A different kind of Omicron
Over the last few months you must have read dozens of Skyward articles , online or in print , about the Omicron variant of COVID-19 . Fortunately , this is not one of them . This article is about Omicron ² Eridani . It is a faint star in the constellation of Eridanus , the River . Actually , there are two Omicron stars in that constellation . The first by David is brighter , and is a variable star . The
Levy second one is one of the closest stars to the Sun . Omicron ², also known as 40 Eridani , happens to be not a disease but one of the most interesting star systems in the entire sky . Omicron ² is a triple star system that is only about 16 light years away . Its brightest component is a Sunlike star faintly visible to the unaided eye on a good night . It lies in northern Eridanus , the River , just a few degrees west of Rigel at the foot of Orion . The secondary is a white dwarf star . Unlike the companion of Sirius , this star is 9th magnitude and not near the brighter star so it is easy to see in a small telescope . The third star is not far from the secondary , but at 11th magnitude it is also not difficult to spot . This third star is a red dwarf . Although red dwarf stars are the most plentiful , by far , in our region of the Milky Way galaxy , they are almost impossible to see because they are so small . The closest one to us is Proxima Centauri , or Alpha Centauri C , which at 4.24 light years is the closest star to the Sun . Also because they are so small and intrinsically faint , only a few of them are easy to find . 40 Eridani C is one of the easiest to find . This interesting star has something else going for it . In 2018 astronomers discovered a planet orbiting the primary star . With a rapid orbit around Omicron ², such a planet would receive much more radiation from the primary star than Earth gets from the Sun . But in 2021 new observations cast doubt on whether this planet exists at all .
COURTESY OF Tim Hunter
Tim Hunter took this beautifully focused picture showing Omicron 2 Eridani . The primary star , named Keid , is the bright one ; just to the left is the secondary , a white dwarf ; the tertiary , a red dwarf , is fainter still . Used with permission and thanks .
Whether Omicron ² Eridani really hosts a planet is subject to debate . But in the universe of Star Trek , it surely does . It is the home of Vulcan , Mr . Spock ’ s home world . In the episode “ Operation Annihilate ”, which appears near the end of the first season , Spock is blinded by the intense light used to immobilize the invading parasites on the planet Deneva . However his blindness is temporary because of the existence of an inner eyelid . Vulcan is said to orbit Omicron ² Eridani ’ s primary star , and since it is so much brighter than our Sun , even though Vulcan is at the same distance that Earth is from our Sun , they need the inner eyelid to protect their eyes . I rather enjoy the idea that the fictitious Vulcan happens to orbit one of my favorite real stars . And unlike the Omicron variant , which one hopes will be eradicated soon , we admire Omicron ² Eridani , the real star , and wish it to “ Live long and prosper .”
n n n David H Levy is arguably one of the most enthusiastic and famous amateur astronomers of our time . Although he has never taken a class in astronomy , he has written over three dozen books , has written for three astronomy magazines and has appeared on television programs featured on the Discovery and the Science Channels . Among David ’ s accomplishments are 23 comet discoveries , the most famous being Shoemaker-Levy 9 that collided with Jupiter in 1994 , a few hundred shared asteroid discoveries , an Emmy for the documentary Three Minutes to Impact , five honorary doctorates in Science and a PhD which combines astronomy and English Literature . Currently , he is the editor of the web magazine Sky ’ s Up !, has a monthly column , Skyward , in our local Vail Voice paper . David continues to hunt for comets and asteroids , and lectures worldwide .
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