I rolled up at the University of Hertfordshire eager, ready and prepped for a hard day of work. I’d tried to conceal the bags under my eyes from accidentally getting ready an hour before I needed to (Reading emails properly has never been my strong-suit) and grinned a slightly weary grin. Then the day really began. There was the requisite meet-and-greet with the head of department Dr Pinfield, and he showed me and the other couple ofstudents around all the various bits of the department we’d be getting to know quite well. Namely, the room with our desks in and the canteen. As I saw the postgraduates sitting in front of computer screens covered in lines of coding I had a feeling that this astrophysics business was more about number-crunching and less about stargazing than that Brian Cox fella would lead you to believe! Turns out, I was absolutely right! Within roughly an hour of getting introduced to my desk (replete with temperamental computer and ominous telephone) I was getting down to some serious spreadsheeting. Now, you may think that you have experience with spreadsheets, that the few IT lessons you spent learning how to divide a cell by another cell were hard work. When you have a spreadsheet that is 500 rows long and 20 columns wide, however, the story is somewhat different!
This was an astrological database, created for me by my supervisor Ben, showing various groups of objects that might be linked together, their movements in the heavens and their magnitudes of brightness. My first task was to sort out the objects that seemed to be moving similarly to one another, as this would mean that they were (hopefully) in some sort of binary arrangement. If two objects are close together and moving at roughly the same rate (This is measured by a process called Proper Motion*) and in the same direction then chances are they’re a binary! Whether or not one or more of the objects is a Brown Dwarf comes later on in our calculations.
Now, all this talk of databases and celestial motion is probably making some of you weak at the knees, and I don’t blame you one bit! Some of the calculations were pains in the backside, but luckily for me, I traded in people skills for number skills a long time ago, and set about squaring this, subtracting that, and performing a logic calculation based on the suitability of the other. Pretty soon we had a nice list of stellar objects that we could begin investigating further.
We’ve now begun to use images collected from the SDSS (Sloan Digital Sky Survey) and the UKIDSS (UK Infra-red Deep Sky Survey) surveys to actually try and see some of the objects behind the numbers. At first, trying to orientate yourself using these pictures is difficult, which is annoying when you’re trying to find where the two objects are in relation to each other, but nevertheless I’m pressing on and trying to pick up the knack. Sometimes this is made especially difficult with the UKIDSS pictures, because, although they show the objects we are looking for more clearly, the orientation is often different for each picture! This basically means that in one picture north is up, but east is left, and in another picture north is down and east is still left! Needless to say this is really confusing, but once you’ve finished tilting your head to the side you can pretty much understand where you are.
That’s pretty much it for the moment, but I’m sure I’ll have a whole smorgasbord of astro-facts next week! Mine’s a brown dwarf with a slice of lemon, Chin-chin!
Harry Saban – The Octave Doctor
*Proper Motion: This is used to describe the movement of a celestial object, relative to the center of the solar system, using a sort of co-ordinates system. The co-ordinates work like this:
(Image from Wikimedia Commons)
Right Ascension (RA) is like longitude but for space, as if we were looking from the center of a sphere to its inner surface. Unlike normal co-ordinates it increases from right to left and has no negative values.
Declination (Dec) is basically the angle from the equator, and goes from +90 (North Pole) to -90 (South Pole).
Both of these values are generally measured in Arc-Seconds (1/3600 of a degree), Arc-Minutes (1/60 of a degree) or Degrees (1/1 of a degree).