Blog 5 Some of our closest neighboring stars. Why do we want to study our neighbors nearby? That will be our chance to study new life forms. First, we must get there by Award-winning author, adventurer and scientist Mark Kingston Levin PhD
Figure 1. The closest stars are a triplet system called Alpha Centauri A and B and Proxima Centauri. These are just over 4 light years away.
Take a look at our closest neighboring stars below in Figure 2. Over 63 stars are within 5.0 parsecs (16.3 light-years) of our Sun. Fifty of these 63 are red stars, the most common type of star in the Milky Way Galaxy. Much more massive stars, such as our own, make up the remaining 13. In addition to these stars, there are 11 brown dwarfs (objects not quite massive enough to fuse hydrogen), and 4 white dwarfs (extremely dense objects that remain after stars such as our Sun exhaust all fusable hydrogen in their core and slowly shed their outer layers while only the collapsed core remains). Despite the relative proximity of these objects to Earth, only nine (not including the Sun) are brighter than 6.5 apparent magnitude, according to Wikipedia.
Figure 2. A look at our closest 53 stars to the Sun. All are less than 17 light years away from Earth.
In the early night sky in early May, a bright blue-white star may be observed near the horizon toward the southwest. Sirius is the brightest star in Earth’s nighttime sky. Sirius looks so bright because it is a relatively powerful light generator, about 20 times as bright our yellow Sun. Other nearby stars such as Alpha Centauri are not as bright; its two main components taken together can be seen in the southern constellation Centaurus.. Sirius is the nearest single neighbor star to the Sun that can be seen with the naked eye if you have good vision.
The space between stars is enormous–so large that it is helpful to express the distances using the light-year, the distance light travels in one year, as a unit of measure. In this way of expressing distances, Alpha Centauri is about four light-years away, and Sirius is about eight and a half light-years away from Earth. Let us assume that we can travel at 0.1 times the speed of light, or about 18.6-thousand miles per second. How long will it take to travel to our nearest star? It will take 40 years to get to the nearest star and 40 years to get back.
What is the nearest planetary system with Earth-like planets? That is the red dwarf Proxima Centauri, which has an exoplanet named Proxima Centauri b, or Proxima b. Liquid water could exist on this planet.
Proxima b could support life, although conditions there are not exactly like Earth so life, if it does exist, might be very different from Earth’s, but we do not know. We could send a probe, but I would guest in a century or two. The star is a dim (cool) red dwarf. This means that a planet in the “just right” Goldilocks zone would be tidally locked—one side perpetually facing its sun.
The other side would be in perpetual darkness. The sunlit side would be very hot, while the dark side would be frozen. Life might exist near the terminator—the shadow line between light and dark—but it would be a brutal existence, forever buffeted by dangerously cold winds from the night side.
A better shot at finding life could be a nearby moon that would force the planet to rotate in a period more closely resembling our own day. This would be the sweetest configuration for any red dwarf.
Proxima Centauri is a flare type of star. It has large changes in output brightness, which we believe would alternately cook and freeze an Earth-like planet.
Figure 3. Artist view of a planet in and out of the habitual zone. This tidal lock planet orbits a M-type star named Gliese 832. There are at least two planets orbiting this star, which has a mass of 0.45 M☉ and a radius of 0.48 R☉. It has a temperature of 3620 K and is estimated to be about 9.54 billion years old. In comparison, the Sun is 4.6 billion years old and has a temperature of 5778 K.
The apparent magnitude of this star, or how bright it appears from Earth’s perspective, is 10.19, which is too dim to be seen with the naked eye from Earth. Lower numbers are brighter, 6.5 may be seen from Earth or lower.
Mark Kingston Levin PhD author of 30th Century series book 2 30th Century: Revived, which was release on Amazon April 29, 2018.
Dr. Levin won the IRWIN for the Best Science Fiction Book of 2017 for the first book in the series, 30th Century: Escape. To read the first three chapters, see www.markkingstonlevin.com.
For questions and comments write to Dr. Levin firstname.lastname@example.org
Dr. Levin was born and grew up in Vermont with many winters spent in Florida as a child. As a teenager he wrote poetry, served as a lifeguard and played football. He currently enjoys sailing, exploring underwater caves, snorkeling, writing science fiction and other pursuits. After working on the Apollo and Mars projects, he returned to school to study under Nobel Laureate Paul Dirac, obtaining his PhD in 2.5 years. Dr. Levin founded two companies and served the science policy apparatus in President Ford’s administration. He has been published over 44 times in scientific literature and was awarded over 32 US patents. The science fiction writer is now emerging with his first work, a trilogy titled 30th Century.
The first award-winning book, 30th Century: Escape, is currently available on Amazon both in its original erotic form BUY HERE and the new, toned-down General Audience Edition in both Kindle and in full-color print BUY PRINT HERE. Book two in the series, 30th Century: Revived, is available HERE in both e-book and print. Look for book 3 in the series, 30th Century: Contact, by early 2019!
NEW: Your opportunity to be part of the process! If you sign up to be a Beta Reader, I will email you an Advanced Reader Copy (ARC) of Book 3, 30th Century: Contact, in either PDF or Kindle. You read and tell me how you would make it stronger by sending an email to Dr. Levin email@example.com