Discover exoplanets with Planet Hunters

Hi guys, today I’m going to start a new
series of videos about how you can easily look for potentially habitatable exoplanets
from your home, without the need of any telescope. In this first episode I’m going to show
you how to use an online project, which is free and gives you the opportunity to find
exoplanets by analyzing data from the Kepler Space Telescope. How? Well the method you are going to use is called
transit photometry. You are going to look for a drop in a star’s brightness produced
by an exoplanet crossing the star from our line of sight. The link to the project, called planet hunters,
is in the description, so now, let’s begin First of all, I recommend you to create an
account in order to receive credit for your discoveries. Now, in the light curves, the x-axis shows
you the days spent observing the star, the y-axis shows the brightness of the star and
each dot represents one measurement of that brightness. Depending on how far the exoplanet is from
the star or if several exoplanets are transiting, you may see one or many drops in the light
curve with the same or different deepness and distance among them. For example, these
drops are caused by a single exoplanet because they have the same deepness and they are equally
spaced. Moreover, this light curve tells you that
the exoplanet is close to the star because the orbital period only have 2,4,6, 8 days
and it also gives you an estimate of the size because the deeper the transit, the larger
the exoplanet. So you’re looking for dots that appear lower
than the rest for a short period of time, usually hours and when you spot a potential
transit, mark it on the light curve and click on finished. Curves of 30 days with transiting exoplanets
that are potentially habitable usually have most of the dots at the same height, which
means that the star only suffers decreases in its brightness when exoplanets or a star
transit. However, you can also find exoplanets orbiting
for example variable stars, but these planets are unlikely to host intelligent life Actually, variable stars are one of the most
common false positives, let’s say, curve lights that seem to have a transit, but they
don’t. Variable stars tend to suffer from changes
in its brightness over a long period of time, usually days, and they can be periodic, or
not, so if this transit is not here, and this one is not here, both curves would be false
positives. Another typical false positive are eclipsing
binaries, which are stars transited by another one. They produce curves with 2 drops, one
of them being less deep than the other when the smaller star passes behind the large one So far, several people have found exoplanets
through this project. One of them is for example Kepler 64-b, a Neptune-size exoplanet found
in 2012. Another example is Kepler 86-b, a Jupiter-size exoplanet discovered in 2013.
This one is interesting because it is located in the habitable zone and, if it has moon,
this one would probably have a rocky core and a green-house atmosphere that could allow
to have liquid water on the surface. Finally, I would like to say that NASA needs
you. They have millions of data that needs to be analyzed by humans and they don’t
have the resources to do so, For this reason I encourage you to participate
in the project. You don’t have to spend too much time, 5 minutes per day would be
enough. What is your reward if you succeed? Well,
not only that you can say you have found a potentially habitable exoplanet, but also
that you will enter in the small group of people that have discovered one and your name
will appear in the research paper, in news, etc.. Moreover, the faster we find more potentially
habitable exoplanets, the sooner we will start sending satellites and robots to them. Remember
for example the announcement of the Breakthrough Starshot project last year by the billionaire
Yuri Milner after the discovery of the exoplanet proxima b. By the way, if you haven’t watched
my video on Proxima b, I encourage you to watch it now Alright that’s all for today. Thank you
very much for watching. Please like, subscribe, click on the bell
and share this video if you want. Feel free to leave any comment, suggestion
or question below. And see you in the next video on how to find
exoplanets from home. Bye bye.


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