LARA, our Astronomer from Texas!
The Bell: Is there/was there a Christmas star?
That’s a great question and one that doesn’t have a definite answer. There are several theories but we’ll never know for sure if one (or any) of them is correct. And there is the possibility that it was just meant to be a symbol or metaphor and isn’t representing something that was actually seen in the sky.One of the possibilities is a comet and another is a nova (a star that regularly brightens dramatically) or a supernova (a star that has exploded). All of these possibilities are mostly conjecture since we can’t easily know for sure if there are any objects that fit. For example, there aren’t any comets with regular passes through the inner solar system that would fit, but it is possible that it was a comet that was on a really long orbit (thousands of years) or was ejected from the solar system after its close pass to the sun. Another intriguing possibility is a close conjunction of the two brightest planets – Venus and Jupiter – that would have been spectacular. The problem is that the conjunction happened two years later than would probably fit into the Christmas story.
How did you become an astronomer?
I was interested in space from a young age and I was 8 years old when Carl Sagan’s “Cosmos” series started on television and really inspired me. I was pretty sure by the time I got to high school that I was going to end up in some sort of space-related field. For a while I thought about trying to become an astronaut, but I ended up studying astronomy in college and getting a job at the university where I obtained my degree at and I have been here ever since!
The Bell: Do you think being an astronomer is a hard job?
It can be at times! And it somewhat depends on what you mean by “hard”. Sometimes you get hard questions to answer that require a lot of work to solve (if they are ever solved). And sometimes astronomy can be physically hard since a lot of observers have to work on telescopes in uncomfortable conditions (cold, thin air on top of mountains) and stay up all night.
The Bell: Other than an astronomer, what other career would be interested in?
That’s a great question. I have a feeling that I would have ended up in a science field no matter what – my other big interests in science are paleoanthropology and paleontology. I also think that I could have ended up a historian. I guess I like old things!
The Bell: Do you think there is life on other planets?
If you mean life on planets anywhere in the galaxy (or the universe) then the answer is almost certainly yes. If you mean in our solar system, then I think it’s likely that there once was life on Mars, but I don’t think it is there now (although I’d be very happy to be proven wrong!). There are also at least two moons in the solar system that have some interesting potential for having basic life – Europa, a moon of Jupiter, and Enceladus, a moon of Saturn.
The Bell: Do you use much equipment for astronomy?
I personally use a fair amount – mostly telescopes (and the accessories that go with that), cameras and computers. Some of my co-workers use lots of different instruments on lots of different telescopes, while others just mainly use a computer since they do more with the mathematical and physics side of astronomy – theoretical models and things like that. And a few of my colleagues even get to have their images taken with the Hubble Space Telescope and other space-based observatories (such as Kepler, Spitzer, etc.)!
The Bell: What is the brightest star’s name?
Well, I could get very technical and say “The Sun”, but I’m guessing you all are asking about the brightest star in our night sky.
The brightest star in the Earth’s night sky is Sirius, in the constellation Canis Major (“the great dog”) and Sirius is known as “The Dog Star” (which might sound familiar to Harry Potter fans!).
There is also a question of what the brightest star is that we know of, regardless of where we’re seeing it. We have a way of measuring how bright a star is that isn’t dependent on its distance. If you think about how bright a light bulb is three feet away compared to how bright the same light bulb would be if it was 100 feet away, you can see that we have to come up with a standardized way of measuring “brightness”. If you go by that measurement, the most luminous star found to date is a blue hypergiant star in the Large Magellanic Cloud that is 8,700,000 times brighter than our sun!
The Bell: Do you have a favourite star?
That’s a good question – I don’t think anyone has actually asked me that before! I usually get asked what my favorite planet is (and I always have a hard time choosing between Mars and Saturn), but I’m not sure about stars. One of my favorites to show people in the telescope is actually a pair of stars called Albireo, in the constellation Cygnus. They have a single name since they appear to be a single star to the unaided eye, but if you look at them in a telescope you see that they are actually a pretty pair of blue and yellow stars.
How many black holes have you spotted?
I haven’t actually discovered or seen any black holes myself, but I work with people who have! We don’t actually see the black hole itself, since, of course, it’s black. They are found by looking at how they affect the gas and stars around them, including the supermassive black holes that we think are in the middle of most galaxies. When we’re looking for black holes that are formed from the collapse of a large star (what we call a “stellar mass black hole”), we look for gas being pulled into the black hole very, very quickly. When that happens, the gas gets very hot and gives off x-rays, and we look for those.