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View from a Scope | July 25, 2021

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Sit Canis Major, Sit, Good Dog

Sit Canis Major, Sit, Good Dog

After a few nights of bad weather, finally we have a another clear sky. Only problem is that this clear sky is at 6 in the morning.

The fact that I got up this morning to take advantage of this view confirms that I have caught the astronomy bug.

I had the alarm set this morning for 6 o’clock and woke up with it. I was my usual zombified state at this time of the morning, however when I looked out the window and seen the clear skies I immediately got up and dressed and outside to see what views were on offer. It was extremely cold. So a quick cup of coffee was needed before I went any further.

When I did get outside I was glad to see that the moon had almost gone behind the horizon. The problem with the moon at this time of the month is the light pollution it creates. The full moon almost completely wipes out the deep space objects of interest, and any long exposure photography turns out as if it was taken during the day. This can give a kind of cool effect as if the stars are appearing during the day. See my image of Polaris below.


What to look for?

After playing with my camera and trying to identify the constellations I had become familiar with, I decided to focus my attention to the south

Here I could see the Orion constellation and to the left a bright star close to the horizon. slightly below this was a triangle of stars that caught my attention.

After consulting the star charts I identified the bright star as well as the triangle of stars below it. These stars are all part of the constellation Canis Major.






The bright star I had spotted was called Sirius, the brightest star in the northern hemisphere (apart from our own sun of course), and the triangle of stars I spotted below this made up the hind legs and tail of the Canis Major constellation.






These stars are called


End of the tail.

Aludra is a blue supergiant star and although a lot younger than our sun is already approaching the end of its life.

It will first expand into a red supergiant and become a super nova in a few million years. (so you know keep and eye out for that).



Hind leg.

Adhara is a binary star, that is 430 light years from earth,

A few million years ago this star this star was much closer to the earth than it is now, about 34 light years, and was the brightest star in the sky.

No other star has been has bright since nor will any be as bright for another another 5 million years.






Base of the tail.

Another contender for a supernova, Wezen is 10 million years old but has already stopped fusing hydrogen in its core.

It’s outer envelope is already expanding and cooling and in about 100,000 years it will become a red supergiant.

At this point its core will start to fuse heavier and heavier elements. Once it has a core of iron it will collapse and explode as a supernova.




Base of the neck. (Brightest star in the sky)

Sirius is the brightest star in the sky and although, with the naked eye appears as one star it is in fact a binary star system. Sirius is also known as the dog star given its prominence in the Canis Major constellation. The reason sirius appears so bright is that it is very close to Earth only 8.6 light years. Initially Sirius A and Sirius B were to blue stars until the more massive star Sirius B consumed all its resources and became a red giant about 120 million years ago


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