Sunday, August 23, 2009

How Far We Have Come

The last couple of days I have been doing updates on some presentations I give to keep them current. When I give a presentation I like to have it an up to date affair instead of an ancient history lesson. I had to make at least seven major reworks of information within this one presentation on Exoplanets. Wow Seven new and exciting discoveries since I wrote the piece less than six months ago. I woke up this morning and just could not shake that awe struck feeling that we are living in some very exciting times, crappy economy aside. This is an age of discovery that rivals the renaissance period of history. It is arguable that today surpasses the discoveries of Copernicus, Galileo, Kepler and beyond. One thing is certain. We scientists of today stand squarely on the shoulders of those giants just mentioned. Just 400 years ago man invents the telescope and now some 10 generations later I am seeing data from the Kepler space telescope as it searches for new planets not here within our solar system, but in star systems some 400 light years away or farther. Now get this... Kepler is looking at not one star at a time oh no... try 100,000 at a time! It will stare at this area for 3 1/2 years measuring drops in brightness from each of those stars and determine the mass and orbit of earth sized planets as they transit their star from the telescope's viewpoint. Are you kidding me? 400 years ago we had a heck of a time getting bubbles out of the glass well enough to make a lens for a telescope. I had a chance to put together a 15 dollar Galileo scope These were put out by the International year of Astronomy For 15 dollars you get a pretty cool scope and you can also see what Galileo saw when he turned his scope on the moon or Jupiter. What would he say now about the Hubble telescope? This last 400 years has been a total blur when it comes to science. 400 years a go we were blood letting as a cure. Today we have mapped out the human genome.With as much as we now know about the world and universe we live in, there is a lot more we do not know. Like why is there an acceleration in the expansion of the universe? What made it speed up? Dark energy? What the heck is Dark energy? I could go on... There is one area of Astronomy that needed to catch up to the rest of the pack. Astrometry was like the little guy on the playground. Try as he would he could never get the touchdown. Undeterred, out he came every day to try. Well boys and girls the Touchdown has come for that little man!

Astrometry is the science of measuring stars and their exact positions in the sky. I know that sounds kind of easy to do. right? Hardly! Astrometry goes back way before Galileo. Way back to the astrologers of ancient times They would use a simple instruments to measure angle and distance between stars. This has been going on for some time and as time moved on the instruments got better and better. They got to a point in the early 40's that Astronomers were usin
g astrometry to look for planets circling a distant star. Yes, the first exoplanet search was on! Alas it was not to be... Oh there were the announcements in 1943 of astronomer Kaj Strand. He was working at the Sproul Observatory at Swarthmore College and announced that his astrometric measurements revealed the presence of a planet orbiting the star 61 Cygni. This claim remains unproven... Sproul was at it again in 1960 as Sarah Lippincott announced that she had located a planet circling around Lalande 21185 again the scientific community was sceptical of the find. Oh and how about Bernard's star? the director of Sproul, Peter Van De Camp detected a planet orbiting this red wonder of a star. The lack of proving it was the problem because there is a huge amount of difficulties with measurements this precise here on Earth Proper motion orbital mechanics, atmospherics the precision of the instruments being used as well as the calibration of those instruments. You need a calculator to keep up with the amount of variables involved.

Things quieted
down for astrometry for awhile with no wild claims being bandied about. You can only get so many black eyes. But just because no one was making claims did not mean that work was progressing on this very old branch of astronomy. Move forward they did, perfecting instrumentation, eliminating variables trying to bring astrometry back into the mainstream of exoplanet searching. In 1995 astrometry's hopes were dashed to bits as Radial velocity or Doppler spectroscopy bagged that first exoplanet so Now we stand at about 356 planets found so far using every way except Astrometry,that is up until May of 2009. The team at Mount Palomar, using the (ground based!) 200 inch Hale Telescope, delivered. Steven Pravdo and Stuart Shaklan of JPL announce the detection of VB 10b -- the first planet discovered through astrometry. The crowd goes Wild!!! Finally Astrometry has put the big boy pants on and moved up to the big show.

So what is next on the continuing parade of firsts? Your guess is as good as mine but it is so refreshing to me to see the little guy make it finally.The theory was genius. It just took a little time for the tools of the trade to catch up. We now have the twin Keck scopes out in Hawaii doing astrometry as well as others in Chile and around the world. It will not be long and we will start seeing exoplanets discovered by astrometry more and more. When Gaia is launched by the ESA, the numbers should really start to fall for astrometry. We have come a long way indeed!!!

Clear skies and great seeing too,

Steve T

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