Profile

My name is Sarah and I am an observational astronomer. This means I use telescopes, both on the ground and in space to study astronomical objects – in my case stars. I research two types of dwarf star – brown dwarfs and white dwarfs.

Brown dwarfs are failed stars – they form like stars, but never burn hydrogen into helium. This means they end up about the size of Jupiter, with masses between 70 and 13 jupiter masses. They start off quite hot, 3000 degrees or so, but then cool over time. This means they get cool enough to have molecules, like water and methane in their atmospheres. They have weather, and clouds and even lightning. I study these objects when they are in binaries with other stars, and are being heated by their hotter companion.

White dwarfs are dead stars – our Sun will become on in 5 billion years time. They are vey dense, with about the mass of the sun squeezed into a sphere the size of the Earth. Because they are so dense, they have unusual properties and are very hot – hotter than the sun.

I study the relationship between their current mass, and their mass when they were a star, as well as the relationship between their mass and radius.

I have 2 sorts of day.

My favourite day is when I’m observing and have to fly to Chile, Hawaii or the canary islands to use telescopes. There I get up at lunchtime and  have a look at the previous night’s data – see if I need to observe anything again, check if the instrument was working ok, etc. I then check the weather report for the coming night.  Then I have to have dinner at about 5pm, pick up my packed lunch and drive up the mountain to the telescope.   At the telescope, I then make sure everything is turned on, open the dome and sides to get the airflow in, and start to do the evening calibrations. Once the sun has set we can start the twilight calibrations, and then when it’s dark begin observing! I normally finish between 7 and 9am depending on the season.

My more normal day involves checking email, reducing data and analysing it. Writing reports of my work and writing proposals for more telescope time. Sometimes I also have to give lectures to the undergraduates or meet students who need help reducing data or with their analysis.