Saturday, November 30, 2013

Intelligence in Astronomy: Preview 3

Ugh! So full. (credit)
Stuffed with turkey, tired of family, bummed about the post-Thanksgiving workweek? Well, at least you have tomorrow evening to look forward to! The Intelligence in Astronomy post series starts at 4pm Eastern Sunday Dec 1. Sign up to follow this blog by clicking the little blue button on the right-hand panel of this page. Add this to your RSS feed. We're almost there!

Wednesday, November 27, 2013

Intelligence in Astronomy: Preview 2

Do you have Successful Intelligence? How do you project into the 7-dimensional hyperspace of excellence devised by Turner & Tremaine in the late 1970s? What is you-dot, or


and why do I think it's one of the most important ingredients for success in science, and vastly more important than you(t).

Answers to these questions and more starting this Sunday, and running for several weeks thereafter.

First Planet Detection From Minerva

An artist's impression of the WASP-12 planetary system.
IMAGE COURTESY ESA, NASA AND FRÉDÉRIC PONT, GENEVA UNIVERSITY OBSERVATORY
The Project Minerva team has been hard at work calibrating and characterizing Telescope #1, which is in an Aqawan enclosure on California Blvd, on the Caltech campus in Pasadena. This test rig allows us to work out the kinks with the telescope and enclosure control systems without having to fly/drive back and forth from campus to an observatory. Having a test rig right next to the Minerva team's offices has paid huge dividends thus far. We have overcome a major telescope hardware/software malfunction, identified improper coatings on some of our optical elements, and brought our telescope throughput up to spec, all in far less time than it would have taken if we went straight to the mountaintop.

This past Sunday night, Caltech postdoc Jon Swift and fourth-year PhD candidate Mike Bottom were at the controls of the telescope measuring the amount of starlight that makes it through the telescope optics and onto the actual detector, known as the telescope throughput. To do this, they measured the flux received from several well-characterized standard stars over a range of air masses. After running their tests they found a system throughput of 72%, which is very close to spec (at long last!).
Jon Swift and me giving a tour of the Minerva test facility at Caltech.
Photo courtesy Mike Wong.
With clear, stable skies overhead, they decided to look at a far less stable star named WASP-12. The star has a hot Jupiter that was discovered by the Wide-Angle Search for Planets (WASP) team back in 2009, in a paper led by my collaborator Leslie Hebb (See Hebb et al. 2009 for the gory details). With the planet scheduled to transit WASP-12 in less than an hour, Jon and Mike slewed the telescope to the star's coordinates and set up on the field. The plan was to repeatedly image WASP-12 and the stars within ~10 arcminutes (~1/6 of a degree) on either side of it. 

When photons from the star strike pixels on our CCD array, electrons are freed via the photoelectric effect from the silicon substrate, and the number of free electrons floating in each pixel is proportional to the amount of flux received. By summing the total number of electrons in all of the pixels on which the star's image fell, Jon and Mike measured the star's flux in time. However, due to variations in the transparency in the Earth's atmosphere above the telescope, these absolute flux levels vary. Fortunately, the other stars in the field of view also vary with the atmospheric transparency, so the ratio of WASP-12 to the nearby comparison stars provides a relative flux measurement.

Once the planet blocked the star, the flux level dropped by an amount approximately equal to the radius of the planet squared, $R_P^2$, divided by the radius of the star, $R_\star^2$, or ${\rm depth} = (R_P/R_\star)^2$. Here's what Jon and Mike observed during the 4.8 hour observing sequence:

This is Project Minerva's first planet! Granted, it had already been discovered, but this light curve is ours and we're very, very proud of it. See also Jason Wright's writeup over at his blog.

Our primary science goal is to search for planets using precise Doppler-shift measurements. Our secondary science goal is to search for previously unknown transits of RV-detected planets, and until our spectrometer is ready, we'll be doing a lot of transit work. For our targets we'll know that our transit targets have planets, and we'll have predictions for when transits should occur if the geometry of the orbit is just right. 

This test shows that we can achieve the precision necessary to detect a transiting hot Jupiter. The great news is that Jon did the simplest possible data reduction and analysis procedure, so this is likely an underestimate of our attainable photometric precision. Also, the camera was a loaner; we'll soon purchase a camera better optimized for transit work. Says Jon:
You also might want to add the fun facts that these measurements were made 40 ft from E. California Blvd. where cars whiz by, street lights flicker, and we are losing anywhere from 20 to 50% of our light just from the atmosphere alone!
Our hope is to regularly achieve a photometric precision better than 1 part in a 1000 per minute, or about 1 millimag per minute (For more, check out Greg Laughlin's post on ground-based photometry.)

Kepler 2: Photometry, With a Vengance


The highly successful NASA Kepler Mission was a beautiful thing, and its beauty was primarily in its simplicity. The mission is based on a 1-meter Schmidt camera in space that resides in an orbit about the Sun with a semimajor axis slightly larger than the Earth's. This "Earth-trailing" orbit allowed it to maintain a continuous gaze on a single target field near the constellations Cygnus and Lyra, just off of the Galactic plane.

Once Kepler reached its orbit, it blew away a dust shield that covered the front of the telescope and from that point onward there were very minimal moving parts. On the space telescope there is only a single instrument: a 340 megapixel CCD imager of epic proportions. There are no other instruments to swap in and out of the light path, no filters, not even a shutter. For four years Kepler measured the brightnesses (relative fluxes) of ~150,000 target stars searching for periodic eclipses of planetary companions.
One of Kepler's infamous reaction wheels.

The Kepler telescopes only major moving parts were four "reaction wheels," which used the principle of the conservation of angular momentum to keep the telescope precisely aimed at the target field. Early in the mission, one of these wheels failed. Fortunately, only three wheels were needed, and Kepler soldiered on past its expected mission lifetime of 3.5 years and was poised to enter into a glorious extended mission, with a target list modified to include thousands of additional red dwarfs, the stars my group and I love so much. However, on the eve of the extended mission, a second reaction wheel failed, leaving Kepler without the ability to maintain precise pointing. Cue sad trombone.

However, there were rumors and stirrings that there may be a way to operate the telescope using only two reaction wheels. The space-flight and control-theory wizards at NASA Ames Research Center have been working tirelessly since Kepler's death was announced. Using creativity, grit and the power of engineering and science, the wizards have come up with a viable plan. Instead of a third reaction wheel to stabilize the telescope, they'll use radiation pressure supplied by the Sun. That's right, the Sun will be Kepler's third wheel!

Light can be thought of as a wave or particle phenomenon. Light doesn't care which, but if you think of light as discrete particles, their collision with, say, a spacecraft imparts a bit of an impulse. Not much, mind you. But there are many, many photons streaming out of the Sun, and their individual momenta adds up. And since the Kepler spacecraft has a nice house-roof-shaped ridge along its back solar panels, the spacecraft can be oriented like a rudder in the stream of photons coming from the Sun. Viola!

Now let's hope that the preliminary tests show that this is truly viable, and then let's hope that NASA has the funding and will to make K2 a reality.


Monday, November 25, 2013

Intelligence in Astronomy: Preview 1

A big stage
As my mentor Sara Seager recently told me, my appointment at Harvard is a huge honor, a huge opportunity and also a huge responsibility. I have been given tremendous resources and a highly supportive department with strong leadership. I also have a big, highly visible stage on which to perform. On the research front, I have ambitious plans to discover and characterize the nearest Earth-like planets using existing and new instrumentation (Project Minerva), with an eye toward the NASA TESS mission and JWST. My goal is to make the discoveries and do the careful statistical analyses necessary to advance our knowledge of the formation and evolution of planets like our own.

My opportunities and responsibilities do not end there, nor do my ambitions. Here's an exerpt from my recently updated teaching statement:
I recognize that just because institutions produce good outcomes does not mean that those institutions are optimized. Astronomy is an excellent, yet non-optimized institution. I will work optimize the scientific productivity of Astronomy through a better understanding of the psychological and sociological factors that lead astronomers to not only succeed, but thrive in their careers.
I will work on this optimization process in my department (with the full support of my new department chair, Avi Loeb, and my fellow faculty members), on the various committees on which I serve including the AAS Committee on the Status of Women in Astronomy, and right here on this blog.

Starting the Sunday after Thanksgiving, I will publish a series of posts that I've been working on over the past month. My focus will be on the optimization of the field of astronomy with an eye toward untapped research potential, creativity and overall success in academia. Stay tuned!

Saturday, November 23, 2013

You think you have problems?

Well, they have solutions. Just like the solution offered to 17-year-old Dee, who has brittle-bone disease. All he wanted was to turn his light on and off, or pick things off of the floor. Thanks to some engineering students, he can now. h/t Claude for the video

Monday, November 18, 2013

Poll on attitudes about intelligence

I'm curious what you, dear reader, think about intelligence, both in yourself and others. Please take < 1 minute to fill out this quick poll. Seriously, it's super-fast because it only involves reading and clicking a mouse. (Note that the form scrolls within the blog-post frame. Scroll down to see the last bit of the final question)


(Note that the form scrolls within the blog-post frame. Scroll down to see the last bit of the final question)

Thursday, November 14, 2013

Thursday afternoon music break: DMK, Everything Counts

Speaking of facilitating the synchronization of gene expression, here's DMK, a Depeche Mode cover band from Bogatá,performing Everything Counts (h/t Erin):

Tuesday, November 12, 2013

Intelligence: Nature or Nurture? Both, together!

Image credit: sciencedaily.com
Lately, I've become obsessed with understanding a fundamental problem in astronomy. We're all familiar with this problem, yet I've found very few good answers among my conversations with astronomers. I've found many clues, plenty of leads, but no fundamental understanding. For better answers, I have decided that I need to turn to psychology. But I digress. What's the question?! I'm interested in the nature of intelligence, and the role intelligence plays in success, particularly in the realm of astrophysics. More specifically: why do some students excel while others struggle, when all of them look about the same when we admit them? (And: is this even a well-posed question?!)

I'm currently reading Ungifted: Intelligence Redefined by Scott Barry Kaufman. The book is absolutely fascinating. I'm very much looking forward to meeting him in person during an upcoming trip to NYC (he's a prof at NYU).

I'm on chapter 3, but today I felt compelled to reread chapter 1, where I found my head spinning with what psychology has to say about the question of nature vs. nurture in the development of intelligence in people. It turns out that nature (genetics) and nurture (environment) work hand-in-hand to shape intelligence, talent and academic achievement at the highest levels.

Most people sense, properly, that there is a strong genetic component to talent. After all, many human traits are inherited. My quiet, soft-spoken friends often had quiet, soft-spoken parents. Athletic people often have athletic parents. Since mental abilities are traits just like speaking style or athleticism, shouldn't they, too, be heritable? My sons both show interest in many of the things I was interested in growing up, such as ninjas, fighter jets, math, Legos, cards and board games. So it seems pretty obvious that they'll succeed in academia just like their dad, right? (what do you mean that you don't see the connection between ninjas and astronomy?!)

Monday, November 11, 2013

2013 NBA Countdown: #5 Paul George

From Wired.com
Yes, the season started a couple weeks ago. But that's also when I went out of town for a couple of trips. I'm back now and Owen and I want to continue our countdown, T-plus-N days from the start of the season. Number five on our list is 6-foot-8 small forward, Paul George, out of Fresno State. So far, Owen and I have partial toward guards, perhaps because we're both fairly short, ourselves. George was a big surprise to me last season, mainly because living in LA didn't afford me many opportunities to watch the Indiana Pacers play. But the team went deep into the playoffs, crushing their opponents before eventually squaring off against Lebron, Wade and the Heat. George just blew up, scoring 27 in two different games in the series, against a strong Heat backcourt, and hitting a key jumper at the end of game six. My prediction is that George will have a big year in 2013-2014.

Owen's take on George:
  1. Shoots lots of 3s
  2. Shoots from the side of the court
  3. Doesn't do much layups
  4. Dunks a lot
  5. Runs away with the ball
  6. Is kind of a show-off