Astronomers discover two exoplanets that orbit a star similar to the Sun

Astronomers report the discovery of two new exoplanets orbiting a bright Sun-like star about 175 light-years away. The newly discovered alien worlds, designated HIP 104045 b and HIP 104045 c, were classified as a Jupiter analogue and a Neptune superplanet, respectively. The finding was detailed in a paper posted March 2 on the arXiv preprint server. The radial velocity (RV) method for detecting an exoplanet is based on detecting variations in the velocity of the central star, due to the change in direction of the gravitational pull of an unseen exoplanet while it orbits the star. Thanks to this technique, more than 600 exoplanets have been detected so far.

Now, a team of astronomers led by Thiago Ferreira from the University of São Paulo in Brazil, reports the detection of two new exoplanets using the VR method. They observed a solar-type star HIP 104045 with the High Precision Radial Velocity Planet Searcher (HARPS) spectrograph at the European Southern Observatory (ESO) 3.6-m telescope in La Silla, Chile. The observations, made as part of the Solar Twin Planet Search (STPS) program, resulted in the discovery of two massive extrasolar worlds. “In this paper, we present the discovery of two planets in the HIP 104045 system: HIP 104045 c, which is a super Neptune located closest to the star, and HIP 104045 b, which is the second Jupiter-like planet to orbit a sun. . as a star observed with the ESO/HARPS spectrograph for the STPS program, plus additional campaigns, totaling nearly 13 years of observations,” the researchers wrote.

HIP 104045 b has a minimum mass of about 0.5 Jupiter masses and orbits the host star every 2,315 days, at a distance of about 3.46 AU from it. When it comes to HIP 104045 c, it has a mass of at least 0.136 Jupiter masses and its orbital period is 316 days. This super-Neptune exoplanet lies approximately 0.92 AU from its parent star. HIP 104045 is a relatively bright main-sequence non-reddened star of the solar age of spectral type G5V with a size and mass a few percent greater than that of the Sun. The star has an effective temperature of 5,826 K and its age is estimated at 4,500 million years. The astronomers noted that HIP 104045 is highly similar to the sun in terms of its pattern of chemical abundance, having fewer refractory/volatile elements compared to the solar twins. They assume that the moderate enhancement of refractories in HIP 104045 means that it may have engulfed some rocky planet material.

“Based on the refractory composition of HIP 104045, which is situated between that of the refractory-poor sun and the most refractory-rich solar twin (Meléndez et al. 2009), we initially postulated that its planetary system might resemble our own. sun. system: gaseous and ice giants that populate the outer region (𝑎 > 3 AU), and the interior populated by rocky planets”, concluded the authors of the article.

Source: ArXiv