle the telescope a little bit
and you can see it better when you do that.
Especially the hole
in the middle, it looks like a big smoke ring
in sky when you use
those tricks. Now you won't see the center
star because that's pretty faint and
although I took this
photo with just a
general DSLR and
modest telescope
the camera is more sensitive then your
eye and so it can pick up on this star.
You'd need probably
a 14" telescope
to see that star.
So we are going from the theme of dead stars to something now
very different and that is the birth of stars.
Messier discovered things that represent all
the different fazes of the life cycles of stars.
So we're going to start talking about young stars.
Yeah, while we walk over to talk about
the young stars over here, I wanted to remind
everybody to continue to send in questions
we are really great ones.
Were still here at Goddard Space Flight Center talking about
Hubble Messier catalog
and now we're going to be talking about young stars
so take it away, I'll get out of your way.
Well that's right, these are stars that are being born.
The next object we're going to talk about is one of my
favorites in the sky, it's like an old friend
returning every time the fall sky rolls around.
And that's M42, this is the
Orion Nebula and as you can see in this
wonderful animation with the Orion Nebula
really is, is a giant
cloud of dust and gas
and inside it there are stars
forming that are lighting us this cloud.
There are 4 very bright
stars at the very heart of the nebula called
the Trapezium Cluster and these stars
are larger then the Sun.
More massive then the Sun and brighter
and the light from them is lighting up the whole area
that we know of as the Orion Nebula.
To me this is one of the most beautiful images ever taken
by Hubble. It's not only beautiful
but it's very dramatic when you think about
this is a cloud of dust and gas
many, many hundreds of light years across
and inside it there are
dozens, if not hundreds of new stars
forming right now.
So this is a beautiful object and I have to say the image
you took of this is spectacular.
I mean you are an amazing astro-photographer.
Let's take a look at what you got with this on.
Well it is one of one of my
better efforts, but they are all work
and I want to really communicate
that taking pictures
is another aspect of astronomy that is
enjoyable and has it's technical challenges
but I've spent most of my life
observing these things with binoculars or a telescope
and it's as much fun
it's probably more fun then
trying to take pictures of them which is just hard.
So here you see
an image
of Orion Nebula
and I want to point out the contrast between this one
and this one. It took Hubble
about 500
different pointing's
mosaics stitched together to form
this image because Hubble
zooms in and has such
high magnification, it zooms in to
a smaller part of the
object, this could all fit
in the field of view of my telescope.
When you are looking at this object
just with a telescope
and not worried about taking pictures
you want to look for it beneath the 3
stars that form Orion's belt
the sheath for his sword
if you will, right in that
area from a dark spot
you can see a faint cloud
and put a telescope on it
and you can see, right there
is an image of where
M42 is.
Again, this is on our website
so you can find
these for all the Messier objects there.
But you put a telescope
on it and you can see this trapezium
4 little stars in a
trapezoid shape and
enjoy the dark and light bands
of this nebula.  It's truly spectacular.
Messier found a number of examples
of young stars, in the case of the Orion
Nebula the stars are still forming
in this cloud of dust and gas
but then there are other stars that are a little farther long
that have moved out of the clouds they
were born in. In many cases
just the radiation and also the particle winds
coming off these birth young stars
blows away the cloud and so the next
thing we are going to is an example of a young
cluster of stars, stars that
all formed probably in the least tens of millions of years.
Doesn't sound very you to us but
for stars that they are and this is a
cluster called the Pleiades and the Pleiades
is a wonderful thing to see to see in the
autumn and winter sky it's always
wonderful for me that wonderful, beautiful
autumn sky is rolling around.
These images look very different, so here's
image that you took of this young cluster of stars
and in fact the Hubble image
has so much resolution
and so much focus that it's only a tiny
part of your image here. Right.
So compare the Hubble image that we have here
with what you were able to see with the Pleiades.
So it's a very tiny portion, the Pleiades
is a naked eye object
and it's somewhat
like 3 or 4 times
the size of the full moon.
It's very big on the sky.
This image
taken by Hubble
of part of the gas and dust
surrounding these stars
is right in between this bright star
called Merope and these two little stars
next to it, so it's a very
tiny portion of
the actual Pleiades.
Pleiades is also known as the
Seven Sisters, a lot of people mistake it for
the Little Dipper, cause it has this
dipper shape.
With your eye you really only see six, there's
this legend of the
missing Pleiad because you don't see
seven but this
cluster is also know in Japan
as Subaru so when you look at the
logo on the back of a Subaru
you're looking at this star pattern, most people
don't know that.
It's a very, very beautiful cluster
and best appreciated
in binoculars or a small telescope
where you can see just
these diamonds
on a black background.
So we're talking about families of stars
and the type of cluster that the Pleiades
is something called an open cluster
these are stars that form relatively close to each other
in one of these big clouds
but the sun was probably in a cluster like this billions
of years ago, but over that time
we've been around the galaxy so many times
that just the gravitational interaction between
the stars have peeled off all the other
members of our star cluster, we don't really know
where in the sky our brother and sister
stars are. So an open cluster
is a family of stars that all formed together
and we're go over and talk a bit more
about some different families of stars now.
Yeah, once again while we're walking
over, I just want to remind everyone to keep
sending in your questions. I'm getting some really
really great ones.
We are here at Goddard Space Flight Center talking about
Hubble's Messier catalog so continue
sending in your question and I'll let you guys talk
about clusters.
Here's another example of an open cluster
this is M11 Wild Duck Cluster.
Open clusters are
stars that form together relatively
recently in the last millions or tens of millions
of years and are slowly peeling apart
over time so this is another one that
you have a very different image
Hubble is taking sort of picture here of the heart
of this cluster and you have picture of the larger
cluster so people can see that.
Right, neither one looks much like a wild duck, do they?
If you had a small
telescope or a pair of binoculars
and looked at this object which is in the summer
sky in the Milky Way
you'll see a V-shaped
grouping of stars
the brighter stars are V-shaped and
reminded the early observers
of a flight of ducks or geese that
are characteristically flying in a V.
When I look at this
and this is one of my favorites too
you notice right away and so did
Messier, he wrote in his catalog
about this that
there is a very bright star
in the center of the cluster.
Hard to make out here because
it just gets lost with all the others.
It's very, very noticeable.
When you look at it in a telescope
this amazing
grouping of stars
and this one bright one
in the middle. Now I found this
cluster is particularly
fun to look at
in higher magnification
and I like to use a zoom eye piece
so I look at it
at low magnification
and the stars are really tight
and then as you twist the eye
piece it zooms in
and you see hundreds more.
It's a remarkable beautiful
open cluster
and there is
something like, oh gee
hundred of stars in the cluster.
That's right an open cluster can have
dozens or hundreds of stars but
there are much larger star cluster as well.
Certainly the largest ones that are in our own
galaxy, the Milky Way, are called the globular clusters.
We have an absolutely spectacular
picture of a globular cluster here.
This is the globular cluster M15
the 15th thing on the list of things that where not comets.
This is actually a cluster of
stars that contains millions of stars.
Now, astronomers believe
that globular clusters are ancient clusters
they probably formed very early on
in the lifetime of our galaxy
and if you think about the Milky Way galaxy
we live in a spiral galaxy that is kind of shaped like a Frisbee.
It's a disk of stars and gas
and dust, but the globular clusters
orbit around the entire
galaxy almost like a swarm
of angry bees. They are going all
different directions around the Milky Way.
In fact globular clusters were one of the
first ways that we discovered our
own place in the Milky Way.
It turns out we are nowhere near the center
of the Milky Way, we live out in the suburbs
about three quarters of the way out into the disk
from the center. So that's a long way from
the middle of the galaxy.
And all these globular clusters orbit around the center
of mass of our galaxy.
Astronomer along time ago realized
that most of the globular clusters were
in one half of the sky
fewer on the other half of the sky and that's
cause we were looking from a vantage point of being very
far out from the center of the galaxy.
When ever I see globular clusters
I really aware of the
place, the roll that they had in
giving us a map as to where we are in the galaxy.
As really good
thing that we're not on a planet inside
a globular cluster cause we wouldn't
see much of the sky at all right?
It would be like daytime all the time.
Just look at all of those stars packed into
that little area.
Yes so it's very good for observing that we are
where are.
See you have another great image here.
Yeah, this image is fun
because I took it two nights ago, right?
I took it with a very small telescope.
It's in the constellation
of Pegasus.
The flying horse, which if you go out
in tonight
in tonight's sky
it will appear as a square
they call the square
Pegasus, very prominent square
in the sky and I like to
consider it like a baseball diamond.
Cause it's oriented that way.
This object is located
off first base
and there is a
L-shaped string of stars
is right at the tip of the L.
It's very easy to find. Right there. There you go.
So we've been talking about families
of stars, the star clusters and in fact
the largest families of stars in the universe
are the galaxies.
These are families of stars that include hundreds
of billions of stars.
So let's talk a bit about some of the galaxies
that we are looking at.
While we walk over to the biggest
screen in the room, we'll talk about the biggest objects, right?
I just want to remind everybody
once again we're here at Goddard.
We're talking about Hubble's Messier objects
and please continue to send in your questions,
we've got a ton of good ones and I'll let you talk about galaxies.
Sounds good, yes, right.
We're going to end with looking at some of these beautiful
spiral galaxies and the first one we are looking at
is something the Whirlpool galaxy which is know
as M51 and the
Whirlpool galaxy is a spiral galaxy
about half the size of our own Milky Way
and is at a distance of about
23 million light years away.
You can see here in this beautiful
Hubble image the detail on the spiral
arms of this galaxy.
The dark areas are actually lanes of gas
and dust where new stars are forming
inside that right now. In fact,
when ever you see red areas along the spiral
arm, that's active star formation.
That's where young stars are still embedded
in the dust and they are lighting up the
dust and making glow red.
It is an absolutely beautiful spiral.
The thing that is amazing about
this, is looks quite different
through a telescope and some people might be
disappointed but I still think it's a wonder thing to look at.
So tell us a bit about what it's like to observe
a beautiful galaxy like this.
I tell you, it's fun
to glimpse these things
even if you're not seeing them particularly
clearly in the night sky.
There's a
connection with the universe
by looking at the light of
these things with your own eye.
Just like Messier would have
seen this, it was a smudge but know you know
what it really is and that's electrifying.
If you're, at night, searching for these
things with your telescope and finding
it and realizing what you're seeing
there is nothing really quite like it.
Messier would not have seen the spiral arms
because you need a large a telescope
to do that and his telescopes where not
very good, they weren't even made of glass.
The ones that we use now
with mirrors, the mirrors were made out of metal
back then and we've
looked at these globular clusters
in M15
Messier noted he didn't see one
star in that globular cluster
that we now know has
millions of stars.
So his view was very very different.
This is an image I took, it took about 4 hours
to layup that image. In a second
I'll show you what one little frame looked like.
But this object was
not seen by Messier
at the time, it's a neighboring galaxy.
He only saw the very
core of this and it looked like a little blob.
So the thing is
even if your telescope image
doesn't look like this, it's still wonderful
to think the lights your looking, even when you see a little
smudge on the sky, in this case it's
23 millions years old.
23 million light years away, means the light
took that long to get to us so when you see
this beautiful as just a smudge
in the sky, that light left long before
there were humans on the earth.
You mention you were going to show us
so this is what you'd see through even a large telescope.
Yeah, this was taken through a 8" diameter
telescope and it took
I'm trying to remember now, about 3 minutes
or 4 minutes to layup this particular
image and you see you get
all the light pollution
right? The sky glow in the back
too. The trick
that amateurs use
is to stack
all these up, line them up
and so I took, what ever, 4 hours
of 3 minute exposures
and you can get software free off the web
now to align them all and stack
them up and you learn some about processing.
Honestly,
although I don't want you to think
that your going to see these marvelous images,
the pictures
from Hubble or even my telescope
by looking through the eye piece.
It is encouraging
or it should be encouraging you that, I've only been
at astro-photography for maybe 4 years
with a digital camera
and so you can learn very quickly with a lot of
resources on the web but
start with the Hubble site.
You can find out where the Messier's
are in the sky
and what instrument to use
look at them and once you get more
familiar with the sky, like I've done over many
years then dabble in astro-photography.
So we are going to wrap up our
catalog of the Messier objects
with one of the most beautiful things in the sky called
the Andromeda galaxy, this is M31
and I have to say Kevin this your image.
This is absolutely spectacular. The Andromeda
galaxy is a galaxy very much like the Milky Way
it's a distance of a little bit more then 2 million light years away.
The thing that is amazing about the Andromeda
galaxy is that edge to edge this
is as large on the sky as
three full moons.
Think about lining full moon up
across that galaxy.
At night when this thing is up, there's this
giant galaxy actually covering a fairly large
part of our sky but the reason we don't see
it's very faint and in fact
Messier could only see the very very central
part of the galaxy but this other objects
in here as well that Messier saw
in this gorgeous image that you took.  Tell us about that.
Wouldn't we all had eyes to see this
thing in the sky hanging
there in the autumn sky as big
as 6 full moons across, right?
It's just an amazingly big object.
It's faint because it's a long way away.
So when you look at this in a telescope
or with binoculars, in fact you can see this object
with the naked eye from a dark place.
You're really only seeing the very bright core
but that is what you'll see in a scope
or binoculars. Very fun to see.
I remember dragging my whole family when I was maybe 15
and it was in the winter and
I said, now that I found you have to see it so
it was like 20 degrees out, drag all my sisters out
to see this thing because it's just
it's a classic. It's very spectacular.
This object, Messier also found probably within
the same night that he looked at M31.
This is called M32.
Again, very easy to see because it's so close to N31
and it looks like a slightly out of focus star.
Little harder to see is this on down here
a companion galaxy, now known as
M110 you have to use that
little trick I mention earlier, looking to the
side of M110 to see it more clearly. I like to
take people out and show them Andromeda
through the telescope, it's very easy to see this
little harder to see this and they have to really work to see
M110 so it's a great learning experience.
Going to the Hubble image of Andromeda,
this is something that is kind of mind blowing.
Hubble is so powerful that it can see the individual
stars in this galaxy
2 million light years away.
Now this galaxy contains hundreds of
billions of stars and when you look
this image there is kind of graininess to the image
and that is real. These are all individual
stars that Hubble can pick out.
Now the amazing thing, it Hubble over
400 pointing's to stitch
together this giant mosaic of Andromeda
and in fact Hubble only had the time
to image about 1/3 of the galaxy.
So think about that. More then
400 Hubble images all put together in a
mosaic to cover just about 1/3
of the Andromeda galaxy.
That's amazing thing to see and an
incredible Messier object.
Hopefully in talking about these wonderful
objects you can see in the sky, things like
dead stars, stars being born,
galaxy, star clusters. You might want to
go out and look at them yourself and this is
where Kevin is the expert and he's going to talk to you
a bit about what you can do, to go out
and make your own Messier catalog.
So you brought some telescopes here so let's go
over here and take a look at this.
So I should probably start here.
Because
from a dark sky
you can see
most of the Messier
objects with a good pair of binoculars.
From the Washington, DC
area maybe a
quarter of them but if you're out
in a dark spot you can see
many of these so get yourself
a star chart like this
and find
them or use the star charts that
are on the Hubble
site and you'll
know where to look.
It's good to use a set of
binoculars at night that's,
one like this.
This is a 10x50
10 is the magnification
50 is the size and milometer
of the glass up front.
Most of us have 7x35 at home they're
great for terrestrial viewing,
looking at things in the yard
or what ever.
But you want a little more power and you want to
gather more light because the stars are faint.
You want this
lens to be as big as you can hold
lens to be as big as you can hold steady.
That's the other caveat, right?
So if you get to heavy of a binocular you can't hold it steady
and you won't get a very good view.
So just 2 other representitives
scopes you might
be fascinated to know that the
beautiful that I took
and the one of the Pleiades was taken with
almost exactly this size, it wasn't this particular one
but I had it mounted on the back
of a larger scope and more
expensive mount that was tracking the star
cause again I had to layup these time
exposures. But you can enjoy
the Pleiades and the Orion
nebula and M31
all as beautiful objects in a scope this size.
Our website says
for each individual object it's best seen or
can be see with a large, medium, or small
telescope. This is what we mean by small.
Up to 3 or 4 inches.
Medium would be more in the class of a 6
to 10 inch diameter telescope.
The size of the
lens again is
the size of the
it's what collecting
the light so think of it as you eyeball.
Imagine your eyeball being 8
inches wide, you'd collect a lot more light.
Then larger scopes,
we didn't have room on set to bring it in here,
can be 10, 12, 16
some amateurs have 20 inch telescopes,
great big things. But the get
obviously difficult to move around.
So
each has their own price range
and pros and cons
read up on a web site that describes
telescopes before buying one and really I
recommend learning your constellations,
finding Messier objects
with a binocular and then
stepping up as your interest continues.
Here's a zoom eye piece
that I was mentioning before
so you just twist it and it
magnifies so you don't have to keep
reaching for different eye pieces.
If you do want to do that
there are many different types
and
it just makes it easier, I find it easier
to just zoom in. Interesting
Charles Messier, he
looked through about every telescope he could get his
hands on and
they were very good
and they didn't have eye pieces
The eye piece they had weren't
replaceable, I should say
they were a fixed magnification.
Interesting different.
Before we go on to some questions from the audience
the question I have for you is how many Messier
objects have you personally seen?
Oh boy! Yeah so.
I've seen just about all of them.
We didn't talk about tonight but there's a
large group of galaxies
in the constellation Coma Berenices
off the tail of Leo and next to Virgo
where there are just
literally scores of galaxies.
Some of them are Messier objects
many of them are not. They didn't make his list.
So I've looked at that cluster
and when you
look through the field of view
you might see 2 or 3 Messier objects
but 2 or 3 that are almost
as bright that he missed somehow.
I've seen
them all, I haven't cataloged
all but I'm starting to do that
now, it kind of a bucket list thing
for me. If you write
down the day, time, and scope
that you used and details
about the sky
and send that log
to the Astronomical League
you can get a certificate.
Which is really cool. Say you've seen all
the Messier objects. So I'm now
logging them all, I've probably seen them all.
But I didn't log them all.
Excellent! Before we go we have some
time for questions.
Yeah, we do and it seems like we have a couple
Messier collection
hopefuls in here.
We have one question asking,
what is the best kind of telescope for
a beginner? While we are over here we might as well
start with the telescope questions, yeah?
The best answer I've heard to that question is
one that you use. OK?
So it can't be to heavy, it can't be
too complicated,
can't be to expensive.
Right? If you're just a beginner.
Because you want to get your feet wet.
Right?
Realize I really can find things.
Enjoy them and then
move up from there.
I find ones that have this
style of mount helpful.
It's called a azimuth and
elevation and so it's very intuitive to just
swing it around and bring it up
and look for your object in the
one of these types of telescopes.
I think this a good choice
not maybe this big but
an azimuth elevation kind of
mount on the telescope.
Then similar we got a different question
from someone else asking, what are the best
kind of binoculars for back yard astronomy?
Yeah, well again a
I would say shoot for something
like a 10x50
like these
and not to heavy.
If you get much heavier then this they
sell stands you can put them on
but you'll want something to steady them.
I think a 10x50 is a
pretty good size for most places.
That's always my problem but I love using binoculars
but it's hard to keep them steady in your hands.
So people have techniques like resting your
elbows on knees
and steadying that way or actually going up against
a wall. That's one of the harder things, learning to
steady the image. Right.
Speaking of images maybe we'll come out here
so we can see some more of these
images in the background
while we take a few more questions.
Watch your step.
Kelly wants to know, what
causes new stars to move
away from the cloud that they were born in?
Well there are a lot of reasons for this.
There an intrinsic movement of the stars.
That when stars form they pick
up angular momentum, they begin to spin
and the clusters of stars spin in different ways too.
Over time this can actually spin some
of the stars out of the cluster entirely.
The other thing to remember is that star clusters
never live just by themselves.
We go around the galaxy.
Right now we actually flying around the center
of the Milky Way galaxy at about a
half a million miles an hour.
Good thing we don't actually feel that.
As the Sun moves around the galaxy it has
very gentle gravitation encounters
with other stars. Over billions
of years, over many passes around
the galaxy, this spreads the cluster out.
We've left probably some of our sister stars
way on the other side of the galaxy.
The star formed right near us but now
it's 100 thousand light years away.
And that's just the regular gravitational attraction
of the different stars as we move through the galaxy.
Great! It seems like these clusters
kind of resonated with people.
Someone else wanted to know,
how far away are stars
in a cluster?
That's an interesting question. I don't have an exact number
for some of the clusters that we've been showing you.
But as Kevin mentioned, if you were in a globular
cluster. If you were in a planet
around a star in the heart of a globular
cluster, the night sky would be
brilliantly bright. So the closest
star to us is about 4 light years away
and in the heart of a globular cluster
it would be a lot closer then that.
I don't have an exact number but I do know
the night sky would look a lot different.
4 light years is a long way.
Right? And so
I've read if
you considered the volume
of sphere
this 4 light years in
radius some of these globular
cluster there could be as many as
10 thousand stars within that
that sphere and so
imagine being on a planet around one of those
it would be just dazzling.
And then another question.
This one looks it's specifically
for Kevin. How do you deal with light pollution?
Yes... Well
I cry a lot I guess is the answer.
[Laughter]
If you have a
portable telescope which some of my are.
You get to a dark spot. In that way
you can just enjoy the night sky and
find things easier.
Taking pictures, see
is one of the strategies that I have
to fight light pollution because
you can play tricks with a digital camera.
Digital camera is very very
sensitive as you've seen in these
images and so
you can play these tricks
about stacking up photos
and processing them and get these
amazing results. I live north
of Washington, DC where it's very
bright and yet
you can play these tricks
with a digital camera.
Some of the same tricks Hubble
plays actually.
Taking an image
and then basically covering
the shutter
and putting up a black
cover on the telescope
and taking another image. You'd say
why would you do that? You record the
noise in the camera
and then there is software
that you can use to subtract off the noise
so this is the way to fight light
pollution. You subtract it off with
a digital camera. Can't do that with your eye.
But Hubble plays that same trick.
Not to fight light pollution so much but
just to get that noise that is
inherent in the camera because of it's
thermal qualities
and subtract that out.
It's amazing to me just how much we are missing with
light pollution. The most beautiful sky I've ever saw
was when I was in Chile, I was in the
Atacama desert where there were no lights around at all
and somebody pointed out that
the Milky Way was so bright over head
it was making me cry. It was so beautiful
I was getting tears in my eyes. I looked down
at the ground and someone pointed out that I was
casting a very dim shadow on the ground.
But there was no moon out that night,
none of the bright planets were out that night
I was actually a shadow being cast by the Milk Way.
That's how bright the Milky Way can get.
So get yourself
to a dark sky if you possible can.
Wow! That's crazy. So we have a question
about Hubble specifically.
How does Hubble take so many sharp
images when it's moving so fast?
Pointing. I think
I'll leave this to the Hubble operation manager.
Absolutely. That's for you Kev. Yes no.
You don't think about it much
that would be more of a problem if
the stars were closer but they're
so far away that the light
that's coming anywhere Earth
is coming in parallel beams.
And so, yes Hubble is moving around the Earth
but it's still seeing these
parallel beams that come from these
distant stars.
If an object was closer like
the moon,
you don't see many Hubble pictures
of the moon do you? See,
Hubble was never designed to look at the moon.
Now we've
over the years that Hubble's been operating
we know have modes that can but they are very
seldom used because you have a
what they have a parallax problem.
The moon is to close
and Hubble is moving to fast
that light beams aren't coming to you
in a parallel fashion.
And so, the secret is
the stars are so far way.
Wow that fascinating.
Some asked, what is the best
telescope for astro-photography?
OK.I don't know how to answer that
question, that's why I'm asking you.
[laughter]
There is different types of targets
what we've been calling
these ones would be classified as
deep space objects
(DOS's). There's also like the moon
and planets. You would
want a different type of telescope
to do lunar and
planetary work then you would
for deep sky objects.
And so that's part of the answer.
For deep sky objects I think
most web sites
I would go to and people more
experience then I at this would say
get medium size
refracting telescope.
It's the type that has the lens up front.
With a
fairly short focal length
and that will probably do the best
for you for these things.
Lot's of reason why
those kind of telescope can
range from the $600 that I bought
to $6000 so
you kind of go with your budget too.
And so much of it appears to be in the way you process the images.
I mean you image of Andromeda was
spectacular. I remember when I first saw it
we were rehearsing for this, I said that was something
that the Mt Wilson telescope would have taken
a 100 years ago. That would have been the best
astronomical image in the world but here you did this out of the
small scope. Yeah, there it is.
So that has to do a lot with what you do
with the imagery afterwards too.
So true. Yes
The more you stack the more signals
noise you get and the more you learn
about Photoshop and
these other processing techniques.
They just
the better you get at it. I really consider myself
a baby at it.
This one again was about a 4 hours exposure.
Many many times more then
4 hours in processing.
And you only have been doing this about 4 years.
Yep. It's because there's so many resources online.
We're bringing you the
Hubble Messier catalog
online with all its information
there's lots and lots of helpful
resources out there about astro-photography.
The Messier catalog is
such an inspiration to me, sort of wrapping
it all up again, we talk about avoiding these things that
aren't comets but instead
it turns out to be the catalog of wonders.
Everything from dead stars to baby stars to
these vast galaxies that you took a picture of
well in some strange way we have
Charles Messier even though
it wasn't what he was looking for.
Yes, he found 13
comets on his own.
Remarkable for the instruments he had and
operating from the center of Paris.
Can you imagine it?
In an observatory there and he
co-discovered 7 others with
his friends. So the man found 20
comets in his lifetime.
Very remarkable for the instruments he had
and the place he was doing it from.
Try to discover one from the center of Paris right now.
Pretty hard to do. OK.
Are you ready for another question? Sure!
Alahondra wants to know what are your favorite
locations for stargazing? I guess I can ask both
of you that question.
Well I just mention the Atacama Desert but that's kind
hard to get to. So it is
amazing to me how much you actually
can see from a relatively dark back yard.
If you can get yourself to a nice clear
horizon. I've seen comets
through small binoculars.
I've seen small telescopes where you can see the rings
of Saturn. Saturn in particular
is an object a lot closer to us
then the Messier objects are but
this is one of the things where if you're a little disappointed
by the Andromeda galaxy just being a smudge.
When you see Saturn and it's rings
right there in front of you and the moons of Saturn
as well, that's something that just floored
me the first time I saw it. It looked like somebody
had taken a picture of Saturn from a textbook and
just kind of pasted on the end of the telescope.
So some of these objects are very easy to
see, they are very bright
don't need a dark sky to see them.
Yeah that's right.
The moon and planets
in even a very modest size scope
can be a
unforgettable
experience.
As you mentioned, seeing the rings of Saturn
I've been at so many
star parties, we call them, we have telescopes
out and have fun with
the heavens.
It's so fun to see people
see the moon or the planets
Saturn or Jupiter with it's
moons and bands for the first time.
They never forget it. I never forget it.
That's what got me into astronomy
many, many years ago
seeing Saturn
there is connection with the universe
that you feel and it's really
unforgettable. Where would I go
around here? I have a brother-in-law
that lives down in Virginia in the mountains
and so that's a good spot to go
and the eastern shore is pretty
good dark spot with nice horizons.
So you can see things
from horizon to horizon
but if I were going to pay money and go some
place it would probably Chile or someplace like that
or Hawaii
to have, be on top of a mountain
where all the other great telescopes are
and observe from there.
One thing I have to say is take advantage of
your local amateur astronomy societies.
Because pretty much where ever you are in the US
there is local club where if don't know what
sort of telescope you'd like
or you don't know how to use a telescope
if you don't where the nearest dark sky
areas are around you. Your local astronomy
club will know these things. And they are an
incredible resource. As a professional
astronomer I would go to these large
observatories and people would type coordinates
in the computers and I would make my observations
I often feel that the amateur astronomy
community are the real astronomers.
They're the people who really know the sky
like the back of their hand.
Right.
Amateur astronomy
groups will also
love to show you telescopes
and so you can try
before you buy. If you
go to a club and that's
also helpful.
Great!
It's kind of like asking someone about
their job,
asking someone about their telescope
they can talk for days.
So unfortunately we only have time for
one more question.
We're going to keep answering some of your questions on
Facebook as they are coming in later on but
unfortunately we only have so much camera time so.
One more question.
What is your favorite object you've view
through a telescope?
Awe, it's like choosing between your children.
Oh wow. OK so I guess.
We just mentioned Saturn
so I think that actually is my favorite.
In the southern sky
there is something called the Carina nebula
and the Carina nebula is an area where
can see star birth and star death
all happening at once. There are young
clusters of stars, then there's a star called
Eta Carinae which is very close
we think to blowing itself up in a supernova
explosion. This part of the sky
has these vast bands of
dark dust and bright gas
and I have to say
those are some of the things that I've
seen with my own eyes
when I was living in the southern hemisphere
that just blew me away.
I mean this is probably the closest thing
I've seen with my
naked eyes looking through a telescope
that looked like a Hubble image.
Eda Carinae would have to be one of my favorites.
Yeah and for me
It is like deciding between
your children I guess.
I really love to look
visually at M11
that Wild Duck cluster.
Because when you first look at it in the scope
you can
imagine how Messier
didn't see any stars in, they're very
very close and yet you
zoom in and
it's almost like the
fly through that we saw.
It turns into something else.
And it's in the heart of the Milky Way where
it's surrounded by hundreds and hundreds stars
to begin with and so it's just
it's
I don't know how to describe it.
It's just beautiful. I could look at it
a long time.
If we don't know how to
describe it, you need to try it yourself.
That's right.
So get out there and
find the Messier catalog yourself
and enjoy the absolutely
beautiful that the Hubble Space Telescope
has made of these objects.
Absolutely, like they said
if you want more we've got
the catalog up on our web site at
nasa.gov/hubble and if you want
to know anything about Hubble
at anytime you can follow
us on twitter
@nasahubble
Thank you both so so much for being
here and thank you all for tuning into us
and we'll see you next time.
Bye
