by Two scientists are conducting new research on Obi-Wan Kenobi from Star Wars: A New Hope regarding the proposed detection of two moons orbiting planets outside the solar system. In short, they are not sure that humanity’s first ever exomoon detection is accurate. In fact, the same results also showed that hexemons in general can only show themselves if they are extremely large.
The research shows that while there is no reason to suggest that moons are not orbiting in other planetary systems, finding them is a tricky business. In the three decades since the first exoplanet or “exoplanet” was detected, the catalog of worlds around other stars has grown and more than 5,000 examples have been confirmed so far. However, astronomers have ruled out any exomoons or “exomoons” that may be orbiting these worlds.
That was until 2018, when astronomers believed they had finally spotted an exomoon orbiting the planet Kepler-1625 b, a Jupiter-like world located about 8,000 light-years from Earth. Then, in January 2022, astronomers believed they had seen a second exomoon, this time orbiting the exoplanet Kepler-1708 b, a gas giant 4.6 times the mass of Jupiter located 5,400 light years from Earth. Kepler-1708 b itself was only discovered in 2021.
But still, this meant the 5,000 that were known exoplanet or so, only two were found with moons. This was not too much of a concern for the astronomers, however, because they reasoned that the worlds themselves are extremely distant, and the exomoons must be much smaller than the exoplanets. So they should be much harder to find, right? But now, even those feelings are in doubt.
Related: This ‘forbidden’ exoplanet is too massive for its star
“Exomoons are so far away that we cannot see them directly, even with the most powerful modern telescopes,” René Heller, team leader and scientist at the Max Planck Institute for Solar System Research (MPS), said in a statement. “We would like to confirm that exomoons have been discovered around Kepler-1625 b and Kepler-1708 b, but unfortunately, our analyzes show otherwise.”
Pandora’s box reveals grim ‘one planet’ predictions
Exoplanets are often seen orbiting their host stars when they cross in front of, or “cross over” that star, causing a tiny diminution in the star’s light output. The method should also work on exoplanets, but because these satellites are much smaller than the worlds they orbit, a potential dip in light would be negligible. caused them.
Additionally, an exomoon would have to be at a precise point in its orbit for scientists to observe it in transit, with its host planet also transiting the star. Basically, that moon has to be in a very specific position in relation to the planet so that it can block some of its own starlight. This is actually one of the reasons why the exomoon Kepler-1625 b appeared and then disappeared in the Kepler Space Telescope data – only to appear again in Hubble Space Telescope observations later.
Heller and his colleagues discovered the disappointing news regarding exomoons Kepler-1625 b and Kepler-1708 b using a computer algorithm they developed called “Pandora.” Applying Pandora, which is designed to speed exomoon discovery, to data collected by NASA’s Kepler Space Telescope Kepler-1708 b revealed that observations of that exoplanet and its only star were as likely to be explained in cases where there were no exemplars.
“The probability of a moon orbiting Kepler-1708b is clearly lower than previously reported. The data do not indicate the existence of an exomoon around Kepler-1708b,” said Michael Hippke, study co-author and astronomer at the Sonneberg Observatory, in the statement.
For Kepler-1625 b, Hippke and Heller suggest that an effect called “stellar limb darkening”, which can cause variations in brightness across stars, affected the proposed exomoon signal. A dark limb of a star, they say, would better explain observations of the parent star than the darkness caused by the presence of a potential alien moon.
Related Stories:
— Secrets of space: Why are there no gas moons?
— This rare exoplanet system has 6 ‘sub-Neptunes’ with mathematically perfect orbits
— Hubble Telescope probes nearby exoplanet, finds size of Earth
In addition, the team’s research presented bad news for exomoon hunters in general. When the duo used Pandora to predict the types of exomoons that Kepler and other space telescopes might detect from falling light, they found that only very large moons — about twice the size of the moon Ganymede largest in our solar system — i. wide orbits around their planet can be seen with current technology.
If there are other planetary systems like the solar system, an extreme moon of this type would be very strange indeed. There are about 290 known solar system moons, none of which fit this bill – meaning that exomoon detections may be even fewer than before.
This research was published on 7 December in the journal Natural Astronomy.
