The story of a butterfly that explains how species evolve.

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People often wonder or rather doubt how new species are formed. Some people doubt the whole phenomenon of evolution because it's "a theory of evolution". However, in reality, evolution happens and we can find evidence of it in nature. Here, for instance, a species of butterfly in Amazon region was found to have evolved from the hybridization of two other species of butterflies. Interestingly, the descendants of all these three lineages of butterflies coexist in same geographical region and two of these occasionally mate with each other.
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First exoplanet confirmed to be tidally locked to its star.

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LHS3844b is a large rocky planet revolving around a star located about 48.5 light years from Earth. It has been confirmed in recent study that it is tidally locked with its star. 

The observations of intensities light reflected from it throughout it's transit around it's star could be used to estimate it's days-side surface temperature. It's surface temperature is estimated to be about 1300 degree Celsius. 

It was found that the estimated temperatures were lower than what they would if it was in a kind of synchronous rotation like that of Mercury. Heating could also be cause due to elliptical orbit. By comparing the predicted temperature  and the observed temperature, it come out that the planet's orbit should be nearly circular with very tiny amount of eccentricity.

 

Image from exoplanets.nasa.gov

About LHS3844b

The planet has mass of 1.3 times that of the Earth and is one of the Super-Earth planets. It revolves at just about 150 million km from its star which is 1/160 of the distance between Earth and Sun. It takes 11 hours to complete one revolution around its star. The orbit of the star is nearly circular.

Thermal Phase Curve

As the planet revolves around its sun the telescopes could measure the light intensities from the planet at different phases of it's transit. This light-intesity data is called as the thermal phase curve. The Spitzer Space telescope was used for these measurements. The thermal phase curve data can be fitted into models that would give an estimate about the surface temperature of the planet.

Eccentricity of orbit

Eccentricity of the orbit shows how elliptical the orbit is. The eccentricity of a circle is zero. The models suggested a tiny bit of tidal heating of the planet caused by either a small amount of eccentricity of the orbit (less than 0.005) or heating by space weathering. Space weathering happen when tiny space debris falls on the surface of planets. Specially, when there is no atmosphere around the planet there is nothing to stop the debris from falling onto it's surface. It like tiny meteorites falling on the planet. This  causes heating of the surface of the planet.

Between the two causes the researchers concluded that the heating is caused due to space weather and not due to the eccentricity of the orbit. However, a previous study had suggested the presence of a thin atmosphere. Therefore, we may need to further wait and see how the space weathering theory holds.

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