Spotting the most distant object seen through a medium sized telescope
Objects in the night sky are so far away, unimaginably distant. The most distant object you can see with a medium telescope is at an incredible distance away. With a reasonable telescope and some perseverance, you can travel back in time to see it for yourself. A couple of weeks ago, the constellation of Virgo was nice and high in the North Eastern sky. This placed it in a great spot to observe a strange object that goes by the even stranger name, 3C-273.
Various cultures and history have given us names for the brightest objects in the night sky but not for the faint objects. These objects end up having quite boring names that represent a line in a catalog. This is the case for 3C-273, which simply means it was the 273rd object in the 3rd Cambridge Catalog of Radio Sources. If you are really keen to learn about the first 272 radio source then check here where you search loads of catalogs.
What is 3C-273?
What’s so special about 3C-273? It’s what is known as a quasar, or quasi stellar object. Back when astronomers first identified these objects they looked a lot like stars. The only problem was that they were enormous distances away so could not have been stars. The most distant object with a medium telescope that you can see is the quasar 3C-273. It too looks like a very faint star, not much to it at all but what is mind boggling is that it is 2.4 billion light years away.
At the centre of nearly every galaxy that astronomers have found out in the Universe there are super massive black holes. These monsters go through periods in their lives when they are very active. Gas is swirling around the event horizon. During these periods they release an enormous amount of energy, often more than the galaxy that hosts them. Our galaxy has a super massive black hole at its centre. Lucky for us it is quiet so it is not a quasar.
The monster quasar in question, 3C-273, blasts out more than 4 trillion times as much energy as our Sun. All of that is coming from the region around a super massive black hole that is nearly 900 million times the mass of the Sun.
How do I find 3C-273?
First you’ll need a reasonable sized telescope. This object is only Magnitude 12.9 so it’s pretty faint. Despite that it is the most optically bright quasar in the night sky, so all of the others are much harder to find.
The fist step is to locate the constellation of Virgo. It is quite close to the easier to find constellation of Leo.
The view from a medium telescope
Once you’ve found the stars that make up Virgo, you try and find the star Zaniah. That is the star next to the bright one to the left of the V in Virgo in the above image.
Now things get a bit tricky as we have to start hoping around the faint stars. For those of you familiar with star hoping you’ll be able to find you way to the quasar. The next view is the zoomed in area around Zaniah:
The next shot will show what you are looking for in the eyepiece. We used a 16″ reflector with a 32mm eyepiece which was quite wide.
It is worth giving this a go, I haven’t tried finding it with our 10″ reflector but I might give that a go next weekend!
