New Exoplanet Discoveries Challenge Our Understanding of Planetary Systems

By Pranav Mahapatra

March 11, 2023
artist impression of exoplanets
An artist's depiction of exoplanet. Credits: NASA, Jet Propulsion Laboratory/California Institute of Technology, Ames Research Center

The search for exoplanets has become a crucial field of study in astronomy, as it has the potential to expand our understanding of the universe and the formation of planetary systems.

Recently, the discovery of HIP 104045 b and HIP 104045 c has provided exciting new insights into exoplanet research.

HIP 104045 b, a Jupiter analogue, and HIP 104045 c, an inner Super-Earth, were discovered as part of the ESO/HARPS STPS observing program1.

Discovery of a Jupiter-Like Planet and a Super-Earth

Jupiter analogues are a critical component of exoplanet research, as they provide insight into the formation and evolution of planetary systems, in fact, planets “Hot Jupiters” (not in this discovery) are one of the most common exoplanets.

They are defined as gas giant planets with a dynamical role similar to Jupiter and orbiting a Sun-like star, with a minimum mass ranging between 0.3 and 3 Mjup, orbital semi-major axis between 3 and 7 AU, and orbital eccentricity 𝑒 ≤ 0.3

Super-Earths, on the other hand, are rocky exoplanets with a mass higher than Earth’s but lower than that of Uranus or Neptune.

The refractory composition of the HIP 104045 system initially suggested that it might resemble our own Solar System, with gas and ice giants populating the outer region and rocky planets in the inner region and the discovery of HIP 104045 c further emphasizes it.

In addition to the discovery of HIP 104045 b, a Jupiter analogue, the team also found an inner super-Earth, HIP 101045 c.

This planet is about 2.4 times the size of Earth and has a minimum mass of 8.2 Earth masses.

It orbits its star in just 8.4 days and is located much closer to the star than the Jupiter analogue, with a semi-major axis of only 0.07 AU.

The Discovery’s Implications for Planetary System Formation

The discovery of both a Jupiter analogue and a super-Earth in the same system is particularly interesting for planetary system formation theories.


The Solar System is home to both gas giants like Jupiter and Saturn and smaller, rocky planets like Earth and Mars.

The fact that both types of planets are present in the HIP 104045 system suggests that it may have formed similarly to our own Solar System.

Furthermore, the discovery of an inner super-Earth challenges the initial hypothesis that the system is lacking in refractory elements, which are important building blocks for rocky planets.

It is possible that the system formed in a way that allowed for the formation of both gas giants and rocky planets in the inner regions.

Future Research

The discovery of the Jupiter analogue and super-Earth in the HIP 104045 system opens up new avenues for research.

Further observations with HARPS and other telescopes could reveal additional planets in the system, including smaller rocky planets that may be lurking in the inner regions.

Additionally, studying the atmospheres of the two known planets could provide insights into their composition and formation history.

Observations of the Jupiter analogue could also reveal more about the star itself, including its age and metallicity.


The discovery of a Jupiter analogue and super-Earth in the HIP 104045 system is a significant milestone in the study of exoplanets.

The presence of both gas giants and rocky planets in the same system challenges our understanding of the planetary formation and opens up new possibilities for research.

As telescopes and observation techniques continue to improve, we can expect to learn even more about this fascinating planetary system and the wider universe beyond.



  1. Thiago Ferreira, Jorge Meléndez, Diego Lorenzo-Oliveira, et al., ‘A Jupiter analogue and a cold Super-Neptune orbiting the solar-twin star HIP 104045‘, Arxiv, 2 March 2023[]