Mounting the Spectrograph

The York University Astronomical Observatory has two telescopes under two domes. One of the scopes is 40cm in diameter the other is 60cm in diameter. Both of these use an SBIG ST-9 CCD camera for us to take pictures with. Currently, the 60cm is engaged in a variable star monitoring campaign, wherein we continually image a series of stars known to periodically change their brightness. We literally take a picture of the star every few minutes and measure the brightness of the star, and how it changes over a 10 hour time-scale. The act of taking the picture is called ‘photometry.’

The other side of the astronomy coin is ‘spectroscopy,’ where instead of taking an image of the sky, you first pass the light from an object (like a star) through a prism. Sir Isaac Newton figured out (and you may remember this from elementary school science class), that light is made up of smaller components. When you pass light through a prism, it breaks up into a rainbow. A spectrum of a star/galaxy/nebula can tell you a lot more about that object than its corresponding photometry. It can tell you what elements are present and tell you how much of them are there. Spectra are pivotal to modern day astrophysics!
The good news is, the York Observatory now has a Spectrograph!

This is the spectrograph, an SBIG instrument with a ST-7 CCD on the back, sitting on a desk, about to be mounted onto the 60cm telescope. 

Here is the spectrograph (on the left) attached to the back end of the 60cm telescope, with the ST-9 camera on the right. We use a box with a mirror in it to switch between the two instruments. 


Moving forward, we’ll see what we can do with this spectrograph, in terms of science. The first step is to understand what we’re looking at after taking a spectrum. Now that it’s on the back of the scope, we just have to wait for a clear night!