Do Massive Stars host Larger Planets?

 

Key Highlights:

1. Study applicable to G & K Stars. (Sun is Type G Star)
2. Planets forming around more massive stars tend to keep H & He in their atmosphere.
3. Planets surrounding more massive stars tend to be higher in mass and larger in radius.

Ever wondered if...would there be a connection between Star’s & Planet’s Size? Scientists have found a tendency for More Massive Stars to host More Massive Planets!

Image Credit: NASA

This can be explained by 3 possible cases:

Case 1 : Because of Thermal Inflation — More massive star — More luminous — In turn might inflate planet’s radius by more stellar radiation.

Case 2: Simply because more massive a star — more massive is its proto-planetary disk — more massive is the planet.

Case 3: More massive a star — more the amount of volatile substance(Substances that evaporate quickly) — in turn more massive the planet.

For this study they used data from the NASA Exoplanet Archive selected transiting planets and segregated the planet's samples on basis of their parent star stellar classification, only selecting planets orbiting G & K type stars.

The Planets selected were only the one’s having temperatures below 2000 K as the latter are considered as Ultra-Hot Planets and have their own set of different issues. The planets included were thus selected so that they would have lesser measurement uncertainties.

Now one issue to eliminate here was that Smaller planets were hard to detect around massive stars and they would give rise to an artificial co-relation between the size of a star & planet.

This was eliminated by comparing it with a wider sample of Kepler data without any restriction on planetary mass.

So, to conclude we find that, they suggested that “This correlation might
be the result of characteristically different planetary composition or structure of the planets that surround different stellar types.” Previous studies have also found that there are fewer Gaint planets around class M dwarfs, whereas the occurrence of smaller planets around this type of star is higher.No strong evidence for a dependence of the planetary M-R relation on host star mass for small planets has been reported so far. So, as of now, we can only confirm that: Planets surrounding more massive stars tend to be higher in mass and larger in radius.

 

Reference: Why do more massive stars host larger planets?