How the star system 40 Eridani became the location for Vulcan, Spock’s home in the universe, is kind of a funny story. In 1968, science fiction writer James Blish published a collection of adapted Star Trek episode scripts in a book called Star Trek 2. But Blish granted himself artistic license and added depth to those TV stories, which included identifying Vulcan’s address as 40 Eridani. Gene Roddenberry, the creator of Star Trek, confirmed this addition as canon in a 1991 article in Sky & Telescope.

This week, astronomers have identified a planet that rotates around the main star of 40 Eridani, which has since been re-designated HD 26965. To put it another way, astronomers have discovered a real-life planet where Vulcan was in the series. Their finding is described in a paper published in the journal Monthly Notices of the Royal Astronomical Society. A preprint of the paper is available on arxiv.org.

University of Florida astronomer Jian Ge, Ph.D., led the research, a part of the Dharma Planet Survey, which monitors 150 or so very bright stars nearby. The DEFT telescope, located on the 9,100-foot-tall Mount Lemmon in southern Arizona, was used to discover the planet.

40 Eridani A
The green area surrounding 40 Eridani A depicts the habitable zone of the star, the area where temperatures would be right for liquid water, an essential ingredient for life (Vulcan or otherwise). The habitable zone of Vulcan is closer to its dwarf star than the Earth's is to the sun because 40 Eridani A is cooler and dimmer than our sun.

They discovered a super-Earth orbiting the star HD 26965. It’s 16 light-years from Earth, making it the closest super-Earth orbiting a sun-like star we have ever discovered.

On the real-life Vulcan, which is twice the size of Earth, a year lasts only 42 days. But there’s good news for advanced human civilizations: Its orbit around the star HD 26965 is inside the “habitable zone” of the star, which is not too hot and not too cold.

This new Vulcan’s sun is slightly cooler and smaller than our own sun, but is thought to be about the same age, which is 4.6 billion years old. It also has a similar magnetic cycle, a shared quality that gives us a sense of the amount of cosmic radiation that hits the planet and thus, of how friendly to life this new planet might be.

'Star Trek 2'
The cover of the 1968 book 'Star Trek 2', which identified Vulcan as being located in the 40 Erdani star system. 

“HD 26965 may be an ideal host star for an advanced civilization,” says Tennessee State University astronomer Matthew Muterspaugh, Ph.D., who contributed to the study that describes the new planet.

Based on what we know about the super-Earth’s star and proximity to it, scientists can begin estimating whether it’s anything like the Vulcan of Star Trek — deserts and mountains, largely rural, much hotter with a thin atmosphere, higher gravity than Earth.

“This star can be seen with the naked eye, unlike the host stars of most of the known planets discovered to date. Now anyone can see 40 Eridani on a clear night and be proud to point out Spock’s home,” Bo Ma, Ph.D., a University of Florida post-doc on the team and the first author of the paper, says in a statement released with the research.

At least we know that Vulcan is still there, unlike in the movies, where it was destroyed.

Abstract

The Dharma Planet Survey (DPS) aims to monitor about 150 nearby very bright FGKM dwarfs (within 50 pc) during 2016−2020 for low-mass planet detection and characterization using the TOU very high resolution optical spectrograph (R≈100,000, 380-900nm). TOU was initially mounted to the 2-m Automatic Spectroscopic Telescope at Fairborn Observatory in 2013-2015 to conduct a pilot survey, then moved to the dedicated 50-inch automatic telescope on Mt. Lemmon in 2016 to launch the survey. Here we report the first planet detection from DPS, a super-Earth candidate orbiting a bright K dwarf star, HD 26965. It is the second brightest star (V = 4.4 mag) on the sky with a super-Earth candidate. The planet candidate has a mass of 8.47±0.47MEarth, period of 42.38 ± 0.01 d, and eccentricity of 0.04+0.05 −0.03. This RV signal was independently detected by Diaz et al. (2018), but they could not confirm if the signal is from a planet or from stellar activity. The orbital period of the planet is close to the rotation period of the star (39−44.5 d) measured from stellar activity indicators. Our high precision photometric campaign and line bisector analysis of this star do not find any significant variations at the orbital period. Stellar RV jitters modeled from star spots and convection inhibition are also not strong enough to explain the RV signal detected. After further comparing RV data from the star’s active magnetic phase and quiet magnetic phase, we conclude that the RV signal is due to planetary-reflex motion and not stellar activity.