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In this episode of Star Hopping with Kissimmee Park Observatory, we'll look at the Centaurus
region, and show you how to find these beautiful deep sky objects:
The barred spiral galaxy Messier 83 The peculiar galaxy NGC 5128
And the largest Globular Cluster, Omega Centauri
Alright, Let's Go Star Hopping!
Hey Hello Hi and welcome to Episode 30 of Star Hopping with Kissimmee Park Observatory!
I'm Dave Hearn, and I'm very simply, pleased to be your host.
In this series of programs we'll show you the most beautiful sights in the night sky,
and explain exactly how to find them with your binoculars or telescope.
Well we are back to locating some great deep sky objects, and this week I have a trio of
very southern objects for you. For this of you located at about 30 degrees north latitude
or below, these three targets are located in the deep southern sky. At this springy
time of the year, of course we’re talking about the rich constellation of Centaurus,
the Centaur. Spring is the best time to view Centaurus, and to take advantage of its highest
culmination in our skies.
I think I have mentioned it before on Star Hopping, that for many years, I attended the
Winter Star Party in the Florida Keys. The campsite where they have the WSP is between
Marathon and Key West, and it lies at only 24 degrees north latitude. Having full ocean
at the southern exposure, it is possible to see some extreme southerly celestial sights,
such as Crux, the Southern Cross, and the great nebula Eta Carina, which only gets about
5 degrees up. But I have seen it from the Winter Star Party site, when we were lucky
enough to have a clear sky right down to the ocean.
Positioned quite a bit above these low targets is the main body of the constellation of Centaurus,
who is depicted as a Centaur; half man, half horse. Centaurus’ left front leg dips well
below the horizon, even in the Florida Keys, and it contains our closest neighboring star,
Rigil Kentaurus, also known as Alpha Centauri. This is the third brightest star in the sky,
after Sirius and Canopus. The Rigil Kentaurus system lies only 4.3 light years away from
Earth, essentially right down the block from us. If our own Sun were viewed from the Alpha
Centauri system, it would appear as a bright yellow star of magnitude +0.46 in the constellation
Cassiopeia, very similar to bright Capella that lies closeby in Auriga.
But well above Rigil Kentaurus, Crux, and Eta Carina are a pair of gorgeous galaxies
and a massive globular cluster. Let’s check out the first one right after this.
Messier 83, also called the Southern Pinwheel Galaxy is an amazing face on barred Spiral
that we have discussed before, in episode 15 of Star Hopping, but we’ve never gone
through the effort of locating it. M83 is very bright as galaxies go, glowing at magnitude
7.6. It’s also very large, spanning 11 minutes of arc across.
To get your bearings and to move your attention into this part of the sky, we’ll be using
the first magnitude star Spica in Virgo as our starting point. At 11:30 local time, Spica
is about 48 degrees above the southeast horizon. About 25 degrees straight down you will find
the fairly bright 2nd magnitude star Menkent, which is Theta Centauri. Now we’re in the
ballpark, and there are lots of pretty bright stars in the area. Ready to star hop to M83?
Let’s go.
Move about 3 degrees to the upper right to 4th magnitude 2 Centauri.
Now move about 2 degrees upward to 4th magnitude i Centauri.
Now this one is a little tough. Move about 3 degrees up, across the border into the constellation
of Hydra, to a 6th magnitude star.
Now slide just a quarter degree to the lower right, and you will see the oval glow of M83
appear in your eyepiece.
So what’s our normal practice with a face on spiral? Use averted vision to see if you
can determine which way the spiral arms are rotating. Also, if you have a larger telescope,
see if you can recognize the shape of the central bar.
M 83 lies 15 million light years away, and its true diameter is over 100,000 light years.
Ready for an unusual but very bright galaxy? Come check it out with us right after this.
NGC 5128 is a peculiar lenticular galaxy right in the middle of Centaurus. It’s even brighter
than our last target, shining at magnitude 7.0. The galaxy is the result of a merger
between two smaller galaxies, so we see two galactic disks with a frenzy of star formation
between them. Because of it’s appearance and shape, it’s been given the proper name
“The Hamburger Galaxy”.
Also, because of the cataclysms going on in the center of it, it’s very bright in radio
waves, and has been cataloged as “Centaurus A”. It’s definitely one of my favorite
galaxies to find and image.
There’s a great little asterism that I use in Centaurus to find this target and the next
one - it’s a little triangle just to the lower right of Menkent. See if you can see
this triangle with your naked eye, and then confirm it with your binoculars.
So let’s get started in our search for NGC 5128, and center your scope on the bright
star Menkent.
Now move down to the lower right about 6 degrees to find that little triangle I mentioned.
These are Pi, Nu, and Mu Centauri, all about 3rd magnitude. Mu and Nu are the pair on the
right - move to the bottom star, which is Mu.
Now move about 3 degrees to the right and very slightly up, and you’ll see the bright
Hamburger Galaxy coming into view.
At magnitude 7.0, this galaxy is the fifth brightest in the sky, making it ideal for
observation, although it is really only visible from the southern hemisphere and low northern
latitudes. Centaurus A has been spotted with the naked eye by expert observers under very
good dark sky conditions. The bright central bulge and dark dust lane are visible in finderscopes
and large binoculars, and additional structure can be seen in larger telescopes.
So are you ready for our last target? We’re definitely leaving the best for last, and
it’s the largest and brightest globular cluster in the entire sky. Check it out right
after this!
The massive globular cluster Omega Centauri is one of the most amazing things you’ll
ever see in a telescope. Omega is easily visible to the naked eye, super impressive in binoculars,
and is simply stunning when viewed through a telescope of any size. With a visual magnitude
of 3.7 and a diameter of about 36 minutes of arc, it appears about as large as the full
Moon. It fills a low power eyepiece, and with higher magnifications you can see individual
stars.
I can’t say enough about this globular; words really cannot describe the amazing view
you’ll see. You just have to see it for your self.
And see it you will! Here we go on our star hop to Omega Centauri.
From our little triangle, start again on the lower of the close pair of stars: Mu Centauri.
Move straight down about 5 degrees to 2nd magnitude Alnair.
Now move about 5 degrees to the right, and hold on to your hat, you’ll see over 1 million
stars enter your eyepiece, the grand globular cluster Omega Centauri.
I expect you’ll spend the next hour looking at this beast if it’s the first time you’ve
seen it. Throw in a high power eyepiece and scan from one side to the other. The center
is amazingly dense, and you’ll be amazed at how far this dense region extends before
you start to see black space between the stars.
Omega Centauri has been known since antiquity. The Greek astronomer Ptolemy listed it in
the star catalogue that he compiled in the mid-2nd century. When Johannes Bayer assigned
Greek letters to the brighter stars, he also mistook this amazing cluster for a star, and
designated it Omega Centauri. I guess no one wanted to take this designation away from
the king of all globulars, so the name has stuck right into the present.
Wow, so these were three really great objects. It’s rare you get galaxies that shine brighter
than 8 magnitude, and we saw two of them, starting with Messier 83, just slightly across
the border into Hydra the water snake. Then we moved into the center of Centaurus to find
that galaxy that made you want to eat dinner again, NGC 5128, the Hamburger Galaxy. Then
we moved a bit downward, deeper into Centaurus to knock your socks off with the amazing Omega
Centauri.
I know those were three very southern objects, and I apologize for teasing all our northern
viewers of Star Hopping. Well, all I can say is, if you ever visit Florida in the spring,
look me up and I’ll show you Omega Centauri through the KPO 18” Reflector, and that’s
one amazing sight!
So that does it for this week’s episode. You can find the show notes on our website
at kpobservatory.org/SH030, (that’s pretty great - 30 episodes! Wow.) where you can comment
and leave any questions that you may have.
So in this week’s KPO newsletter, I spilled the beans to all the KPO insiders about our
new astronomy video series coming up this summer! My family and I will be heading to
Northern Europe and the UK this summer for a couple months. During that time I’ve set
up many visits and interviews at some of the great observatories and astronomical landmarks
through the region. I’ll be creating a series of 10 episodes of what will be called "KPO's
European Astronomy Tour". There are at least 3 great interviews with professional astronomers
planned, and I am working on the fourth. One of these interviews will be really amazing!!!
This new program will replace the Star Hopping series while I'm gone, and then we'll resume
Star Hopping after I return in September. I am super excited about it, and I hope you’ll
enjoy this new high level astronomy content from KPO.
If you’d like to get some inside information about the new series, also also get a lot
of other Star Hopping content for free, you can sign up for our newsletter at kpobservatory.org/newsletter.
Well thank you very much for for joining me here, and I’ll see you next week with more
Star Hopping tips and tricks.
I'm Cassie, and I hope you've enjoyed star hopping around the Milky Way. We'll continue
to bring you these video astronomy tutorials every week on Thursday, and in their podcast
format on Fridays. They will be designed to help you find deep sky objects that are up
in the sky at the time we post them on the Internet.
The reason we create these video and podcasts is to help beginning amateur astronomers learn
the sky and get more enjoyment out of their telescopes and astronomy in general. If you
have any requests or suggestions of potential targets in the night sky that you would like
to see us present, just let us know down in the comment section below, or on our website
blog.
Don’t miss our free Field Notes for this episode, basically the script of the show,
with all the images and start charts we use for our star hopping activities. You can get
them for free at kpobservatory.org/FieldNotes.
If this is the first time you’re checking out Star Hopping, and if you found this video
useful, please consider Subscribing to our Channel by clicking the Big Yellow Button
down there, click the Thumbs Up on the video, and please share this tutorial out to your
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Also, please follow KPO on Facebook, where we post all of our astrophotos and keep everyone
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this great stuff up in the sky.
All the links to these places including our website kpobservatory.org, can be found below
in the Episode Notes as well.
And finally, if you feel this video provides you value, and if you'd like to see more,
please consider supporting us on Patreon, where for a small amount per video, you can
support our efforts and let us make even more great astronomy tutorials like this one.
Well thanks again for watching, and we'll see you next time on Star Hopping with Kissimmee
Park Observatory.