While astronomers are constantly searching for possible life sustaining planets they sometimes stumble upon something they do not want. There are around 400 billion stars alone in our Milky Way and astronomers estimate that there may be tens of billion of solar system in our galaxy. Now it should not be hard for you to predict the number of hot and roasting planets present in this galaxy alone. We won’t brag about anything here, see the 10 hottest planet in the galaxy yourself.
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10. Gliese 436 b
Surface Temperature: 710 Kelvin
Gliese 436 b was the first hot Neptune discovered back in 2004 by researchers from the University of California and Carnegie Institute of Washington. Its surface temperature has been estimated to be around 712 K, though it could be higher if a greenhouse effect is going on in the lower atmosphere of the planet.
Researchers have also been able to find out that Gliese 436 b was initially a gas giant, formed further away from its current location. Like the other gas giants, with the passage of time it was attracted inwards and closer to the host star. After it moved in, the star may have just engulfed the planet’s hydrogen layer in a process known as coronal mass ejections
9. Venus
Surface Temperature: 737 Kelvin
The planet Venus is perhaps the hottest of all the planets in our solar system. Wait a minute, we all know that mercury is the closest planet to the Sun, then how come Venus is in the list and not Mercury? Well, the answer lies in just one word ‘atmosphere.’ As you know, that atmosphere here on Earth makes life as we know it possible, essentially by trapping the heat, along with other important tasks.
Mercury, the innermost planet in our solar system has almost no atmosphere, due to its relative distance to the Sun. This means that it does not have the ability to trap heat, unlike our Earth. But for Venus, it’s totally a different story. Not only it has a solid atmosphere, it’s basically composed carbon dioxide, making it a one-way road, anything can go in but nothing comes out. Thus making a hot oven like environment.
8. Kepler-7b
Surface Temperature: 1,540 Kelvin
Orbiting around slightly hotter and more massive star than the Sun, Kepler-7b is among one of the first hot exoplanets discovered by the Kepler space telescope. Classified as a hot Jupiter, it’s nearly 1.5 times bigger than the Jovian planet but has only half of its mass. The planet has an overall density of just 0.166 g/cm3, which is far less compared to 5.43 g/cm³ density of Mercury. Its orbital period is short – completes one orbit around its host star in every five days.
7. Kepler-10b
Image Courtesy: NASA
Surface Temperature: 1,833 Kelvin (Day side)
With a rocky outer surface and temperature above 1800 k, the massive Earth-like planet is surely one of the hottest and most hostile planets in our galaxy. Kepler-10b orbits its parent star, Kepler-10 in such a close proximity that it completes a single orbit in less than an Earth day. It’s also tidally locked to its host star resulting in a huge temperature difference between planet’s night and day sides.
6. WASP-12b
Surface Temperature: 2,500 Kelvin
With temperature more than enough to melt Titanium, the WASP-12b is not exactly the kind of planet astronomers wish to discover. The planet orbits around a yellow dwarf at a distance of just 2,115,000 miles, which is way less than Earth’s distance from the Sun. At this distance, it only takes WASP-12b slightly over a day to complete an orbit. In 2010, for the first time astronomers witnessed that WASP-12b is being eaten by its own parent star.
5. Kepler-13Ab
Surface Temperature: 2,700 Kelvin
Not only Kepler-13Ab is a sizzling hot planet, but in a recent study, astronomers have discovered an extremely rare phenomena which is currently going on the planet’s surface that will astonish you. Lying 1700 light years away from the Earth, the so called hot Jupiter is experiencing snow falls, would you believe that? Apparently, NASA’s Hubble telescope has detected a sunscreen made of titanium oxide on the planet’s permanent night side which causes snow fall. You can read more about Snows ‘Sunscreen’ on NASA’s website.
4. COROT-7b
Surface Temperature: 2,873 Kelvin
COROT-7b is perhaps one of the scariest planets, you are going to find out here. Located in the constellation of Monoceros, COROT-7b was first detected in 2009 by the French initiated COROT mission. After its discovery, it became the smallest exoplanet with a diameter 1.58 times that of the Earth. The planet is so close to its parent star that it only takes almost 21 Earth hours to complete one orbit.
Many have named it the ‘Hell Planet’ and rightfully so due to its extremely hot temperature, which can reach up to 2600 C or 2,873 K. Due to these extreme conditions, it’s been estimated that the entire planet may just be covered with oceans of lava. A research paper published in 2011 has concluded that despite its unknown mass, COROT-7b is most likely to be Earth-like in composition.
3. WASP-33b
Surface Temperature: 3473 Kelvin
The detection of WASP-33b was announced back in 2010 by the SuperWASP project, which is responsible for detecting more than 100 exoplanets in the Milky Way galaxy including many distant ones too. The planet orbits in a very close proximity to the star and complete one in 1.2 days. It has been estimated that the surface temperature of WASP-33b is around 3500 K, making it one of the hottest planets known so far.
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2. KELT-9b
Surface Temperature: 4600 Kelvin
Until now we have seen some really hot planets, where life isn’t possible at any cost, but what if I say that there is a planet even hotter than the stars? Recently, astronomers have detected an exoplanet, just to fit that bill, which has stunned the entire community of space scientists.
With raging temperature, reaching up to 4600° K, the surface of KELT-9b is not only hotter than the exoplanets, but even hotter than the M type and K type stars. Located at 615 light years away from the Earth, this extreme planet has almost thrice the mass of the Jupiter and orbits the parent star in every 18 hours.
What came as even more of a surprise to astronomers is that the planet is orbiting an A-type star, third hottest star type (after O-type and B-type) with its own temperature around 10170 Kelvin, which is extraordinary as transiting planets are not generally detected in exceptionally hot stars and only a few exoplanets have been detected so far.
1. Kepler-70b
Surface Temperature: 6000 Kelvin
How much hotter can it get? Right now the Kepler-70b is the hottest planet in the galaxy with an unrealistic surface temperature of 6000 K (approx). The planet is orbiting a subdwarf B star designated as Kepler-70 in the constellation Cygnus. The Kepler-70b has the second smallest orbital period (only after the pulsar planet PSR 1719-14 b), completing a single orbit around its host in just 5.6 hours.
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While the exact temperature of the planet is not known, it’s believed to be hotter than the visible surface of our Sun. It also has a density somewhat similar to that of the Earth.