Did you think about the most beautiful stars in our universe? They glow in an orange-yellow color that gives them a dreamy fantasy-type look. Not only in look these stars could become our next home if we can live on their planets. There are a lot of possibilities for terraforming their planets and creating human colonies. Hello and Welcome to our Blog where we discuss Astronomical objects and structures with little to no use of math only in simple language. Today in this post we are going to learn about K type Stars Hi I'm your friend K* and I'll give you some amazing info and facts so without wasting any time let's get started.
Let's know what kind of stars are called K types, well, Stars that emit wavelength radiation at 7250 Å (angstrom) are called K-type Stars which gives them mixtures of Orange, Red and Yellow colors. These stars have temperatures around 5200 - 3700 Kelvins and are 0.9 to 0.6 times more massive than our Sun. Their radii vary from 0.7 to 0.96 times than the sun so they are usually smaller than our sun. Their Fusion in the core is powered by the PP Chain (Proton-Proton Chain) this method works well in Low temperatures That's why it gives lower luminosities which are only 0.08 to 0.6 times luminous than The sun but don't say they are dimmer. Do you know what it means if an Object has half the solar luminosity it would radiate half the amount of energy than our sun which is about 192 Septillions Didn't get anything? Just write 192 and add 24 Zeroes, which is still enough to Sustain life on planets.
Main Sequence Stars or Orange Dwarfs (V)
These stars are formed after the protostar phase you can say they are orange dwarf since birth, Such stars Fuse Hydrogen in the core that creates a sort of "Ash" called helium, they can stay in this phase for 17 to 70 Billion years. This fusion is dominated by the PP (proton-proton) Chain which is a main characteristic of the low-mass stars and burns fuel at a slower rate This is the secret behind their very long life. These stars are productive and radiate energy at a balanced rate, They are balanced Thermally, Nuclearly and Morphologically. They are small in size too. You can look at this image.
Sub giant Stars or Orange Subgiants (IV)
In the picture above we can see many examples bear mass more than The Orange main sequences. Other striking peculiarities are their tremendous Radii and volumes because Orange and Red stars expand way more than Similar masses of Blue and White Stars when they evolve. Its reason is not the topic of today's post there will be a separate article where we'll discuss such things in detail.
Giant Stars or Orange Giants (III)
These Giants have come through their expansion period after the subgiant phase. Like the previous category, they started their main sequence life as an F, A or B-types and lost their temperature but gained more luminosity and size So they are here. However, there is less chance If they lose their temperature further they will sit in the Same section of M-type stars. You can look at this picture for comparison and other stuff.
Orange Bright Giants (II)
These are similar to giants But they have evolved from More massive giant stars than regular ones. They are slightly rare and bear more Size, luminosity and rarity. It's possible they were Blue Bright giants that have lost their temperature and reached here. You can look in the Chart below.
Orange Supergiants (I):
These are the largest kinds of stars that have large masses, Radii but low temperatures yet very high luminosity. Perhaps some of these stars are in their transition period from Blue to Red Supergiants as we know that Stars can change their color on account of changes in their fusion processes and other factors that we aren't discussing here. You can see their specs in this image.
Stars With Cultural Importance
Since Stars are not a new thing, Early humans have observed them from time immemorial and it is natural to be accustomed to recognizing and making the stars important when you see them every night. In this chain, Our ancestors distributed so many names and importance if the star was visible with the naked eye, poets and writers added them to their great works of literature so let's explore such stars that belong to this K class.
Aldebaran ( α Tauri )
This is a well-known star from ancient times, it is a member of the Taurus constellation and keep in mind wherever you see alpha (α) in a star's scientific name you may be certain that the star can be seen without any technical aid in 90% cases because very few constellations don't have an α letter for Star. Anyway, Let's see its significance in various cultures.
- Persian culture describes it as one of the 4 royal stars.
- Indigenous Australian Says this star was a human named Karambal, who stole the wife of a great warrior Bullabogabun. The Karambal was hiding in the branches of a huge tree but the husband of the stolen woman found him, gathered a pile of logs and set fire to the base of that large tree. The fire reached high into the air, its smoke carried Karambal and put him near Pleiades stars known as Wareenggary. The group of 7 Young women were sisters and Karambal wanted one of these girls. The Karambal Also became a Star which is represented by Aldebaran.
- In modern culture, this is the Brightest Star in Zodiac constellations and holds great significance in astrology.
- Indian mythology describes the Favorite wife of the Moon god Chandra.
Arcturus (α Boötis)
This star is the brightest Star in the Boötis constellation around
40 light years away. In many cultures, it has been a subject of
their Lores or Myths. Hipparchus and Ptolemy have mentioned
in their star catalogs.
- In Indian Astrology, it has been referred to as Swati nakshatra which is related to the creation of the Pearl.
- In Chinese Astronomy, Arcturus is called Da Jiao which is the Brightest Star in the Chinese constellation Jiao Xiu. However, It became part of another constellation called Kang Xiu.
- Ancient Polynesian Navigators Know Arcturus as 'Star of Joy', it is a Hawaiian zenith star meaning a Star is seen directly above in the sky. Using this and other stars they used to travel other islands.
This is considered Host star of planet Vulcan in Science Fiction series.
Search for Life
Why do we Need Another Planet?
You may heave heard a lot of times our Earth will able to support life Due to Sun's Evolution. After 5 Billion Years, The Sun will start to expand, Temperature on earth will also rise. During the last moments of the sun, it will swallow Mercury, Venus and Earth. If we humans are not aware of our Environment our earth can still become a Cemetary planet for all its living entities and it can happen in the near future meaning The sun will become a Red giant after 5 Billion Years but Humanity will Suicide in just a few years if War and pollutions doesn't stop. We need The Earth but Earth Doesn't need us She is fine whether we exist or don't. If we humans stay peacefully we have a home for around 1.5 Billion years on the surface and another 2 or 3 Billion years for underground life. How can this happen it's another topic.
Are they Reliable and become our next home?
It is been clear that K-type stars Are Cooler than our Sun and emit very amount of UV radiation these stars are often called Goldilocks Stars They have large habitable zones extending 0.1 to 1.3 AUs If you don't know about Astronomical Unit (AU) it is Average Distance of Earth from Sun its value is around 150 Million Kilometers. If any planet is orbiting in this area we'll say this planet is in habitable or Goldilocks zone where Water can remain liquid. However, Water is not the only thing to consider for survival we should also check the planet, Moons and Stars. Almost the entire system because Such system members Interact with each other and change the planetary stability and properties. Let's See Their Stars.
Are They any better Than Other Stars?
K-type Stars are often said they emit less radiation. Their Main Sequence period is also Very long around 17 to 70 Billion years. They show less activity like Stellar flares and CMEs, mostly they don't tidally lock their planets in habitable zones. If any form of life emerges on their planets these stars will nurture them with huge love they will provide extra time to evolve and Grow. It will be like heaven for Living beings whether they are Bacteria, Algae or different kinds of life which doesn't exist on Earth. Also, Their Habitable zone is Very stable with little Difference in Stellar Luminosity but that's fine.
So Our Sun is any less than these Stars?
Our sun is 5800K Hot and Brighter than 90% of Stars in the Milky Way alone. It shows a lot of Activities like CMEs, Powerful Solar Winds, and Magnetic Storms. After 2025 it Became even Aggressive and will show more such phenomena like these. It is getting hotter day by day also it will last only 10 Billion years after 4 Billion years it will Fry the Inner planets of our solar system.
However, It doesn't mean our Sun is an angry devil star instead it has supported Earthly life for more than 3 Billion years and Emits Solar wind to Protect us from other Dangerous Cosmic Entities that can Destroy our whole solar system So it is natural to be Aggressive. On top of that, There are more Dangerous Stars than the Sun you check them out in our other posts. It is true that K stars are Quieter Than the Sun and live a longer life But When You see the sun in next morning, Don't forget to say thanks to it.
They are also Dangerous !
Don't plan to go to their planets soon because like every natural thing They also have some Demerits or Negative points to consider. Some of them emit Higher amounts of UVs and X-rays that can Halt the Biological Evolution of their planets if they don't harm their Atmosphere. It will emit much more powerful radiation than Dangerous G-type and M-type Stars do. Anyway 9 out of 10 times they are gentle and quiet.
Let's See some New Planets For us
 |
| Morning on an Exoplanet with K type |
Kepler 442 b:
Kepler 62 e:
 |
| Rocky moon with oceans, orbiting its Gas giant planet and K star |
Kepler 62 f:
At the End
