text-only page produced automatically by LIFT Text
Transcoder Skip all navigation and go to page contentSkip top navigation and go to directorate navigationSkip top navigation and go to page navigation
National Science Foundation
News
design element
News
News From the Field
For the News Media
Special Reports
Research Overviews
NSF-Wide Investments
Speeches & Lectures
NSF Current Newsletter
Multimedia Gallery
News Archive
 


Astronomers Announce Exciting New Discovery Made with Microlensing Technique

Telephone News Conference
Feb. 13, 2008
Participants in the conference are:

  • Scott Gaudi, lead author and assistant professor of astronomy, Ohio State University
  • Andrew Gould, professor of astronomy, Ohio State University
  • David Bennett, associate professor of physics, University of Notre Dame
  • Michael Briley, program manager, National Science Foundation

>> Operator: Welcome, and thank you for standing by. At this time, all participants are in a listen-only mode. To ask a question during the question-and-answer session, please press *1 on your touchtone phone. Today's conference is being recorded. If you have any objections, you may disconnect at this time. Now, I will turn the call over to Mr. Rick McCourt. Sir, you may begin.

>> Rick McCourt: Thanks very much. This is Rick McCourt. I'm here at the National Science Foundation. I'll be moderating the news conference. It's hosted by the National Science Foundation in cooperation with AAAS. I assume you all probably know is the publisher of the journal Science, where the work that we'll be discussing today will be published soon. First, thanks to the panelists who are here: Scott Gaudi, David Bennett and Andy Gould. I'll introduce them in just a moment and have them chime in and let you hear their voices. Also, all the reporters, I think there are 10 of you who phoned in. MCI is managing the phone lines for today, and an audio file of this will be posted on the Science Press Package Web site today, and also (inaudible) MCI. We don't know who all the 10 people are so when you do have a question and the MCI operator connects you, I'm sure you're used to this, but please identify yourself and where you're from and that will be good. Please note that all the information disclosed in the teleconference today were embargoed by Science at 2:00 p.m. Eastern Standard Time on Valentine's Day, Thursday, the 14th of February. The paper covering the research results that we're discussing today will appear Friday in the February 15th issue of the journal of Science. So, the authors who will be our speakers today will each offer about a 5-minute summary or so of their primary conclusions. They are Scott Gaudi, the lead author and assistant professor of astronomy at Ohio State University. Scott, are you there?

>> Scott Gaudi: I'm here. This is Scott Gaudi

>> Rick McCourt: Great, and then David Bennett is also here with us. He's an associate professor of physics at the University of Notre Dame.

>> David Bennett: Hi. Yeah, I’m ready to go.

>> Rick McCourt: Good morning, and then Andy Gould, a professor of astronomy at Ohio State University. Andy?

>> Andy Gould: I'm here as well.

>> Rick McCourt: OK, and so, just try to chime in with their names rather when they make comments but if you need to clarify who said what, feel free to do that. The authors will be available for a question-and-answer session following their remarks and so if you have a question, the MCI operator has probably already told you how to sort of queue up for that. And also available online are several other people who can comment on this. Jenny McCormick is the amateur astronomer, who along with fellow New Zealander Grant Christie, contributed some crucial data to this discovery. I think they're online. Are you folks there?

>> Grant Christie: Yes, I'm here. Hello.

>> Rick McCourt: That must be Grant Christie.

>> Grant Christie: That's me.

>> Rick McCourt: I can tell by the New Zealand accent, and also, I guess Jenny McCormick is not online yet but she may join us, and then Sara Seager is a distinguished professor of astronomy at MIT, and she's also on call today as our designated outside expert, so to speak, and she'll make some comments and I suppose she can answer questions too. So, if everyone's ready to start, let's begin with Scott Gaudi. You want to tell us your--a brief summary of what it was you discovered.

>> Scott Gaudi: Sure. I'd be happy to. So, basically what we found is a scaled down analog of our solar system. We found a star with two planets that look a lot like our Jupiter and Saturn, so by analog here, what I mean is that mass ratios of these two planets and the ratio of their separations from their parent star are very similar to that of Jupiter and Saturn, and by scaled down, I mean that the host star of these two planets is smaller, less massive and dimmer and fainter than our sun, but the planets themselves are also less massive and closer to their parent star so it looks like a scale model of our solar system, a scaled down version of our solar system. So, it's an unprecedented discovery and quite exciting because, as a community, the extra-solar planet community, we've not found any planetary systems that really look like solar system analogs before, and the reason why we found it now and why this discovery was possible is because of the technique we used, which is called microlensing, and microlensing is intrinsically sensitive to planets in the cold distant outer regions of planetary systems like the places where our Jupiter and Saturn live. Now, this is not actually the first planetary system that's been found by any technique. In fact, the Doppler technique, which has found over 250 planets to date, has found about 25 planetary systems with systems with more than one planet. But the Doppler method, by its very nature, is intrinsically sensitive to planets that are much closer to their parent star, planets that are in the warm regions of the planetary system. So, all of the planetary systems we found to date have been sort of have planets packed in much closer to their parent star than, for example, our Jupiter and Saturn. So you really can't consider them to be analog to our solar system whereas the system that we found has, you know, two giant planets, very similar to Jupiter and Saturn, but much further out than the planets that can be found by radio velocity. Now, it's not even the first time that microlensing has found a giant Jupiter-like planet. We found, with this technique, two Jupiters before, but it is the first time that we found a Jupiter where we were simultaneously sensitive to a Saturn. So the first time we could find a Jupiter/Saturn analog, we did, and that provides us a hint, anyway, that these kind of solar system analogs might be quite common, and that's, obviously, incredibly exciting and just, you know, has a lot of implications for many different things. Now, an obvious question you might have here is, you know, is this really a true solar system analog? In other words, are there--is there an Earth there in this system? Are their rocky planets close in, and for all we know, there could be rocky planets close in, but we couldn't actually detect them if they were there. We're not sensitive to small planets close in to the parent star but we do know that there are no additional giant planets close in so we know that these are the biggest planets probably in this system, at least anywhere near where we might expect to have planets. So, for all we know, there could be rocky planets in there. There could be a true analog, an Earth analog. This could be a true solar system analog. So, another obvious question you might have is, why is microlensing sensitive to these distant cold planets whereas these other techniques that have found so many planets are not? And the reason why that is, is detailed about the way the method works. So, microlensing works by using the gravity of the star and the planets to bend and focus light rays from a star behind it. So, what happens is, is you have--you're looking at a star and then this--another star in your foreground happens to pass very close to your line of sight to this very distant star. That foreground star will take the light rays from the background star and focus them and bend them in our line of sight, and that will cause the background star to be magnified. Now, if this foreground star happens to have a planet and the planet is located in the outer regions of the planetary system where these light rays pass, then the planet will give you a little bump or a little extra magnification on top of that that you get from the foreground star that it's orbiting, and so because these light rays pass in these outer regions and you have to have the planet perturb the light rays, you're automatically sensitive to planets in these distant cold outer regions of the planetary system. So, microlensing is sensitive, more sensitive to these cold distant planets than the radio velocity method, by its nature, and so it's the only method that really can probe Jupiter/Saturn analogs, and this is a discovery shows that the method works and that these things might actually be quite common.

>> Rick McCourt: Great. OK, and the next person with a brief summary is David Bennett from Notre Dame.

>> David Bennett: Yeah, we were actually a bit surprised by this event. The thing we were surprised by was actually how much we were able to learn about the planetary system. Those of us who had written theoretical papers on the microlensing method in the past, we had basically assumed that microlensing was going to tell us just the planet to star mass ratio and an approximate separation. But for this event, we've learned much more, and so we used to think generally that the orbital motion of the planets were something that would be basically invisible to us because the alignment between the background and foreground star only lasts a short amount of time and so the effective orbital motion would seem to be pretty small. But for this event, when we tried to fit it with a two-planet model, it seemed to cover all the features, but it didn't give a good fit to the data. It didn't quite fit all the data, but when we added the orbital motion of the Saturn-like planet, then it gave an excellent fit to the data, and so we can really measure some parameters of orbital motion even though the planetary signal could only be seen for about 11 days out of a 10 to 15 year orbit. We were not able to completely measure all the orbital parameters, but we do constrain both the orbital inclination and the centricity. In addition to the fact of the orbit of the planet, we could also see an effect of the orbital motion in the Earth. Basically it changes the way the brightness variations, the lensing brightness variations change with time. We've heard of this as a light curve, and so it has an affect on the light curve that we measure and we can use this affect, the amplitude of Earth orbital motion affect to tell us mass of a host star and its planets, and so, this tells us that the mass of a host star is half a solar mass, and the planets are--the inner planet is 70% of Jupiter's mass and outer planet is 90% of Saturn's mass, and it's actually fairly rare when studying extra-solar planetary systems to be able to directly measure the mass. Most of the 270 known extra-solar planets have been discovered by this Doppler radio velocity method and this method generally only yields just a minimum planetary mass because orbital inclination is unknown, but in some cases, when the planet can be detected by another method, then the mass can be measured. But prior to this discovery, there was only one planet orbiting a normal star with a period longer than two months and at a measured mass, and so now there are three. So, we've increased from one to three, and our measurement of the mass has been confirmed with observations of its brightness and color from the Keck Telescope, and that's sort of the way that the mass of the host stars are estimated for most other extra-solar planets. So, basically, this event has taught us, you know, with very careful monitoring of data and, of course, with very good data coverage from all the telescopes, we're able to learn a lot more about these planets than we previously thought possible, and in fact, we’ve learned more about this planetary system than most other extra-solar planets that have been discovered.

>> Rick McCourt: Thanks, David. And, finally, Andy Gould, who is also at Ohio State University like Scott. Andy?

>> Andy Gould: Yeah, so I wanted to focus on the observational aspects of this discovery, which are also fairly unique. Most of the observations were carried about by the microFUN Collaboration, which is a worldwide network of professional and amateur astronomers who are dedicated to finding planets in high magnification microlensing events like this one. This event was, like quite a few others of the high magnification events we've followed, extremely frenetic. We tried to get 24/7 coverage of the event during all the period when it's doing something interesting, which in this case was about 10 days. So, as the Earth is spinning at about 1,000 miles an hour, we have to keep up with it, so that means it gets to be gone in one place and we have to get somebody else to start observing another place, and that gets into why we are a network of professional and amateur astronomers. So, the amateurs and the professionals bring different things to this collaboration. What the amateurs bring is flexibility, location and ability to respond. So, when one of these microlensing events goes off, it's totally unpredictable. We have to get a hold of people who are at the telescope who are capable of making excellent observations and get the observations made. Once the event's gone, then we can't ever make the observations again. So they have to be in whatever location it is, and that's why we need people in remote locations, and they have to be, you know, in control of their telescope. They can't be somebody on the telescope who says, "Oh yeah, that's very interesting. Maybe I'd like to observe that tomorrow." They have to be ready to observe it right away. Of course, we also need very sophisticated software to reduce the data and to make sense of the data, and so that's why professionals are involved and, you know, there are also professional telescopes where the people have made commitments to take off from whatever they’re doing and to focus on these events. So, we have amateurs and professionals working together, and in fact, we have at least one and maybe two amateurs on the line who played a crucial role in this discovery.

>> Rick McCourt: One of those is Grant Christie. Grant, are you calling from one of those remote locations? Are you in New Zealand?

>> Grant Christie: I'm in Auckland, New Zealand.

>> Rick McCourt: Maybe you could tell us a bit about, first of all, what is your amateur status? What's that mean exactly, and also what you did in the process?

>> Grant Christie: Well, I've been an amateur astronomer since my youth, and I guess it means I don't get paid, that's one consequence of being an amateur, but down here we sort of do a lot of the stuff. There isn't a funding so we just do it because we think it's important to do it. That's ultimately the thing. I don't get a big joy, particularly, out of having to stay up all night, but it's--the payoff for us is the, you know, the great science that is coming from this sort of work.

>> Rick McCourt: Great, and OK. I'd like to open up to questions. There are probably some--.

>> Sara Seager: Actually, before we open to questions, I wanted to just make a few general remarks. This is Sara Seager making some, as the independent commentator.

>> Rick McCourt: Sure. Go ahead, Sara.

>> Sara Seager: Yeah, first I just wanted to try to put it into context, and I have one other comment. Right now, in exoplanets, we're on an inexorable path to finding other Earths. We want to answer this age-old question, is our planetary--are there other Earths, and are other planetary systems like our own? But, right now, no exoplanet technique can find Earths, and if you think of our own solar system, the biggest things in it are the sun, Jupiter and Saturn, and those are the most massive things that are easiest to detect, and the breakthrough in this discovery is that one such system has been found. If you were to take the masses and the distances in our solar system and divide by 2, it's like a miniature version of our solar system. So, I think it's a big breakthrough and a step to understanding whether our planetary system is alone. Then I have one more brief remark about the microlensing technique itself. As we've already heard, this is the only technique that can find Saturn mass planets at Saturn-like distances from the star and I'm amazed with this discovery because microlensing opens up an entirely new capability in terms of planet finding, and in sort of in a more colloquial way you can think of this as the planet finding flavor of the month or of the year, and for over a decade, the microlensing community were somewhat ignored or accidentally not invited to meetings and they were actually always kind of complaining and trying to, you know, make themselves heard, but we're seeing the triumph of a new technique and a vindication for the people who have been working so hard for well over a decade to not just find planets, but find the kind of planets that no other technique can find.

>> Rick McCourt: Thank you very much for the comments. Also, I'll mention just before we take the live comments, if you have an email question and you don't want to queue up for it, you can email the questions to Diane Vanegas here at NSF. Her email address is dvanegas@nsf.gov. That's dvanegas@nsf.gov, and she'll relay them to me and we might be able to (inaudible). So, if the operator has any questions, are there any at the moment?

>> Jenny: Good morning. Can you hear me? This is Jenny from New Zealand

>> Rick McCourt: Yes. Oh, hi, Jenny.

>> Jenny McCormick: Hi. How are you? Sorry, we got cut off before, but I just wanted to say good morning and Happy Valentine's Day and it's great to be here.

>> Rick McCourt: Well, it's a day early for us but Happy Valentine's Day to you. Thanks. Feel free to comment. Jenny is one of the other amateur astronomers in New Zealand along with Grant who worked on this.

>> Jenny McCormick: I just wanted to say that I'm very privileged to be involved with Scott and Andrew on the microFUN team, and I think the work we've done sort of will result as a just reward for the hard work and dedication shown by all collaborative teams. So, I'm very excited to be involved. To the next one.

>> Rick McCourt: Thank you. Is the operator there?

>> Operator: Yes. To ask a question, please press *1. Please unmeet your phone and record your name clearly when prompted. Your name is required to introduce your question. To withdraw your request, please press *2. Once again, to ask a question, please pre-existing *1. One moment, please. Our first question comes from Dennis Overby. Your line is open.

>> Dennis Overby: Hi. I guess this is for Scott. Can you explain why this was the first chance to see both a Jupiter and a Saturn-like planet?

>> Scott Gaudi: Sure. I can explain that. So, the previous two detections of a Jupiter with microlensing, one of them came in a--was the first planet that was ever found by microlensing and it came sort of by accident. It was a lower magnification event. Lower magnification events are less intrinsically sensitive to planets, and so you have to have your alignment just exactly right in order to have a planet, and as a result, you find the one planet, you really aren't sensitive to additional planets. The second Jupiter mass planet that was found was in a higher magnification event, but not very high, and so the sensitivity to the second planet was, again, not very high. This is the first time we found a Jupiter mass planet in an event that had very high magnification, had very good alignment between the foreground and background star, and as a result of that, very good alignment. You're not just sensitive to planets that happen to be right where you need them. You're sensitive to planets all over this cool outer region of the planetary system, and so if there's multiple planet systems out there, you'll find them all and that's--and so in this case, you know, our first time we’ve really done that we found them all. We found at least these two giant ones, sorry.

>> Dennis Overby: When this first starts, do you know immediately that it's gonna be a high or low magnification event?

>> Scott Gaudi: This is Scott. Absolutely not, but I probably think Andy should tell you about that because it's a very human and very interesting story about how we finally pick out the high magnification events.

>> Andy Gould: So, we start--we get notifications of microlensing events from two collaborations, from the OGLE collaboration and the MOA collaboration, which in 2006 probably together found about 700 microlensing events, and every day we inspect these events and try to tease out how they're going to proceed in the future, and what we do is we come up with a list of events that might possibly become high magnification, and then sometimes we try to get extra data on them to figure out if they will become high magnification, but other times we just guess and kind of go after them, because we can't be--we have limited resources and we can't just observe all the events all the time so it's partly an art and partly a science. However, I do have to say that, in this case, in this particular event, it had a tiny little bump at the, you know, onset, which was actually noted by the OGLE collaboration, and they--Andre Dowski, the leader of that collaboration, actually said this might be a planet. So, in this particular case, we were really alerted to it ahead of time and we were--we noticed it becoming higher magnification but that, in combination with the fact that it was, you know, already had something going on, made us very dedicated to getting good data on it.

>> Rick McCourt: Great. Dennis, anything else?

>> Dennis Overby: No, that's it.

>> Rick McCourt: OK. Are there other questions, operator?

>> Operator: Not at this time. Once again, to ask a question, please press *1.

>> Rick McCourt: OK. I have a question. In relation to theories of solar system formation, what does this tell us about that? Does it test any ideas or any of those theories?

>> David Bennett: I can answer that. This is Dave Bennett. Well, it used be that, you know, solar--theories of solar system formation were basically aimed at trying to explain the formation of our own solar system, and it was a bit of a shock then when the first planets were discovered that were very different from our own solar system, and so people began to wonder whether, you know, maybe these theories were not on the right track, but this discovery is actually, you know, a planetary system similar to our own solar system, and since we found it, the first chance we could find, you know, a Saturn-like planet, it sort of suggest that maybe those theories were right after all, that solar systems like our own are common and the only mistake that the theorists were making early on was just that they didn't appreciate a variety of possibilities.

>> Rick McCourt: Great. Thanks. I'm a little bit interested--well, if there are any questions, Operator, feel free to break in and interrupt me.

>> Operator: Yes, sir. We do have another question from Maggie Fox. Your line is open.

>> Maggie Fox: Hi. It's Maggie Fox at Reuters. I'm sorry. I got knocked off before, but I wanted to ask what kind of telescopes these amateurs have around the world, and how many of them are there in the network?

>> Andy Gould: So, in terms of the number--this is Andy Gould. In terms of the number in the network, now there are about a dozen, but at the time of this discovery, there were only two, who are the ones on the line. So, I think that they should answer about what sort of telescopes they have.

>> Rick McCourt: Grant or Jenny, would you like to pick up?

>> Jenny McCormick: Yeah, sure. At the time of this discovery I was using rather a small telescope, the Meade LX-200 10". Of course, being with the aperture so small I was quite limited so when this object got--was rather faint on the 8th of April, it was actually a struggle to really obtain good data, as I thought anyway. So, at the present time, thanks to microFUN I now have a brand-new 14" Meade which is working very well and I'm looking forward to the new season.

>> Maggie Fox: I'm sorry. I didn't hear what kind of--it's a--what was the one--

>> Jenny McCormick: It's a--sorry about that. It is a Meade LX-200 14" telescope I have at the present time.

>> Maggie Fox: What was the one you used though?

>> Jenny McCormick: The one I used was a 10" LX-200 Meade, one of the old classic design telescopes.

>> Maggie Fox: OK, great. Thank you.

>> Jenny McCormick: No problem.

>> Grant Christie: The one that I was using was rather similar to Jenny's. It was a--the optical path was a Celestron 14" telescope, quite an elderly one that we'd been given. It was 1980 vintage, one of the earlier ones that Celestron ever made. We have that telescope on a somewhat more sophisticated mount than what Celestron do. It's a power mount mounting, which gives us excellent tracking and pointing. So, that's the instrument, and we have a CCD camera on the telescope as well to take the images, so it--we are working, of course, from within a city although Auckland, by North American standards, isn't probably as well lit, it's still, you know, light contaminated and that's probably, you know, puts quite a bit of a limitation on the faintness that we can go, but as, I think, Scott mentioned, the advantage of these events is that when you get a high magnification one, they get bright so they come within the--they become accessible to small telescopes of the type we're using, which, of course, are very numerous around the world.

>> Maggie Fox: And what kind of, I mean, I’m sorry. I'm calling from the lay press and I only cover--astronomy is one of many subjects so forgive this question, but are you academic amateurs? How do we describe what you're doing? Are you people who are very interested and you go out and you buy your own telescope or is there a group that collaborates to spend the money. These are expensive pieces of equipment, I take it.

>> Grant Christie: Perhaps I'll answer that too. I mean, I'm a professional scientist. I've got a Ph.D. in Engineering Science, and I worked in biomedical engineering so, you know, I have a background, a lifetime background, in science and research, so I'm probably not entirely typical of most amateur astronomers. The telescope that we use is based at a public observatory in Auckland called--it's now known as Stardome Observatory, formerly called Auckland Observatory, and it's funded by basically donations that we get, charging people to come in and look at the planetarium and that sort of thing so it's actually a public observatory, but it's a working observatory as well.

>> Jenny McCormick: As for myself, I would classify myself as an ordinary New Zealand mother. I'm now a personal assistant to a general manager and I do not have any qualifications so I do it from home in our home-built observatory which is quite useful so it's very easy to get on taking data, cooking dinner and ironing clothes. That's said, that's just what it's like, and I wouldn't have it any other way.

>> Maggie Fox: Thank you.

>> Jenny McCormick: No problem.

>> Sara Seager: OK. This is Sara Seager from MIT. I wanted to just offer a comment on a previous question about planet formation, and I would say that this discovery is going to add fuel to a fire about the debate of how giant planets form. There are really--there's not a consistent agreement across all of exoplanetary science about how planets form, but it was thought that stars that are less massive than our sun, because they also have less massive protoplanetary discs, that it could be difficult to form a giant planet by the most conventionally accepted method, which is building up small rocks together which eventually are able to capture all the surrounding gas, and because these discs are proportionally smaller than the sun's protoplanetary disc was, it takes a long time to build up enough rocks to capture that gas. So, I think this is going to be an important discovery for planet formation.

>> Rick McCourt: Exactly how is going to add fuel to the fire?

>> Sara Seager: Let me back up then. There are really two different people--there are two different ways to form a giant planet. One is we call top-down approach. You have a big disc of gas and some of it collapses into a giant planet, which can happen very quickly, and the bottom-up approach is where rocks and ices stick together very slowly and eventually they become big enough, about ten masses, to capture gas from the whole surrounding area, but that second process takes a very long time to happen and so many people have thought that around low mass stars, like this one that has--like this discovery that we're talking about, it would take too long to build a planet from this so-called core accretion to capture gas before the gas completely goes away.

>> Rick McCourt: This would support the top-down model to some extent.

>> Sara Seager: Yes. So, this supports the top-down model.

>> Scott Gaudi: Right. I'd like to add to this a little bit. This is Scott Gaudi. One, and it's just sort of another plug for microlensing. One of the things about microlensing is its not very sensitive to the mass of the host star around which we're looking for planets. So, you can find planets around stars that are very, very low mass because we're not sensitive to--we don't need the light from the star. We just use the gravity of the star. So, in fact, if you look at the range of host stars that have had planets detected around them with microlensing, they range all the way from maybe .2 or a fifth of the mass of the sun, to may be 80% of the mass of the sun. this one that we're talking about today is half the mass of the sun, and so we're finding planets around stars that have all sorts of masses and so we’ll be able to test this idea, at least on the low mass end, the smaller stars, smaller than the mass of the sun, quite well.

>> Sara Seager: Right. So, the underdog in the planet formation theory for Jupiter mass planets is the top-down approach, so it's going to fuel the debate because it gives more support to that community.

>> Rick McCourt: Thanks. Operator, are there any more questions in the line?

>> Operator: There are no questions at this time.

>> Rick McCourt: I’d like to ask one more. Do we still have some listeners in though?

>> Operator: Yes, sir. We do.

>> Rick McCourt: OK, good. I wanted to ask a little bit about what this has, in terms of implications, about the origin and evolution of life on other planets, if any. Does it have any implications for that?

>> Scott Gaudi: I can start off with that and maybe someone else can take over, probably Sara or Dave. So, I mean, I think that you can just take a step--this is Scott Gaudi, by the way. You can take a step back and ask, you know, why is it that we're doing this. Why are we talking about these extra-solar planets at all, and I think at least one motivation for a lot of people is that we really want to look and see if there's life out there. Now, at the moment, we're so far from answering that question that it's more of a question of philosophy than actual science, but what we can actually do is that we can try to break that question down and answer parts of it, and so the first thing you might want to know is, well are there planets around stars at all? Well, back in 1995, you know, Mayor and Queloz and Geoff Marcy and Paul Butler answered that for us, and by finding the first planets around normal stars, but those planets obviously looked very much--nothing like our solar system. They were giant planets very close in, and you know, again, this is just intrinsic to the Doppler method. It's most sensitive to the biggest planets that are the closest in. So, that answered one part of the question but then the next part of the question, of course, is well, are there solar systems like our own out there? Are there planets with the masses of Jupiter and Saturn that are further out in the solar system, and then rocky planets on the interior part of the solar system, and you know, our discovery here seems to answer at least that the Jupiter/Saturn analogs, solar system analogs, are, or seem to be like they might be, fairy common. Then the next step, of course, is to actually find Earth in the habitable zone, the range of distances where you might have liquid water. Now, likely Sara will remind me that we shouldn’t be too restrictive in our search for life, but at least that's one way in which you can frame this question.

>> Sara Seager: I'll add to that just by saying that I think this discovery is the tip of the iceberg for microlensing discoveries. This technique is powerful in ways that no one had anticipated, apparently not even members of the discovery team, and so they are, in some ideal configurations, they will be able to find Earth mass planets and I think in the next few years, we have a lot to look forward to.

>> David Bennett: This is Dave. I just had something to add to that. I think in terms of understanding life on other planets, it's actually--it's fairly important to understand how planetary systems form because it's not just enough to know, you know, what sort of planets and what masses they have out there. To form life, you also need, you know, you need to know what sort of--what the composition of the planets are, whether they say a planet, you know, in the Earth's position would actually have enough water to support life to develop, or other volatile compounds, and the water on Earth is thought to have actually condensed further out in the protoplanetary disc and so the details of the planet formation process might turn out to be very important for understanding how life develops, and so, to the extent that these results help us understand planet formation, it's also bringing us closer to understanding whether there might be life on other planets.

>> Sara Seager: This is Sara Seager. I also wanted to clarify again that with microlensing, we'll never have a chance to observe the star at--we'll never have a chance to observe the planet again. It's a snapshot of information about the planet so we won't be able to tell if these planets have life. However, back to what Scott was saying about a hierarchy of questions, are there extra-solar planets? We've answered that. Are there other Earths? We haven't answered that yet. Are the Earths we find habitable or do they have life? We're going on that hierarchy of questions so microlensing will be able to tell us if there are other planets with Earth's mass in what kind of orbits.

>> David Bennett: Sara, this is Dave again, Dave Bennett. I just wanted to contradict you slightly on this. For this particular system, we actually have a pretty tight constraint on the inclination, and the host star is--it's bright by microlensing standards. It's the brightest host star that, you know, with detected planets around. It's, unfortunately, extremely faint by radio velocity standards, but it's not so faint that, you know, that it'll be completely impossible for the foreseeable future to actually confirm this detection. I think it might be the case that the next generation of even larger telescopes, 30-meter telescopes, that we might be able to actually confirm this detection with another method. So, we're hoping to get some in the future that would actually have brighter stars and maybe we could get a confirmation sooner, but--

>> Rick McCourt: What kind of technology are you talking about in terms of being able to detect an Earth-like planet and about how far away do you think we are technologically from getting there?

>> Andy Gould: This is Andy Gould. The technology to detect Earth's mass planets is here. It's just really that the, you know, it could be that next month we detect one. They're hard to detect because it's less probable than an Earth will become so closely aligned to the light coming from the source that it will give itself away, but if it does become closely aligned, the signature is quite within the capabilities of the present networks. In the future, we, you know, look to developing space observatories that might, you know, dramatically enhance the capabilities of the microlensing technique and then we could detect far more, but it's quite possible that we could detect an Earth mass planet soon.

>> Sara Seager: I would say that--this is Sara Seager again. I would say that everyone’s racing to try to find an Earth, all the different techniques and there are other things going on in other areas of planet finding that will find Earths eventually, such as NASA's Kepler space telescope that will be launched in 2009, and there are other efforts on the ground that are trying to find Earths around--that are trying to find big Earths around small stars.

>> Rick McCourt: And what they're looking for is the right size planet at the right distance?

>> Sara Seager: That's what Kepler is doing, but like microlensing, they'll be taking a census and getting some properties, but not all.

>> Rick McCourt: OK. Great. Are there other questions, Operator?

>> Operator: There are no further questions.

>> Rick McCourt: OK. I guess we can probably wrap it up then unless anybody has any closing comments they’d like to make? David, Andy, Scott, Sara, or Jenny and Grant? Any of you.

>> Grant Christie: I've just got a quick question. It's Grant here. The previous placement we did on the events as far as 1-6-9 implied that most of these red dwarf systems are dominated by Neptune. I guess I'm just asking the question as does this current result raise any questions about that conclusion?

>> David Bennett: This is Dave Bennett. No, not really. We're, you know, it’s easier to detect the more massive planets than the less massive planets, and the fact that we're continuing to discover these lower mass Neptune type planets, you know, tends that confirm that previous conclusion. So, you know, we basically, with this discovery, we've shown that, you know, that Jupiters are likely to be accompanied by Saturns, but you know, this previous discovery was that it may be even more likely to have a Neptune in place of the Jupiter.

>> Scott Gaudi: So these sort of--this is Scott. I guess a very fast and loose way of saying this would be that what we're finding--what our result here today suggests is that these kind of solar Jupiter/Saturn analogs are common, however, the result that we had before in the previous paper is that the Neptune mass planets or the systems where you just have a Neptune are even more common than that.

>> Rick McCourt: Great. All right. Well, thanks again to Scott Gaudi and Andy Gould from Ohio State, and David Bennett at Notre Dame, and also Jenny McCormick and Grant Christie down in New Zealand, our amateur astronomers, and Sara Seager at MIT. I'd just like to remind everybody that the, again, the embargo date and time on this information is 2:00 p.m. tomorrow, February 14th, and recording of the call will be available through Sci-Pec and also at the MCI url. You can contact Diane Banegas with any questions you may have about this at dbanegas@nsf.gov. Thanks again everybody, and see you next time, maybe, for another news conference. Who knows?

>> David Bennett: Thank you.

>> Scott Gaudi: Bye.

>> Sara Seager: Bye everybody.

>> Jenny McCormick: Bye-bye.

>> Operator: Thank you for participating in today's conference call. You may disconnect at this time.

>> Rick McCormick: Thank you, Operator.

>> Operator: You're welcome.

Return to the news release and audio. Also see the media advisory about this event.


Email this pagePrint this page
Back to Top of page