The Hunt for Exoplanets, more exoplanets, and NASA announcements. Oh and more exoplanets.

Well first off, Hello, this is my first time making a thread here at ATS so bare with me.

Anyway I'd like this thread to serve a few purposes, so i will begin by stating those purposes before i get into the meat of the thread.


To educate people on Exoplanets, how they are found and a basic understanding of light curves.
To Encourage you to join the hunt
And to briefly discuss the problems I've seen with members here at ATS whenever there is an announcement made by NASA.

[atsimg]http://files.abovetopsecret.com/images/member/d561e188bb11.png[/atsimg]

As you may have heard NASA has announced it will be expanding it's list of Exoplanet Candidates on February 2nd, however there is some more info you may have not heard about this. Today (February 1st), the Kepler Team will also be releasing more data to the public (light curves of distant stars in the search for
planetary transits and/or Eclipsing Binaries).

In order to understand what NASA is making announcements about, you should probably understand what Exoplanets are, how we find and detect them, the difference between an exoplanet candidate and an exoplanet, and understand just how much data we have already collected.

Exoplanets, a shorter version of the same term, Extrasolar Planets, are planets that exist outside (exo) of our solar system. Their existence was speculative until 1992 when radio astronomers Aleksander Wolszczan and Dale Frail announced the discovery of planets around another pulsar, PSR 1257+12, which was quickly
confirmed and generally thought of as the first definitive exoplanet. 1995 however, was when the first definitive announcement was made that a Main Sequence star (51 Pegasi, 51 light years from earth) much like our own sun was confirmed to host an orbiting planet. It was this discovery in 1995 with improvements in high
resolution spectroscopy that opened the gates to a vast amount of more confirmed exoplanets. Another system discovered in 1988 that was thought to have hosted a planet, but such a claim could not be definitively proven until 2002 with improved techniques. As of January 20th, 2011, 519 Extrasolar planets have been confirmed through various methods of detection.

So how are these planets detected? Well, there are quite a few methods of detecting a planet around a star. Such methods include: Radial Velocity (or the Doppler Method), the Transit Method (the one Kepler uses and i will be focusing on later), Transit Timing Variation, Gravitational Microlensing, and Direct Imaging. For the purpose of this thread I'll only go into depth on the Transit method but I'll give a brief explanation of each method so you don't have to go look them up.

1) Radial Velocity and the Doppler Effect. Planet's don't just orbit around their star, rather the star and the planet will both orbit around the center of gravity in that system. Variations in the speed at which the star moves towards and away from Earth (Radial Velocity) can be detected by the movement of the Star's spectral lines due to the Doppler Effect. Thus far this method has been the most successful with 369 confirmed exoplanets.

2) Transit Method. Ill cover more of this method later on in the thread. But basically it measures the observed brightness of a star and looks for slight dimming in the light due to transits, which could be a planet or an eclipsing binary. 114 confirmed planets have been discovered using this method.
[atsimg]http://files.abovetopsecret.com/images/member/5286e172cc03.jpg[/atsimg]

3) Transit Timing Variation. This method is a variation of the transit method and requires a known transit of an existing planet. Variations in the transit of one planet can be used to detect the existence of another. WASP-3c was found using the transit of WASP-3b in this very method. The variance in the duration of the transit can also be attributed to exomoons. A possibility that makes me appreciate the transit method, and the seemingly uninteresting majority of Jovian planets discovered with this method. An expanse of even more possible habitable worlds when we look at just how many moons the Gas Giant planets of our own solar system. 10 planet's have been discovered using this method.

4) Gravitational MicroLensing is the occurrence of a star's gravitational field acting like a lens that magnify the light of a distant star in the background. However, this is only useful when two stars are almost exactly aligned in relation to the Earth. Not particularly difficult to observe such occurance but the window of time available to use the micro lense isn't exactly "ideal", what with the constant motion of all celestial bodies. 11 confirmed planets have been found using this method.
[atsimg]http://files.abovetopsecret.com/images/member/d29fe0aaa512.jpg[/atsimg]
-planetquest.jpl.nasa.gov...

5) Direct imaging. The method I'm sure most all of you are familiar with. When you look up at the night sky and are able to see Mercury, Venus, Mars, Jupiter, the rings of Saturn with the help of binoculars or a telescope...However, direct imaging is a very different story for exoplanets and the extremely faint light from the
planets is almost always lost in the glare of their host star. Although recently, projects to upgrade scopes with new vortex coronagraphs have increased the success of this method by blocking much of the star's glare. 15 confirmed planets have been discovered using this method.

[atsimg]http://files.abovetopsecret.com/images/member/c4588e2a1442.png[/atsimg]

The image above shows the light from three planets orbiting a star 120 light-years away. The planets' star, called HR8799, is located at the spot marked with an "X."
-www.nasa.gov...

So now you've got a pretty good understanding of exoplanets and how they are found. But why am i so concerned with the Transit Method and why am i telling you this? It has to do with the Kepler Telescope and the data that the Kepler Team has been releasing to the public. Kepler was launched on March 7, 2009 and is a space-borne telescope equipped with a photometer to gather light intensity data over 30minute intervals for over 145 main sequence stars in a fixed field of view. Well what makes Kepler so special? It is the increased ability to discover much smaller planets of a size similar to that of Earth (with the smallest confirmed planet being Kepler 10-b, 1.4x the size of Earth). This increased ability may lead to the understanding that rocky, terrestrial planets in fact populate more of our galaxy than Gas-Giants. An important idea considering the required conditions for life (as we know it, big emphasis on this part here, big emphasis!) to take hold would be on those terrestrial planets rather than Jupiter sized planets.

The Kepler Team has up to this point has found over 700 Planet Candidates, 1800 Eclipsing binaries, and 9 confirmed planets

So what makes the difference between a planet candidate and a confirmed planet? Well the key difference is that at least 3 Transits must be observed and follow up observations must have been met.

But the main impetus for making this thread was to encourage you to take part in going through the public data. So far Kepler has made available 30 days worth of data for 150,000 Main Sequence stars in which they found over 700 planet Candidates, and the community has found at minimum about 90 planet candidates and 50 eclipsing binary candidates. Pretty good for only thirty days. The announcement that you've heard about to be made on February 2nd will be on the 2nd data set that is being released today and tomorrow.

Now why should people take part and help look through the public data, don't computers do a pretty good job of discovering these small dips? Yes, in fact they do a wonderful job, but computers aren't perfect. The human brain does a wonderful job at observing and recognizing patterns and anomalies, this is where you come in! The easiest way to look through this public data is through the ZOONIVERSE team at Yale. You may have seen other Zooniverse projects like GalaxyZoo, Solar Storm Watch, Moonzoo and a few others, but PlanetHunters.Org is the most exciting in my opinion. PlanetHunters taps into the remarkable talent of the human brain and the mass number of people with a desire to investigate the cosmos to pluck out transits that computer algorithms WILL have missed. An easy to use interface (quite a beautiful design i might add, coming from a web designer/developer), helpful community, and awesome staff makes this website and community one you should consider joining, helping, and learning with. Oh and I almost forgot to mention, yes, you do get credit when you discover a planet or eclipsing binary.

Im going to go through a bit about the PlanetHunters first run at the data now that the new (good stuff) information will be coming out today and tomorrow. 150,000 stars and 1.2million classifications later, completed by the community and PlanetHunters, 3553 stars had been picked out that were marked for a transit by at least 5 people and were not already published by the Kepler team in the first data set. Out of this selection of 3553 stars an astronomy team at Yale working with the PlanetHunters staff went through and rated on a scale of 1-5 how promising the transits looked for either a planetary transit or eclipsing binary system, narrowing down the data set to about 800 stars that fell into one or both of those categories. Further yet, three senior "dip spotters" went through this list even more carefully rating them again and excluding every transit that wasn't at a 4 or higher leaving quite a good number of planet candidates that would have been missed by planet hunting teams and data sifting computer algorithms. Final Result: 90 planet candidates and 42 possible eclipsing binaries.

Hopefully by now you either feel like signing up and sifting through the data that will nearly quadruple the current data, coming out today...Or you may have a more humble approach upon criticizing NASA and planet hunters everywhere at their "slow progress".

NASA's Kepler spacecraft is one of the most powerful tools in the hunt for extrasolar planets. The Kepler team's computers are sifting through the data, but we at Planet Hunters are betting that there will be planets which can only be found via the remarkable human ability for pattern recognition. This is a gamble, a bet if you will, on the ability of humans to beat machines just occasionally. It may be that no new planets are found or that computers have the job down to a fine art. And yet, it's just possible that you might be the first to know that a star somewhere out there in the Milky Way has a companion, just as our Sun does. Fancy giving it a try?

To try and accomplish one of the last things i listed earlier in the thread im going to go through and explain Light curves a bit for those who may find themselves venturing over to PlanetHunters.org to being searching and discovering for themselves. As i mentioned in the methods of discovery section, the method used by the Kepler Space Telescope to discover planets is the Transit method, in which an extremely slight dimming of the Star's light can indicate a transit of some sort. First, let's see what a normal lightcurve looks like, and for the sake of this thread and people who may decide to head on over to Planethunters.org I will use their interface
of display.
[atsimg]http://files.abovetopsecret.com/images/member/07933b10f842.png[/atsimg]
Click Here to enlarge the view to be able to read it more clearly. I have labeled a few things in orange on the picture. The star we are looking at in this picture is a star very much like our own sun, pretty close in size and the same spectral type. When you look at the graph you will notice it is a scatter plot of little dots. Each dot represents one measurement taken by the Kepler spacecraft of the stars light, each dot seperated by 30 minute intervals. The above picture is a star i have already classified but when you go through classification of the star you will have a slightly different view. Not every star is quiet like this one, in fact many of them are variable in their light output, meaning the apparent light as seen from Earth varies in intensity due either to blocking of some of the light in space, or an actual change in the star's intensity. Our own star varies by about 0.1% over an 11 year cycle. So when you are classifying, you will see a bubble that will ask you to try and identify what type the star is, Variable (including further regular, pulsating, or irregular), or Quiet (a flat band of light like the above picture).
[atsimg]http://files.abovetopsecret.com/images/member/a5a3f94574f5.png[/atsimg]

Now what do the transits look like? Well before i show some pictures, there is going to be 2 different types of "transits" you will encounter if you decide to take part. One being a planetary transit, and the other not really a transit but an eclipsing binary. Eclipsing binaries are very different from planetary transits, because it is in fact an eclipse of one of the stars in a binary system by the other and vice versa. In a binary system both stars orbit around a common center of gravity (this same mechanic was mentioned earlier in radial velocity). The following GIF animation uploaded by Wikipedia user Stanlekub demonstrates the nature of eclipsing binaries very well. When both stars are visible we see that highest amount of light, but when the larger star totally eclipses the smaller we get a dip in the light curve. One way we distinguish this from a planetary transit is observing this eclipse in reverse, when the smaller star only partially eclipses the larger star but still blocks out more light than the previous eclipse where we can see a much larger dip
[atsimg]http://files.abovetopsecret.com/images/member/2f0a799db01f.gif[/atsimg]

Okay now you can see some pictures of this in action courtesy of the PlanetHunters and the individuals credited with the discoveries.

[atsimg]http://files.abovetopsecret.com/images/member/8ecfffa42783.png[/atsimg]
This first picture is that of a possible eclipsing binary SPH10133951 first identified on 01/01/11 by planet hunters hillbillybob, samasinter, cyril.tabut, liszu, echong, Vince1912, zephyr7, cmorford, Zaberish, honken, marrigo, robert gagliano, marcosmza62. I tried to pick an example with a very extreme difference in the dips.

[atsimg]http://files.abovetopsecret.com/images/member/ac9be73cd407.png[/atsimg]
And this second picture is that of planet candidate SPH10007403 First identified on 01/01/11 by planet hunters snitramoriaj, jayrhns, rlangos, marmet, howardhallmark, fbarnet, nhazel.


And finally i would like to address the NASA announcements. First off, these announcements which come very often and regularly aren't supposed to be revolutionary and Earth-Shattering, though it's possible it may one day be, but expecting that type of an announcement EACH and EVERY time is going to do you no good. Especially when you haven't bothered to look at what the announcement is going to be about, nearly every time I come across a thread about one of these announcements, most of the replies consist of highly speculative ideas on what the announcement will be about. Typically, NASA has either already said what the topic will be about or has been dedicating a significant amount of attention of one team/project towards the topic of the future announcement. Such is the case with the conference tomorrow. If you had been paying attention to exoplanetology, which i won't assume you have, you would know about the Kepler telescope and it's scheduled public data release dates.
Last time they released Quarter 1 of the Data they followed it with a conference of their planet candidates and confirmations. Now they plan to release the data today, and follow that with a conference about guess what...Yup you got it, exoplanet candidates. And for those of you always want to be disappointed with NASA going "Ahh only more boring planets" hopefully this thread may have humbled you on the amount of work, confirmation, reconfirmation, rereconfirmation required, the difficulty at picking out buried planet transits in this field, and maybe even sparked some interest in you. Astronomy and Astrophysics is cool damnit! Haha thank you.

The Kepler team will have a press conference on 2 February 2011, announcing their new candidates and releasing new data that will more than quadruple the amount of data that is available on Planethunters.org. You can join the live broadcast on NASA TV at 1pm EST

Well now you know, and im hungry after writing this thread. Thanks for taking the time to read/comment ATS. Deny Ignorance!

Some good links:

www.planethunters.org...
en.wikipedia.org...
exoplanet.eu... - Confirmed Exoplanets
archive.stsci.edu... - Released Kepler Candidates
kepler.nasa.gov... - Released Kepler Confirmations
www.physics.sfasu.edu... - Eclipsing Binaries

So exoplanets are planets that other stars have. That's very interesting. - Thank you.




.

reply to post by EssenSieMich



Basically, although the term also includes rogue planets expelled by their stellar system and no longer belong to a star.

reply to post by Stuffed


Woops just noticed a typo in there.

Meant to say 145,000 stars in the following passage.

"Kepler was launched on March 7, 2009 and is a space-borne telescope equipped with a photometer to gather light intensity data over 30minute intervals for over 145,000 main sequence stars in a fixed field of view."

Flag and star. Loved your thread and the fact that you truly worked hard on bringing information to the subject and relaying it to us in a lucid and intelligent matter.

The search for exoplanets may not seem to be like a big deal to many, but the simple fact is that if we don't find a viable exoplanet then we are doomed to the death of our species as the Sun will make Earth's planet too hot to be habitable in the next 500 million years. Not to mention the litany of other scenarios that would guarantee our deaths that will probably happen before that such as massive solar flares; asteroids and comets; gamma ray bursts; or whatever else is out there that we don't know about yet.

reply to post by Stuffed


Great first thread..
S&F for the effort..

The problem I have with NASA is what's the point of looking for all these new planets, some they say may one day be viable, if we can't get there???

NASA should be concerned with GETTING into space not LOOKING at it.....

reply to post by backinblack


Oh believe me, I'd much rather be getting out there and going through space, in fact I'm pretty sure a lot of people at NASA would love to do the same. It's just much more accomplish-able and cost effective than the travel issue.

Another thing is, we need to know what's out there, where it is, what it's like before we just go blindly flying out into space. Not just for our safety but because space travel takes a long time even at the speed of light, now imagine trying to cruise around without a clue and how horribly inefficient that would be for your relatively short life span.

The biggest problem, In my opinion, is the lack of interest the public has in space. It almost seems like when asked about space the people of this world know literally nothing about it and just shrug it off. Sure some people go, yeah that's a cool picture but the interest really ends there. It is this very same disinterest that let's the Governments of the world focus on what they want rather than what the careless people "maybe want like whatever man". And we've all seen what the governments of the world want, they could care less about understanding, there's too much power and control to be fought for on our own planet at the moment.

That being said, It's the research of space that will not only lead into travel because we know where were going as i pointed out earlier, but because it will have peaked the interest of the people finally. Popularizing science has got to be one of the most important challenges humanity has faced, but I have faith, that day will come soon enough. I just hope it's within my life time haha.

Thanks for the comments.

reply to post by Stuffed

The biggest problem, In my opinion, is the lack of interest the public has in space. It almost seems like when asked about space the people of this world know literally nothing about it and just shrug it off. Sure some people go, yeah that's a cool picture but the interest really ends there.

Well after the great space race of the 60's where a huge amount of GDP was pumped into NASA etc, I think the puplic expected more..
I mean what have we done since then?
Most expected exotic new drives etc and yet we've seen nothing..
Some say they have these things but are black ops..

But to tell us their is a suitable new home millions of light years away is really a waste of time..
Focus on how we would get there , then look for where we may go..

reply to post by backinblack


The space race was somewhat of an unfortunate turn of events once everything had subsided. Getting to the moon was of course a huge stepping stone but in terms of public interest, it peaked at our infancy of space exploration. We spent what? 100billion in getting to the moon and we got what? We got to the moon, a significant achievement in my eyes but for everyone else, boom it ended there. Where as today we could construct a space elevator for something in the ballpark of 40billion, something that would seriously change the space game and produce real results, hell even damn profitable results for all the greedy corporations once the ball get's rolling.

The research side and the physical travel side aren't mutually exclusive though, we should be pursuing both to the fullest extent.

Sure it's always a possibility that "Black Ops" have the real technology, I just don't think it's that likely. Make no mistake i wouldn't doubt for a second though that top secret tech and knowledge is beyond what's public, that much should be expected. Just not to the level of technological superiority many on this site would believe.

Edit: Oh and I should have added this to the OP but if anyone joins Planethunters leave a comment about it. And if you've got any questions about the site or data you're looking at just shoot me a message or leave a comment. I'd like to know about any progress people make and if they find any planets!

This is a great post S&F! I think many people don't really get excited about most announcements that NASA makes because they don't really understand what it is really about and might not understand the science behind it or what possible use it has to us. So to educate people, explain the meaning and reason of these experiments is a good way to get people involved and excited about new discoveries in science. This post surely helps do that!

The biggest problem, In my opinion, is the lack of interest the public has in space. It almost seems like when asked about space the people of this world know literally nothing about it and just shrug it off. Sure some people go, yeah that's a cool picture but the interest really ends there. It is this very same disinterest that let's the Governments of the world focus on what they want rather than what the careless people "maybe want like whatever man". And we've all seen what the governments of the world want, they could care less about understanding, there's too much power and control to be fought for on our own planet at the moment.

It's difficult for the average Joe to be concerned about space travel when they worry about rent and putting food on the table. Just a consequence of the times...and politicians respond to it. When the American people didn't want to be second to the Russians, there was more "political" capital for NASA to spend in getting out there. Now, that political capital is deeply in the red, so it's a miracle we get ANY space exploration done. While I'd love to see it as a higher priority, right now, the people have decided the money is best spent elsewhere.

Personally, I think the future of space will be in the private sector (ultimately)...but time will tell.

reply to post by Gazrok


The "political capital" you mentioned is entirely correct, as well as the private sector being the future. But from what I've seen it looks like the private sector is going to be waiting until the Government lays out that first big stride for private entities.

You do remind me to be thankful that we even have any money at all for our space program which I am indeed thankful for heh.

I'm pretty sure we just need another show like Cosmos though, with a new Carl Sagan. Neil deGrasse Tyson maybe, he makes things sound pretty interesting haha. Michio Kaku makes things sound too interesting it get's lost on some of the normal people.

Live at 1pm EST today: NASA announces new exoplanet findings from our Kepler mission. Watch online: www.nasa.gov...

Originally posted by martinkb
Live at 1pm EST today: NASA announces new exoplanet findings from our Kepler mission. Watch online: www.nasa.gov...

Yup! It's important to note that this new data release in total will quadruple the amount of data released previously. Should be able to expect maybe 1000+ new planet candidates by the Kepler team alone, with many more to be found by all of you and myself at Planethunters. 3 months of data on 150,000 stars available here: archive.stsci.edu... Or by data releases of 5,000 stars a day for a month at Planethunters.

Here's a good article about exoplanets released yesterday with Geoff Marcy, a leading exoplanet astronomer.
www.space.com...

Originally posted by Stuffed
reply to post by backinblack

 

It's just much more accomplish-able and cost effective than the travel issue.

Another thing is, we need to know what's out there, where it is, what it's like before we just go blindly flying out into space. Not just for our safety but because space travel takes a long time even at the speed of light, now imagine trying to cruise around without a clue and how horribly inefficient that would be for your relatively short life span.

The biggest problem, In my opinion, is the lack of interest the public has in space. It almost seems like when asked about space the people of this world know literally nothing about it and just shrug it off. Sure some people go, yeah that's a cool picture but the interest really ends there. It is this very same disinterest that let's the Governments of the world focus on what they want rather than what the careless people "maybe want like whatever man". And we've all seen what the governments of the world want, they could care less about understanding, there's too much power and control to be fought for on our own planet at the moment.

So its the lack of interest that is keeping us from going into space? I have to disagree. Think of all of the movies that have come out over the years suggesting travel to Mars and other planetary bodies. I mean there were articles last year claiming that people wanted to kill themselves after seeing Avatar b/c they feared they would never see a place that beautiful in their lifetime.

I wonder how much interest would we have if Obama said we will land a person on the Moon by next year?
There was a sort of outrage when Dr. Howard Smith said that extrasolar system life was possibly non existant, but where is the outrage at our own space program? Where are the Aliens? Well my friend they are waiting for us...we are the Aliens.

The sooner we start thinking of possibilities like Terraforming the better.

reply to post by packinupngoin


Well certainly it looks like interest has increased slightly recently, with thanks due to Avatar most likely. But overall, around the globe it still isn't a priority. It may be interesting in the realm of science fiction to most, but interest will determine political goals, and right now it would take a hell of a lot of interest (most likely in the form of money) to get us to start devoting the amount of resources that space exploration and travel (Not the shuttle to orbit launches we think of as travel haha) is going to require.

I think I posted this already, or did you beat me?


www.abovetopsecret.com...

reply to post by v1rtu0s0


This thread isn't just about the news NASA is releasing, it's more of an informative topic on exoplanets i wrote up rather than an external article. Although i will include what the press conference brings up in an hour on this thread.

I scanread through the OP, finding it interesting. However for not paying so much attention to it I wasn't exactly sure what 'dip' it was about. Going to planethunters.org, it presented the simple tutorial, and only after I had done that I figured it was about the dots appearing seemingly lower in the graph from other dots.

So planethunters.org tutorial is a shortcut to what its about. The original post is a more detailed version of it

I thought I would try registering and see what other features I will be seeing on the site. Once I registered and logged in, it throwed me a random stars graph as it does for guests, but as a guest I was only asked whether there is transit, now I was asked the following. This first one is I guess quite explanatory: "Are there any big breaks or gaps in the light curve?"I think I have a hunch to answer the question correctly. Answering 'No', it then asks whether the star is a 'variable' or a 'quiet'. OP explains briefly this, but I'm not sure how much of wave effect or dips(?) will be considered as 'variable'... Are the SPH10133951 and SPH10007403 mentioned in OP quiet with transits or variable with transits? If they are quiet with transits, can I see an image of a variable one ? Anyway, after that it then asks what it asks from the guest: "Does the star have any transit features?" - meaning those dips (dots appearing abnormally low in the graph).

In overall, helping with planet hunting with that website is faster and easier than I thought. If I have the site in favorites, it is a matter of couple clicks of a mouse and I have classified a star. I guess it can be thought of as going for a slot machine pull. So as OP said, the interface is very friendly, I suggest everyone to try it out.

So if possible I would like some further info on defining whether the star is a quiet or variable one. Like for example the star APH10109646 that I was just showed shows some zig-zaging, but I'm not sure if that is what I should be looking for: up.k10x.net...

reply to post by inthemistandfog


Great question and good for you signing up! I'll post up my own tutorial after this press conference at some point but in the meantime, on that chat bubble they have the option for "help" and that should briefly explain some of the differences. I'll make another post in this thread to try and clarify the planethunters experience and go a little more in depth though, so don't worry. Thanks for the interest.

www.nasa.gov...

Right off the bat we got a heavily populated steller system


Edit: Ahh it appears that 1000+ number wasn't "new" entirely but also including the previous 700. But stil 1200 total candidates is quite a good number for a year and a half

Especially these numbers
68 Earth Size Candidates from about .5R(Earth Radius) to 1.5R
and about 280 Super-Earths