Astronomy with an online telescope
Astronomy with an online telescope

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Astronomy with an online telescope

Week 4: Imaging Messier objects with COAST


Having spent the last three weeks building up your skills with Stellarium and knowledge of the night sky and telescopes it is now time to start using COAST and the website to take your first astronomical images.

This week you will take a look at the Messier catalogue – this is a collection of some of the most spectacular objects that you can see in the night sky. You will learn about the different types of objects mentioned by Alan in the video and select one of these Messier objects to be the first image that you will take with COAST.

To take your image you will submit an observation request to COAST and, sometime later when the request has been completed, collect that image. We hope that you are excited as we are to see what you achieve with your first use of COAST.

Download this video clip.Video player: boc_aot_1_video_week4_intro.mp4
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This week, we’re going to be taking images using COAST. And I've got some examples here. I requested these images just the other night. And it’s always exciting to come back the following day and see what's happened. So let's take a look.
The first one that I’ve got here is M13. It’s a Messier object. This is the great globular cluster in Hercules. And these globular clusters are ancient conglomerations of stars in the halo of our own galaxy, hundreds of thousands of stars in this roughly spherical cluster.
The next object that I requested is the spiral galaxy M51, another Messier object. And this is known as the Whirlpool Galaxy with the spiral arms clearly seen, the bright blue areas of star formation, dust trails in between, and even a small companion galaxy.
And then the third object that I looked at was a nebula. This is within our own galaxy. This is the Dumbbell Nebula, M27. And this is a star that's come to the end of its lifetime and has thrown off an expanding shell of gas. So the original object is this star in the middle, and it's thrown off this shell of gas, which is emitting light in the various colours. Some hydrogen there and some other elements in that cloud of gas.
So these are all objects that I've taken using COAST. And I just want to think for a moment about resolution and fields of view with telescopes. So I'm going to compare with an image of the same object that I took with PIRATE. That's the larger of the two telescopes that we have here in Tenerife.
So this is the same object, M27, imaged with PIRATE. And the first thing that you'll notice is that the image is slightly smaller in the frame. That's because Pirate has a larger field of view. The field of view of COAST is about the size of the full moon. PIRATE field of view is about half as big again.
The other thing you'll notice, PIRATE being a slightly larger telescope is that the resolution is slightly higher on this second image. But I think you'll agree that the image quality that we can get with COAST is quite impressive. And now it's your turn. You'll be taking your own images with COAST this week, and we're very excited to find out how you get on.
End transcript
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By the end of this week you will be able to:

  • distinguish between the various types of Messier objects
  • request an image from COAST using the interface
  • collect and view your images from COAST using the interface.

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