At its simplest, the field of stellar astrophysics is the general study of stars. However, it is a broad field that includes many topics. Stars generate energy in their core and radiate it into their surrounding environment. They are full of magnetic fields and nuclear reactions. They blow away stellar winds and flares. They are born, evolve, and (explosively!) die. Stars are very complex objects and a lot of research is needed to understand all the different processes.
know your star know your planet
Scientists have been studying stars long before exoplanets were discovered, and the two fields are now very closely linked. There is a saying among exoplanet researchers: “Know thy star, know thy planet.” This means that to truly understand exoplanets, we must first understand their host stars. For example, many of the quantities we try to measure about exoplanets (such as size and mass) are known only in relation to the stars they orbit. Finding out that a planet is 10% the size and 0.1% of the mass of its star is only useful if you know the size and mass of the star well.
Furthermore, most exoplanet detection methods are indirect and only tell us about exoplanets through starlight signals. This can make it difficult to separate the planetary signal from the stellar signal. Stars are not completely static objects. There are hot and cool spots that change over time, and as the star rotates, the face of the star changes, pulsating in irregular patterns and sometimes spitting hot material out of the surface. All of these processes can subtly alter the brightness and spectrum of stars, making it difficult to determine which of the observed features are caused by orbiting planets and which are from stars. will be If we could understand what was happening to stars, it would be much easier to distinguish between planetary influences.
In pursuit of this great understanding, some iREx researchers are studying stars full-time.using spiro Instruments, made by our team Unbelievably Detailed measurements of a nearby red dwarf called bernard starThe data shows more capabilities than even the best computer simulations, and helps us understand how to create better models and understand our stars more fully.
Young Stars and the Stellar Society
Other iREx scientists are analyzing how stars are grouped and move within the galaxy. These “star associations” can be incredibly useful when they are identified. The stars in the association probably formed at the same time and were built from the same mixture of gas and dust. This helps determine the age of the star and also indicates the age of the planets around it. Knowing the age of exoplanets can help researchers understand how planets form and evolve.
Age is particularly important information when taking direct images of exoplanets. Exoplanets are so small and so far away that you can’t really see them. “look” It can photograph planets in a way that we can with the planets of our own solar system, but sometimes we can detect specks of light coming directly from the planets. The inability to tell the difference between a large planet and a hot one. Both properties make exoplanets brighter. However, if we know the age of the planet, we can estimate how much it has cooled since it formed, and ultimately determine its size.
Impact on livability
of habitable zone The ambient temperature of a star is related to the temperature range in which liquid water can exist. But that’s not all. Stars have many other properties that either enhance or detract from the habitability of planets.
The largest, hottest, and brightest stars have very large habitable zones that can accommodate multiple planets, but these stars are extremely rare and can only last (relatively speaking) long before violently exploding in a supernova. I won’t live Even if the planet formed in the habitable zone, such a hot star would emit large amounts of high-energy radiation that would be extremely harmful to life like Earth, and could even strip the atmosphere from the planet.
Small, cold red dwarfs, on the other hand, are by far the most common type of star in our galaxy. Their small size and low mass make it much easier to actually detect small planets around them, especially since there are so many to search for. I still think it might be the best place to find a habitable world.
Stellar Astrophysics at iREx
Understanding how stars behave is so important to exoplanetary science that many experts in astrophysics are participating in iREx. Combining knowledge from these complementary fields will benefit both areas of research and help us learn more about stars and the planets that orbit them. Please read my profile.