- Planet name: 75 Ceti b
- Planet mass (J): 0.0078 (compares to Earth at 0.00315)
- Planet semi-major axis (AU): 1.912 (compares to Earth at 1, compares to Mars at 1.5)
- Orbital Period (sidereal days): 696.6 (compares to Earth at 365.26)
- Star name: 75 Ceti
- Star distance: 81.5 parsecs (266 light years)
- Spectral type: G3III (a very bright sun-like yellow star)
- Star mass (solar masses): 2.49 (compares to the sun at 1 solar mass)
- Star luminosity (solar luminosity): 53.25 (compares to the sun at 1.0 solar luminosity)
- Theoretical max. time star in main sequence (billion years): 0.33 (compares to sun at 10)
- Habitable zone inner radius (AU): 6.96 (compares to the sun’s at 0.95 AU)
- Habitable zone outer radius (AU): 10.02 (compares to the sun’s at 1.37 AU)
- Planet orbits in star's circumstellar habitable zone: No. In hot zone.
- Theoretical max. time planet will reside in habitable zone (billion years): Not possible. (compares to Earth at 5.5)
Comments
This exoplanet is about 2.48 times the mass of Earth, orbiting an extremely bright sun-like star at 1.912 AU, nearly twice the distance that Earth orbits the sun. Slightly farther out than Mars which orbits the sun at about 1.52 AU. And Jupiter which orbits at 5.20 AU. So, this planet’s orbital path is something like between Mars and Jupiter. At this distance, the host star would appear about the same size as our sun looks to us, when viewed by the planet. This is because, despite the planet’s larger orbit, the star is about 2.5 times the mass of the sun.
Even though this planet has a larger orbit, it is still far starward to the star’s habitable zone (it’s in the hot zone). This is because the star is burning so bright – about 53 times brighter than our sun.
This planet's host star will be in its main sequence for a very short time (330 million years). If there are any other planets in the habitable zone farther out in this system, they would have relatively little time for life to become established and progress. Probably just log it as an interesting and very dangerous system to avoid.
A planet 2.5 times as massive as Earth normally would be expected to attract and hold gases in a settled atmosphere. But I predict that is not the case for this planet. It is being bombarded with very intense radiation from its host star. That radiation is intense enough to erode any gases that might appear on the surface – which I am guessing would look very much like our own moon.
In addition to eroding gases from the surface, the star’s intense radiation would appear to wash out all reflected colors – of which there would be none – only white. All pigments would be super saturated with ambient light such that any absorbed colors would be overwhelmed by and overcome by the intense white light washing over the surface. Special optical filters would be needed in order to see colors and details on surface objects. Radiation of this intensity probably would quickly penetrate protective shielding on spacecraft, and protective suits on astronauts. This is an extremely dangerous system that is best studied at a great distance.
Getting there. As this planet is 266 light years away, rockets using gravitational slings can attain speeds of over 394,736 miles per hour (NASA Parker solar probe). At that speed, it would take 452,000 years to get there.
My imagined visualization of 75 Ceti b viewed from the terminator.
My imagined visualization of 75 Ceti b exoplanet (foreground), with its host star in background.
My imagined visualization of 75 Ceti b as seen in exoExplorer.
exoplanet 75 Ceti b visualization on YouTube