Tag Archives: Proxima Centauri

A Is for Alpha Centauri

Here it is! It’s the Blogging from A to Z April Challenge! Two years ago, I participated in it, and now I’m doing it again. This time, I have a science theme, and I am featuring videos.

For the first topic, we have Alpha Centauri. Check out the video below. After the video, the facts are available for you to read.

  1. It’s a triple star system 4.37 ly from the sun.
  2. Alpha Centauri A is also known as Rigil Kentaurus, while Alpha Centauri C is known as Proxima Centauri. B has no other name.
  3. Alpha Centauri A is a G2 yellow dwarf star similar to the sun, although 10% brighter and 23% larger.
  4. Alpha Centauri B is a K1 orange dwarf star 90% the mass and 14% smaller radius than the sun.
  5. Proxima Centauri is an M6 class red dwarf star with 0.123 solar masses.
  6. Proxima Centauri orbits the AB pair at a massive distance of 15,000 AU or 0.24 light years, though it’s not completely certain it is a member of the system.
  7. Discovered in 2012, Alpha Centauri Bb was an extrasolar planet that was found in 2015 to be an artefact of data analysis. It doesn’t exist.
  8. In 2016, Proxima Centauri b was announced. It’s an extrasolar planet a bit larger than the earth, but is in the star’s habitable zone. It’s likely to be tidally locked, making life difficult to take hold. It’s also likely to be one of the easiest extrasolar planets to study in the near future because of it’s proximity.
  9. The Alpha Centauri system is estimated to be between 4.5 and 7 billion years old, around the same age of our sun or older.
  10. Due to Proxima Centauri being a flare star, life may never have a chance to become established on b because the flares may strip the planet of its atmosphere.

Coming on Monday is the letter B, which will have a more biological topic. Comments are always welcome!

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Proxima Centauri b – Our Newest Neighbour

This is the biggest exoplanet news ever. 4.25 light years away, a tiny red dwarf star has revealed something extremely important: a potentially Earth-like planet. The ESO announced today that they have discovered a planet orbiting the nearest star to our solar system, Proxima Centauri.

Artist's impression of Proxima Centauri b. Credit: ESO/M. Kornmesser. Source.
Artist’s impression of Proxima Centauri b. Credit: ESO/M. Kornmesser. Source.

So, how big is this planet? At least 1.3 times the size of Earth, or possibly up to 3 Earths. This would mean it’s either an Earth-like planet or a Super Earth. It is most likely to be terrestrial and due to its proximity to its star, it’s tidally locked. One side always faces its star. However, it’s in that very special place in a star’s orbit where liquid water can exist. That’s the good thing. The bad thing is that ultraviolet and X-rays from Proxima Centauri could make the surface of the planet potentially uninhabitable. With that being said, life could thrive below the surface.

What would it be like on the planet, though? The side facing the star would be hot and blasted by radiation. The side facing away from the star would probably be extremely cold, possibly covered in ice. The area that’s perpetually at sunset would be the most habitable and comfortable. If there’s a significant atmosphere, then temperatures could be stabilised all around the planet, and likely to be a constant wind flowing from the day side to the night side.

Breakthrough Starshot, a project started by billionaire Yuri Milner, physicist Stephen Hawking, and others, now has a destination. This project, designed to send tiny probes at 20% the speed of light into interstellar space, could reach Proxima Centauri b in only 20 years, then another 4.25 years to transmit data back to the Earth. The probes would take pictures and send them back. However, the estimated launch date is 2060, so many of us today would unlikely get to see this. Well, I plan to be around in 2084. I’ll only be 107 years old. I want to see this planet!

This has a lot of people excited, including me. I really want to know more about this planet. I wish we could go now. To see the surface of a world orbiting another star would be the dream of any astronomer or astronomy enthusiast. This is big!