Its about Trappist-1

Hi,
I noticed that in the last days lot of attention was given to this new exoplanets. Well, I guess I have to stay in the “popular sphere” and follow with my post!


Around star called TRAPPIST-1 also known as 2MASS J23062928-0502285 were found together 7 exoplanets, more on this down in the post.

First the star.

Trappist-1 is very small star in special category L which means that it is a red dwarf. You wont find this category in the normal stellar classification because this one and other are made for brown and red dwarfs and were introduced later on. This of course means that Trappist-1 is not very bright or very hot and NOT visible to naked eye (it has apparent magnitude of 18.8 which is way outside of what human eye can see).

All pictures of these planets are artist’s impression.

 

The planets were discovered using transit photometry. Method that takes advantage of the planets blocking out some of the star’s light. In 2015 there were 3 discovered already and in February this year, astronomers in Belgium found another 4.

There names are truly beautiful: b,c,d,e,f,g,h (aka. Trappist-1b…)
b,c,e,f,g have similar size to Earth and d,h have radius somewhere between Mars and Earth. e,f,g also orbit in the habitable zone of planet which is an area around the star where liquid water might stay on the surface.

Bit of a problem is that since the planets are so close they receive lot of radiation from Trappist-1 and are also probably tidaly locked, which means that they are facing the star with always the same side, thats what is happening to our Moon too. All of their orbits’ radiuses (semimajor axes) are in matter of few millions of kilometers. For Earth this is 1 AU or 150 millions and for Mercury roughly one third. Their years last few days, for Trappist-1b it is just 1,5 days. Those are definitely some crazy numbers but since we know so little about formation of new life we can not really say how high the probability of something living there is.

NO signals were detected from that direction.

Dragallur

PS: You would have amazing view from the planets since they are so close together.

Source of picture: By NASA/JPL-Caltech – Catalog page · Full-res (JPEG · TIFF), Public Domain, https://commons.wikimedia.org/w/index.php?curid=56513150

Space NEWS #10 (Very close exoplanet)

Hi,
today I am bringing news about the closest ever found exoplanet that is also potentially habitable. This planet is orbiting Proxima Centauri, the closest star to Sun.


This is great news. Like really, what is the probability of finding one of the best candidates for Earth like planet closest to us that it could get. But to be clear of what is really going on, it is not as that we are going to get a picture of it. Not at all, we do not even know its size (is probably above 1.3 of Earth’s) or anything about its composition. Its just that it is very very likely that the planet is there because of Doppler shifts and other fancy astronomical tools that enable scientists to discover exoplanets.

No, this is not how the planet looks like.. but yay! Random artistic pictures!

Proxima is red dwarf. This means that it is smaller and cooler than Sun. The difference is so huge that the planet may be in habitable zone even though it is probably only 7.3 million kilometers away compared to Earth’s 150 [1]. So if there is water it may be liquid but nothing is very sure. If there are some greenhouse gases it is probably warm enough.

Before leaving, just check out this cool comparison of the angular diameter (size) of Sun and Proxima from Earth and from the new planet (Proxima b):

Sun and Proxima compared

Yes, any life on Proxima b would have much bigger and redder star to look on.

Dragallur

Check out these two pages for more info: 1) 2)

[1]Proxima has surface temperature of 3050K, 0.1 percent of SOlar luminosity, radius 0.14 and 12% of Sun’s mass.

What is going up on Mars?

Hi,
while thinking about today’s topic I find some random stuff and decided to share it with you. So here you go, new exoplanets, tsunami on Mars, good view on Mars and SpaceX announcement.

Artist’s impression of exoplanet.


Thanks to new statistical method there were 1,284 exoplanets confirmed[1].
This is biggest number ever in one shot. There is of course lot of data form Kepler which observes stars for those exoplanets. You can not be sure always if what you saw was really exoplanet so you need more data. When uncertainity is below 1%, it is officially agreed that the planet is there. With this new method, lot of those uncertainities went below 1% so yes they were “discovered”. Other data was “thrown away” because the percentage went lower and generally this was nice breakthrough.[2]

For long time it was thought that Mars’s terrain was shaped by its ocean that later on evaporated. But the shoreline would be graduall which is not what we observe, rather exact opposite with many geological features along it. These features could rather be explained by huge tsunamis that were formed by asteroid impacts.

Also Mars is going to be these weeks in oposition to Sun and basically really close to Earth, on about 1/2 of AU. The closest it could be would be about 1/3 of AU because its orbit is kind of excentric. If you want to see it well, just take a telescope and with good one you should be able to see even some of its geological features. If you get to see (if it is possible for normal people) Olympus Mons, say hello from me 😉

After SpaceX landed second time on the barge, Elon Musk stated that they want to land on Mars in the year of 2018, which is in two years! They have really lot of work to do so lets see where they will be in that time! (Read more here on the blog of Phil Plait)

Dragallur

[1]Exoplanets are planets that orbit around other stars.
[2]From the data we also know that 550 are probably rocky and 21 are in habitable zone.

Transit photometry

Kepler 186f

Hi,
Today I will write about transit photometry.
This is method of finding exoplanets (means those which are not in our Solar System).

Of course we can not see any of those planets because they are too small. But what we can see or better what can Kepler Space Telescope see is effect of such a exoplanet when it transits around its star. To see this clearly, watch this video.

To describe it with words, when planet transits (orbits) star and Kepler is watching it he will see the little difference in its brightness, some of the light will be blocked by some planet. When this happens periodically we know that there is some planet.
Of course this has some limitations, we can only see objects that are orbiting close to its star because no telescope or satellite has service life of 30 years which would be needed
for Saturn if some extraterrestrial life would watch Sun. Those 30 years are counting with Saturn transiting Sun at the time of telescope´s start.

So this is transit photometry which can be used only for enough large planets that are not really far away from their stars. Usually scientist are mostly trying to find planets in “life zones”. Those zones are in some fixed distance depending on the type of star and it means that we think there could be live. There is lot of candidates for habitable planets and probably best of them is Kepler 452b which is orbiting G type star (same as Sun). Kepler Small Habitable Zone Dozen
Because legendary Kepler is getting old and he is able to watch only fixed part of sky there is TESS (Transiting Exoplanet Survey Satellite) which will be able to watch 90%.

In the year of 2024 there will also come PLATO (Planetary Transits and Oscillations of stars). This mission is planned for six years but still it will no be able to find planets with the size of Mars or Mercury.

Last one is NGTS (Next Generation Transit Survey) which is trying to find planets smaller than Neptune around stars with apparent magnitude lower than 13 (7 is not visible to average human eye).

Also astronomers can find out how big is exoplanet by its gravitational effect on star and from this we can even count what is its density.

Dragallur