How the sky might look from a planet located within a cluster of stars. Credit: David A. Aguilar (Harvard-Smithsonian Center for Astrophysics)

The European Space Observatory (ESO) just released the newest findings in exoplanetary sciences. FQtQ was lucky enough to be privy to the information, and believe us when we say that the news is very exciting.

According to the press release, a team of astronomers, led by Anna Brucalassi (of the Max Planck Institute for Extraterrestrial Physics), have discovered 3 exoplanets in orbit around three different stars. One of these stars has been dubbed, a “solar twin“, meaning that it has many of the same attributes (including size, spectral class, and composition) as our friendly neighborhood star. Only, its local neighborhood is vastly different from ours, as the star in question is a member of Messier 67 (M67); an open cluster of some 500 stars.


The cluster, which can be found about 2,800 light-years from Earth in the constellation of Cancer, contains a number of stars in various stages of development. The sizes and spectral classifications of these stars vary greatly, which would make for a spectacular view; however, it does present a challenge for planet hunters.

You see, to date, very few planets have been found lurking within the confines of star clusters. This is partially because said planets would be a bit harder to spot than those found in single, binary, or multiple-star systems. Another reason that few planets have been discovered in star clusters is due to how planets form. Ultimately, current planetary formation theories hint that planet development might be more difficult in such chaotic environments.

M67 (Image courtesy of the Sloan Digital Sky Survey)

Another difficulty that astronomers face when hunting for planets in this region is that many of the stars within M67 are far more faint than the stars that are typically targeted. This makes it difficult to detect changes in their luminosity. However,  HARPS keen eyes were up for the challenge (an acronym for “High Accuracy Radial Velocity Planet Searcher”). Along with the ESO’s 3.6m telescope, the special spectrography tool used its power to monitor over 88 stars in the cluster, looking for telltale signs of an unseen orbiting planet. Finally, after 6 years of gathering data, the team found three planetary candidates.


An artist rendering of an exoplanet located in a star cluster. (Image Credit: Michael Bachofner)

Two of the planets discovered were found in orbit around two different, sun-like stars. Whereas the third was found orbiting an older, more massive and evolved red-giant (at one point in its evolution, it was likely similar to the sun as well) All three of these newly discovered planets are rather small compared to the other exoplanets HARPS has found — with two coming in at approximately 1/3rd of the overall mass of Jupiter (that may sound rather massive, but most of the exoplanets we’ve discovered are extremely massive).

These planets make one full orbit around their parent stars once a week (every seven and five days, respectively). The third planet, which is a bit more massive than Jupiter,  has a much longer orbital period, completing a full orbit in 122 Earth days.

All of the planets are much too large and located far too close to their parent star to be considered habitable,  but their discovery will prove to be an important milestone in exoplanet detection. If we can pinpoint these planets in the most difficult of circumstances, we can bet that, in the future, we’ll come even closer to finding a truly Earth-like world.

You can read the whole press release here .  Love exoplanets? You can also read up on all of the amazing, far-away worlds we’ve discovered in recent years. Click here .



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